4877 lines
199 KiB
C++
4877 lines
199 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* This Source Code is subject to the terms of the Mozilla Public License
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* version 2.0 (the "License"). You can obtain a copy of the License at
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* http://mozilla.org/MPL/2.0/. */
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/* rendering object for CSS "display: flex" */
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#include "mozilla/UniquePtr.h"
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#include "nsFlexContainerFrame.h"
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#include "nsContentUtils.h"
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#include "nsCSSAnonBoxes.h"
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#include "nsDisplayList.h"
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#include "nsIFrameInlines.h"
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#include "nsLayoutUtils.h"
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#include "nsPlaceholderFrame.h"
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#include "nsPresContext.h"
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#include "nsRenderingContext.h"
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#include "nsStyleContext.h"
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#include "mozilla/Logging.h"
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#include <algorithm>
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#include "mozilla/LinkedList.h"
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#include "mozilla/FloatingPoint.h"
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#include "WritingModes.h"
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using namespace mozilla;
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using namespace mozilla::layout;
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// Convenience typedefs for helper classes that we forward-declare in .h file
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// (so that nsFlexContainerFrame methods can use them as parameters):
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typedef nsFlexContainerFrame::FlexItem FlexItem;
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typedef nsFlexContainerFrame::FlexLine FlexLine;
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typedef nsFlexContainerFrame::FlexboxAxisTracker FlexboxAxisTracker;
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typedef nsFlexContainerFrame::StrutInfo StrutInfo;
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typedef nsFlexContainerFrame::CachedMeasuringReflowResult
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CachedMeasuringReflowResult;
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static mozilla::LazyLogModule gFlexContainerLog("nsFlexContainerFrame");
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// XXXdholbert Some of this helper-stuff should be separated out into a general
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// "main/cross-axis utils" header, shared by grid & flexbox?
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// (Particularly when grid gets support for align-*/justify-* properties.)
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// Helper enums
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// ============
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// Represents a physical orientation for an axis.
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// The directional suffix indicates the direction in which the axis *grows*.
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// So e.g. eAxis_LR means a horizontal left-to-right axis, whereas eAxis_BT
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// means a vertical bottom-to-top axis.
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// NOTE: The order here is important -- these values are used as indices into
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// the static array 'kAxisOrientationToSidesMap', defined below.
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enum AxisOrientationType {
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eAxis_LR,
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eAxis_RL,
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eAxis_TB,
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eAxis_BT,
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eNumAxisOrientationTypes // For sizing arrays that use these values as indices
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};
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// Represents one or the other extreme of an axis (e.g. for the main axis, the
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// main-start vs. main-end edge.
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// NOTE: The order here is important -- these values are used as indices into
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// the sub-arrays in 'kAxisOrientationToSidesMap', defined below.
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enum AxisEdgeType {
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eAxisEdge_Start,
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eAxisEdge_End,
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eNumAxisEdges // For sizing arrays that use these values as indices
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};
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// This array maps each axis orientation to a pair of corresponding
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// [start, end] physical mozilla::Side values.
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static const mozilla::Side
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kAxisOrientationToSidesMap[eNumAxisOrientationTypes][eNumAxisEdges] = {
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{ eSideLeft, eSideRight }, // eAxis_LR
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{ eSideRight, eSideLeft }, // eAxis_RL
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{ eSideTop, eSideBottom }, // eAxis_TB
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{ eSideBottom, eSideTop } // eAxis_BT
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};
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// Helper structs / classes / methods
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// ==================================
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// Returns true iff the given nsStyleDisplay has display:-webkit-{inline-}-box.
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static inline bool
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IsDisplayValueLegacyBox(const nsStyleDisplay* aStyleDisp)
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{
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return aStyleDisp->mDisplay == mozilla::StyleDisplay::WebkitBox ||
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aStyleDisp->mDisplay == mozilla::StyleDisplay::WebkitInlineBox;
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}
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// Returns true if aFlexContainer is the frame for an element with
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// "display:-webkit-box" or "display:-webkit-inline-box". aFlexContainer is
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// expected to be an instance of nsFlexContainerFrame (enforced with an assert);
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// otherwise, this function's state-bit-check here is bogus.
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static bool
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IsLegacyBox(const nsIFrame* aFlexContainer)
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{
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MOZ_ASSERT(aFlexContainer->GetType() == nsGkAtoms::flexContainerFrame,
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"only flex containers may be passed to this function");
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return aFlexContainer->HasAnyStateBits(NS_STATE_FLEX_IS_LEGACY_WEBKIT_BOX);
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}
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// Returns the "align-items" value that's equivalent to the legacy "box-align"
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// value in the given style struct.
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static uint8_t
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ConvertLegacyStyleToAlignItems(const nsStyleXUL* aStyleXUL)
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{
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// -[moz|webkit]-box-align corresponds to modern "align-items"
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switch (aStyleXUL->mBoxAlign) {
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case StyleBoxAlign::Stretch:
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return NS_STYLE_ALIGN_STRETCH;
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case StyleBoxAlign::Start:
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return NS_STYLE_ALIGN_FLEX_START;
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case StyleBoxAlign::Center:
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return NS_STYLE_ALIGN_CENTER;
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case StyleBoxAlign::Baseline:
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return NS_STYLE_ALIGN_BASELINE;
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case StyleBoxAlign::End:
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return NS_STYLE_ALIGN_FLEX_END;
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}
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MOZ_ASSERT_UNREACHABLE("Unrecognized mBoxAlign enum value");
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// Fall back to default value of "align-items" property:
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return NS_STYLE_ALIGN_STRETCH;
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}
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// Returns the "justify-content" value that's equivalent to the legacy
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// "box-pack" value in the given style struct.
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static uint8_t
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ConvertLegacyStyleToJustifyContent(const nsStyleXUL* aStyleXUL)
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{
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// -[moz|webkit]-box-pack corresponds to modern "justify-content"
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switch (aStyleXUL->mBoxPack) {
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case StyleBoxPack::Start:
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return NS_STYLE_ALIGN_FLEX_START;
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case StyleBoxPack::Center:
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return NS_STYLE_ALIGN_CENTER;
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case StyleBoxPack::End:
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return NS_STYLE_ALIGN_FLEX_END;
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case StyleBoxPack::Justify:
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return NS_STYLE_ALIGN_SPACE_BETWEEN;
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}
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MOZ_ASSERT_UNREACHABLE("Unrecognized mBoxPack enum value");
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// Fall back to default value of "justify-content" property:
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return NS_STYLE_ALIGN_FLEX_START;
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}
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// Indicates whether advancing along the given axis is equivalent to
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// increasing our X or Y position (as opposed to decreasing it).
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static inline bool
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AxisGrowsInPositiveDirection(AxisOrientationType aAxis)
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{
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return eAxis_LR == aAxis || eAxis_TB == aAxis;
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}
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// Given an AxisOrientationType, returns the "reverse" AxisOrientationType
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// (in the same dimension, but the opposite direction)
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static inline AxisOrientationType
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GetReverseAxis(AxisOrientationType aAxis)
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{
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AxisOrientationType reversedAxis;
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if (aAxis % 2 == 0) {
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// even enum value. Add 1 to reverse.
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reversedAxis = AxisOrientationType(aAxis + 1);
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} else {
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// odd enum value. Subtract 1 to reverse.
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reversedAxis = AxisOrientationType(aAxis - 1);
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}
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// Check that we're still in the enum's valid range
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MOZ_ASSERT(reversedAxis >= eAxis_LR &&
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reversedAxis <= eAxis_BT);
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return reversedAxis;
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}
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/**
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* Converts a "flex-relative" coordinate in a single axis (a main- or cross-axis
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* coordinate) into a coordinate in the corresponding physical (x or y) axis. If
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* the flex-relative axis in question already maps *directly* to a physical
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* axis (i.e. if it's LTR or TTB), then the physical coordinate has the same
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* numeric value as the provided flex-relative coordinate. Otherwise, we have to
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* subtract the flex-relative coordinate from the flex container's size in that
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* axis, to flip the polarity. (So e.g. a main-axis position of 2px in a RTL
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* 20px-wide container would correspond to a physical coordinate (x-value) of
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* 18px.)
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*/
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static nscoord
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PhysicalCoordFromFlexRelativeCoord(nscoord aFlexRelativeCoord,
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nscoord aContainerSize,
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AxisOrientationType aAxis) {
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if (AxisGrowsInPositiveDirection(aAxis)) {
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return aFlexRelativeCoord;
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}
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return aContainerSize - aFlexRelativeCoord;
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}
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// Helper-macro to let us pick one of two expressions to evaluate
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// (a width expression vs. a height expression), to get a main-axis or
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// cross-axis component.
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// For code that has e.g. a nsSize object, FlexboxAxisTracker::GetMainComponent
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// and GetCrossComponent are cleaner; but in cases where we simply have
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// two separate expressions for width and height (which may be expensive to
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// evaluate), these macros will ensure that only the expression for the correct
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// axis gets evaluated.
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#define GET_MAIN_COMPONENT(axisTracker_, width_, height_) \
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(axisTracker_).IsMainAxisHorizontal() ? (width_) : (height_)
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#define GET_CROSS_COMPONENT(axisTracker_, width_, height_) \
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(axisTracker_).IsCrossAxisHorizontal() ? (width_) : (height_)
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// Logical versions of helper-macros above:
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#define GET_MAIN_COMPONENT_LOGICAL(axisTracker_, wm_, isize_, bsize_) \
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wm_.IsOrthogonalTo(axisTracker_.GetWritingMode()) != \
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(axisTracker_).IsRowOriented() ? (isize_) : (bsize_)
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#define GET_CROSS_COMPONENT_LOGICAL(axisTracker_, wm_, isize_, bsize_) \
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wm_.IsOrthogonalTo(axisTracker_.GetWritingMode()) != \
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(axisTracker_).IsRowOriented() ? (bsize_) : (isize_)
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// Flags to customize behavior of the FlexboxAxisTracker constructor:
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enum AxisTrackerFlags {
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eNoFlags = 0x0,
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// Normally, FlexboxAxisTracker may attempt to reverse axes & iteration order
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// to avoid bottom-to-top child ordering, for saner pagination. This flag
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// suppresses that behavior (so that we allow bottom-to-top child ordering).
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// (This may be helpful e.g. when we're only dealing with a single child.)
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eAllowBottomToTopChildOrdering = 0x1
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};
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MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(AxisTrackerFlags)
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// Encapsulates our flex container's main & cross axes.
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class MOZ_STACK_CLASS nsFlexContainerFrame::FlexboxAxisTracker {
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public:
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FlexboxAxisTracker(const nsFlexContainerFrame* aFlexContainer,
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const WritingMode& aWM,
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AxisTrackerFlags aFlags = eNoFlags);
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// Accessors:
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// XXXdholbert [BEGIN DEPRECATED]
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AxisOrientationType GetMainAxis() const { return mMainAxis; }
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AxisOrientationType GetCrossAxis() const { return mCrossAxis; }
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bool IsMainAxisHorizontal() const {
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// If we're row-oriented, and our writing mode is NOT vertical,
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// or we're column-oriented and our writing mode IS vertical,
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// then our main axis is horizontal. This handles all cases:
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return mIsRowOriented != mWM.IsVertical();
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}
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bool IsCrossAxisHorizontal() const {
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return !IsMainAxisHorizontal();
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}
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// XXXdholbert [END DEPRECATED]
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// Returns the flex container's writing mode.
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WritingMode GetWritingMode() const { return mWM; }
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// Returns true if our main axis is in the reverse direction of our
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// writing mode's corresponding axis. (From 'flex-direction: *-reverse')
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bool IsMainAxisReversed() const {
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return mIsMainAxisReversed;
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}
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// Returns true if our cross axis is in the reverse direction of our
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// writing mode's corresponding axis. (From 'flex-wrap: *-reverse')
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bool IsCrossAxisReversed() const {
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return mIsCrossAxisReversed;
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}
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bool IsRowOriented() const { return mIsRowOriented; }
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bool IsColumnOriented() const { return !mIsRowOriented; }
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nscoord GetMainComponent(const nsSize& aSize) const {
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return GET_MAIN_COMPONENT(*this, aSize.width, aSize.height);
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}
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int32_t GetMainComponent(const LayoutDeviceIntSize& aIntSize) const {
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return GET_MAIN_COMPONENT(*this, aIntSize.width, aIntSize.height);
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}
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nscoord GetCrossComponent(const nsSize& aSize) const {
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return GET_CROSS_COMPONENT(*this, aSize.width, aSize.height);
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}
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int32_t GetCrossComponent(const LayoutDeviceIntSize& aIntSize) const {
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return GET_CROSS_COMPONENT(*this, aIntSize.width, aIntSize.height);
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}
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nscoord GetMarginSizeInMainAxis(const nsMargin& aMargin) const {
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return IsMainAxisHorizontal() ?
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aMargin.LeftRight() :
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aMargin.TopBottom();
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}
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nscoord GetMarginSizeInCrossAxis(const nsMargin& aMargin) const {
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return IsCrossAxisHorizontal() ?
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aMargin.LeftRight() :
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aMargin.TopBottom();
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}
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// Returns aFrame's computed value for 'height' or 'width' -- whichever is in
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// the cross-axis. (NOTE: This is cross-axis-specific for now. If we need a
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// main-axis version as well, we could generalize or clone this function.)
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const nsStyleCoord& ComputedCrossSize(const nsIFrame* aFrame) const {
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const nsStylePosition* stylePos = aFrame->StylePosition();
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return IsCrossAxisHorizontal() ?
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stylePos->mWidth :
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stylePos->mHeight;
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}
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/**
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* Converts a "flex-relative" point (a main-axis & cross-axis coordinate)
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* into a LogicalPoint, using the flex container's writing mode.
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*
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* @arg aMainCoord The main-axis coordinate -- i.e an offset from the
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* main-start edge of the flex container's content box.
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* @arg aCrossCoord The cross-axis coordinate -- i.e an offset from the
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* cross-start edge of the flex container's content box.
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* @arg aContainerMainSize The main size of flex container's content box.
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* @arg aContainerCrossSize The cross size of flex container's content box.
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* @return A LogicalPoint, with the flex container's writing mode, that
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* represents the same position. The logical coordinates are
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* relative to the flex container's content box.
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*/
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LogicalPoint
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LogicalPointFromFlexRelativePoint(nscoord aMainCoord,
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nscoord aCrossCoord,
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nscoord aContainerMainSize,
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nscoord aContainerCrossSize) const {
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nscoord logicalCoordInMainAxis = mIsMainAxisReversed ?
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aContainerMainSize - aMainCoord : aMainCoord;
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nscoord logicalCoordInCrossAxis = mIsCrossAxisReversed ?
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aContainerCrossSize - aCrossCoord : aCrossCoord;
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return mIsRowOriented ?
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LogicalPoint(mWM, logicalCoordInMainAxis, logicalCoordInCrossAxis) :
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LogicalPoint(mWM, logicalCoordInCrossAxis, logicalCoordInMainAxis);
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}
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/**
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* Converts a "flex-relative" size (a main-axis & cross-axis size)
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* into a LogicalSize, using the flex container's writing mode.
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*
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* @arg aMainSize The main-axis size.
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* @arg aCrossSize The cross-axis size.
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* @return A LogicalSize, with the flex container's writing mode, that
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* represents the same size.
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*/
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LogicalSize LogicalSizeFromFlexRelativeSizes(nscoord aMainSize,
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nscoord aCrossSize) const {
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return mIsRowOriented ?
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LogicalSize(mWM, aMainSize, aCrossSize) :
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LogicalSize(mWM, aCrossSize, aMainSize);
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}
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// Are my axes reversed with respect to what the author asked for?
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// (We may reverse the axes in the FlexboxAxisTracker constructor and set
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// this flag, to avoid reflowing our children in bottom-to-top order.)
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bool AreAxesInternallyReversed() const
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{
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return mAreAxesInternallyReversed;
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}
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private:
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// Delete copy-constructor & reassignment operator, to prevent accidental
|
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// (unnecessary) copying.
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FlexboxAxisTracker(const FlexboxAxisTracker&) = delete;
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FlexboxAxisTracker& operator=(const FlexboxAxisTracker&) = delete;
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// Helpers for constructor which determine the orientation of our axes, based
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// on legacy box properties (-webkit-box-orient, -webkit-box-direction) or
|
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// modern flexbox properties (flex-direction, flex-wrap) depending on whether
|
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// the flex container is a "legacy box" (as determined by IsLegacyBox).
|
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void InitAxesFromLegacyProps(const nsFlexContainerFrame* aFlexContainer);
|
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void InitAxesFromModernProps(const nsFlexContainerFrame* aFlexContainer);
|
||
|
||
// XXXdholbert [BEGIN DEPRECATED]
|
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AxisOrientationType mMainAxis;
|
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AxisOrientationType mCrossAxis;
|
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// XXXdholbert [END DEPRECATED]
|
||
|
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const WritingMode mWM; // The flex container's writing mode.
|
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|
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bool mIsRowOriented; // Is our main axis the inline axis?
|
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// (Are we 'flex-direction:row[-reverse]'?)
|
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|
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bool mIsMainAxisReversed; // Is our main axis in the opposite direction
|
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// as mWM's corresponding axis? (e.g. RTL vs LTR)
|
||
bool mIsCrossAxisReversed; // Is our cross axis in the opposite direction
|
||
// as mWM's corresponding axis? (e.g. BTT vs TTB)
|
||
|
||
// Implementation detail -- this indicates whether we've decided to
|
||
// transparently reverse our axes & our child ordering, to avoid having
|
||
// frames flow from bottom to top in either axis (& to make pagination saner).
|
||
bool mAreAxesInternallyReversed;
|
||
};
|
||
|
||
/**
|
||
* Represents a flex item.
|
||
* Includes the various pieces of input that the Flexbox Layout Algorithm uses
|
||
* to resolve a flexible width.
|
||
*/
|
||
class nsFlexContainerFrame::FlexItem : public LinkedListElement<FlexItem>
|
||
{
|
||
public:
|
||
// Normal constructor:
|
||
FlexItem(ReflowInput& aFlexItemReflowInput,
|
||
float aFlexGrow, float aFlexShrink, nscoord aMainBaseSize,
|
||
nscoord aMainMinSize, nscoord aMainMaxSize,
|
||
nscoord aTentativeCrossSize,
|
||
nscoord aCrossMinSize, nscoord aCrossMaxSize,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Simplified constructor, to be used only for generating "struts":
|
||
// (NOTE: This "strut" constructor uses the *container's* writing mode, which
|
||
// we'll use on this FlexItem instead of the child frame's real writing mode.
|
||
// This is fine - it doesn't matter what writing mode we use for a
|
||
// strut, since it won't render any content and we already know its size.)
|
||
FlexItem(nsIFrame* aChildFrame, nscoord aCrossSize, WritingMode aContainerWM);
|
||
|
||
// Accessors
|
||
nsIFrame* Frame() const { return mFrame; }
|
||
nscoord GetFlexBaseSize() const { return mFlexBaseSize; }
|
||
|
||
nscoord GetMainMinSize() const {
|
||
MOZ_ASSERT(!mNeedsMinSizeAutoResolution,
|
||
"Someone's using an unresolved 'auto' main min-size");
|
||
return mMainMinSize;
|
||
}
|
||
nscoord GetMainMaxSize() const { return mMainMaxSize; }
|
||
|
||
// Note: These return the main-axis position and size of our *content box*.
|
||
nscoord GetMainSize() const { return mMainSize; }
|
||
nscoord GetMainPosition() const { return mMainPosn; }
|
||
|
||
nscoord GetCrossMinSize() const { return mCrossMinSize; }
|
||
nscoord GetCrossMaxSize() const { return mCrossMaxSize; }
|
||
|
||
// Note: These return the cross-axis position and size of our *content box*.
|
||
nscoord GetCrossSize() const { return mCrossSize; }
|
||
nscoord GetCrossPosition() const { return mCrossPosn; }
|
||
|
||
nscoord ResolvedAscent(bool aUseFirstBaseline) const {
|
||
if (mAscent == ReflowOutput::ASK_FOR_BASELINE) {
|
||
// XXXdholbert We should probably be using the *container's* writing-mode
|
||
// here, instead of the item's -- though it doesn't much matter right
|
||
// now, because all of the baseline-handling code here essentially
|
||
// assumes that the container & items have the same writing-mode. This
|
||
// will matter more (& can be expanded/tested) once we officially support
|
||
// logical directions & vertical writing-modes in flexbox, in bug 1079155
|
||
// or a dependency.
|
||
// Use GetFirstLineBaseline() or GetLastLineBaseline() as appropriate,
|
||
// or just GetLogicalBaseline() if that fails.
|
||
bool found = aUseFirstBaseline ?
|
||
nsLayoutUtils::GetFirstLineBaseline(mWM, mFrame, &mAscent) :
|
||
nsLayoutUtils::GetLastLineBaseline(mWM, mFrame, &mAscent);
|
||
|
||
if (!found) {
|
||
mAscent = mFrame->SynthesizeBaselineBOffsetFromBorderBox(mWM,
|
||
BaselineSharingGroup::eFirst);
|
||
}
|
||
}
|
||
return mAscent;
|
||
}
|
||
|
||
// Convenience methods to compute the main & cross size of our *margin-box*.
|
||
// The caller is responsible for telling us the right axis, so that we can
|
||
// pull out the appropriate components of our margin/border/padding structs.
|
||
nscoord GetOuterMainSize(AxisOrientationType aMainAxis) const
|
||
{
|
||
return mMainSize + GetMarginBorderPaddingSizeInAxis(aMainAxis);
|
||
}
|
||
|
||
nscoord GetOuterCrossSize(AxisOrientationType aCrossAxis) const
|
||
{
|
||
return mCrossSize + GetMarginBorderPaddingSizeInAxis(aCrossAxis);
|
||
}
|
||
|
||
// Returns the distance between this FlexItem's baseline and the cross-start
|
||
// edge of its margin-box. Used in baseline alignment.
|
||
// (This function needs to be told which edge we're measuring the baseline
|
||
// from, so that it can look up the appropriate components from mMargin.)
|
||
nscoord GetBaselineOffsetFromOuterCrossEdge(
|
||
AxisEdgeType aEdge,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
bool aUseFirstLineBaseline) const;
|
||
|
||
float GetShareOfWeightSoFar() const { return mShareOfWeightSoFar; }
|
||
|
||
bool IsFrozen() const { return mIsFrozen; }
|
||
|
||
bool HadMinViolation() const { return mHadMinViolation; }
|
||
bool HadMaxViolation() const { return mHadMaxViolation; }
|
||
|
||
// Indicates whether this item received a preliminary "measuring" reflow
|
||
// before its actual reflow.
|
||
bool HadMeasuringReflow() const { return mHadMeasuringReflow; }
|
||
|
||
// Indicates whether this item's cross-size has been stretched (from having
|
||
// "align-self: stretch" with an auto cross-size and no auto margins in the
|
||
// cross axis).
|
||
bool IsStretched() const { return mIsStretched; }
|
||
|
||
// Indicates whether we need to resolve an 'auto' value for the main-axis
|
||
// min-[width|height] property.
|
||
bool NeedsMinSizeAutoResolution() const
|
||
{ return mNeedsMinSizeAutoResolution; }
|
||
|
||
// Indicates whether this item is a "strut" left behind by an element with
|
||
// visibility:collapse.
|
||
bool IsStrut() const { return mIsStrut; }
|
||
|
||
WritingMode GetWritingMode() const { return mWM; }
|
||
uint8_t GetAlignSelf() const { return mAlignSelf; }
|
||
|
||
// Returns the flex factor (flex-grow or flex-shrink), depending on
|
||
// 'aIsUsingFlexGrow'.
|
||
//
|
||
// Asserts fatally if called on a frozen item (since frozen items are not
|
||
// flexible).
|
||
float GetFlexFactor(bool aIsUsingFlexGrow)
|
||
{
|
||
MOZ_ASSERT(!IsFrozen(), "shouldn't need flex factor after item is frozen");
|
||
|
||
return aIsUsingFlexGrow ? mFlexGrow : mFlexShrink;
|
||
}
|
||
|
||
// Returns the weight that we should use in the "resolving flexible lengths"
|
||
// algorithm. If we're using the flex grow factor, we just return that;
|
||
// otherwise, we return the "scaled flex shrink factor" (scaled by our flex
|
||
// base size, so that when both large and small items are shrinking, the large
|
||
// items shrink more).
|
||
//
|
||
// I'm calling this a "weight" instead of a "[scaled] flex-[grow|shrink]
|
||
// factor", to more clearly distinguish it from the actual flex-grow &
|
||
// flex-shrink factors.
|
||
//
|
||
// Asserts fatally if called on a frozen item (since frozen items are not
|
||
// flexible).
|
||
float GetWeight(bool aIsUsingFlexGrow)
|
||
{
|
||
MOZ_ASSERT(!IsFrozen(), "shouldn't need weight after item is frozen");
|
||
|
||
if (aIsUsingFlexGrow) {
|
||
return mFlexGrow;
|
||
}
|
||
|
||
// We're using flex-shrink --> return mFlexShrink * mFlexBaseSize
|
||
if (mFlexBaseSize == 0) {
|
||
// Special-case for mFlexBaseSize == 0 -- we have no room to shrink, so
|
||
// regardless of mFlexShrink, we should just return 0.
|
||
// (This is really a special-case for when mFlexShrink is infinity, to
|
||
// avoid performing mFlexShrink * mFlexBaseSize = inf * 0 = undefined.)
|
||
return 0.0f;
|
||
}
|
||
return mFlexShrink * mFlexBaseSize;
|
||
}
|
||
|
||
const AspectRatio IntrinsicRatio() const { return mIntrinsicRatio; }
|
||
bool HasIntrinsicRatio() const { return !!mIntrinsicRatio; }
|
||
|
||
// Getters for margin:
|
||
// ===================
|
||
const nsMargin& GetMargin() const { return mMargin; }
|
||
|
||
// Returns the margin component for a given mozilla::Side
|
||
nscoord GetMarginComponentForSide(mozilla::Side aSide) const
|
||
{ return mMargin.Side(aSide); }
|
||
|
||
// Returns the total space occupied by this item's margins in the given axis
|
||
nscoord GetMarginSizeInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
mozilla::Side startSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_Start];
|
||
mozilla::Side endSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_End];
|
||
return GetMarginComponentForSide(startSide) +
|
||
GetMarginComponentForSide(endSide);
|
||
}
|
||
|
||
// Getters for border/padding
|
||
// ==========================
|
||
const nsMargin& GetBorderPadding() const { return mBorderPadding; }
|
||
|
||
// Returns the border+padding component for a given mozilla::Side
|
||
nscoord GetBorderPaddingComponentForSide(mozilla::Side aSide) const
|
||
{ return mBorderPadding.Side(aSide); }
|
||
|
||
// Returns the total space occupied by this item's borders and padding in
|
||
// the given axis
|
||
nscoord GetBorderPaddingSizeInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
mozilla::Side startSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_Start];
|
||
mozilla::Side endSide = kAxisOrientationToSidesMap[aAxis][eAxisEdge_End];
|
||
return GetBorderPaddingComponentForSide(startSide) +
|
||
GetBorderPaddingComponentForSide(endSide);
|
||
}
|
||
|
||
// Getter for combined margin/border/padding
|
||
// =========================================
|
||
// Returns the total space occupied by this item's margins, borders and
|
||
// padding in the given axis
|
||
nscoord GetMarginBorderPaddingSizeInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
return GetMarginSizeInAxis(aAxis) + GetBorderPaddingSizeInAxis(aAxis);
|
||
}
|
||
|
||
// Setters
|
||
// =======
|
||
// Helper to set the resolved value of min-[width|height]:auto for the main
|
||
// axis. (Should only be used if NeedsMinSizeAutoResolution() returns true.)
|
||
void UpdateMainMinSize(nscoord aNewMinSize)
|
||
{
|
||
NS_ASSERTION(aNewMinSize >= 0,
|
||
"How did we end up with a negative min-size?");
|
||
MOZ_ASSERT(mMainMaxSize >= aNewMinSize,
|
||
"Should only use this function for resolving min-size:auto, "
|
||
"and main max-size should be an upper-bound for resolved val");
|
||
MOZ_ASSERT(mNeedsMinSizeAutoResolution &&
|
||
(mMainMinSize == 0 || mFrame->IsThemed(mFrame->StyleDisplay())),
|
||
"Should only use this function for resolving min-size:auto, "
|
||
"so we shouldn't already have a nonzero min-size established "
|
||
"(unless it's a themed-widget-imposed minimum size)");
|
||
|
||
if (aNewMinSize > mMainMinSize) {
|
||
mMainMinSize = aNewMinSize;
|
||
// Also clamp main-size to be >= new min-size:
|
||
mMainSize = std::max(mMainSize, aNewMinSize);
|
||
}
|
||
mNeedsMinSizeAutoResolution = false;
|
||
}
|
||
|
||
// This sets our flex base size, and then sets our main size to the
|
||
// resulting "hypothetical main size" (the base size clamped to our
|
||
// main-axis [min,max] sizing constraints).
|
||
void SetFlexBaseSizeAndMainSize(nscoord aNewFlexBaseSize)
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen || mFlexBaseSize == NS_INTRINSICSIZE,
|
||
"flex base size shouldn't change after we're frozen "
|
||
"(unless we're just resolving an intrinsic size)");
|
||
mFlexBaseSize = aNewFlexBaseSize;
|
||
|
||
// Before we've resolved flexible lengths, we keep mMainSize set to
|
||
// the 'hypothetical main size', which is the flex base size, clamped
|
||
// to the [min,max] range:
|
||
mMainSize = NS_CSS_MINMAX(mFlexBaseSize, mMainMinSize, mMainMaxSize);
|
||
}
|
||
|
||
// Setters used while we're resolving flexible lengths
|
||
// ---------------------------------------------------
|
||
|
||
// Sets the main-size of our flex item's content-box.
|
||
void SetMainSize(nscoord aNewMainSize)
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen, "main size shouldn't change after we're frozen");
|
||
mMainSize = aNewMainSize;
|
||
}
|
||
|
||
void SetShareOfWeightSoFar(float aNewShare)
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen || aNewShare == 0.0f,
|
||
"shouldn't be giving this item any share of the weight "
|
||
"after it's frozen");
|
||
mShareOfWeightSoFar = aNewShare;
|
||
}
|
||
|
||
void Freeze() { mIsFrozen = true; }
|
||
|
||
void SetHadMinViolation()
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen,
|
||
"shouldn't be changing main size & having violations "
|
||
"after we're frozen");
|
||
mHadMinViolation = true;
|
||
}
|
||
void SetHadMaxViolation()
|
||
{
|
||
MOZ_ASSERT(!mIsFrozen,
|
||
"shouldn't be changing main size & having violations "
|
||
"after we're frozen");
|
||
mHadMaxViolation = true;
|
||
}
|
||
void ClearViolationFlags()
|
||
{ mHadMinViolation = mHadMaxViolation = false; }
|
||
|
||
// Setters for values that are determined after we've resolved our main size
|
||
// -------------------------------------------------------------------------
|
||
|
||
// Sets the main-axis position of our flex item's content-box.
|
||
// (This is the distance between the main-start edge of the flex container
|
||
// and the main-start edge of the flex item's content-box.)
|
||
void SetMainPosition(nscoord aPosn) {
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mMainPosn = aPosn;
|
||
}
|
||
|
||
// Sets the cross-size of our flex item's content-box.
|
||
void SetCrossSize(nscoord aCrossSize) {
|
||
MOZ_ASSERT(!mIsStretched,
|
||
"Cross size shouldn't be modified after it's been stretched");
|
||
mCrossSize = aCrossSize;
|
||
}
|
||
|
||
// Sets the cross-axis position of our flex item's content-box.
|
||
// (This is the distance between the cross-start edge of the flex container
|
||
// and the cross-start edge of the flex item.)
|
||
void SetCrossPosition(nscoord aPosn) {
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mCrossPosn = aPosn;
|
||
}
|
||
|
||
// After a FlexItem has had a reflow, this method can be used to cache its
|
||
// (possibly-unresolved) ascent, in case it's needed later for
|
||
// baseline-alignment or to establish the container's baseline.
|
||
// (NOTE: This can be marked 'const' even though it's modifying mAscent,
|
||
// because mAscent is mutable. It's nice for this to be 'const', because it
|
||
// means our final reflow can iterate over const FlexItem pointers, and we
|
||
// can be sure it's not modifying those FlexItems, except via this method.)
|
||
void SetAscent(nscoord aAscent) const {
|
||
mAscent = aAscent; // NOTE: this may be ASK_FOR_BASELINE
|
||
}
|
||
|
||
void SetHadMeasuringReflow() {
|
||
mHadMeasuringReflow = true;
|
||
}
|
||
|
||
void SetIsStretched() {
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mIsStretched = true;
|
||
}
|
||
|
||
// Setter for margin components (for resolving "auto" margins)
|
||
void SetMarginComponentForSide(mozilla::Side aSide, nscoord aLength)
|
||
{
|
||
MOZ_ASSERT(mIsFrozen, "main size should be resolved before this");
|
||
mMargin.Side(aSide) = aLength;
|
||
}
|
||
|
||
void ResolveStretchedCrossSize(nscoord aLineCrossSize,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
uint32_t GetNumAutoMarginsInAxis(AxisOrientationType aAxis) const;
|
||
|
||
// Once the main size has been resolved, should we bother doing layout to
|
||
// establish the cross size?
|
||
bool CanMainSizeInfluenceCrossSize(const FlexboxAxisTracker& aAxisTracker) const;
|
||
|
||
protected:
|
||
// Helper called by the constructor, to set mNeedsMinSizeAutoResolution:
|
||
void CheckForMinSizeAuto(const ReflowInput& aFlexItemReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Our frame:
|
||
nsIFrame* const mFrame;
|
||
|
||
// Values that we already know in constructor: (and are hence mostly 'const')
|
||
const float mFlexGrow;
|
||
const float mFlexShrink;
|
||
|
||
const AspectRatio mIntrinsicRatio;
|
||
|
||
const nsMargin mBorderPadding;
|
||
nsMargin mMargin; // non-const because we need to resolve auto margins
|
||
|
||
// These are non-const so that we can lazily update them with the item's
|
||
// intrinsic size (obtained via a "measuring" reflow), when necessary.
|
||
// (e.g. for "flex-basis:auto;height:auto" & "min-height:auto")
|
||
nscoord mFlexBaseSize;
|
||
nscoord mMainMinSize;
|
||
nscoord mMainMaxSize;
|
||
|
||
const nscoord mCrossMinSize;
|
||
const nscoord mCrossMaxSize;
|
||
|
||
// Values that we compute after constructor:
|
||
nscoord mMainSize;
|
||
nscoord mMainPosn;
|
||
nscoord mCrossSize;
|
||
nscoord mCrossPosn;
|
||
mutable nscoord mAscent; // Mutable b/c it's set & resolved lazily, sometimes
|
||
// via const pointer. See comment above SetAscent().
|
||
|
||
// Temporary state, while we're resolving flexible widths (for our main size)
|
||
// XXXdholbert To save space, we could use a union to make these variables
|
||
// overlay the same memory as some other member vars that aren't touched
|
||
// until after main-size has been resolved. In particular, these could share
|
||
// memory with mMainPosn through mAscent, and mIsStretched.
|
||
float mShareOfWeightSoFar;
|
||
bool mIsFrozen;
|
||
bool mHadMinViolation;
|
||
bool mHadMaxViolation;
|
||
|
||
// Misc:
|
||
bool mHadMeasuringReflow; // Did this item get a preliminary reflow,
|
||
// to measure its desired height?
|
||
bool mIsStretched; // See IsStretched() documentation
|
||
bool mIsStrut; // Is this item a "strut" left behind by an element
|
||
// with visibility:collapse?
|
||
|
||
// Does this item need to resolve a min-[width|height]:auto (in main-axis).
|
||
bool mNeedsMinSizeAutoResolution;
|
||
|
||
const WritingMode mWM; // The flex item's writing mode.
|
||
uint8_t mAlignSelf; // My "align-self" computed value (with "auto"
|
||
// swapped out for parent"s "align-items" value,
|
||
// in our constructor).
|
||
};
|
||
|
||
/**
|
||
* Represents a single flex line in a flex container.
|
||
* Manages a linked list of the FlexItems that are in the line.
|
||
*/
|
||
class nsFlexContainerFrame::FlexLine : public LinkedListElement<FlexLine>
|
||
{
|
||
public:
|
||
FlexLine()
|
||
: mNumItems(0),
|
||
mNumFrozenItems(0),
|
||
mTotalInnerHypotheticalMainSize(0),
|
||
mTotalOuterHypotheticalMainSize(0),
|
||
mLineCrossSize(0),
|
||
mFirstBaselineOffset(nscoord_MIN),
|
||
mLastBaselineOffset(nscoord_MIN)
|
||
{}
|
||
|
||
// Returns the sum of our FlexItems' outer hypothetical main sizes.
|
||
// ("outer" = margin-box, and "hypothetical" = before flexing)
|
||
nscoord GetTotalOuterHypotheticalMainSize() const {
|
||
return mTotalOuterHypotheticalMainSize;
|
||
}
|
||
|
||
// Accessors for our FlexItems & information about them:
|
||
FlexItem* GetFirstItem()
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.getFirst();
|
||
}
|
||
|
||
const FlexItem* GetFirstItem() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.getFirst();
|
||
}
|
||
|
||
FlexItem* GetLastItem()
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.getLast();
|
||
}
|
||
|
||
const FlexItem* GetLastItem() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.getLast();
|
||
}
|
||
|
||
bool IsEmpty() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mItems.isEmpty();
|
||
}
|
||
|
||
uint32_t NumItems() const
|
||
{
|
||
MOZ_ASSERT(mItems.isEmpty() == (mNumItems == 0),
|
||
"mNumItems bookkeeping is off");
|
||
return mNumItems;
|
||
}
|
||
|
||
// Adds the given FlexItem to our list of items (at the front or back
|
||
// depending on aShouldInsertAtFront), and adds its hypothetical
|
||
// outer & inner main sizes to our totals. Use this method instead of
|
||
// directly modifying the item list, so that our bookkeeping remains correct.
|
||
void AddItem(FlexItem* aItem,
|
||
bool aShouldInsertAtFront,
|
||
nscoord aItemInnerHypotheticalMainSize,
|
||
nscoord aItemOuterHypotheticalMainSize)
|
||
{
|
||
if (aShouldInsertAtFront) {
|
||
mItems.insertFront(aItem);
|
||
} else {
|
||
mItems.insertBack(aItem);
|
||
}
|
||
|
||
// Update our various bookkeeping member-vars:
|
||
mNumItems++;
|
||
if (aItem->IsFrozen()) {
|
||
mNumFrozenItems++;
|
||
}
|
||
mTotalInnerHypotheticalMainSize += aItemInnerHypotheticalMainSize;
|
||
mTotalOuterHypotheticalMainSize += aItemOuterHypotheticalMainSize;
|
||
}
|
||
|
||
// Computes the cross-size and baseline position of this FlexLine, based on
|
||
// its FlexItems.
|
||
void ComputeCrossSizeAndBaseline(const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Returns the cross-size of this line.
|
||
nscoord GetLineCrossSize() const { return mLineCrossSize; }
|
||
|
||
// Setter for line cross-size -- needed for cases where the flex container
|
||
// imposes a cross-size on the line. (e.g. for single-line flexbox, or for
|
||
// multi-line flexbox with 'align-content: stretch')
|
||
void SetLineCrossSize(nscoord aLineCrossSize) {
|
||
mLineCrossSize = aLineCrossSize;
|
||
}
|
||
|
||
/**
|
||
* Returns the offset within this line where any baseline-aligned FlexItems
|
||
* should place their baseline. Usually, this represents a distance from the
|
||
* line's cross-start edge, but if we're internally reversing the axes (see
|
||
* AreAxesInternallyReversed()), this instead represents the distance from
|
||
* its cross-end edge.
|
||
*
|
||
* If there are no baseline-aligned FlexItems, returns nscoord_MIN.
|
||
*/
|
||
nscoord GetFirstBaselineOffset() const {
|
||
return mFirstBaselineOffset;
|
||
}
|
||
|
||
/**
|
||
* Returns the offset within this line where any last baseline-aligned
|
||
* FlexItems should place their baseline. Opposite the case of the first
|
||
* baseline offset, this represents a distance from the line's cross-end
|
||
* edge (since last baseline-aligned items are flush to the cross-end edge).
|
||
* If we're internally reversing the axes, this instead represents the
|
||
* distance from the line's cross-start edge.
|
||
*
|
||
* If there are no last baseline-aligned FlexItems, returns nscoord_MIN.
|
||
*/
|
||
nscoord GetLastBaselineOffset() const {
|
||
return mLastBaselineOffset;
|
||
}
|
||
|
||
// Runs the "Resolving Flexible Lengths" algorithm from section 9.7 of the
|
||
// CSS flexbox spec to distribute aFlexContainerMainSize among our flex items.
|
||
void ResolveFlexibleLengths(nscoord aFlexContainerMainSize);
|
||
|
||
void PositionItemsInMainAxis(uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
void PositionItemsInCrossAxis(nscoord aLineStartPosition,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
friend class AutoFlexLineListClearer; // (needs access to mItems)
|
||
|
||
private:
|
||
// Helpers for ResolveFlexibleLengths():
|
||
void FreezeItemsEarly(bool aIsUsingFlexGrow);
|
||
|
||
void FreezeOrRestoreEachFlexibleSize(const nscoord aTotalViolation,
|
||
bool aIsFinalIteration);
|
||
|
||
LinkedList<FlexItem> mItems; // Linked list of this line's flex items.
|
||
|
||
uint32_t mNumItems; // Number of FlexItems in this line (in |mItems|).
|
||
// (Shouldn't change after GenerateFlexLines finishes
|
||
// with this line -- at least, not until we add support
|
||
// for splitting lines across continuations. Then we can
|
||
// update this count carefully.)
|
||
|
||
// Number of *frozen* FlexItems in this line, based on FlexItem::IsFrozen().
|
||
// Mostly used for optimization purposes, e.g. to bail out early from loops
|
||
// when we can tell they have nothing left to do.
|
||
uint32_t mNumFrozenItems;
|
||
|
||
nscoord mTotalInnerHypotheticalMainSize;
|
||
nscoord mTotalOuterHypotheticalMainSize;
|
||
nscoord mLineCrossSize;
|
||
nscoord mFirstBaselineOffset;
|
||
nscoord mLastBaselineOffset;
|
||
};
|
||
|
||
// Information about a strut left behind by a FlexItem that's been collapsed
|
||
// using "visibility:collapse".
|
||
struct nsFlexContainerFrame::StrutInfo {
|
||
StrutInfo(uint32_t aItemIdx, nscoord aStrutCrossSize)
|
||
: mItemIdx(aItemIdx),
|
||
mStrutCrossSize(aStrutCrossSize)
|
||
{
|
||
}
|
||
|
||
uint32_t mItemIdx; // Index in the child list.
|
||
nscoord mStrutCrossSize; // The cross-size of this strut.
|
||
};
|
||
|
||
static void
|
||
BuildStrutInfoFromCollapsedItems(const FlexLine* aFirstLine,
|
||
nsTArray<StrutInfo>& aStruts)
|
||
{
|
||
MOZ_ASSERT(aFirstLine, "null first line pointer");
|
||
MOZ_ASSERT(aStruts.IsEmpty(),
|
||
"We should only build up StrutInfo once per reflow, so "
|
||
"aStruts should be empty when this is called");
|
||
|
||
uint32_t itemIdxInContainer = 0;
|
||
for (const FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
for (const FlexItem* item = line->GetFirstItem(); item;
|
||
item = item->getNext()) {
|
||
if (NS_STYLE_VISIBILITY_COLLAPSE ==
|
||
item->Frame()->StyleVisibility()->mVisible) {
|
||
// Note the cross size of the line as the item's strut size.
|
||
aStruts.AppendElement(StrutInfo(itemIdxInContainer,
|
||
line->GetLineCrossSize()));
|
||
}
|
||
itemIdxInContainer++;
|
||
}
|
||
}
|
||
}
|
||
|
||
// Convenience function to get either the "order" or the "box-ordinal-group"
|
||
// property-value for a flex item (depending on whether the container is a
|
||
// modern flex container or a legacy box).
|
||
static int32_t
|
||
GetOrderOrBoxOrdinalGroup(nsIFrame* aFlexItem, bool aIsLegacyBox)
|
||
{
|
||
if (aFlexItem->GetType() == nsGkAtoms::placeholderFrame) {
|
||
// Always treat placeholders as having the default value, which is
|
||
// 1 for (legacy) 'box-ordinal-group' and 0 for 'order'.
|
||
return aIsLegacyBox ? 1 : 0;
|
||
}
|
||
if (aIsLegacyBox) {
|
||
// We'll be using mBoxOrdinal, which has type uint32_t. However, the modern
|
||
// 'order' property (whose functionality we're co-opting) has type int32_t.
|
||
// So: if we happen to have a uint32_t value that's greater than INT32_MAX,
|
||
// we clamp it rather than letting it overflow. Chances are, this is just
|
||
// an author using BIG_VALUE anyway, so the clamped value should be fine.
|
||
// (particularly since sufficiently-huge values are busted in Chrome/WebKit
|
||
// per https://bugs.chromium.org/p/chromium/issues/detail?id=599645 )
|
||
uint32_t clampedBoxOrdinal = std::min(aFlexItem->StyleXUL()->mBoxOrdinal,
|
||
static_cast<uint32_t>(INT32_MAX));
|
||
return static_cast<int32_t>(clampedBoxOrdinal);
|
||
}
|
||
|
||
// Normal case: just use modern 'order' property.
|
||
return aFlexItem->StylePosition()->mOrder;
|
||
}
|
||
|
||
// Helper-function to find the first non-anonymous-box descendent of aFrame.
|
||
static nsIFrame*
|
||
GetFirstNonAnonBoxDescendant(nsIFrame* aFrame)
|
||
{
|
||
while (aFrame) {
|
||
nsIAtom* pseudoTag = aFrame->StyleContext()->GetPseudo();
|
||
|
||
// If aFrame isn't an anonymous container, then it'll do.
|
||
if (!pseudoTag || // No pseudotag.
|
||
!nsCSSAnonBoxes::IsAnonBox(pseudoTag) || // Pseudotag isn't anon.
|
||
nsCSSAnonBoxes::IsNonElement(pseudoTag)) { // Text, not a container.
|
||
break;
|
||
}
|
||
|
||
// Otherwise, descend to its first child and repeat.
|
||
|
||
// SPECIAL CASE: if we're dealing with an anonymous table, then it might
|
||
// be wrapping something non-anonymous in its caption or col-group lists
|
||
// (instead of its principal child list), so we have to look there.
|
||
// (Note: For anonymous tables that have a non-anon cell *and* a non-anon
|
||
// column, we'll always return the column. This is fine; we're really just
|
||
// looking for a handle to *anything* with a meaningful content node inside
|
||
// the table, for use in DOM comparisons to things outside of the table.)
|
||
if (MOZ_UNLIKELY(aFrame->GetType() == nsGkAtoms::tableWrapperFrame)) {
|
||
nsIFrame* captionDescendant =
|
||
GetFirstNonAnonBoxDescendant(aFrame->GetChildList(kCaptionList).FirstChild());
|
||
if (captionDescendant) {
|
||
return captionDescendant;
|
||
}
|
||
} else if (MOZ_UNLIKELY(aFrame->GetType() == nsGkAtoms::tableFrame)) {
|
||
nsIFrame* colgroupDescendant =
|
||
GetFirstNonAnonBoxDescendant(aFrame->GetChildList(kColGroupList).FirstChild());
|
||
if (colgroupDescendant) {
|
||
return colgroupDescendant;
|
||
}
|
||
}
|
||
|
||
// USUAL CASE: Descend to the first child in principal list.
|
||
aFrame = aFrame->PrincipalChildList().FirstChild();
|
||
}
|
||
return aFrame;
|
||
}
|
||
|
||
/**
|
||
* Sorting helper-function that compares two frames' "order" property-values,
|
||
* and if they're equal, compares the DOM positions of their corresponding
|
||
* content nodes. Returns true if aFrame1 is "less than or equal to" aFrame2
|
||
* according to this comparison.
|
||
*
|
||
* Note: This can't be a static function, because we need to pass it as a
|
||
* template argument. (Only functions with external linkage can be passed as
|
||
* template arguments.)
|
||
*
|
||
* @return true if the computed "order" property of aFrame1 is less than that
|
||
* of aFrame2, or if the computed "order" values are equal and aFrame1's
|
||
* corresponding DOM node is earlier than aFrame2's in the DOM tree.
|
||
* Otherwise, returns false.
|
||
*/
|
||
bool
|
||
IsOrderLEQWithDOMFallback(nsIFrame* aFrame1,
|
||
nsIFrame* aFrame2)
|
||
{
|
||
MOZ_ASSERT(aFrame1->IsFlexItem() && aFrame2->IsFlexItem(),
|
||
"this method only intended for comparing flex items");
|
||
MOZ_ASSERT(aFrame1->GetParent() == aFrame2->GetParent(),
|
||
"this method only intended for comparing siblings");
|
||
if (aFrame1 == aFrame2) {
|
||
// Anything is trivially LEQ itself, so we return "true" here... but it's
|
||
// probably bad if we end up actually needing this, so let's assert.
|
||
NS_ERROR("Why are we checking if a frame is LEQ itself?");
|
||
return true;
|
||
}
|
||
|
||
const bool isInLegacyBox = IsLegacyBox(aFrame1->GetParent());
|
||
|
||
int32_t order1 = GetOrderOrBoxOrdinalGroup(aFrame1, isInLegacyBox);
|
||
int32_t order2 = GetOrderOrBoxOrdinalGroup(aFrame2, isInLegacyBox);
|
||
|
||
if (order1 != order2) {
|
||
return order1 < order2;
|
||
}
|
||
|
||
// The "order" values are equal, so we need to fall back on DOM comparison.
|
||
// For that, we need to dig through any anonymous box wrapper frames to find
|
||
// the actual frame that corresponds to our child content.
|
||
aFrame1 = GetFirstNonAnonBoxDescendant(aFrame1);
|
||
aFrame2 = GetFirstNonAnonBoxDescendant(aFrame2);
|
||
MOZ_ASSERT(aFrame1 && aFrame2,
|
||
"why do we have an anonymous box without any "
|
||
"non-anonymous descendants?");
|
||
|
||
|
||
// Special case:
|
||
// If either frame is for generated content from ::before or ::after, then
|
||
// we can't use nsContentUtils::PositionIsBefore(), since that method won't
|
||
// recognize generated content as being an actual sibling of other nodes.
|
||
// We know where ::before and ::after nodes *effectively* insert in the DOM
|
||
// tree, though (at the beginning & end), so we can just special-case them.
|
||
nsIAtom* pseudo1 =
|
||
nsPlaceholderFrame::GetRealFrameFor(aFrame1)->StyleContext()->GetPseudo();
|
||
nsIAtom* pseudo2 =
|
||
nsPlaceholderFrame::GetRealFrameFor(aFrame2)->StyleContext()->GetPseudo();
|
||
|
||
if (pseudo1 == nsCSSPseudoElements::before ||
|
||
pseudo2 == nsCSSPseudoElements::after) {
|
||
// frame1 is ::before and/or frame2 is ::after => frame1 is LEQ frame2.
|
||
return true;
|
||
}
|
||
if (pseudo1 == nsCSSPseudoElements::after ||
|
||
pseudo2 == nsCSSPseudoElements::before) {
|
||
// frame1 is ::after and/or frame2 is ::before => frame1 is not LEQ frame2.
|
||
return false;
|
||
}
|
||
|
||
// Usual case: Compare DOM position.
|
||
nsIContent* content1 = aFrame1->GetContent();
|
||
nsIContent* content2 = aFrame2->GetContent();
|
||
MOZ_ASSERT(content1 != content2,
|
||
"Two different flex items are using the same nsIContent node for "
|
||
"comparison, so we may be sorting them in an arbitrary order");
|
||
|
||
return nsContentUtils::PositionIsBefore(content1, content2);
|
||
}
|
||
|
||
/**
|
||
* Sorting helper-function that compares two frames' "order" property-values.
|
||
* Returns true if aFrame1 is "less than or equal to" aFrame2 according to this
|
||
* comparison.
|
||
*
|
||
* Note: This can't be a static function, because we need to pass it as a
|
||
* template argument. (Only functions with external linkage can be passed as
|
||
* template arguments.)
|
||
*
|
||
* @return true if the computed "order" property of aFrame1 is less than or
|
||
* equal to that of aFrame2. Otherwise, returns false.
|
||
*/
|
||
bool
|
||
IsOrderLEQ(nsIFrame* aFrame1,
|
||
nsIFrame* aFrame2)
|
||
{
|
||
MOZ_ASSERT(aFrame1->IsFlexItem() && aFrame2->IsFlexItem(),
|
||
"this method only intended for comparing flex items");
|
||
MOZ_ASSERT(aFrame1->GetParent() == aFrame2->GetParent(),
|
||
"this method only intended for comparing siblings");
|
||
|
||
const bool isInLegacyBox = IsLegacyBox(aFrame1->GetParent());
|
||
|
||
int32_t order1 = GetOrderOrBoxOrdinalGroup(aFrame1, isInLegacyBox);
|
||
int32_t order2 = GetOrderOrBoxOrdinalGroup(aFrame2, isInLegacyBox);
|
||
|
||
return order1 <= order2;
|
||
}
|
||
|
||
uint8_t
|
||
SimplifyAlignOrJustifyContentForOneItem(uint16_t aAlignmentVal,
|
||
bool aIsAlign)
|
||
{
|
||
// Mask away any explicit fallback, to get the main (non-fallback) part of
|
||
// the specified value:
|
||
uint16_t specified = aAlignmentVal & NS_STYLE_ALIGN_ALL_BITS;
|
||
|
||
// XXX strip off <overflow-position> bits until we implement it (bug 1311892)
|
||
specified &= ~NS_STYLE_ALIGN_FLAG_BITS;
|
||
|
||
// FIRST: handle a special-case for "justify-content:stretch" (or equivalent),
|
||
// which requires that we ignore any author-provided explicit fallback value.
|
||
if (specified == NS_STYLE_ALIGN_NORMAL) {
|
||
// In a flex container, *-content: "'normal' behaves as 'stretch'".
|
||
// Do that conversion early, so it benefits from our 'stretch' special-case.
|
||
// https://drafts.csswg.org/css-align-3/#distribution-flex
|
||
specified = NS_STYLE_ALIGN_STRETCH;
|
||
}
|
||
if (!aIsAlign && specified == NS_STYLE_ALIGN_STRETCH) {
|
||
// In a flex container, in "justify-content Axis: [...] 'stretch' behaves
|
||
// as 'flex-start' (ignoring the specified fallback alignment, if any)."
|
||
// https://drafts.csswg.org/css-align-3/#distribution-flex
|
||
// So, we just directly return 'flex-start', & ignore explicit fallback..
|
||
return NS_STYLE_ALIGN_FLEX_START;
|
||
}
|
||
|
||
// Now check for an explicit fallback value (and if it's present, use it).
|
||
uint16_t explicitFallback = aAlignmentVal >> NS_STYLE_ALIGN_ALL_SHIFT;
|
||
if (explicitFallback) {
|
||
// XXX strip off <overflow-position> bits until we implement it
|
||
// (bug 1311892)
|
||
explicitFallback &= ~NS_STYLE_ALIGN_FLAG_BITS;
|
||
return explicitFallback;
|
||
}
|
||
|
||
// There's no explicit fallback. Use the implied fallback values for
|
||
// space-{between,around,evenly} (since those values only make sense with
|
||
// multiple alignment subjects), and otherwise just use the specified value:
|
||
switch (specified) {
|
||
case NS_STYLE_ALIGN_SPACE_BETWEEN:
|
||
return NS_STYLE_ALIGN_START;
|
||
case NS_STYLE_ALIGN_SPACE_AROUND:
|
||
case NS_STYLE_ALIGN_SPACE_EVENLY:
|
||
return NS_STYLE_ALIGN_CENTER;
|
||
default:
|
||
return specified;
|
||
}
|
||
}
|
||
|
||
uint16_t
|
||
nsFlexContainerFrame::CSSAlignmentForAbsPosChild(
|
||
const ReflowInput& aChildRI,
|
||
LogicalAxis aLogicalAxis) const
|
||
{
|
||
WritingMode wm = GetWritingMode();
|
||
const FlexboxAxisTracker
|
||
axisTracker(this, wm, AxisTrackerFlags::eAllowBottomToTopChildOrdering);
|
||
|
||
// If we're row-oriented and the caller is asking about our inline axis (or
|
||
// alternately, if we're column-oriented and the caller is asking about our
|
||
// block axis), then the caller is really asking about our *main* axis.
|
||
// Otherwise, the caller is asking about our cross axis.
|
||
const bool isMainAxis = (axisTracker.IsRowOriented() ==
|
||
(aLogicalAxis == eLogicalAxisInline));
|
||
const nsStylePosition* containerStylePos = StylePosition();
|
||
const bool isAxisReversed = isMainAxis ? axisTracker.IsMainAxisReversed()
|
||
: axisTracker.IsCrossAxisReversed();
|
||
|
||
uint8_t alignment;
|
||
if (isMainAxis) {
|
||
alignment = SimplifyAlignOrJustifyContentForOneItem(
|
||
containerStylePos->mJustifyContent,
|
||
/*aIsAlign = */false);
|
||
} else {
|
||
const uint8_t alignContent = SimplifyAlignOrJustifyContentForOneItem(
|
||
containerStylePos->mAlignContent,
|
||
/*aIsAlign = */true);
|
||
if (NS_STYLE_FLEX_WRAP_NOWRAP != containerStylePos->mFlexWrap &&
|
||
alignContent != NS_STYLE_ALIGN_STRETCH) {
|
||
// Multi-line, align-content isn't stretch --> align-content determines
|
||
// this child's alignment in the cross axis.
|
||
alignment = alignContent;
|
||
} else {
|
||
// Single-line, or multi-line but the (one) line stretches to fill
|
||
// container. Respect align-self.
|
||
alignment = aChildRI.mStylePosition->UsedAlignSelf(StyleContext());
|
||
// XXX strip off <overflow-position> bits until we implement it
|
||
// (bug 1311892)
|
||
alignment &= ~NS_STYLE_ALIGN_FLAG_BITS;
|
||
|
||
if (alignment == NS_STYLE_ALIGN_NORMAL) {
|
||
// "the 'normal' keyword behaves as 'start' on replaced
|
||
// absolutely-positioned boxes, and behaves as 'stretch' on all other
|
||
// absolutely-positioned boxes."
|
||
// https://drafts.csswg.org/css-align/#align-abspos
|
||
alignment = aChildRI.mFrame->IsFrameOfType(nsIFrame::eReplaced) ?
|
||
NS_STYLE_ALIGN_START : NS_STYLE_ALIGN_STRETCH;
|
||
}
|
||
}
|
||
}
|
||
|
||
// Resolve flex-start, flex-end, auto, left, right, baseline, last baseline;
|
||
if (alignment == NS_STYLE_ALIGN_FLEX_START) {
|
||
alignment = isAxisReversed ? NS_STYLE_ALIGN_END : NS_STYLE_ALIGN_START;
|
||
} else if (alignment == NS_STYLE_ALIGN_FLEX_END) {
|
||
alignment = isAxisReversed ? NS_STYLE_ALIGN_START : NS_STYLE_ALIGN_END;
|
||
} else if (alignment == NS_STYLE_ALIGN_LEFT ||
|
||
alignment == NS_STYLE_ALIGN_RIGHT) {
|
||
if (aLogicalAxis == eLogicalAxisInline) {
|
||
const bool isLeft = (alignment == NS_STYLE_ALIGN_LEFT);
|
||
alignment = (isLeft == wm.IsBidiLTR()) ? NS_STYLE_ALIGN_START
|
||
: NS_STYLE_ALIGN_END;
|
||
} else {
|
||
alignment = NS_STYLE_ALIGN_START;
|
||
}
|
||
} else if (alignment == NS_STYLE_ALIGN_BASELINE) {
|
||
alignment = NS_STYLE_ALIGN_START;
|
||
} else if (alignment == NS_STYLE_ALIGN_LAST_BASELINE) {
|
||
alignment = NS_STYLE_ALIGN_END;
|
||
}
|
||
|
||
return alignment;
|
||
}
|
||
|
||
bool
|
||
nsFlexContainerFrame::IsHorizontal()
|
||
{
|
||
const FlexboxAxisTracker axisTracker(this, GetWritingMode());
|
||
return axisTracker.IsMainAxisHorizontal();
|
||
}
|
||
|
||
UniquePtr<FlexItem>
|
||
nsFlexContainerFrame::GenerateFlexItemForChild(
|
||
nsPresContext* aPresContext,
|
||
nsIFrame* aChildFrame,
|
||
const ReflowInput& aParentReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
// Create temporary reflow state just for sizing -- to get hypothetical
|
||
// main-size and the computed values of min / max main-size property.
|
||
// (This reflow state will _not_ be used for reflow.)
|
||
ReflowInput
|
||
childRI(aPresContext, aParentReflowInput, aChildFrame,
|
||
aParentReflowInput.ComputedSize(aChildFrame->GetWritingMode()));
|
||
|
||
// FLEX GROW & SHRINK WEIGHTS
|
||
// --------------------------
|
||
float flexGrow, flexShrink;
|
||
if (IsLegacyBox(this)) {
|
||
flexGrow = flexShrink = aChildFrame->StyleXUL()->mBoxFlex;
|
||
} else {
|
||
const nsStylePosition* stylePos = aChildFrame->StylePosition();
|
||
flexGrow = stylePos->mFlexGrow;
|
||
flexShrink = stylePos->mFlexShrink;
|
||
}
|
||
|
||
WritingMode childWM = childRI.GetWritingMode();
|
||
|
||
// MAIN SIZES (flex base size, min/max size)
|
||
// -----------------------------------------
|
||
nscoord flexBaseSize = GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, childWM,
|
||
childRI.ComputedISize(),
|
||
childRI.ComputedBSize());
|
||
nscoord mainMinSize = GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, childWM,
|
||
childRI.ComputedMinISize(),
|
||
childRI.ComputedMinBSize());
|
||
nscoord mainMaxSize = GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, childWM,
|
||
childRI.ComputedMaxISize(),
|
||
childRI.ComputedMaxBSize());
|
||
// This is enforced by the ReflowInput where these values come from:
|
||
MOZ_ASSERT(mainMinSize <= mainMaxSize, "min size is larger than max size");
|
||
|
||
// CROSS SIZES (tentative cross size, min/max cross size)
|
||
// ------------------------------------------------------
|
||
// Grab the cross size from the reflow state. This might be the right value,
|
||
// or we might resolve it to something else in SizeItemInCrossAxis(); hence,
|
||
// it's tentative. See comment under "Cross Size Determination" for more.
|
||
nscoord tentativeCrossSize =
|
||
GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, childWM,
|
||
childRI.ComputedISize(),
|
||
childRI.ComputedBSize());
|
||
nscoord crossMinSize =
|
||
GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, childWM,
|
||
childRI.ComputedMinISize(),
|
||
childRI.ComputedMinBSize());
|
||
nscoord crossMaxSize =
|
||
GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, childWM,
|
||
childRI.ComputedMaxISize(),
|
||
childRI.ComputedMaxBSize());
|
||
|
||
// SPECIAL-CASE FOR WIDGET-IMPOSED SIZES
|
||
// Check if we're a themed widget, in which case we might have a minimum
|
||
// main & cross size imposed by our widget (which we can't go below), or
|
||
// (more severe) our widget might have only a single valid size.
|
||
bool isFixedSizeWidget = false;
|
||
const nsStyleDisplay* disp = aChildFrame->StyleDisplay();
|
||
if (aChildFrame->IsThemed(disp)) {
|
||
LayoutDeviceIntSize widgetMinSize;
|
||
bool canOverride = true;
|
||
aPresContext->GetTheme()->
|
||
GetMinimumWidgetSize(aPresContext, aChildFrame,
|
||
disp->mAppearance,
|
||
&widgetMinSize, &canOverride);
|
||
|
||
nscoord widgetMainMinSize =
|
||
aPresContext->DevPixelsToAppUnits(
|
||
aAxisTracker.GetMainComponent(widgetMinSize));
|
||
nscoord widgetCrossMinSize =
|
||
aPresContext->DevPixelsToAppUnits(
|
||
aAxisTracker.GetCrossComponent(widgetMinSize));
|
||
|
||
// GMWS() returns border-box. We need content-box, so subtract
|
||
// borderPadding (but don't let that push our min sizes below 0).
|
||
nsMargin& bp = childRI.ComputedPhysicalBorderPadding();
|
||
widgetMainMinSize = std::max(widgetMainMinSize -
|
||
aAxisTracker.GetMarginSizeInMainAxis(bp), 0);
|
||
widgetCrossMinSize = std::max(widgetCrossMinSize -
|
||
aAxisTracker.GetMarginSizeInCrossAxis(bp), 0);
|
||
|
||
if (!canOverride) {
|
||
// Fixed-size widget: freeze our main-size at the widget's mandated size.
|
||
// (Set min and max main-sizes to that size, too, to keep us from
|
||
// clamping to any other size later on.)
|
||
flexBaseSize = mainMinSize = mainMaxSize = widgetMainMinSize;
|
||
tentativeCrossSize = crossMinSize = crossMaxSize = widgetCrossMinSize;
|
||
isFixedSizeWidget = true;
|
||
} else {
|
||
// Variable-size widget: ensure our min/max sizes are at least as large
|
||
// as the widget's mandated minimum size, so we don't flex below that.
|
||
mainMinSize = std::max(mainMinSize, widgetMainMinSize);
|
||
mainMaxSize = std::max(mainMaxSize, widgetMainMinSize);
|
||
|
||
if (tentativeCrossSize != NS_INTRINSICSIZE) {
|
||
tentativeCrossSize = std::max(tentativeCrossSize, widgetCrossMinSize);
|
||
}
|
||
crossMinSize = std::max(crossMinSize, widgetCrossMinSize);
|
||
crossMaxSize = std::max(crossMaxSize, widgetCrossMinSize);
|
||
}
|
||
}
|
||
|
||
// Construct the flex item!
|
||
auto item = MakeUnique<FlexItem>(childRI,
|
||
flexGrow, flexShrink, flexBaseSize,
|
||
mainMinSize, mainMaxSize,
|
||
tentativeCrossSize,
|
||
crossMinSize, crossMaxSize,
|
||
aAxisTracker);
|
||
|
||
// If we're inflexible, we can just freeze to our hypothetical main-size
|
||
// up-front. Similarly, if we're a fixed-size widget, we only have one
|
||
// valid size, so we freeze to keep ourselves from flexing.
|
||
if (isFixedSizeWidget || (flexGrow == 0.0f && flexShrink == 0.0f)) {
|
||
item->Freeze();
|
||
}
|
||
|
||
// Resolve "flex-basis:auto" and/or "min-[width|height]:auto" (which might
|
||
// require us to reflow the item to measure content height)
|
||
ResolveAutoFlexBasisAndMinSize(aPresContext, *item,
|
||
childRI, aAxisTracker);
|
||
return item;
|
||
}
|
||
|
||
// Static helper-functions for ResolveAutoFlexBasisAndMinSize():
|
||
// -------------------------------------------------------------
|
||
// Indicates whether the cross-size property is set to something definite.
|
||
// The logic here should be similar to the logic for isAutoWidth/isAutoHeight
|
||
// in nsFrame::ComputeSizeWithIntrinsicDimensions().
|
||
static bool
|
||
IsCrossSizeDefinite(const ReflowInput& aItemReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
const nsStylePosition* pos = aItemReflowInput.mStylePosition;
|
||
if (aAxisTracker.IsCrossAxisHorizontal()) {
|
||
return pos->mWidth.GetUnit() != eStyleUnit_Auto;
|
||
}
|
||
// else, vertical. (We need to use IsAutoHeight() to catch e.g. %-height
|
||
// applied to indefinite-height containing block, which counts as auto.)
|
||
nscoord cbHeight = aItemReflowInput.mCBReflowInput->ComputedHeight();
|
||
return !nsLayoutUtils::IsAutoHeight(pos->mHeight, cbHeight);
|
||
}
|
||
|
||
// If aFlexItem has a definite cross size, this function returns it, for usage
|
||
// (in combination with an intrinsic ratio) for resolving the item's main size
|
||
// or main min-size.
|
||
//
|
||
// The parameter "aMinSizeFallback" indicates whether we should fall back to
|
||
// returning the cross min-size, when the cross size is indefinite. (This param
|
||
// should be set IFF the caller intends to resolve the main min-size.) If this
|
||
// param is true, then this function is guaranteed to return a definite value
|
||
// (i.e. not NS_AUTOHEIGHT, excluding cases where huge sizes are involved).
|
||
//
|
||
// XXXdholbert the min-size behavior here is based on my understanding in
|
||
// http://lists.w3.org/Archives/Public/www-style/2014Jul/0053.html
|
||
// If my understanding there ends up being wrong, we'll need to update this.
|
||
static nscoord
|
||
CrossSizeToUseWithRatio(const FlexItem& aFlexItem,
|
||
const ReflowInput& aItemReflowInput,
|
||
bool aMinSizeFallback,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
if (aFlexItem.IsStretched()) {
|
||
// Definite cross-size, imposed via 'align-self:stretch' & flex container.
|
||
return aFlexItem.GetCrossSize();
|
||
}
|
||
|
||
if (IsCrossSizeDefinite(aItemReflowInput, aAxisTracker)) {
|
||
// Definite cross size.
|
||
return GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, aFlexItem.GetWritingMode(),
|
||
aItemReflowInput.ComputedISize(),
|
||
aItemReflowInput.ComputedBSize());
|
||
}
|
||
|
||
if (aMinSizeFallback) {
|
||
// Indefinite cross-size, and we're resolving main min-size, so we'll fall
|
||
// back to ussing the cross min-size (which should be definite).
|
||
return GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, aFlexItem.GetWritingMode(),
|
||
aItemReflowInput.ComputedMinISize(),
|
||
aItemReflowInput.ComputedMinBSize());
|
||
}
|
||
|
||
// Indefinite cross-size.
|
||
return NS_AUTOHEIGHT;
|
||
}
|
||
|
||
// Convenience function; returns a main-size, given a cross-size and an
|
||
// intrinsic ratio. The caller is responsible for ensuring that the passed-in
|
||
// intrinsic ratio is not zero.
|
||
static nscoord
|
||
MainSizeFromAspectRatio(nscoord aCrossSize,
|
||
const AspectRatio& aIntrinsicRatio,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MOZ_ASSERT(aIntrinsicRatio,
|
||
"Invalid ratio; will divide by 0! Caller should've checked...");
|
||
AspectRatio ratio = aAxisTracker.IsMainAxisHorizontal() ?
|
||
aIntrinsicRatio :
|
||
aIntrinsicRatio.Inverted();
|
||
|
||
return ratio.ApplyTo(aCrossSize);
|
||
}
|
||
|
||
// Partially resolves "min-[width|height]:auto" and returns the resulting value.
|
||
// By "partially", I mean we don't consider the min-content size (but we do
|
||
// consider flex-basis, main max-size, and the intrinsic aspect ratio).
|
||
// The caller is responsible for computing & considering the min-content size
|
||
// in combination with the partially-resolved value that this function returns.
|
||
//
|
||
// Spec reference: http://dev.w3.org/csswg/css-flexbox/#min-size-auto
|
||
static nscoord
|
||
PartiallyResolveAutoMinSize(const FlexItem& aFlexItem,
|
||
const ReflowInput& aItemReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MOZ_ASSERT(aFlexItem.NeedsMinSizeAutoResolution(),
|
||
"only call for FlexItems that need min-size auto resolution");
|
||
|
||
nscoord minMainSize = nscoord_MAX; // Intentionally huge; we'll shrink it
|
||
// from here, w/ std::min().
|
||
|
||
// We need the smallest of:
|
||
// * the used flex-basis, if the computed flex-basis was 'auto':
|
||
// XXXdholbert ('auto' might be renamed to 'main-size'; see bug 1032922)
|
||
if (eStyleUnit_Auto ==
|
||
aItemReflowInput.mStylePosition->mFlexBasis.GetUnit() &&
|
||
aFlexItem.GetFlexBaseSize() != NS_AUTOHEIGHT) {
|
||
// NOTE: We skip this if the flex base size depends on content & isn't yet
|
||
// resolved. This is OK, because the caller is responsible for computing
|
||
// the min-content height and min()'ing it with the value we return, which
|
||
// is equivalent to what would happen if we min()'d that at this point.
|
||
minMainSize = std::min(minMainSize, aFlexItem.GetFlexBaseSize());
|
||
}
|
||
|
||
// * the computed max-width (max-height), if that value is definite:
|
||
nscoord maxSize =
|
||
GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, aFlexItem.GetWritingMode(),
|
||
aItemReflowInput.ComputedMaxISize(),
|
||
aItemReflowInput.ComputedMaxBSize());
|
||
if (maxSize != NS_UNCONSTRAINEDSIZE) {
|
||
minMainSize = std::min(minMainSize, maxSize);
|
||
}
|
||
|
||
// * if the item has no intrinsic aspect ratio, its min-content size:
|
||
// --- SKIPPING THIS IN THIS FUNCTION --- caller's responsibility.
|
||
|
||
// * if the item has an intrinsic aspect ratio, the width (height) calculated
|
||
// from the aspect ratio and any definite size constraints in the opposite
|
||
// dimension.
|
||
if (aFlexItem.IntrinsicRatio()) {
|
||
// We have a usable aspect ratio. (not going to divide by 0)
|
||
const bool useMinSizeIfCrossSizeIsIndefinite = true;
|
||
nscoord crossSizeToUseWithRatio =
|
||
CrossSizeToUseWithRatio(aFlexItem, aItemReflowInput,
|
||
useMinSizeIfCrossSizeIsIndefinite,
|
||
aAxisTracker);
|
||
nscoord minMainSizeFromRatio =
|
||
MainSizeFromAspectRatio(crossSizeToUseWithRatio,
|
||
aFlexItem.IntrinsicRatio(), aAxisTracker);
|
||
minMainSize = std::min(minMainSize, minMainSizeFromRatio);
|
||
}
|
||
|
||
return minMainSize;
|
||
}
|
||
|
||
// Resolves flex-basis:auto, using the given intrinsic ratio and the flex
|
||
// item's cross size. On success, updates the flex item with its resolved
|
||
// flex-basis and returns true. On failure (e.g. if the ratio is invalid or
|
||
// the cross-size is indefinite), returns false.
|
||
static bool
|
||
ResolveAutoFlexBasisFromRatio(FlexItem& aFlexItem,
|
||
const ReflowInput& aItemReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MOZ_ASSERT(NS_AUTOHEIGHT == aFlexItem.GetFlexBaseSize(),
|
||
"Should only be called to resolve an 'auto' flex-basis");
|
||
// If the flex item has ...
|
||
// - an intrinsic aspect ratio,
|
||
// - a [used] flex-basis of 'main-size' [auto?] [We have this, if we're here.]
|
||
// - a definite cross size
|
||
// then the flex base size is calculated from its inner cross size and the
|
||
// flex item’s intrinsic aspect ratio.
|
||
if (aFlexItem.IntrinsicRatio()) {
|
||
// We have a usable aspect ratio. (not going to divide by 0)
|
||
const bool useMinSizeIfCrossSizeIsIndefinite = false;
|
||
nscoord crossSizeToUseWithRatio =
|
||
CrossSizeToUseWithRatio(aFlexItem, aItemReflowInput,
|
||
useMinSizeIfCrossSizeIsIndefinite,
|
||
aAxisTracker);
|
||
if (crossSizeToUseWithRatio != NS_AUTOHEIGHT) {
|
||
// We have a definite cross-size
|
||
nscoord mainSizeFromRatio =
|
||
MainSizeFromAspectRatio(crossSizeToUseWithRatio,
|
||
aFlexItem.IntrinsicRatio(), aAxisTracker);
|
||
aFlexItem.SetFlexBaseSizeAndMainSize(mainSizeFromRatio);
|
||
return true;
|
||
}
|
||
}
|
||
return false;
|
||
}
|
||
|
||
// Note: If & when we handle "min-height: min-content" for flex items,
|
||
// we may want to resolve that in this function, too.
|
||
void
|
||
nsFlexContainerFrame::
|
||
ResolveAutoFlexBasisAndMinSize(nsPresContext* aPresContext,
|
||
FlexItem& aFlexItem,
|
||
const ReflowInput& aItemReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
// (Note: We should never have a used flex-basis of "auto" if our main axis
|
||
// is horizontal; width values should always be resolvable without reflow.)
|
||
const bool isMainSizeAuto = (!aAxisTracker.IsMainAxisHorizontal() &&
|
||
NS_AUTOHEIGHT == aFlexItem.GetFlexBaseSize());
|
||
|
||
const bool isMainMinSizeAuto = aFlexItem.NeedsMinSizeAutoResolution();
|
||
|
||
if (!isMainSizeAuto && !isMainMinSizeAuto) {
|
||
// Nothing to do; this function is only needed for flex items
|
||
// with a used flex-basis of "auto" or a min-main-size of "auto".
|
||
return;
|
||
}
|
||
|
||
// We may be about to do computations based on our item's cross-size
|
||
// (e.g. using it as a contstraint when measuring our content in the
|
||
// main axis, or using it with the intrinsic ratio to obtain a main size).
|
||
// BEFORE WE DO THAT, we need let the item "pre-stretch" its cross size (if
|
||
// it's got 'align-self:stretch'), for a certain case where the spec says
|
||
// the stretched cross size is considered "definite". That case is if we
|
||
// have a single-line (nowrap) flex container which itself has a definite
|
||
// cross-size. Otherwise, we'll wait to do stretching, since (in other
|
||
// cases) we don't know how much the item should stretch yet.
|
||
const ReflowInput* flexContainerRI = aItemReflowInput.mParentReflowInput;
|
||
MOZ_ASSERT(flexContainerRI,
|
||
"flex item's reflow state should have ptr to container's state");
|
||
if (NS_STYLE_FLEX_WRAP_NOWRAP == flexContainerRI->mStylePosition->mFlexWrap) {
|
||
// XXXdholbert Maybe this should share logic with ComputeCrossSize()...
|
||
// Alternately, maybe tentative container cross size should be passed down.
|
||
nscoord containerCrossSize =
|
||
GET_CROSS_COMPONENT_LOGICAL(aAxisTracker, aAxisTracker.GetWritingMode(),
|
||
flexContainerRI->ComputedISize(),
|
||
flexContainerRI->ComputedBSize());
|
||
// Is container's cross size "definite"?
|
||
// (Container's cross size is definite if cross-axis is horizontal, or if
|
||
// cross-axis is vertical and the cross-size is not NS_AUTOHEIGHT.)
|
||
if (aAxisTracker.IsCrossAxisHorizontal() ||
|
||
containerCrossSize != NS_AUTOHEIGHT) {
|
||
aFlexItem.ResolveStretchedCrossSize(containerCrossSize, aAxisTracker);
|
||
}
|
||
}
|
||
|
||
nscoord resolvedMinSize; // (only set/used if isMainMinSizeAuto==true)
|
||
bool minSizeNeedsToMeasureContent = false; // assume the best
|
||
if (isMainMinSizeAuto) {
|
||
// Resolve the min-size, except for considering the min-content size.
|
||
// (We'll consider that later, if we need to.)
|
||
resolvedMinSize = PartiallyResolveAutoMinSize(aFlexItem, aItemReflowInput,
|
||
aAxisTracker);
|
||
if (resolvedMinSize > 0 && !aFlexItem.IntrinsicRatio()) {
|
||
// We don't have a usable aspect ratio, so we need to consider our
|
||
// min-content size as another candidate min-size, which we'll have to
|
||
// min() with the current resolvedMinSize.
|
||
// (If resolvedMinSize were already at 0, we could skip this measurement
|
||
// because it can't go any lower. But it's not 0, so we need it.)
|
||
minSizeNeedsToMeasureContent = true;
|
||
}
|
||
}
|
||
|
||
bool flexBasisNeedsToMeasureContent = false; // assume the best
|
||
if (isMainSizeAuto) {
|
||
if (!ResolveAutoFlexBasisFromRatio(aFlexItem, aItemReflowInput,
|
||
aAxisTracker)) {
|
||
flexBasisNeedsToMeasureContent = true;
|
||
}
|
||
}
|
||
|
||
// Measure content, if needed (w/ intrinsic-width method or a reflow)
|
||
if (minSizeNeedsToMeasureContent || flexBasisNeedsToMeasureContent) {
|
||
if (aAxisTracker.IsMainAxisHorizontal()) {
|
||
if (minSizeNeedsToMeasureContent) {
|
||
nscoord frameMinISize =
|
||
aFlexItem.Frame()->GetMinISize(aItemReflowInput.mRenderingContext);
|
||
resolvedMinSize = std::min(resolvedMinSize, frameMinISize);
|
||
}
|
||
NS_ASSERTION(!flexBasisNeedsToMeasureContent,
|
||
"flex-basis:auto should have been resolved in the "
|
||
"reflow state, for horizontal flexbox. It shouldn't need "
|
||
"special handling here");
|
||
} else {
|
||
// If this item is flexible (vertically), or if we're measuring the
|
||
// 'auto' min-height and our main-size is something else, then we assume
|
||
// that the computed-height we're reflowing with now could be different
|
||
// from the one we'll use for this flex item's "actual" reflow later on.
|
||
// In that case, we need to be sure the flex item treats this as a
|
||
// vertical resize, even though none of its ancestors are necessarily
|
||
// being vertically resized.
|
||
// (Note: We don't have to do this for width, because InitResizeFlags
|
||
// will always turn on mHResize on when it sees that the computed width
|
||
// is different from current width, and that's all we need.)
|
||
bool forceVerticalResizeForMeasuringReflow =
|
||
!aFlexItem.IsFrozen() || // Is the item flexible?
|
||
!flexBasisNeedsToMeasureContent; // Are we *only* measuring it for
|
||
// 'min-height:auto'?
|
||
|
||
nscoord contentHeight =
|
||
MeasureFlexItemContentHeight(aPresContext, aFlexItem,
|
||
forceVerticalResizeForMeasuringReflow,
|
||
*flexContainerRI);
|
||
if (minSizeNeedsToMeasureContent) {
|
||
resolvedMinSize = std::min(resolvedMinSize, contentHeight);
|
||
}
|
||
if (flexBasisNeedsToMeasureContent) {
|
||
aFlexItem.SetFlexBaseSizeAndMainSize(contentHeight);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (isMainMinSizeAuto) {
|
||
aFlexItem.UpdateMainMinSize(resolvedMinSize);
|
||
}
|
||
}
|
||
|
||
/**
|
||
* A cached result for a measuring reflow.
|
||
*
|
||
* Right now we only need to cache the available size and the computed height
|
||
* for checking that the reflow input is valid, and the height and the ascent
|
||
* to be used. This can be extended later if needed.
|
||
*
|
||
* The assumption here is that a given flex item measurement won't change until
|
||
* either the available size or computed height changes, or the flex container
|
||
* intrinsic size is marked as dirty (due to a style or DOM change).
|
||
*
|
||
* In particular the computed height may change between measuring reflows due to
|
||
* how the mIsFlexContainerMeasuringReflow flag affects size computation (see
|
||
* bug 1336708).
|
||
*
|
||
* Caching it prevents us from doing exponential reflows in cases of deeply
|
||
* nested flex and scroll frames.
|
||
*
|
||
* We store them in the frame property table for simplicity.
|
||
*/
|
||
class nsFlexContainerFrame::CachedMeasuringReflowResult
|
||
{
|
||
// Members that are part of the cache key:
|
||
const LogicalSize mAvailableSize;
|
||
const nscoord mComputedHeight;
|
||
|
||
// Members that are part of the cache value:
|
||
const nscoord mHeight;
|
||
const nscoord mAscent;
|
||
|
||
public:
|
||
CachedMeasuringReflowResult(const ReflowInput& aReflowInput,
|
||
const ReflowOutput& aDesiredSize)
|
||
: mAvailableSize(aReflowInput.AvailableSize())
|
||
, mComputedHeight(aReflowInput.ComputedHeight())
|
||
, mHeight(aDesiredSize.Height())
|
||
, mAscent(aDesiredSize.BlockStartAscent())
|
||
{}
|
||
|
||
bool IsValidFor(const ReflowInput& aReflowInput) const {
|
||
return mAvailableSize == aReflowInput.AvailableSize() &&
|
||
mComputedHeight == aReflowInput.ComputedHeight();
|
||
}
|
||
|
||
nscoord Height() const { return mHeight; }
|
||
|
||
nscoord Ascent() const { return mAscent; }
|
||
};
|
||
|
||
NS_DECLARE_FRAME_PROPERTY_DELETABLE(CachedFlexMeasuringReflow,
|
||
CachedMeasuringReflowResult);
|
||
|
||
const CachedMeasuringReflowResult&
|
||
nsFlexContainerFrame::MeasureAscentAndHeightForFlexItem(
|
||
FlexItem& aItem,
|
||
nsPresContext* aPresContext,
|
||
ReflowInput& aChildReflowInput)
|
||
{
|
||
if (const auto* cachedResult =
|
||
aItem.Frame()->GetProperty(CachedFlexMeasuringReflow())) {
|
||
if (cachedResult->IsValidFor(aChildReflowInput)) {
|
||
return *cachedResult;
|
||
}
|
||
}
|
||
|
||
ReflowOutput childDesiredSize(aChildReflowInput);
|
||
nsReflowStatus childReflowStatus;
|
||
|
||
const uint32_t flags = NS_FRAME_NO_MOVE_FRAME;
|
||
ReflowChild(aItem.Frame(), aPresContext,
|
||
childDesiredSize, aChildReflowInput,
|
||
0, 0, flags, childReflowStatus);
|
||
aItem.SetHadMeasuringReflow();
|
||
|
||
// XXXdholbert Once we do pagination / splitting, we'll need to actually
|
||
// handle incomplete childReflowStatuses. But for now, we give our kids
|
||
// unconstrained available height, which means they should always complete.
|
||
MOZ_ASSERT(NS_FRAME_IS_COMPLETE(childReflowStatus),
|
||
"We gave flex item unconstrained available height, so it "
|
||
"should be complete");
|
||
|
||
// Tell the child we're done with its initial reflow.
|
||
// (Necessary for e.g. GetBaseline() to work below w/out asserting)
|
||
FinishReflowChild(aItem.Frame(), aPresContext,
|
||
childDesiredSize, &aChildReflowInput, 0, 0, flags);
|
||
|
||
auto result =
|
||
new CachedMeasuringReflowResult(aChildReflowInput, childDesiredSize);
|
||
|
||
aItem.Frame()->SetProperty(CachedFlexMeasuringReflow(), result);
|
||
return *result;
|
||
}
|
||
|
||
/* virtual */ void
|
||
nsFlexContainerFrame::MarkIntrinsicISizesDirty()
|
||
{
|
||
for (nsIFrame* childFrame : mFrames) {
|
||
childFrame->DeleteProperty(CachedFlexMeasuringReflow());
|
||
}
|
||
nsContainerFrame::MarkIntrinsicISizesDirty();
|
||
}
|
||
|
||
nscoord
|
||
nsFlexContainerFrame::
|
||
MeasureFlexItemContentHeight(nsPresContext* aPresContext,
|
||
FlexItem& aFlexItem,
|
||
bool aForceVerticalResizeForMeasuringReflow,
|
||
const ReflowInput& aParentReflowInput)
|
||
{
|
||
// Set up a reflow state for measuring the flex item's auto-height:
|
||
WritingMode wm = aFlexItem.Frame()->GetWritingMode();
|
||
LogicalSize availSize = aParentReflowInput.ComputedSize(wm);
|
||
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
|
||
ReflowInput
|
||
childRIForMeasuringHeight(aPresContext, aParentReflowInput,
|
||
aFlexItem.Frame(), availSize,
|
||
nullptr, ReflowInput::CALLER_WILL_INIT);
|
||
childRIForMeasuringHeight.mFlags.mIsFlexContainerMeasuringHeight = true;
|
||
childRIForMeasuringHeight.Init(aPresContext);
|
||
|
||
if (aFlexItem.IsStretched()) {
|
||
childRIForMeasuringHeight.SetComputedWidth(aFlexItem.GetCrossSize());
|
||
childRIForMeasuringHeight.SetHResize(true);
|
||
}
|
||
|
||
if (aForceVerticalResizeForMeasuringReflow) {
|
||
childRIForMeasuringHeight.SetVResize(true);
|
||
}
|
||
|
||
const CachedMeasuringReflowResult& reflowResult =
|
||
MeasureAscentAndHeightForFlexItem(aFlexItem, aPresContext,
|
||
childRIForMeasuringHeight);
|
||
|
||
aFlexItem.SetAscent(reflowResult.Ascent());
|
||
|
||
// Subtract border/padding in vertical axis, to get _just_
|
||
// the effective computed value of the "height" property.
|
||
nscoord childDesiredHeight = reflowResult.Height() -
|
||
childRIForMeasuringHeight.ComputedPhysicalBorderPadding().TopBottom();
|
||
|
||
return std::max(0, childDesiredHeight);
|
||
}
|
||
|
||
FlexItem::FlexItem(ReflowInput& aFlexItemReflowInput,
|
||
float aFlexGrow, float aFlexShrink, nscoord aFlexBaseSize,
|
||
nscoord aMainMinSize, nscoord aMainMaxSize,
|
||
nscoord aTentativeCrossSize,
|
||
nscoord aCrossMinSize, nscoord aCrossMaxSize,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
: mFrame(aFlexItemReflowInput.mFrame),
|
||
mFlexGrow(aFlexGrow),
|
||
mFlexShrink(aFlexShrink),
|
||
mIntrinsicRatio(mFrame->GetIntrinsicRatio()),
|
||
mBorderPadding(aFlexItemReflowInput.ComputedPhysicalBorderPadding()),
|
||
mMargin(aFlexItemReflowInput.ComputedPhysicalMargin()),
|
||
mMainMinSize(aMainMinSize),
|
||
mMainMaxSize(aMainMaxSize),
|
||
mCrossMinSize(aCrossMinSize),
|
||
mCrossMaxSize(aCrossMaxSize),
|
||
mMainPosn(0),
|
||
mCrossSize(aTentativeCrossSize),
|
||
mCrossPosn(0),
|
||
mAscent(0),
|
||
mShareOfWeightSoFar(0.0f),
|
||
mIsFrozen(false),
|
||
mHadMinViolation(false),
|
||
mHadMaxViolation(false),
|
||
mHadMeasuringReflow(false),
|
||
mIsStretched(false),
|
||
mIsStrut(false),
|
||
// mNeedsMinSizeAutoResolution is initialized in CheckForMinSizeAuto()
|
||
mWM(aFlexItemReflowInput.GetWritingMode())
|
||
// mAlignSelf, see below
|
||
{
|
||
MOZ_ASSERT(mFrame, "expecting a non-null child frame");
|
||
MOZ_ASSERT(mFrame->GetType() != nsGkAtoms::placeholderFrame,
|
||
"placeholder frames should not be treated as flex items");
|
||
MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
|
||
"out-of-flow frames should not be treated as flex items");
|
||
|
||
const ReflowInput* containerRS = aFlexItemReflowInput.mParentReflowInput;
|
||
if (IsLegacyBox(containerRS->mFrame)) {
|
||
// For -webkit-box/-webkit-inline-box, we need to:
|
||
// (1) Use "-webkit-box-align" instead of "align-items" to determine the
|
||
// container's cross-axis alignment behavior.
|
||
// (2) Suppress the ability for flex items to override that with their own
|
||
// cross-axis alignment. (The legacy box model doesn't support this.)
|
||
// So, each FlexItem simply copies the container's converted "align-items"
|
||
// value and disregards their own "align-self" property.
|
||
const nsStyleXUL* containerStyleXUL = containerRS->mFrame->StyleXUL();
|
||
mAlignSelf = ConvertLegacyStyleToAlignItems(containerStyleXUL);
|
||
} else {
|
||
mAlignSelf = aFlexItemReflowInput.mStylePosition->UsedAlignSelf(
|
||
containerRS->mFrame->StyleContext());
|
||
if (MOZ_LIKELY(mAlignSelf == NS_STYLE_ALIGN_NORMAL)) {
|
||
mAlignSelf = NS_STYLE_ALIGN_STRETCH;
|
||
}
|
||
|
||
// XXX strip off the <overflow-position> bit until we implement that
|
||
mAlignSelf &= ~NS_STYLE_ALIGN_FLAG_BITS;
|
||
}
|
||
|
||
SetFlexBaseSizeAndMainSize(aFlexBaseSize);
|
||
CheckForMinSizeAuto(aFlexItemReflowInput, aAxisTracker);
|
||
|
||
// Assert that any "auto" margin components are set to 0.
|
||
// (We'll resolve them later; until then, we want to treat them as 0-sized.)
|
||
#ifdef DEBUG
|
||
{
|
||
const nsStyleSides& styleMargin =
|
||
aFlexItemReflowInput.mStyleMargin->mMargin;
|
||
NS_FOR_CSS_SIDES(side) {
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
MOZ_ASSERT(GetMarginComponentForSide(side) == 0,
|
||
"Someone else tried to resolve our auto margin");
|
||
}
|
||
}
|
||
}
|
||
#endif // DEBUG
|
||
|
||
// Map align-self 'baseline' value to 'start' when baseline alignment
|
||
// is not possible because the FlexItem's writing mode is orthogonal to
|
||
// the main axis of the container. If that's the case, we just directly
|
||
// convert our align-self value here, so that we don't have to handle this
|
||
// with special cases elsewhere.
|
||
// We are treating this case as one where it is appropriate to use the
|
||
// fallback values defined at https://www.w3.org/TR/css-align-3/#baseline
|
||
if (aAxisTracker.IsRowOriented() ==
|
||
aAxisTracker.GetWritingMode().IsOrthogonalTo(mWM)) {
|
||
if (mAlignSelf == NS_STYLE_ALIGN_BASELINE) {
|
||
mAlignSelf = NS_STYLE_ALIGN_FLEX_START;
|
||
} else if (mAlignSelf == NS_STYLE_ALIGN_LAST_BASELINE) {
|
||
mAlignSelf = NS_STYLE_ALIGN_FLEX_END;
|
||
}
|
||
}
|
||
}
|
||
|
||
// Simplified constructor for creating a special "strut" FlexItem, for a child
|
||
// with visibility:collapse. The strut has 0 main-size, and it only exists to
|
||
// impose a minimum cross size on whichever FlexLine it ends up in.
|
||
FlexItem::FlexItem(nsIFrame* aChildFrame, nscoord aCrossSize,
|
||
WritingMode aContainerWM)
|
||
: mFrame(aChildFrame),
|
||
mFlexGrow(0.0f),
|
||
mFlexShrink(0.0f),
|
||
mIntrinsicRatio(),
|
||
// mBorderPadding uses default constructor,
|
||
// mMargin uses default constructor,
|
||
mFlexBaseSize(0),
|
||
mMainMinSize(0),
|
||
mMainMaxSize(0),
|
||
mCrossMinSize(0),
|
||
mCrossMaxSize(0),
|
||
mMainSize(0),
|
||
mMainPosn(0),
|
||
mCrossSize(aCrossSize),
|
||
mCrossPosn(0),
|
||
mAscent(0),
|
||
mShareOfWeightSoFar(0.0f),
|
||
mIsFrozen(true),
|
||
mHadMinViolation(false),
|
||
mHadMaxViolation(false),
|
||
mHadMeasuringReflow(false),
|
||
mIsStretched(false),
|
||
mIsStrut(true), // (this is the constructor for making struts, after all)
|
||
mNeedsMinSizeAutoResolution(false),
|
||
mWM(aContainerWM),
|
||
mAlignSelf(NS_STYLE_ALIGN_FLEX_START)
|
||
{
|
||
MOZ_ASSERT(mFrame, "expecting a non-null child frame");
|
||
MOZ_ASSERT(NS_STYLE_VISIBILITY_COLLAPSE ==
|
||
mFrame->StyleVisibility()->mVisible,
|
||
"Should only make struts for children with 'visibility:collapse'");
|
||
MOZ_ASSERT(mFrame->GetType() != nsGkAtoms::placeholderFrame,
|
||
"placeholder frames should not be treated as flex items");
|
||
MOZ_ASSERT(!(mFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW),
|
||
"out-of-flow frames should not be treated as flex items");
|
||
}
|
||
|
||
void
|
||
FlexItem::CheckForMinSizeAuto(const ReflowInput& aFlexItemReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
const nsStylePosition* pos = aFlexItemReflowInput.mStylePosition;
|
||
const nsStyleDisplay* disp = aFlexItemReflowInput.mStyleDisplay;
|
||
|
||
// We'll need special behavior for "min-[width|height]:auto" (whichever is in
|
||
// the main axis) iff:
|
||
// (a) its computed value is "auto"
|
||
// (b) the "overflow" sub-property in the same axis (the main axis) has a
|
||
// computed value of "visible"
|
||
const nsStyleCoord& minSize = GET_MAIN_COMPONENT(aAxisTracker,
|
||
pos->mMinWidth,
|
||
pos->mMinHeight);
|
||
|
||
const uint8_t overflowVal = GET_MAIN_COMPONENT(aAxisTracker,
|
||
disp->mOverflowX,
|
||
disp->mOverflowY);
|
||
|
||
mNeedsMinSizeAutoResolution = (minSize.GetUnit() == eStyleUnit_Auto &&
|
||
overflowVal == NS_STYLE_OVERFLOW_VISIBLE);
|
||
}
|
||
|
||
nscoord
|
||
FlexItem::GetBaselineOffsetFromOuterCrossEdge(
|
||
AxisEdgeType aEdge,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
bool aUseFirstLineBaseline) const
|
||
{
|
||
// NOTE: Currently, 'mAscent' (taken from reflow) is an inherently vertical
|
||
// measurement -- it's the distance from the border-top edge of this FlexItem
|
||
// to its baseline. So, we can really only do baseline alignment when the
|
||
// cross axis is vertical. (The FlexItem constructor enforces this when
|
||
// resolving the item's "mAlignSelf" value).
|
||
MOZ_ASSERT(!aAxisTracker.IsCrossAxisHorizontal(),
|
||
"Only expecting to be doing baseline computations when the "
|
||
"cross axis is vertical");
|
||
|
||
AxisOrientationType crossAxis = aAxisTracker.GetCrossAxis();
|
||
mozilla::Side sideToMeasureFrom = kAxisOrientationToSidesMap[crossAxis][aEdge];
|
||
|
||
nscoord marginTopToBaseline = ResolvedAscent(aUseFirstLineBaseline) +
|
||
mMargin.top;
|
||
|
||
if (sideToMeasureFrom == eSideTop) {
|
||
// Measuring from top (normal case): the distance from the margin-box top
|
||
// edge to the baseline is just ascent + margin-top.
|
||
return marginTopToBaseline;
|
||
}
|
||
|
||
MOZ_ASSERT(sideToMeasureFrom == eSideBottom,
|
||
"We already checked that we're dealing with a vertical axis, and "
|
||
"we're not using the top side, so that only leaves the bottom...");
|
||
|
||
// Measuring from bottom: The distance from the margin-box bottom edge to the
|
||
// baseline is just the margin-box cross size (i.e. outer cross size), minus
|
||
// the already-computed distance from margin-top to baseline.
|
||
return GetOuterCrossSize(crossAxis) - marginTopToBaseline;
|
||
}
|
||
|
||
uint32_t
|
||
FlexItem::GetNumAutoMarginsInAxis(AxisOrientationType aAxis) const
|
||
{
|
||
uint32_t numAutoMargins = 0;
|
||
const nsStyleSides& styleMargin = mFrame->StyleMargin()->mMargin;
|
||
for (uint32_t i = 0; i < eNumAxisEdges; i++) {
|
||
mozilla::Side side = kAxisOrientationToSidesMap[aAxis][i];
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
numAutoMargins++;
|
||
}
|
||
}
|
||
|
||
// Mostly for clarity:
|
||
MOZ_ASSERT(numAutoMargins <= 2,
|
||
"We're just looking at one item along one dimension, so we "
|
||
"should only have examined 2 margins");
|
||
|
||
return numAutoMargins;
|
||
}
|
||
|
||
bool
|
||
FlexItem::CanMainSizeInfluenceCrossSize(
|
||
const FlexboxAxisTracker& aAxisTracker) const
|
||
{
|
||
if (mIsStretched) {
|
||
// We've already had our cross-size stretched for "align-self:stretch").
|
||
// The container is imposing its cross size on us.
|
||
return false;
|
||
}
|
||
|
||
if (mIsStrut) {
|
||
// Struts (for visibility:collapse items) have a predetermined size;
|
||
// no need to measure anything.
|
||
return false;
|
||
}
|
||
|
||
if (HasIntrinsicRatio()) {
|
||
// For flex items that have an intrinsic ratio (and maintain it, i.e. are
|
||
// not stretched, which we already checked above): changes to main-size
|
||
// *do* influence the cross size.
|
||
return true;
|
||
}
|
||
|
||
if (aAxisTracker.IsCrossAxisHorizontal()) {
|
||
// If the cross axis is horizontal, then changes to the item's main size
|
||
// (height) can't influence its cross size (width), if the item is a block
|
||
// with a horizontal writing-mode.
|
||
// XXXdholbert This doesn't account for vertical writing-modes, items with
|
||
// aspect ratios, items that are multicol elements, & items that are
|
||
// multi-line vertical flex containers. In all of those cases, a change to
|
||
// the height could influence the width.
|
||
return false;
|
||
}
|
||
|
||
// Default assumption, if we haven't proven otherwise: the resolved main size
|
||
// *can* change the cross size.
|
||
return true;
|
||
}
|
||
|
||
// Keeps track of our position along a particular axis (where a '0' position
|
||
// corresponds to the 'start' edge of that axis).
|
||
// This class shouldn't be instantiated directly -- rather, it should only be
|
||
// instantiated via its subclasses defined below.
|
||
class MOZ_STACK_CLASS PositionTracker {
|
||
public:
|
||
// Accessor for the current value of the position that we're tracking.
|
||
inline nscoord GetPosition() const { return mPosition; }
|
||
inline AxisOrientationType GetAxis() const { return mAxis; }
|
||
|
||
// Advances our position across the start edge of the given margin, in the
|
||
// axis we're tracking.
|
||
void EnterMargin(const nsMargin& aMargin)
|
||
{
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][eAxisEdge_Start];
|
||
mPosition += aMargin.Side(side);
|
||
}
|
||
|
||
// Advances our position across the end edge of the given margin, in the axis
|
||
// we're tracking.
|
||
void ExitMargin(const nsMargin& aMargin)
|
||
{
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][eAxisEdge_End];
|
||
mPosition += aMargin.Side(side);
|
||
}
|
||
|
||
// Advances our current position from the start side of a child frame's
|
||
// border-box to the frame's upper or left edge (depending on our axis).
|
||
// (Note that this is a no-op if our axis grows in the same direction as
|
||
// the corresponding logical axis.)
|
||
void EnterChildFrame(nscoord aChildFrameSize)
|
||
{
|
||
if (mIsAxisReversed) {
|
||
mPosition += aChildFrameSize;
|
||
}
|
||
}
|
||
|
||
// Advances our current position from a frame's upper or left border-box edge
|
||
// (whichever is in the axis we're tracking) to the 'end' side of the frame
|
||
// in the axis that we're tracking. (Note that this is a no-op if our axis
|
||
// is reversed with respect to the corresponding logical axis.)
|
||
void ExitChildFrame(nscoord aChildFrameSize)
|
||
{
|
||
if (!mIsAxisReversed) {
|
||
mPosition += aChildFrameSize;
|
||
}
|
||
}
|
||
|
||
protected:
|
||
// Protected constructor, to be sure we're only instantiated via a subclass.
|
||
PositionTracker(AxisOrientationType aAxis, bool aIsAxisReversed)
|
||
: mPosition(0),
|
||
mAxis(aAxis),
|
||
mIsAxisReversed(aIsAxisReversed)
|
||
{}
|
||
|
||
// Delete copy-constructor & reassignment operator, to prevent accidental
|
||
// (unnecessary) copying.
|
||
PositionTracker(const PositionTracker&) = delete;
|
||
PositionTracker& operator=(const PositionTracker&) = delete;
|
||
|
||
// Member data:
|
||
nscoord mPosition; // The position we're tracking
|
||
// XXXdholbert [BEGIN DEPRECATED]
|
||
const AxisOrientationType mAxis; // The axis along which we're moving.
|
||
// XXXdholbert [END DEPRECATED]
|
||
const bool mIsAxisReversed; // Is the axis along which we're moving reversed
|
||
// (e.g. LTR vs RTL) with respect to the
|
||
// corresponding axis on the flex container's WM?
|
||
};
|
||
|
||
// Tracks our position in the main axis, when we're laying out flex items.
|
||
// The "0" position represents the main-start edge of the flex container's
|
||
// content-box.
|
||
class MOZ_STACK_CLASS MainAxisPositionTracker : public PositionTracker {
|
||
public:
|
||
MainAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker,
|
||
const FlexLine* aLine,
|
||
uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize);
|
||
|
||
~MainAxisPositionTracker() {
|
||
MOZ_ASSERT(mNumPackingSpacesRemaining == 0,
|
||
"miscounted the number of packing spaces");
|
||
MOZ_ASSERT(mNumAutoMarginsInMainAxis == 0,
|
||
"miscounted the number of auto margins");
|
||
}
|
||
|
||
// Advances past the packing space (if any) between two flex items
|
||
void TraversePackingSpace();
|
||
|
||
// If aItem has any 'auto' margins in the main axis, this method updates the
|
||
// corresponding values in its margin.
|
||
void ResolveAutoMarginsInMainAxis(FlexItem& aItem);
|
||
|
||
private:
|
||
nscoord mPackingSpaceRemaining;
|
||
uint32_t mNumAutoMarginsInMainAxis;
|
||
uint32_t mNumPackingSpacesRemaining;
|
||
// XXX this should be uint16_t when we add explicit fallback handling
|
||
uint8_t mJustifyContent;
|
||
};
|
||
|
||
// Utility class for managing our position along the cross axis along
|
||
// the whole flex container (at a higher level than a single line).
|
||
// The "0" position represents the cross-start edge of the flex container's
|
||
// content-box.
|
||
class MOZ_STACK_CLASS CrossAxisPositionTracker : public PositionTracker {
|
||
public:
|
||
CrossAxisPositionTracker(FlexLine* aFirstLine,
|
||
const ReflowInput& aReflowInput,
|
||
nscoord aContentBoxCrossSize,
|
||
bool aIsCrossSizeDefinite,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Advances past the packing space (if any) between two flex lines
|
||
void TraversePackingSpace();
|
||
|
||
// Advances past the given FlexLine
|
||
void TraverseLine(FlexLine& aLine) { mPosition += aLine.GetLineCrossSize(); }
|
||
|
||
private:
|
||
// Redeclare the frame-related methods from PositionTracker as private with
|
||
// = delete, to be sure (at compile time) that no client code can invoke
|
||
// them. (Unlike the other PositionTracker derived classes, this class here
|
||
// deals with FlexLines, not with individual FlexItems or frames.)
|
||
void EnterMargin(const nsMargin& aMargin) = delete;
|
||
void ExitMargin(const nsMargin& aMargin) = delete;
|
||
void EnterChildFrame(nscoord aChildFrameSize) = delete;
|
||
void ExitChildFrame(nscoord aChildFrameSize) = delete;
|
||
|
||
nscoord mPackingSpaceRemaining;
|
||
uint32_t mNumPackingSpacesRemaining;
|
||
// XXX this should be uint16_t when we add explicit fallback handling
|
||
uint8_t mAlignContent;
|
||
};
|
||
|
||
// Utility class for managing our position along the cross axis, *within* a
|
||
// single flex line.
|
||
class MOZ_STACK_CLASS SingleLineCrossAxisPositionTracker : public PositionTracker {
|
||
public:
|
||
explicit SingleLineCrossAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
void ResolveAutoMarginsInCrossAxis(const FlexLine& aLine,
|
||
FlexItem& aItem);
|
||
|
||
void EnterAlignPackingSpace(const FlexLine& aLine,
|
||
const FlexItem& aItem,
|
||
const FlexboxAxisTracker& aAxisTracker);
|
||
|
||
// Resets our position to the cross-start edge of this line.
|
||
inline void ResetPosition() { mPosition = 0; }
|
||
};
|
||
|
||
//----------------------------------------------------------------------
|
||
|
||
// Frame class boilerplate
|
||
// =======================
|
||
|
||
NS_QUERYFRAME_HEAD(nsFlexContainerFrame)
|
||
NS_QUERYFRAME_ENTRY(nsFlexContainerFrame)
|
||
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
|
||
|
||
NS_IMPL_FRAMEARENA_HELPERS(nsFlexContainerFrame)
|
||
|
||
nsContainerFrame*
|
||
NS_NewFlexContainerFrame(nsIPresShell* aPresShell,
|
||
nsStyleContext* aContext)
|
||
{
|
||
return new (aPresShell) nsFlexContainerFrame(aContext);
|
||
}
|
||
|
||
//----------------------------------------------------------------------
|
||
|
||
// nsFlexContainerFrame Method Implementations
|
||
// ===========================================
|
||
|
||
/* virtual */
|
||
nsFlexContainerFrame::~nsFlexContainerFrame()
|
||
{
|
||
}
|
||
|
||
/* virtual */
|
||
void
|
||
nsFlexContainerFrame::Init(nsIContent* aContent,
|
||
nsContainerFrame* aParent,
|
||
nsIFrame* aPrevInFlow)
|
||
{
|
||
nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
|
||
|
||
const nsStyleDisplay* styleDisp = StyleContext()->StyleDisplay();
|
||
|
||
// Figure out if we should set a frame state bit to indicate that this frame
|
||
// represents a legacy -webkit-{inline-}box container.
|
||
// First, the trivial case: just check "display" directly.
|
||
bool isLegacyBox = IsDisplayValueLegacyBox(styleDisp);
|
||
|
||
// If this frame is for a scrollable element, then it will actually have
|
||
// "display:block", and its *parent* will have the real flex-flavored display
|
||
// value. So in that case, check the parent to find out if we're legacy.
|
||
if (!isLegacyBox && styleDisp->mDisplay == mozilla::StyleDisplay::Block) {
|
||
nsStyleContext* parentStyleContext = mStyleContext->GetParent();
|
||
NS_ASSERTION(parentStyleContext &&
|
||
(mStyleContext->GetPseudo() == nsCSSAnonBoxes::buttonContent ||
|
||
mStyleContext->GetPseudo() == nsCSSAnonBoxes::scrolledContent),
|
||
"The only way a nsFlexContainerFrame can have 'display:block' "
|
||
"should be if it's the inner part of a scrollable or button "
|
||
"element");
|
||
isLegacyBox = IsDisplayValueLegacyBox(parentStyleContext->StyleDisplay());
|
||
}
|
||
|
||
if (isLegacyBox) {
|
||
AddStateBits(NS_STATE_FLEX_IS_LEGACY_WEBKIT_BOX);
|
||
}
|
||
}
|
||
|
||
template<bool IsLessThanOrEqual(nsIFrame*, nsIFrame*)>
|
||
/* static */ bool
|
||
nsFlexContainerFrame::SortChildrenIfNeeded()
|
||
{
|
||
if (nsIFrame::IsFrameListSorted<IsLessThanOrEqual>(mFrames)) {
|
||
return false;
|
||
}
|
||
|
||
nsIFrame::SortFrameList<IsLessThanOrEqual>(mFrames);
|
||
return true;
|
||
}
|
||
|
||
/* virtual */
|
||
nsIAtom*
|
||
nsFlexContainerFrame::GetType() const
|
||
{
|
||
return nsGkAtoms::flexContainerFrame;
|
||
}
|
||
|
||
#ifdef DEBUG_FRAME_DUMP
|
||
nsresult
|
||
nsFlexContainerFrame::GetFrameName(nsAString& aResult) const
|
||
{
|
||
return MakeFrameName(NS_LITERAL_STRING("FlexContainer"), aResult);
|
||
}
|
||
#endif
|
||
|
||
nscoord
|
||
nsFlexContainerFrame::GetLogicalBaseline(mozilla::WritingMode aWM) const
|
||
{
|
||
NS_ASSERTION(mBaselineFromLastReflow != NS_INTRINSIC_WIDTH_UNKNOWN,
|
||
"baseline has not been set");
|
||
|
||
if (HasAnyStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE)) {
|
||
// Return a baseline synthesized from our margin-box.
|
||
return nsContainerFrame::GetLogicalBaseline(aWM);
|
||
}
|
||
return mBaselineFromLastReflow;
|
||
}
|
||
|
||
// Helper for BuildDisplayList, to implement this special-case for flex items
|
||
// from the spec:
|
||
// Flex items paint exactly the same as block-level elements in the
|
||
// normal flow, except that 'z-index' values other than 'auto' create
|
||
// a stacking context even if 'position' is 'static'.
|
||
// http://www.w3.org/TR/2012/CR-css3-flexbox-20120918/#painting
|
||
uint32_t
|
||
GetDisplayFlagsForFlexItem(nsIFrame* aFrame)
|
||
{
|
||
MOZ_ASSERT(aFrame->IsFlexItem(), "Should only be called on flex items");
|
||
|
||
const nsStylePosition* pos = aFrame->StylePosition();
|
||
if (pos->mZIndex.GetUnit() == eStyleUnit_Integer) {
|
||
return nsIFrame::DISPLAY_CHILD_FORCE_STACKING_CONTEXT;
|
||
}
|
||
return nsIFrame::DISPLAY_CHILD_FORCE_PSEUDO_STACKING_CONTEXT;
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
|
||
const nsDisplayListSet& aLists)
|
||
{
|
||
// XXXdholbert hacky temporary band-aid for bug 1059138: Trivially pass this
|
||
// assertion (skip it, basically) if the first child is part of a shadow DOM.
|
||
// (IsOrderLEQWithDOMFallback doesn't know how to compare tree-position of a
|
||
// shadow-DOM element vs. a non-shadow-DOM element.)
|
||
NS_ASSERTION(
|
||
(!mFrames.IsEmpty() &&
|
||
mFrames.FirstChild()->GetContent()->GetContainingShadow()) ||
|
||
nsIFrame::IsFrameListSorted<IsOrderLEQWithDOMFallback>(mFrames),
|
||
"Child frames aren't sorted correctly");
|
||
|
||
DisplayBorderBackgroundOutline(aBuilder, aLists);
|
||
|
||
// Our children are all block-level, so their borders/backgrounds all go on
|
||
// the BlockBorderBackgrounds list.
|
||
nsDisplayListSet childLists(aLists, aLists.BlockBorderBackgrounds());
|
||
for (nsIFrame* childFrame : mFrames) {
|
||
BuildDisplayListForChild(aBuilder, childFrame, childLists,
|
||
GetDisplayFlagsForFlexItem(childFrame));
|
||
}
|
||
}
|
||
|
||
void
|
||
FlexLine::FreezeItemsEarly(bool aIsUsingFlexGrow)
|
||
{
|
||
// After we've established the type of flexing we're doing (growing vs.
|
||
// shrinking), and before we try to flex any items, we freeze items that
|
||
// obviously *can't* flex.
|
||
//
|
||
// Quoting the spec:
|
||
// # Freeze, setting its target main size to its hypothetical main size...
|
||
// # - any item that has a flex factor of zero
|
||
// # - if using the flex grow factor: any item that has a flex base size
|
||
// # greater than its hypothetical main size
|
||
// # - if using the flex shrink factor: any item that has a flex base size
|
||
// # smaller than its hypothetical main size
|
||
// http://dev.w3.org/csswg/css-flexbox/#resolve-flexible-lengths-flex-factors
|
||
//
|
||
// (NOTE: At this point, item->GetMainSize() *is* the item's hypothetical
|
||
// main size, since SetFlexBaseSizeAndMainSize() sets it up that way, and the
|
||
// item hasn't had a chance to flex away from that yet.)
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
bool shouldFreeze = (0.0f == item->GetFlexFactor(aIsUsingFlexGrow));
|
||
if (!shouldFreeze) {
|
||
if (aIsUsingFlexGrow) {
|
||
if (item->GetFlexBaseSize() > item->GetMainSize()) {
|
||
shouldFreeze = true;
|
||
}
|
||
} else { // using flex-shrink
|
||
if (item->GetFlexBaseSize() < item->GetMainSize()) {
|
||
shouldFreeze = true;
|
||
}
|
||
}
|
||
}
|
||
if (shouldFreeze) {
|
||
// Freeze item! (at its hypothetical main size)
|
||
item->Freeze();
|
||
mNumFrozenItems++;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Based on the sign of aTotalViolation, this function freezes a subset of our
|
||
// flexible sizes, and restores the remaining ones to their initial pref sizes.
|
||
void
|
||
FlexLine::FreezeOrRestoreEachFlexibleSize(const nscoord aTotalViolation,
|
||
bool aIsFinalIteration)
|
||
{
|
||
enum FreezeType {
|
||
eFreezeEverything,
|
||
eFreezeMinViolations,
|
||
eFreezeMaxViolations
|
||
};
|
||
|
||
FreezeType freezeType;
|
||
if (aTotalViolation == 0) {
|
||
freezeType = eFreezeEverything;
|
||
} else if (aTotalViolation > 0) {
|
||
freezeType = eFreezeMinViolations;
|
||
} else { // aTotalViolation < 0
|
||
freezeType = eFreezeMaxViolations;
|
||
}
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
MOZ_ASSERT(!item->HadMinViolation() || !item->HadMaxViolation(),
|
||
"Can have either min or max violation, but not both");
|
||
|
||
if (eFreezeEverything == freezeType ||
|
||
(eFreezeMinViolations == freezeType && item->HadMinViolation()) ||
|
||
(eFreezeMaxViolations == freezeType && item->HadMaxViolation())) {
|
||
|
||
MOZ_ASSERT(item->GetMainSize() >= item->GetMainMinSize(),
|
||
"Freezing item at a size below its minimum");
|
||
MOZ_ASSERT(item->GetMainSize() <= item->GetMainMaxSize(),
|
||
"Freezing item at a size above its maximum");
|
||
|
||
item->Freeze();
|
||
mNumFrozenItems++;
|
||
} else if (MOZ_UNLIKELY(aIsFinalIteration)) {
|
||
// XXXdholbert If & when bug 765861 is fixed, we should upgrade this
|
||
// assertion to be fatal except in documents with enormous lengths.
|
||
NS_ERROR("Final iteration still has unfrozen items, this shouldn't"
|
||
" happen unless there was nscoord under/overflow.");
|
||
item->Freeze();
|
||
mNumFrozenItems++;
|
||
} // else, we'll reset this item's main size to its flex base size on the
|
||
// next iteration of this algorithm.
|
||
|
||
// Clear this item's violation(s), now that we've dealt with them
|
||
item->ClearViolationFlags();
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
FlexLine::ResolveFlexibleLengths(nscoord aFlexContainerMainSize)
|
||
{
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug, ("ResolveFlexibleLengths\n"));
|
||
|
||
// Determine whether we're going to be growing or shrinking items.
|
||
const bool isUsingFlexGrow =
|
||
(mTotalOuterHypotheticalMainSize < aFlexContainerMainSize);
|
||
|
||
// Do an "early freeze" for flex items that obviously can't flex in the
|
||
// direction we've chosen:
|
||
FreezeItemsEarly(isUsingFlexGrow);
|
||
|
||
if (mNumFrozenItems == mNumItems) {
|
||
// All our items are frozen, so we have no flexible lengths to resolve.
|
||
return;
|
||
}
|
||
MOZ_ASSERT(!IsEmpty(), "empty lines should take the early-return above");
|
||
|
||
// Subtract space occupied by our items' margins/borders/padding, so we can
|
||
// just be dealing with the space available for our flex items' content
|
||
// boxes.
|
||
nscoord spaceReservedForMarginBorderPadding =
|
||
mTotalOuterHypotheticalMainSize - mTotalInnerHypotheticalMainSize;
|
||
|
||
nscoord spaceAvailableForFlexItemsContentBoxes =
|
||
aFlexContainerMainSize - spaceReservedForMarginBorderPadding;
|
||
|
||
nscoord origAvailableFreeSpace;
|
||
bool isOrigAvailFreeSpaceInitialized = false;
|
||
|
||
// NOTE: I claim that this chunk of the algorithm (the looping part) needs to
|
||
// run the loop at MOST mNumItems times. This claim should hold up
|
||
// because we'll freeze at least one item on each loop iteration, and once
|
||
// we've run out of items to freeze, there's nothing left to do. However,
|
||
// in most cases, we'll break out of this loop long before we hit that many
|
||
// iterations.
|
||
for (uint32_t iterationCounter = 0;
|
||
iterationCounter < mNumItems; iterationCounter++) {
|
||
// Set every not-yet-frozen item's used main size to its
|
||
// flex base size, and subtract all the used main sizes from our
|
||
// total amount of space to determine the 'available free space'
|
||
// (positive or negative) to be distributed among our flexible items.
|
||
nscoord availableFreeSpace = spaceAvailableForFlexItemsContentBoxes;
|
||
for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
if (!item->IsFrozen()) {
|
||
item->SetMainSize(item->GetFlexBaseSize());
|
||
}
|
||
availableFreeSpace -= item->GetMainSize();
|
||
}
|
||
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
|
||
(" available free space = %d\n", availableFreeSpace));
|
||
|
||
|
||
// The sign of our free space should agree with the type of flexing
|
||
// (grow/shrink) that we're doing (except if we've had integer overflow;
|
||
// then, all bets are off). Any disagreement should've made us use the
|
||
// other type of flexing, or should've been resolved in FreezeItemsEarly.
|
||
// XXXdholbert If & when bug 765861 is fixed, we should upgrade this
|
||
// assertion to be fatal except in documents with enormous lengths.
|
||
NS_ASSERTION((isUsingFlexGrow && availableFreeSpace >= 0) ||
|
||
(!isUsingFlexGrow && availableFreeSpace <= 0),
|
||
"availableFreeSpace's sign should match isUsingFlexGrow");
|
||
|
||
// If we have any free space available, give each flexible item a portion
|
||
// of availableFreeSpace.
|
||
if (availableFreeSpace != 0) {
|
||
// The first time we do this, we initialize origAvailableFreeSpace.
|
||
if (!isOrigAvailFreeSpaceInitialized) {
|
||
origAvailableFreeSpace = availableFreeSpace;
|
||
isOrigAvailFreeSpaceInitialized = true;
|
||
}
|
||
|
||
// STRATEGY: On each item, we compute & store its "share" of the total
|
||
// weight that we've seen so far:
|
||
// curWeight / weightSum
|
||
//
|
||
// Then, when we go to actually distribute the space (in the next loop),
|
||
// we can simply walk backwards through the elements and give each item
|
||
// its "share" multiplied by the remaining available space.
|
||
//
|
||
// SPECIAL CASE: If the sum of the weights is larger than the
|
||
// maximum representable float (overflowing to infinity), then we can't
|
||
// sensibly divide out proportional shares anymore. In that case, we
|
||
// simply treat the flex item(s) with the largest weights as if
|
||
// their weights were infinite (dwarfing all the others), and we
|
||
// distribute all of the available space among them.
|
||
float weightSum = 0.0f;
|
||
float flexFactorSum = 0.0f;
|
||
float largestWeight = 0.0f;
|
||
uint32_t numItemsWithLargestWeight = 0;
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item,
|
||
"numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
float curWeight = item->GetWeight(isUsingFlexGrow);
|
||
float curFlexFactor = item->GetFlexFactor(isUsingFlexGrow);
|
||
MOZ_ASSERT(curWeight >= 0.0f, "weights are non-negative");
|
||
MOZ_ASSERT(curFlexFactor >= 0.0f, "flex factors are non-negative");
|
||
|
||
weightSum += curWeight;
|
||
flexFactorSum += curFlexFactor;
|
||
|
||
if (IsFinite(weightSum)) {
|
||
if (curWeight == 0.0f) {
|
||
item->SetShareOfWeightSoFar(0.0f);
|
||
} else {
|
||
item->SetShareOfWeightSoFar(curWeight / weightSum);
|
||
}
|
||
} // else, the sum of weights overflows to infinity, in which
|
||
// case we don't bother with "SetShareOfWeightSoFar" since
|
||
// we know we won't use it. (instead, we'll just give every
|
||
// item with the largest weight an equal share of space.)
|
||
|
||
// Update our largest-weight tracking vars
|
||
if (curWeight > largestWeight) {
|
||
largestWeight = curWeight;
|
||
numItemsWithLargestWeight = 1;
|
||
} else if (curWeight == largestWeight) {
|
||
numItemsWithLargestWeight++;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (weightSum != 0.0f) {
|
||
MOZ_ASSERT(flexFactorSum != 0.0f,
|
||
"flex factor sum can't be 0, if a weighted sum "
|
||
"of its components (weightSum) is nonzero");
|
||
if (flexFactorSum < 1.0f) {
|
||
// Our unfrozen flex items don't want all of the original free space!
|
||
// (Their flex factors add up to something less than 1.)
|
||
// Hence, make sure we don't distribute any more than the portion of
|
||
// our original free space that these items actually want.
|
||
nscoord totalDesiredPortionOfOrigFreeSpace =
|
||
NSToCoordRound(origAvailableFreeSpace * flexFactorSum);
|
||
|
||
// Clamp availableFreeSpace to be no larger than that ^^.
|
||
// (using min or max, depending on sign).
|
||
// This should not change the sign of availableFreeSpace (except
|
||
// possibly by setting it to 0), as enforced by this assertion:
|
||
MOZ_ASSERT(totalDesiredPortionOfOrigFreeSpace == 0 ||
|
||
((totalDesiredPortionOfOrigFreeSpace > 0) ==
|
||
(availableFreeSpace > 0)),
|
||
"When we reduce available free space for flex factors < 1,"
|
||
"we shouldn't change the sign of the free space...");
|
||
|
||
if (availableFreeSpace > 0) {
|
||
availableFreeSpace = std::min(availableFreeSpace,
|
||
totalDesiredPortionOfOrigFreeSpace);
|
||
} else {
|
||
availableFreeSpace = std::max(availableFreeSpace,
|
||
totalDesiredPortionOfOrigFreeSpace);
|
||
}
|
||
}
|
||
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
|
||
(" Distributing available space:"));
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
|
||
// NOTE: It's important that we traverse our items in *reverse* order
|
||
// here, for correct width distribution according to the items'
|
||
// "ShareOfWeightSoFar" progressively-calculated values.
|
||
for (FlexItem* item = mItems.getLast();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getPrevious()) {
|
||
MOZ_ASSERT(item,
|
||
"numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
// To avoid rounding issues, we compute the change in size for this
|
||
// item, and then subtract it from the remaining available space.
|
||
nscoord sizeDelta = 0;
|
||
if (IsFinite(weightSum)) {
|
||
float myShareOfRemainingSpace =
|
||
item->GetShareOfWeightSoFar();
|
||
|
||
MOZ_ASSERT(myShareOfRemainingSpace >= 0.0f &&
|
||
myShareOfRemainingSpace <= 1.0f,
|
||
"my share should be nonnegative fractional amount");
|
||
|
||
if (myShareOfRemainingSpace == 1.0f) {
|
||
// (We special-case 1.0f to avoid float error from converting
|
||
// availableFreeSpace from integer*1.0f --> float --> integer)
|
||
sizeDelta = availableFreeSpace;
|
||
} else if (myShareOfRemainingSpace > 0.0f) {
|
||
sizeDelta = NSToCoordRound(availableFreeSpace *
|
||
myShareOfRemainingSpace);
|
||
}
|
||
} else if (item->GetWeight(isUsingFlexGrow) == largestWeight) {
|
||
// Total flexibility is infinite, so we're just distributing
|
||
// the available space equally among the items that are tied for
|
||
// having the largest weight (and this is one of those items).
|
||
sizeDelta =
|
||
NSToCoordRound(availableFreeSpace /
|
||
float(numItemsWithLargestWeight));
|
||
numItemsWithLargestWeight--;
|
||
}
|
||
|
||
availableFreeSpace -= sizeDelta;
|
||
|
||
item->SetMainSize(item->GetMainSize() + sizeDelta);
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
|
||
(" child %p receives %d, for a total of %d\n",
|
||
item, sizeDelta, item->GetMainSize()));
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
// Fix min/max violations:
|
||
nscoord totalViolation = 0; // keeps track of adjustments for min/max
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
|
||
(" Checking for violations:"));
|
||
|
||
// Since this loop only operates on unfrozen flex items, we can break as
|
||
// soon as we have seen all of them.
|
||
uint32_t numUnfrozenItemsToBeSeen = mNumItems - mNumFrozenItems;
|
||
for (FlexItem* item = mItems.getFirst();
|
||
numUnfrozenItemsToBeSeen > 0; item = item->getNext()) {
|
||
MOZ_ASSERT(item, "numUnfrozenItemsToBeSeen says items remain to be seen");
|
||
if (!item->IsFrozen()) {
|
||
numUnfrozenItemsToBeSeen--;
|
||
|
||
if (item->GetMainSize() < item->GetMainMinSize()) {
|
||
// min violation
|
||
totalViolation += item->GetMainMinSize() - item->GetMainSize();
|
||
item->SetMainSize(item->GetMainMinSize());
|
||
item->SetHadMinViolation();
|
||
} else if (item->GetMainSize() > item->GetMainMaxSize()) {
|
||
// max violation
|
||
totalViolation += item->GetMainMaxSize() - item->GetMainSize();
|
||
item->SetMainSize(item->GetMainMaxSize());
|
||
item->SetHadMaxViolation();
|
||
}
|
||
}
|
||
}
|
||
|
||
FreezeOrRestoreEachFlexibleSize(totalViolation,
|
||
iterationCounter + 1 == mNumItems);
|
||
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
|
||
(" Total violation: %d\n", totalViolation));
|
||
|
||
if (mNumFrozenItems == mNumItems) {
|
||
break;
|
||
}
|
||
|
||
MOZ_ASSERT(totalViolation != 0,
|
||
"Zero violation should've made us freeze all items & break");
|
||
}
|
||
|
||
#ifdef DEBUG
|
||
// Post-condition: all items should've been frozen.
|
||
// Make sure the counts match:
|
||
MOZ_ASSERT(mNumFrozenItems == mNumItems, "All items should be frozen");
|
||
|
||
// For good measure, check each item directly, in case our counts are busted:
|
||
for (const FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
MOZ_ASSERT(item->IsFrozen(), "All items should be frozen");
|
||
}
|
||
#endif // DEBUG
|
||
}
|
||
|
||
MainAxisPositionTracker::
|
||
MainAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker,
|
||
const FlexLine* aLine,
|
||
uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize)
|
||
: PositionTracker(aAxisTracker.GetMainAxis(),
|
||
aAxisTracker.IsMainAxisReversed()),
|
||
mPackingSpaceRemaining(aContentBoxMainSize), // we chip away at this below
|
||
mNumAutoMarginsInMainAxis(0),
|
||
mNumPackingSpacesRemaining(0),
|
||
mJustifyContent(aJustifyContent)
|
||
{
|
||
// 'normal' behaves as 'stretch', and 'stretch' behaves as 'flex-start',
|
||
// in the main axis
|
||
// https://drafts.csswg.org/css-align-3/#propdef-justify-content
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_NORMAL ||
|
||
mJustifyContent == NS_STYLE_JUSTIFY_STRETCH) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
|
||
}
|
||
|
||
// XXX strip off the <overflow-position> bit until we implement that
|
||
mJustifyContent &= ~NS_STYLE_JUSTIFY_FLAG_BITS;
|
||
|
||
// mPackingSpaceRemaining is initialized to the container's main size. Now
|
||
// we'll subtract out the main sizes of our flex items, so that it ends up
|
||
// with the *actual* amount of packing space.
|
||
for (const FlexItem* item = aLine->GetFirstItem(); item;
|
||
item = item->getNext()) {
|
||
mPackingSpaceRemaining -= item->GetOuterMainSize(mAxis);
|
||
mNumAutoMarginsInMainAxis += item->GetNumAutoMarginsInAxis(mAxis);
|
||
}
|
||
|
||
if (mPackingSpaceRemaining <= 0) {
|
||
// No available packing space to use for resolving auto margins.
|
||
mNumAutoMarginsInMainAxis = 0;
|
||
}
|
||
|
||
// If packing space is negative, 'space-between' falls back to 'flex-start',
|
||
// and 'space-around' & 'space-evenly' fall back to 'center'. In those cases,
|
||
// it's simplest to just pretend we have a different 'justify-content' value
|
||
// and share code.
|
||
if (mPackingSpaceRemaining < 0) {
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_SPACE_BETWEEN) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
|
||
} else if (mJustifyContent == NS_STYLE_JUSTIFY_SPACE_AROUND ||
|
||
mJustifyContent == NS_STYLE_JUSTIFY_SPACE_EVENLY) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_CENTER;
|
||
}
|
||
}
|
||
|
||
// Map 'left'/'right' to 'start'/'end'
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_LEFT ||
|
||
mJustifyContent == NS_STYLE_JUSTIFY_RIGHT) {
|
||
if (aAxisTracker.IsColumnOriented()) {
|
||
// Container's alignment axis is not parallel to the inline axis,
|
||
// so we map both 'left' and 'right' to 'start'.
|
||
mJustifyContent = NS_STYLE_JUSTIFY_START;
|
||
} else {
|
||
// Row-oriented, so we map 'left' and 'right' to 'start' or 'end',
|
||
// depending on left-to-right writing mode.
|
||
const bool isLTR = aAxisTracker.GetWritingMode().IsBidiLTR();
|
||
const bool isJustifyLeft = (mJustifyContent == NS_STYLE_JUSTIFY_LEFT);
|
||
mJustifyContent = (isJustifyLeft == isLTR) ? NS_STYLE_JUSTIFY_START
|
||
: NS_STYLE_JUSTIFY_END;
|
||
}
|
||
}
|
||
|
||
// Map 'start'/'end' to 'flex-start'/'flex-end'.
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_START) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
|
||
} else if (mJustifyContent == NS_STYLE_JUSTIFY_END) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_FLEX_END;
|
||
}
|
||
|
||
// If our main axis is (internally) reversed, swap the justify-content
|
||
// "flex-start" and "flex-end" behaviors:
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
if (mJustifyContent == NS_STYLE_JUSTIFY_FLEX_START) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_FLEX_END;
|
||
} else if (mJustifyContent == NS_STYLE_JUSTIFY_FLEX_END) {
|
||
mJustifyContent = NS_STYLE_JUSTIFY_FLEX_START;
|
||
}
|
||
}
|
||
|
||
// Figure out how much space we'll set aside for auto margins or
|
||
// packing spaces, and advance past any leading packing-space.
|
||
if (mNumAutoMarginsInMainAxis == 0 &&
|
||
mPackingSpaceRemaining != 0 &&
|
||
!aLine->IsEmpty()) {
|
||
switch (mJustifyContent) {
|
||
case NS_STYLE_JUSTIFY_BASELINE:
|
||
case NS_STYLE_JUSTIFY_LAST_BASELINE:
|
||
NS_WARNING("NYI: justify-content:left/right/baseline/last baseline");
|
||
MOZ_FALLTHROUGH;
|
||
case NS_STYLE_JUSTIFY_FLEX_START:
|
||
// All packing space should go at the end --> nothing to do here.
|
||
break;
|
||
case NS_STYLE_JUSTIFY_FLEX_END:
|
||
// All packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining;
|
||
break;
|
||
case NS_STYLE_JUSTIFY_CENTER:
|
||
// Half the packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining / 2;
|
||
break;
|
||
case NS_STYLE_JUSTIFY_SPACE_BETWEEN:
|
||
case NS_STYLE_JUSTIFY_SPACE_AROUND:
|
||
case NS_STYLE_JUSTIFY_SPACE_EVENLY:
|
||
nsFlexContainerFrame::CalculatePackingSpace(aLine->NumItems(),
|
||
mJustifyContent,
|
||
&mPosition,
|
||
&mNumPackingSpacesRemaining,
|
||
&mPackingSpaceRemaining);
|
||
break;
|
||
default:
|
||
MOZ_ASSERT_UNREACHABLE("Unexpected justify-content value");
|
||
}
|
||
}
|
||
|
||
MOZ_ASSERT(mNumPackingSpacesRemaining == 0 ||
|
||
mNumAutoMarginsInMainAxis == 0,
|
||
"extra space should either go to packing space or to "
|
||
"auto margins, but not to both");
|
||
}
|
||
|
||
void
|
||
MainAxisPositionTracker::ResolveAutoMarginsInMainAxis(FlexItem& aItem)
|
||
{
|
||
if (mNumAutoMarginsInMainAxis) {
|
||
const nsStyleSides& styleMargin = aItem.Frame()->StyleMargin()->mMargin;
|
||
for (uint32_t i = 0; i < eNumAxisEdges; i++) {
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][i];
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
// NOTE: This integer math will skew the distribution of remainder
|
||
// app-units towards the end, which is fine.
|
||
nscoord curAutoMarginSize =
|
||
mPackingSpaceRemaining / mNumAutoMarginsInMainAxis;
|
||
|
||
MOZ_ASSERT(aItem.GetMarginComponentForSide(side) == 0,
|
||
"Expecting auto margins to have value '0' before we "
|
||
"resolve them");
|
||
aItem.SetMarginComponentForSide(side, curAutoMarginSize);
|
||
|
||
mNumAutoMarginsInMainAxis--;
|
||
mPackingSpaceRemaining -= curAutoMarginSize;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
MainAxisPositionTracker::TraversePackingSpace()
|
||
{
|
||
if (mNumPackingSpacesRemaining) {
|
||
MOZ_ASSERT(mJustifyContent == NS_STYLE_JUSTIFY_SPACE_BETWEEN ||
|
||
mJustifyContent == NS_STYLE_JUSTIFY_SPACE_AROUND ||
|
||
mJustifyContent == NS_STYLE_JUSTIFY_SPACE_EVENLY,
|
||
"mNumPackingSpacesRemaining only applies for "
|
||
"space-between/space-around/space-evenly");
|
||
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"ran out of packing space earlier than we expected");
|
||
|
||
// NOTE: This integer math will skew the distribution of remainder
|
||
// app-units towards the end, which is fine.
|
||
nscoord curPackingSpace =
|
||
mPackingSpaceRemaining / mNumPackingSpacesRemaining;
|
||
|
||
mPosition += curPackingSpace;
|
||
mNumPackingSpacesRemaining--;
|
||
mPackingSpaceRemaining -= curPackingSpace;
|
||
}
|
||
}
|
||
|
||
CrossAxisPositionTracker::
|
||
CrossAxisPositionTracker(FlexLine* aFirstLine,
|
||
const ReflowInput& aReflowInput,
|
||
nscoord aContentBoxCrossSize,
|
||
bool aIsCrossSizeDefinite,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
: PositionTracker(aAxisTracker.GetCrossAxis(),
|
||
aAxisTracker.IsCrossAxisReversed()),
|
||
mPackingSpaceRemaining(0),
|
||
mNumPackingSpacesRemaining(0),
|
||
mAlignContent(aReflowInput.mStylePosition->mAlignContent)
|
||
{
|
||
MOZ_ASSERT(aFirstLine, "null first line pointer");
|
||
|
||
// 'normal' behaves as 'stretch'
|
||
if (mAlignContent == NS_STYLE_ALIGN_NORMAL) {
|
||
mAlignContent = NS_STYLE_ALIGN_STRETCH;
|
||
}
|
||
|
||
// XXX strip of the <overflow-position> bit until we implement that
|
||
mAlignContent &= ~NS_STYLE_ALIGN_FLAG_BITS;
|
||
|
||
const bool isSingleLine =
|
||
NS_STYLE_FLEX_WRAP_NOWRAP == aReflowInput.mStylePosition->mFlexWrap;
|
||
if (isSingleLine) {
|
||
MOZ_ASSERT(!aFirstLine->getNext(),
|
||
"If we're styled as single-line, we should only have 1 line");
|
||
// "If the flex container is single-line and has a definite cross size, the
|
||
// cross size of the flex line is the flex container's inner cross size."
|
||
//
|
||
// SOURCE: https://drafts.csswg.org/css-flexbox/#algo-cross-line
|
||
// NOTE: This means (by definition) that there's no packing space, which
|
||
// means we don't need to be concerned with "align-conent" at all and we
|
||
// can return early. This is handy, because this is the usual case (for
|
||
// single-line flexbox).
|
||
if (aIsCrossSizeDefinite) {
|
||
aFirstLine->SetLineCrossSize(aContentBoxCrossSize);
|
||
return;
|
||
}
|
||
|
||
// "If the flex container is single-line, then clamp the line's
|
||
// cross-size to be within the container's computed min and max cross-size
|
||
// properties."
|
||
aFirstLine->SetLineCrossSize(NS_CSS_MINMAX(aFirstLine->GetLineCrossSize(),
|
||
aReflowInput.ComputedMinBSize(),
|
||
aReflowInput.ComputedMaxBSize()));
|
||
}
|
||
|
||
// NOTE: The rest of this function should essentially match
|
||
// MainAxisPositionTracker's constructor, though with FlexLines instead of
|
||
// FlexItems, and with the additional value "stretch" (and of course with
|
||
// cross sizes instead of main sizes.)
|
||
|
||
// Figure out how much packing space we have (container's cross size minus
|
||
// all the lines' cross sizes). Also, share this loop to count how many
|
||
// lines we have. (We need that count in some cases below.)
|
||
mPackingSpaceRemaining = aContentBoxCrossSize;
|
||
uint32_t numLines = 0;
|
||
for (FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
mPackingSpaceRemaining -= line->GetLineCrossSize();
|
||
numLines++;
|
||
}
|
||
|
||
// If packing space is negative, 'space-between' and 'stretch' behave like
|
||
// 'flex-start', and 'space-around' and 'space-evenly' behave like 'center'.
|
||
// In those cases, it's simplest to just pretend we have a different
|
||
// 'align-content' value and share code.
|
||
if (mPackingSpaceRemaining < 0) {
|
||
if (mAlignContent == NS_STYLE_ALIGN_SPACE_BETWEEN ||
|
||
mAlignContent == NS_STYLE_ALIGN_STRETCH) {
|
||
mAlignContent = NS_STYLE_ALIGN_FLEX_START;
|
||
} else if (mAlignContent == NS_STYLE_ALIGN_SPACE_AROUND ||
|
||
mAlignContent == NS_STYLE_ALIGN_SPACE_EVENLY) {
|
||
mAlignContent = NS_STYLE_ALIGN_CENTER;
|
||
}
|
||
}
|
||
|
||
// Map 'left'/'right' to 'start'/'end'
|
||
if (mAlignContent == NS_STYLE_ALIGN_LEFT ||
|
||
mAlignContent == NS_STYLE_ALIGN_RIGHT) {
|
||
if (aAxisTracker.IsRowOriented()) {
|
||
// Container's alignment axis is not parallel to the inline axis,
|
||
// so we map both 'left' and 'right' to 'start'.
|
||
mAlignContent = NS_STYLE_ALIGN_START;
|
||
} else {
|
||
// Column-oriented, so we map 'left' and 'right' to 'start' or 'end',
|
||
// depending on left-to-right writing mode.
|
||
const bool isLTR = aAxisTracker.GetWritingMode().IsBidiLTR();
|
||
const bool isAlignLeft = (mAlignContent == NS_STYLE_ALIGN_LEFT);
|
||
mAlignContent = (isAlignLeft == isLTR) ? NS_STYLE_ALIGN_START
|
||
: NS_STYLE_ALIGN_END;
|
||
}
|
||
}
|
||
|
||
// Map 'start'/'end' to 'flex-start'/'flex-end'.
|
||
if (mAlignContent == NS_STYLE_ALIGN_START) {
|
||
mAlignContent = NS_STYLE_ALIGN_FLEX_START;
|
||
} else if (mAlignContent == NS_STYLE_ALIGN_END) {
|
||
mAlignContent = NS_STYLE_ALIGN_FLEX_END;
|
||
}
|
||
|
||
// If our cross axis is (internally) reversed, swap the align-content
|
||
// "flex-start" and "flex-end" behaviors:
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
if (mAlignContent == NS_STYLE_ALIGN_FLEX_START) {
|
||
mAlignContent = NS_STYLE_ALIGN_FLEX_END;
|
||
} else if (mAlignContent == NS_STYLE_ALIGN_FLEX_END) {
|
||
mAlignContent = NS_STYLE_ALIGN_FLEX_START;
|
||
}
|
||
}
|
||
|
||
// Figure out how much space we'll set aside for packing spaces, and advance
|
||
// past any leading packing-space.
|
||
if (mPackingSpaceRemaining != 0) {
|
||
switch (mAlignContent) {
|
||
case NS_STYLE_ALIGN_SELF_START:
|
||
case NS_STYLE_ALIGN_SELF_END:
|
||
case NS_STYLE_ALIGN_BASELINE:
|
||
case NS_STYLE_ALIGN_LAST_BASELINE:
|
||
NS_WARNING("NYI: align-items/align-self:left/right/self-start/self-end/baseline/last baseline");
|
||
MOZ_FALLTHROUGH;
|
||
case NS_STYLE_ALIGN_FLEX_START:
|
||
// All packing space should go at the end --> nothing to do here.
|
||
break;
|
||
case NS_STYLE_ALIGN_FLEX_END:
|
||
// All packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining;
|
||
break;
|
||
case NS_STYLE_ALIGN_CENTER:
|
||
// Half the packing space goes at the beginning
|
||
mPosition += mPackingSpaceRemaining / 2;
|
||
break;
|
||
case NS_STYLE_ALIGN_SPACE_BETWEEN:
|
||
case NS_STYLE_ALIGN_SPACE_AROUND:
|
||
case NS_STYLE_ALIGN_SPACE_EVENLY:
|
||
nsFlexContainerFrame::CalculatePackingSpace(numLines,
|
||
mAlignContent,
|
||
&mPosition,
|
||
&mNumPackingSpacesRemaining,
|
||
&mPackingSpaceRemaining);
|
||
break;
|
||
case NS_STYLE_ALIGN_STRETCH: {
|
||
// Split space equally between the lines:
|
||
MOZ_ASSERT(mPackingSpaceRemaining > 0,
|
||
"negative packing space should make us use 'flex-start' "
|
||
"instead of 'stretch' (and we shouldn't bother with this "
|
||
"code if we have 0 packing space)");
|
||
|
||
uint32_t numLinesLeft = numLines;
|
||
for (FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
// Our share is the amount of space remaining, divided by the number
|
||
// of lines remainig.
|
||
MOZ_ASSERT(numLinesLeft > 0, "miscalculated num lines");
|
||
nscoord shareOfExtraSpace = mPackingSpaceRemaining / numLinesLeft;
|
||
nscoord newSize = line->GetLineCrossSize() + shareOfExtraSpace;
|
||
line->SetLineCrossSize(newSize);
|
||
|
||
mPackingSpaceRemaining -= shareOfExtraSpace;
|
||
numLinesLeft--;
|
||
}
|
||
MOZ_ASSERT(numLinesLeft == 0, "miscalculated num lines");
|
||
break;
|
||
}
|
||
default:
|
||
MOZ_ASSERT_UNREACHABLE("Unexpected align-content value");
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
CrossAxisPositionTracker::TraversePackingSpace()
|
||
{
|
||
if (mNumPackingSpacesRemaining) {
|
||
MOZ_ASSERT(mAlignContent == NS_STYLE_ALIGN_SPACE_BETWEEN ||
|
||
mAlignContent == NS_STYLE_ALIGN_SPACE_AROUND ||
|
||
mAlignContent == NS_STYLE_ALIGN_SPACE_EVENLY,
|
||
"mNumPackingSpacesRemaining only applies for "
|
||
"space-between/space-around/space-evenly");
|
||
|
||
MOZ_ASSERT(mPackingSpaceRemaining >= 0,
|
||
"ran out of packing space earlier than we expected");
|
||
|
||
// NOTE: This integer math will skew the distribution of remainder
|
||
// app-units towards the end, which is fine.
|
||
nscoord curPackingSpace =
|
||
mPackingSpaceRemaining / mNumPackingSpacesRemaining;
|
||
|
||
mPosition += curPackingSpace;
|
||
mNumPackingSpacesRemaining--;
|
||
mPackingSpaceRemaining -= curPackingSpace;
|
||
}
|
||
}
|
||
|
||
SingleLineCrossAxisPositionTracker::
|
||
SingleLineCrossAxisPositionTracker(const FlexboxAxisTracker& aAxisTracker)
|
||
: PositionTracker(aAxisTracker.GetCrossAxis(),
|
||
aAxisTracker.IsCrossAxisReversed())
|
||
{
|
||
}
|
||
|
||
void
|
||
FlexLine::ComputeCrossSizeAndBaseline(const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
nscoord crossStartToFurthestFirstBaseline = nscoord_MIN;
|
||
nscoord crossEndToFurthestFirstBaseline = nscoord_MIN;
|
||
nscoord crossStartToFurthestLastBaseline = nscoord_MIN;
|
||
nscoord crossEndToFurthestLastBaseline = nscoord_MIN;
|
||
nscoord largestOuterCrossSize = 0;
|
||
for (const FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
nscoord curOuterCrossSize =
|
||
item->GetOuterCrossSize(aAxisTracker.GetCrossAxis());
|
||
|
||
if ((item->GetAlignSelf() == NS_STYLE_ALIGN_BASELINE ||
|
||
item->GetAlignSelf() == NS_STYLE_ALIGN_LAST_BASELINE) &&
|
||
item->GetNumAutoMarginsInAxis(aAxisTracker.GetCrossAxis()) == 0) {
|
||
const bool useFirst = (item->GetAlignSelf() == NS_STYLE_ALIGN_BASELINE);
|
||
// FIXME: Once we support "writing-mode", we'll have to do baseline
|
||
// alignment in vertical flex containers here (w/ horizontal cross-axes).
|
||
|
||
// Find distance from our item's cross-start and cross-end margin-box
|
||
// edges to its baseline.
|
||
//
|
||
// Here's a diagram of a flex-item that we might be doing this on.
|
||
// "mmm" is the margin-box, "bbb" is the border-box. The bottom of
|
||
// the text "BASE" is the baseline.
|
||
//
|
||
// ---(cross-start)---
|
||
// ___ ___ ___
|
||
// mmmmmmmmmmmm | |margin-start |
|
||
// m m | _|_ ___ |
|
||
// m bbbbbbbb m |curOuterCrossSize | |crossStartToBaseline
|
||
// m b b m | |ascent |
|
||
// m b BASE b m | _|_ _|_
|
||
// m b b m | |
|
||
// m bbbbbbbb m | |crossEndToBaseline
|
||
// m m | |
|
||
// mmmmmmmmmmmm _|_ _|_
|
||
//
|
||
// ---(cross-end)---
|
||
//
|
||
// We already have the curOuterCrossSize, margin-start, and the ascent.
|
||
// * We can get crossStartToBaseline by adding margin-start + ascent.
|
||
// * If we subtract that from the curOuterCrossSize, we get
|
||
// crossEndToBaseline.
|
||
|
||
nscoord crossStartToBaseline =
|
||
item->GetBaselineOffsetFromOuterCrossEdge(eAxisEdge_Start,
|
||
aAxisTracker,
|
||
useFirst);
|
||
nscoord crossEndToBaseline = curOuterCrossSize - crossStartToBaseline;
|
||
|
||
// Now, update our "largest" values for these (across all the flex items
|
||
// in this flex line), so we can use them in computing the line's cross
|
||
// size below:
|
||
if (useFirst) {
|
||
crossStartToFurthestFirstBaseline =
|
||
std::max(crossStartToFurthestFirstBaseline, crossStartToBaseline);
|
||
crossEndToFurthestFirstBaseline =
|
||
std::max(crossEndToFurthestFirstBaseline, crossEndToBaseline);
|
||
} else {
|
||
crossStartToFurthestLastBaseline =
|
||
std::max(crossStartToFurthestLastBaseline, crossStartToBaseline);
|
||
crossEndToFurthestLastBaseline =
|
||
std::max(crossEndToFurthestLastBaseline, crossEndToBaseline);
|
||
}
|
||
} else {
|
||
largestOuterCrossSize = std::max(largestOuterCrossSize, curOuterCrossSize);
|
||
}
|
||
}
|
||
|
||
// The line's baseline offset is the distance from the line's edge (start or
|
||
// end, depending on whether we've flipped the axes) to the furthest
|
||
// item-baseline. The item(s) with that baseline will be exactly aligned with
|
||
// the line's edge.
|
||
mFirstBaselineOffset = aAxisTracker.AreAxesInternallyReversed() ?
|
||
crossEndToFurthestFirstBaseline : crossStartToFurthestFirstBaseline;
|
||
|
||
mLastBaselineOffset = aAxisTracker.AreAxesInternallyReversed() ?
|
||
crossStartToFurthestLastBaseline : crossEndToFurthestLastBaseline;
|
||
|
||
// The line's cross-size is the larger of:
|
||
// (a) [largest cross-start-to-baseline + largest baseline-to-cross-end] of
|
||
// all baseline-aligned items with no cross-axis auto margins...
|
||
// and
|
||
// (b) [largest cross-start-to-baseline + largest baseline-to-cross-end] of
|
||
// all last baseline-aligned items with no cross-axis auto margins...
|
||
// and
|
||
// (c) largest cross-size of all other children.
|
||
mLineCrossSize = std::max(
|
||
std::max(crossStartToFurthestFirstBaseline + crossEndToFurthestFirstBaseline,
|
||
crossStartToFurthestLastBaseline + crossEndToFurthestLastBaseline),
|
||
largestOuterCrossSize);
|
||
}
|
||
|
||
void
|
||
FlexItem::ResolveStretchedCrossSize(nscoord aLineCrossSize,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
AxisOrientationType crossAxis = aAxisTracker.GetCrossAxis();
|
||
// We stretch IFF we are align-self:stretch, have no auto margins in
|
||
// cross axis, and have cross-axis size property == "auto". If any of those
|
||
// conditions don't hold up, we won't stretch.
|
||
if (mAlignSelf != NS_STYLE_ALIGN_STRETCH ||
|
||
GetNumAutoMarginsInAxis(crossAxis) != 0 ||
|
||
eStyleUnit_Auto != aAxisTracker.ComputedCrossSize(mFrame).GetUnit()) {
|
||
return;
|
||
}
|
||
|
||
// If we've already been stretched, we can bail out early, too.
|
||
// No need to redo the calculation.
|
||
if (mIsStretched) {
|
||
return;
|
||
}
|
||
|
||
// Reserve space for margins & border & padding, and then use whatever
|
||
// remains as our item's cross-size (clamped to its min/max range).
|
||
nscoord stretchedSize = aLineCrossSize -
|
||
GetMarginBorderPaddingSizeInAxis(crossAxis);
|
||
|
||
stretchedSize = NS_CSS_MINMAX(stretchedSize, mCrossMinSize, mCrossMaxSize);
|
||
|
||
// Update the cross-size & make a note that it's stretched, so we know to
|
||
// override the reflow state's computed cross-size in our final reflow.
|
||
SetCrossSize(stretchedSize);
|
||
mIsStretched = true;
|
||
}
|
||
|
||
void
|
||
SingleLineCrossAxisPositionTracker::
|
||
ResolveAutoMarginsInCrossAxis(const FlexLine& aLine,
|
||
FlexItem& aItem)
|
||
{
|
||
// Subtract the space that our item is already occupying, to see how much
|
||
// space (if any) is available for its auto margins.
|
||
nscoord spaceForAutoMargins = aLine.GetLineCrossSize() -
|
||
aItem.GetOuterCrossSize(mAxis);
|
||
|
||
if (spaceForAutoMargins <= 0) {
|
||
return; // No available space --> nothing to do
|
||
}
|
||
|
||
uint32_t numAutoMargins = aItem.GetNumAutoMarginsInAxis(mAxis);
|
||
if (numAutoMargins == 0) {
|
||
return; // No auto margins --> nothing to do.
|
||
}
|
||
|
||
// OK, we have at least one auto margin and we have some available space.
|
||
// Give each auto margin a share of the space.
|
||
const nsStyleSides& styleMargin = aItem.Frame()->StyleMargin()->mMargin;
|
||
for (uint32_t i = 0; i < eNumAxisEdges; i++) {
|
||
mozilla::Side side = kAxisOrientationToSidesMap[mAxis][i];
|
||
if (styleMargin.GetUnit(side) == eStyleUnit_Auto) {
|
||
MOZ_ASSERT(aItem.GetMarginComponentForSide(side) == 0,
|
||
"Expecting auto margins to have value '0' before we "
|
||
"update them");
|
||
|
||
// NOTE: integer divison is fine here; numAutoMargins is either 1 or 2.
|
||
// If it's 2 & spaceForAutoMargins is odd, 1st margin gets smaller half.
|
||
nscoord curAutoMarginSize = spaceForAutoMargins / numAutoMargins;
|
||
aItem.SetMarginComponentForSide(side, curAutoMarginSize);
|
||
numAutoMargins--;
|
||
spaceForAutoMargins -= curAutoMarginSize;
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
SingleLineCrossAxisPositionTracker::
|
||
EnterAlignPackingSpace(const FlexLine& aLine,
|
||
const FlexItem& aItem,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
// We don't do align-self alignment on items that have auto margins
|
||
// in the cross axis.
|
||
if (aItem.GetNumAutoMarginsInAxis(mAxis)) {
|
||
return;
|
||
}
|
||
|
||
uint8_t alignSelf = aItem.GetAlignSelf();
|
||
// NOTE: 'stretch' behaves like 'flex-start' once we've stretched any
|
||
// auto-sized items (which we've already done).
|
||
if (alignSelf == NS_STYLE_ALIGN_STRETCH) {
|
||
alignSelf = NS_STYLE_ALIGN_FLEX_START;
|
||
}
|
||
|
||
// Map 'left'/'right' to 'start'/'end'
|
||
if (alignSelf == NS_STYLE_ALIGN_LEFT || alignSelf == NS_STYLE_ALIGN_RIGHT) {
|
||
if (aAxisTracker.IsRowOriented()) {
|
||
// Container's alignment axis is not parallel to the inline axis,
|
||
// so we map both 'left' and 'right' to 'start'.
|
||
alignSelf = NS_STYLE_ALIGN_START;
|
||
} else {
|
||
// Column-oriented, so we map 'left' and 'right' to 'start' or 'end',
|
||
// depending on left-to-right writing mode.
|
||
const bool isLTR = aAxisTracker.GetWritingMode().IsBidiLTR();
|
||
const bool isAlignLeft = (alignSelf == NS_STYLE_ALIGN_LEFT);
|
||
alignSelf = (isAlignLeft == isLTR) ? NS_STYLE_ALIGN_START
|
||
: NS_STYLE_ALIGN_END;
|
||
}
|
||
}
|
||
|
||
// Map 'start'/'end' to 'flex-start'/'flex-end'.
|
||
if (alignSelf == NS_STYLE_ALIGN_START) {
|
||
alignSelf = NS_STYLE_ALIGN_FLEX_START;
|
||
} else if (alignSelf == NS_STYLE_ALIGN_END) {
|
||
alignSelf = NS_STYLE_ALIGN_FLEX_END;
|
||
}
|
||
|
||
// If our cross axis is (internally) reversed, swap the align-self
|
||
// "flex-start" and "flex-end" behaviors:
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
if (alignSelf == NS_STYLE_ALIGN_FLEX_START) {
|
||
alignSelf = NS_STYLE_ALIGN_FLEX_END;
|
||
} else if (alignSelf == NS_STYLE_ALIGN_FLEX_END) {
|
||
alignSelf = NS_STYLE_ALIGN_FLEX_START;
|
||
}
|
||
}
|
||
|
||
switch (alignSelf) {
|
||
case NS_STYLE_ALIGN_SELF_START:
|
||
case NS_STYLE_ALIGN_SELF_END:
|
||
NS_WARNING("NYI: align-items/align-self:left/right/self-start/self-end");
|
||
MOZ_FALLTHROUGH;
|
||
case NS_STYLE_ALIGN_FLEX_START:
|
||
// No space to skip over -- we're done.
|
||
break;
|
||
case NS_STYLE_ALIGN_FLEX_END:
|
||
mPosition += aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis);
|
||
break;
|
||
case NS_STYLE_ALIGN_CENTER:
|
||
// Note: If cross-size is odd, the "after" space will get the extra unit.
|
||
mPosition +=
|
||
(aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis)) / 2;
|
||
break;
|
||
case NS_STYLE_ALIGN_BASELINE:
|
||
case NS_STYLE_ALIGN_LAST_BASELINE: {
|
||
const bool useFirst = (alignSelf == NS_STYLE_ALIGN_BASELINE);
|
||
|
||
// Normally, baseline-aligned items are collectively aligned with the
|
||
// line's cross-start edge; however, if our cross axis is (internally)
|
||
// reversed, we instead align them with the cross-end edge.
|
||
// A similar logic holds for last baseline-aligned items, but in reverse.
|
||
AxisEdgeType baselineAlignEdge =
|
||
aAxisTracker.AreAxesInternallyReversed() == useFirst ?
|
||
eAxisEdge_End : eAxisEdge_Start;
|
||
|
||
nscoord itemBaselineOffset =
|
||
aItem.GetBaselineOffsetFromOuterCrossEdge(baselineAlignEdge,
|
||
aAxisTracker,
|
||
useFirst);
|
||
|
||
nscoord lineBaselineOffset = useFirst ? aLine.GetFirstBaselineOffset()
|
||
: aLine.GetLastBaselineOffset();
|
||
|
||
NS_ASSERTION(lineBaselineOffset >= itemBaselineOffset,
|
||
"failed at finding largest baseline offset");
|
||
|
||
// How much do we need to adjust our position (from the line edge),
|
||
// to get the item's baseline to hit the line's baseline offset:
|
||
nscoord baselineDiff = lineBaselineOffset - itemBaselineOffset;
|
||
|
||
if (aAxisTracker.AreAxesInternallyReversed() == useFirst) {
|
||
// Advance to align item w/ line's flex-end edge (as in FLEX_END case):
|
||
mPosition += aLine.GetLineCrossSize() - aItem.GetOuterCrossSize(mAxis);
|
||
// ...and step *back* by the baseline adjustment:
|
||
mPosition -= baselineDiff;
|
||
} else {
|
||
// mPosition is already at line's flex-start edge.
|
||
// From there, we step *forward* by the baseline adjustment:
|
||
mPosition += baselineDiff;
|
||
}
|
||
break;
|
||
}
|
||
default:
|
||
MOZ_ASSERT_UNREACHABLE("Unexpected align-self value");
|
||
break;
|
||
}
|
||
}
|
||
|
||
// Utility function to convert an InlineDir to an AxisOrientationType
|
||
static inline AxisOrientationType
|
||
InlineDirToAxisOrientation(WritingMode::InlineDir aInlineDir)
|
||
{
|
||
switch (aInlineDir) {
|
||
case WritingMode::eInlineLTR:
|
||
return eAxis_LR;
|
||
case WritingMode::eInlineRTL:
|
||
return eAxis_RL;
|
||
case WritingMode::eInlineTTB:
|
||
return eAxis_TB;
|
||
case WritingMode::eInlineBTT:
|
||
return eAxis_BT;
|
||
}
|
||
|
||
MOZ_ASSERT_UNREACHABLE("Unhandled InlineDir");
|
||
return eAxis_LR; // in case of unforseen error, assume English LTR text flow.
|
||
}
|
||
|
||
// Utility function to convert a BlockDir to an AxisOrientationType
|
||
static inline AxisOrientationType
|
||
BlockDirToAxisOrientation(WritingMode::BlockDir aBlockDir)
|
||
{
|
||
switch (aBlockDir) {
|
||
case WritingMode::eBlockLR:
|
||
return eAxis_LR;
|
||
case WritingMode::eBlockRL:
|
||
return eAxis_RL;
|
||
case WritingMode::eBlockTB:
|
||
return eAxis_TB;
|
||
// NOTE: WritingMode::eBlockBT (bottom-to-top) does not exist.
|
||
}
|
||
|
||
MOZ_ASSERT_UNREACHABLE("Unhandled BlockDir");
|
||
return eAxis_TB; // in case of unforseen error, assume English TTB block-flow
|
||
}
|
||
|
||
FlexboxAxisTracker::FlexboxAxisTracker(
|
||
const nsFlexContainerFrame* aFlexContainer,
|
||
const WritingMode& aWM,
|
||
AxisTrackerFlags aFlags)
|
||
: mWM(aWM),
|
||
mAreAxesInternallyReversed(false)
|
||
{
|
||
if (IsLegacyBox(aFlexContainer)) {
|
||
InitAxesFromLegacyProps(aFlexContainer);
|
||
} else {
|
||
InitAxesFromModernProps(aFlexContainer);
|
||
}
|
||
|
||
// Master switch to enable/disable bug 983427's code for reversing our axes
|
||
// and reversing some logic, to avoid reflowing children in bottom-to-top
|
||
// order. (This switch can be removed eventually, but for now, it allows
|
||
// this special-case code path to be compared against the normal code path.)
|
||
static bool sPreventBottomToTopChildOrdering = true;
|
||
|
||
// Note: if the eAllowBottomToTopChildOrdering flag is set, that overrides
|
||
// the static boolean and makes us skip this special case.
|
||
if (!(aFlags & AxisTrackerFlags::eAllowBottomToTopChildOrdering) &&
|
||
sPreventBottomToTopChildOrdering) {
|
||
// If either axis is bottom-to-top, we flip both axes (and set a flag
|
||
// so that we can flip some logic to make the reversal transparent).
|
||
if (eAxis_BT == mMainAxis || eAxis_BT == mCrossAxis) {
|
||
mMainAxis = GetReverseAxis(mMainAxis);
|
||
mCrossAxis = GetReverseAxis(mCrossAxis);
|
||
mAreAxesInternallyReversed = true;
|
||
mIsMainAxisReversed = !mIsMainAxisReversed;
|
||
mIsCrossAxisReversed = !mIsCrossAxisReversed;
|
||
}
|
||
}
|
||
}
|
||
|
||
void
|
||
FlexboxAxisTracker::InitAxesFromLegacyProps(
|
||
const nsFlexContainerFrame* aFlexContainer)
|
||
{
|
||
const nsStyleXUL* styleXUL = aFlexContainer->StyleXUL();
|
||
|
||
const bool boxOrientIsVertical = (styleXUL->mBoxOrient ==
|
||
StyleBoxOrient::Vertical);
|
||
const bool wmIsVertical = mWM.IsVertical();
|
||
|
||
// If box-orient agrees with our writing-mode, then we're "row-oriented"
|
||
// (i.e. the flexbox main axis is the same as our writing mode's inline
|
||
// direction). Otherwise, we're column-oriented (i.e. the flexbox's main
|
||
// axis is perpendicular to the writing-mode's inline direction).
|
||
mIsRowOriented = (boxOrientIsVertical == wmIsVertical);
|
||
|
||
// XXXdholbert BEGIN CODE TO SET DEPRECATED MEMBER-VARS
|
||
if (boxOrientIsVertical) {
|
||
mMainAxis = eAxis_TB;
|
||
mCrossAxis = eAxis_LR;
|
||
} else {
|
||
mMainAxis = eAxis_LR;
|
||
mCrossAxis = eAxis_TB;
|
||
}
|
||
// "direction: rtl" reverses the writing-mode's inline axis.
|
||
// So, we need to reverse the corresponding flex axis to match.
|
||
// (Note this we don't toggle "mIsMainAxisReversed" for this condition,
|
||
// because the main axis will still match mWM's inline direction.)
|
||
if (!mWM.IsBidiLTR()) {
|
||
AxisOrientationType& axisToFlip = mIsRowOriented ? mMainAxis : mCrossAxis;
|
||
axisToFlip = GetReverseAxis(axisToFlip);
|
||
}
|
||
// XXXdholbert END CODE TO SET DEPRECATED MEMBER-VARS
|
||
|
||
// Legacy flexbox can use "-webkit-box-direction: reverse" to reverse the
|
||
// main axis (so it runs in the reverse direction of the inline axis):
|
||
if (styleXUL->mBoxDirection == StyleBoxDirection::Reverse) {
|
||
mMainAxis = GetReverseAxis(mMainAxis);
|
||
mIsMainAxisReversed = true;
|
||
} else {
|
||
mIsMainAxisReversed = false;
|
||
}
|
||
|
||
// Legacy flexbox does not support reversing the cross axis -- it has no
|
||
// equivalent of modern flexbox's "flex-wrap: wrap-reverse".
|
||
mIsCrossAxisReversed = false;
|
||
}
|
||
|
||
void
|
||
FlexboxAxisTracker::InitAxesFromModernProps(
|
||
const nsFlexContainerFrame* aFlexContainer)
|
||
{
|
||
const nsStylePosition* stylePos = aFlexContainer->StylePosition();
|
||
uint32_t flexDirection = stylePos->mFlexDirection;
|
||
|
||
// Inline dimension ("start-to-end"):
|
||
// (NOTE: I'm intentionally not calling these "inlineAxis"/"blockAxis", since
|
||
// those terms have explicit definition in the writing-modes spec, which are
|
||
// the opposite of how I'd be using them here.)
|
||
AxisOrientationType inlineDimension =
|
||
InlineDirToAxisOrientation(mWM.GetInlineDir());
|
||
AxisOrientationType blockDimension =
|
||
BlockDirToAxisOrientation(mWM.GetBlockDir());
|
||
|
||
// Determine main axis:
|
||
switch (flexDirection) {
|
||
case NS_STYLE_FLEX_DIRECTION_ROW:
|
||
mMainAxis = inlineDimension;
|
||
mIsRowOriented = true;
|
||
mIsMainAxisReversed = false;
|
||
break;
|
||
case NS_STYLE_FLEX_DIRECTION_ROW_REVERSE:
|
||
mMainAxis = GetReverseAxis(inlineDimension);
|
||
mIsRowOriented = true;
|
||
mIsMainAxisReversed = true;
|
||
break;
|
||
case NS_STYLE_FLEX_DIRECTION_COLUMN:
|
||
mMainAxis = blockDimension;
|
||
mIsRowOriented = false;
|
||
mIsMainAxisReversed = false;
|
||
break;
|
||
case NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE:
|
||
mMainAxis = GetReverseAxis(blockDimension);
|
||
mIsRowOriented = false;
|
||
mIsMainAxisReversed = true;
|
||
break;
|
||
default:
|
||
MOZ_ASSERT_UNREACHABLE("Unexpected flex-direction value");
|
||
}
|
||
|
||
// Determine cross axis:
|
||
// (This is set up so that a bogus |flexDirection| value will
|
||
// give us blockDimension.
|
||
if (flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN ||
|
||
flexDirection == NS_STYLE_FLEX_DIRECTION_COLUMN_REVERSE) {
|
||
mCrossAxis = inlineDimension;
|
||
} else {
|
||
mCrossAxis = blockDimension;
|
||
}
|
||
|
||
// "flex-wrap: wrap-reverse" reverses our cross axis.
|
||
if (stylePos->mFlexWrap == NS_STYLE_FLEX_WRAP_WRAP_REVERSE) {
|
||
mCrossAxis = GetReverseAxis(mCrossAxis);
|
||
mIsCrossAxisReversed = true;
|
||
} else {
|
||
mIsCrossAxisReversed = false;
|
||
}
|
||
}
|
||
|
||
// Allocates a new FlexLine, adds it to the given LinkedList (at the front or
|
||
// back depending on aShouldInsertAtFront), and returns a pointer to it.
|
||
static FlexLine*
|
||
AddNewFlexLineToList(LinkedList<FlexLine>& aLines,
|
||
bool aShouldInsertAtFront)
|
||
{
|
||
FlexLine* newLine = new FlexLine();
|
||
if (aShouldInsertAtFront) {
|
||
aLines.insertFront(newLine);
|
||
} else {
|
||
aLines.insertBack(newLine);
|
||
}
|
||
return newLine;
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::GenerateFlexLines(
|
||
nsPresContext* aPresContext,
|
||
const ReflowInput& aReflowInput,
|
||
nscoord aContentBoxMainSize,
|
||
nscoord aAvailableBSizeForContent,
|
||
const nsTArray<StrutInfo>& aStruts,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
nsTArray<nsIFrame*>& aPlaceholders, /* out */
|
||
LinkedList<FlexLine>& aLines /* out */)
|
||
{
|
||
MOZ_ASSERT(aLines.isEmpty(), "Expecting outparam to start out empty");
|
||
|
||
const bool isSingleLine =
|
||
NS_STYLE_FLEX_WRAP_NOWRAP == aReflowInput.mStylePosition->mFlexWrap;
|
||
|
||
// If we're transparently reversing axes, then we'll need to link up our
|
||
// FlexItems and FlexLines in the reverse order, so that the rest of flex
|
||
// layout (with flipped axes) will still produce the correct result.
|
||
// Here, we declare a convenience bool that we'll pass when adding a new
|
||
// FlexLine or FlexItem, to make us insert it at the beginning of its list
|
||
// (so the list ends up reversed).
|
||
const bool shouldInsertAtFront = aAxisTracker.AreAxesInternallyReversed();
|
||
|
||
// We have at least one FlexLine. Even an empty flex container has a single
|
||
// (empty) flex line.
|
||
FlexLine* curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
|
||
nscoord wrapThreshold;
|
||
if (isSingleLine) {
|
||
// Not wrapping. Set threshold to sentinel value that tells us not to wrap.
|
||
wrapThreshold = NS_UNCONSTRAINEDSIZE;
|
||
} else {
|
||
// Wrapping! Set wrap threshold to flex container's content-box main-size.
|
||
wrapThreshold = aContentBoxMainSize;
|
||
|
||
// If the flex container doesn't have a definite content-box main-size
|
||
// (e.g. if main axis is vertical & 'height' is 'auto'), make sure we at
|
||
// least wrap when we hit its max main-size.
|
||
if (wrapThreshold == NS_UNCONSTRAINEDSIZE) {
|
||
const nscoord flexContainerMaxMainSize =
|
||
GET_MAIN_COMPONENT_LOGICAL(aAxisTracker, aAxisTracker.GetWritingMode(),
|
||
aReflowInput.ComputedMaxISize(),
|
||
aReflowInput.ComputedMaxBSize());
|
||
|
||
wrapThreshold = flexContainerMaxMainSize;
|
||
}
|
||
|
||
// Also: if we're column-oriented and paginating in the block dimension,
|
||
// we may need to wrap to a new flex line sooner (before we grow past the
|
||
// available BSize, potentially running off the end of the page).
|
||
if (aAxisTracker.IsColumnOriented() &&
|
||
aAvailableBSizeForContent != NS_UNCONSTRAINEDSIZE) {
|
||
wrapThreshold = std::min(wrapThreshold, aAvailableBSizeForContent);
|
||
}
|
||
}
|
||
|
||
// Tracks the index of the next strut, in aStruts (and when this hits
|
||
// aStruts.Length(), that means there are no more struts):
|
||
uint32_t nextStrutIdx = 0;
|
||
|
||
// Overall index of the current flex item in the flex container. (This gets
|
||
// checked against entries in aStruts.)
|
||
uint32_t itemIdxInContainer = 0;
|
||
|
||
for (nsIFrame* childFrame : mFrames) {
|
||
// Don't create flex items / lines for placeholder frames:
|
||
if (childFrame->GetType() == nsGkAtoms::placeholderFrame) {
|
||
aPlaceholders.AppendElement(childFrame);
|
||
continue;
|
||
}
|
||
|
||
// Honor "page-break-before", if we're multi-line and this line isn't empty:
|
||
if (!isSingleLine && !curLine->IsEmpty() &&
|
||
childFrame->StyleDisplay()->mBreakBefore) {
|
||
curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
}
|
||
|
||
UniquePtr<FlexItem> item;
|
||
if (nextStrutIdx < aStruts.Length() &&
|
||
aStruts[nextStrutIdx].mItemIdx == itemIdxInContainer) {
|
||
|
||
// Use the simplified "strut" FlexItem constructor:
|
||
item = MakeUnique<FlexItem>(childFrame, aStruts[nextStrutIdx].mStrutCrossSize,
|
||
aReflowInput.GetWritingMode());
|
||
nextStrutIdx++;
|
||
} else {
|
||
item = GenerateFlexItemForChild(aPresContext, childFrame,
|
||
aReflowInput, aAxisTracker);
|
||
}
|
||
|
||
nscoord itemInnerHypotheticalMainSize = item->GetMainSize();
|
||
nscoord itemOuterHypotheticalMainSize =
|
||
item->GetOuterMainSize(aAxisTracker.GetMainAxis());
|
||
|
||
// Check if we need to wrap |item| to a new line
|
||
// (i.e. check if its outer hypothetical main size pushes our line over
|
||
// the threshold)
|
||
if (wrapThreshold != NS_UNCONSTRAINEDSIZE &&
|
||
!curLine->IsEmpty() && // No need to wrap at start of a line.
|
||
wrapThreshold < (curLine->GetTotalOuterHypotheticalMainSize() +
|
||
itemOuterHypotheticalMainSize)) {
|
||
curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
}
|
||
|
||
// Add item to current flex line (and update the line's bookkeeping about
|
||
// how large its items collectively are).
|
||
curLine->AddItem(item.release(), shouldInsertAtFront,
|
||
itemInnerHypotheticalMainSize,
|
||
itemOuterHypotheticalMainSize);
|
||
|
||
// Honor "page-break-after", if we're multi-line and have more children:
|
||
if (!isSingleLine && childFrame->GetNextSibling() &&
|
||
childFrame->StyleDisplay()->mBreakAfter) {
|
||
curLine = AddNewFlexLineToList(aLines, shouldInsertAtFront);
|
||
}
|
||
itemIdxInContainer++;
|
||
}
|
||
}
|
||
|
||
// Retrieves the content-box main-size of our flex container from the
|
||
// reflow state (specifically, the main-size of *this continuation* of the
|
||
// flex container).
|
||
nscoord
|
||
nsFlexContainerFrame::GetMainSizeFromReflowInput(
|
||
const ReflowInput& aReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
if (aAxisTracker.IsRowOriented()) {
|
||
// Row-oriented --> our main axis is the inline axis, so our main size
|
||
// is our inline size (which should already be resolved).
|
||
NS_WARNING_ASSERTION(
|
||
aReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE,
|
||
"Unconstrained inline size; this should only result from huge sizes "
|
||
"(not intrinsic sizing w/ orthogonal flows)");
|
||
return aReflowInput.ComputedISize();
|
||
}
|
||
|
||
// Note: This may be unconstrained, if our block size is "auto":
|
||
return GetEffectiveComputedBSize(aReflowInput);
|
||
}
|
||
|
||
// Returns the largest outer hypothetical main-size of any line in |aLines|.
|
||
// (i.e. the hypothetical main-size of the largest line)
|
||
static nscoord
|
||
GetLargestLineMainSize(const FlexLine* aFirstLine)
|
||
{
|
||
nscoord largestLineOuterSize = 0;
|
||
for (const FlexLine* line = aFirstLine; line; line = line->getNext()) {
|
||
largestLineOuterSize = std::max(largestLineOuterSize,
|
||
line->GetTotalOuterHypotheticalMainSize());
|
||
}
|
||
return largestLineOuterSize;
|
||
}
|
||
|
||
/* Resolves the content-box main-size of a flex container frame,
|
||
* primarily based on:
|
||
* - the "tentative" main size, taken from the reflow state ("tentative"
|
||
* because it may be unconstrained or may run off the page).
|
||
* - the available BSize (needed if the main axis is the block axis).
|
||
* - the sizes of our lines of flex items.
|
||
*
|
||
* Guaranteed to return a definite length, i.e. not NS_UNCONSTRAINEDSIZE,
|
||
* aside from cases with huge lengths which happen to compute to that value.
|
||
*
|
||
* (Note: This function should be structurally similar to 'ComputeCrossSize()',
|
||
* except that here, the caller has already grabbed the tentative size from the
|
||
* reflow state.)
|
||
*/
|
||
static nscoord
|
||
ResolveFlexContainerMainSize(const ReflowInput& aReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
nscoord aTentativeMainSize,
|
||
nscoord aAvailableBSizeForContent,
|
||
const FlexLine* aFirstLine,
|
||
nsReflowStatus& aStatus)
|
||
{
|
||
MOZ_ASSERT(aFirstLine, "null first line pointer");
|
||
|
||
if (aAxisTracker.IsRowOriented()) {
|
||
// Row-oriented --> our main axis is the inline axis, so our main size
|
||
// is our inline size (which should already be resolved).
|
||
return aTentativeMainSize;
|
||
}
|
||
|
||
if (aTentativeMainSize != NS_INTRINSICSIZE) {
|
||
// Column-oriented case, with fixed BSize:
|
||
if (aAvailableBSizeForContent == NS_UNCONSTRAINEDSIZE ||
|
||
aTentativeMainSize < aAvailableBSizeForContent) {
|
||
// Not in a fragmenting context, OR no need to fragment because we have
|
||
// more available BSize than we need. Either way, we don't need to clamp.
|
||
// (Note that the reflow state has already done the appropriate
|
||
// min/max-BSize clamping.)
|
||
return aTentativeMainSize;
|
||
}
|
||
|
||
// Fragmenting *and* our fixed BSize is larger than available BSize:
|
||
// Mark incomplete so we get a next-in-flow, and take up all of the
|
||
// available BSize (or the amount of BSize required by our children, if
|
||
// that's larger; but of course not more than our own computed BSize).
|
||
// XXXdholbert For now, we don't support pushing children to our next
|
||
// continuation or splitting children, so "amount of BSize required by
|
||
// our children" is just the main-size (BSize) of our longest flex line.
|
||
NS_FRAME_SET_INCOMPLETE(aStatus);
|
||
nscoord largestLineOuterSize = GetLargestLineMainSize(aFirstLine);
|
||
|
||
if (largestLineOuterSize <= aAvailableBSizeForContent) {
|
||
return aAvailableBSizeForContent;
|
||
}
|
||
return std::min(aTentativeMainSize, largestLineOuterSize);
|
||
}
|
||
|
||
// Column-oriented case, with auto BSize:
|
||
// Resolve auto BSize to the largest FlexLine length, clamped to our
|
||
// computed min/max main-size properties.
|
||
// XXXdholbert Handle constrained-aAvailableBSizeForContent case here.
|
||
nscoord largestLineOuterSize = GetLargestLineMainSize(aFirstLine);
|
||
return NS_CSS_MINMAX(largestLineOuterSize,
|
||
aReflowInput.ComputedMinBSize(),
|
||
aReflowInput.ComputedMaxBSize());
|
||
}
|
||
|
||
nscoord
|
||
nsFlexContainerFrame::ComputeCrossSize(const ReflowInput& aReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
nscoord aSumLineCrossSizes,
|
||
nscoord aAvailableBSizeForContent,
|
||
bool* aIsDefinite,
|
||
nsReflowStatus& aStatus)
|
||
{
|
||
MOZ_ASSERT(aIsDefinite, "outparam pointer must be non-null");
|
||
|
||
if (aAxisTracker.IsColumnOriented()) {
|
||
// Column-oriented --> our cross axis is the inline axis, so our cross size
|
||
// is our inline size (which should already be resolved).
|
||
NS_WARNING_ASSERTION(
|
||
aReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE,
|
||
"Unconstrained inline size; this should only result from huge sizes "
|
||
"(not intrinsic sizing w/ orthogonal flows)");
|
||
*aIsDefinite = true;
|
||
return aReflowInput.ComputedISize();
|
||
}
|
||
|
||
nscoord effectiveComputedBSize = GetEffectiveComputedBSize(aReflowInput);
|
||
if (effectiveComputedBSize != NS_INTRINSICSIZE) {
|
||
// Row-oriented case (cross axis is block-axis), with fixed BSize:
|
||
*aIsDefinite = true;
|
||
if (aAvailableBSizeForContent == NS_UNCONSTRAINEDSIZE ||
|
||
effectiveComputedBSize < aAvailableBSizeForContent) {
|
||
// Not in a fragmenting context, OR no need to fragment because we have
|
||
// more available BSize than we need. Either way, just use our fixed
|
||
// BSize. (Note that the reflow state has already done the appropriate
|
||
// min/max-BSize clamping.)
|
||
return effectiveComputedBSize;
|
||
}
|
||
|
||
// Fragmenting *and* our fixed BSize is too tall for available BSize:
|
||
// Mark incomplete so we get a next-in-flow, and take up all of the
|
||
// available BSize (or the amount of BSize required by our children, if
|
||
// that's larger; but of course not more than our own computed BSize).
|
||
// XXXdholbert For now, we don't support pushing children to our next
|
||
// continuation or splitting children, so "amount of BSize required by
|
||
// our children" is just the sum of our FlexLines' BSizes (cross sizes).
|
||
NS_FRAME_SET_INCOMPLETE(aStatus);
|
||
if (aSumLineCrossSizes <= aAvailableBSizeForContent) {
|
||
return aAvailableBSizeForContent;
|
||
}
|
||
return std::min(effectiveComputedBSize, aSumLineCrossSizes);
|
||
}
|
||
|
||
// Row-oriented case (cross axis is block axis), with auto BSize:
|
||
// Shrink-wrap our line(s), subject to our min-size / max-size
|
||
// constraints in that (block) axis.
|
||
// XXXdholbert Handle constrained-aAvailableBSizeForContent case here.
|
||
*aIsDefinite = false;
|
||
return NS_CSS_MINMAX(aSumLineCrossSizes,
|
||
aReflowInput.ComputedMinBSize(),
|
||
aReflowInput.ComputedMaxBSize());
|
||
}
|
||
|
||
void
|
||
FlexLine::PositionItemsInMainAxis(uint8_t aJustifyContent,
|
||
nscoord aContentBoxMainSize,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
MainAxisPositionTracker mainAxisPosnTracker(aAxisTracker, this,
|
||
aJustifyContent,
|
||
aContentBoxMainSize);
|
||
for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
nscoord itemMainBorderBoxSize =
|
||
item->GetMainSize() +
|
||
item->GetBorderPaddingSizeInAxis(mainAxisPosnTracker.GetAxis());
|
||
|
||
// Resolve any main-axis 'auto' margins on aChild to an actual value.
|
||
mainAxisPosnTracker.ResolveAutoMarginsInMainAxis(*item);
|
||
|
||
// Advance our position tracker to child's upper-left content-box corner,
|
||
// and use that as its position in the main axis.
|
||
mainAxisPosnTracker.EnterMargin(item->GetMargin());
|
||
mainAxisPosnTracker.EnterChildFrame(itemMainBorderBoxSize);
|
||
|
||
item->SetMainPosition(mainAxisPosnTracker.GetPosition());
|
||
|
||
mainAxisPosnTracker.ExitChildFrame(itemMainBorderBoxSize);
|
||
mainAxisPosnTracker.ExitMargin(item->GetMargin());
|
||
mainAxisPosnTracker.TraversePackingSpace();
|
||
}
|
||
}
|
||
|
||
/**
|
||
* Given the flex container's "flex-relative ascent" (i.e. distance from the
|
||
* flex container's content-box cross-start edge to its baseline), returns
|
||
* its actual physical ascent value (the distance from the *border-box* top
|
||
* edge to its baseline).
|
||
*/
|
||
static nscoord
|
||
ComputePhysicalAscentFromFlexRelativeAscent(
|
||
nscoord aFlexRelativeAscent,
|
||
nscoord aContentBoxCrossSize,
|
||
const ReflowInput& aReflowInput,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
return aReflowInput.ComputedPhysicalBorderPadding().top +
|
||
PhysicalCoordFromFlexRelativeCoord(aFlexRelativeAscent,
|
||
aContentBoxCrossSize,
|
||
aAxisTracker.GetCrossAxis());
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::SizeItemInCrossAxis(
|
||
nsPresContext* aPresContext,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
ReflowInput& aChildReflowInput,
|
||
FlexItem& aItem)
|
||
{
|
||
if (aAxisTracker.IsCrossAxisHorizontal()) {
|
||
MOZ_ASSERT(aItem.HasIntrinsicRatio(),
|
||
"For now, caller's CanMainSizeInfluenceCrossSize check should "
|
||
"only allow us to get here for items with intrinsic ratio");
|
||
// XXXdholbert When we finish support for vertical writing-modes,
|
||
// (in bug 1079155 or a dependency), we'll relax the horizontal check in
|
||
// CanMainSizeInfluenceCrossSize, and this function will need to be able
|
||
// to measure the baseline & width (given our resolved height)
|
||
// of vertical-writing-mode flex items here.
|
||
// For now, we only expect to get here for items with an intrinsic aspect
|
||
// ratio; and for those items, we can just read the size off of the reflow
|
||
// state, without performing reflow.
|
||
aItem.SetCrossSize(aChildReflowInput.ComputedWidth());
|
||
return;
|
||
}
|
||
|
||
MOZ_ASSERT(!aItem.HadMeasuringReflow(),
|
||
"We shouldn't need more than one measuring reflow");
|
||
|
||
if (aItem.GetAlignSelf() == NS_STYLE_ALIGN_STRETCH) {
|
||
// This item's got "align-self: stretch", so we probably imposed a
|
||
// stretched computed height on it during its previous reflow. We're
|
||
// not imposing that height for *this* measuring reflow, so we need to
|
||
// tell it to treat this reflow as a vertical resize (regardless of
|
||
// whether any of its ancestors are being resized).
|
||
aChildReflowInput.SetVResize(true);
|
||
}
|
||
|
||
// Potentially reflow the item, and get the sizing info.
|
||
const CachedMeasuringReflowResult& reflowResult =
|
||
MeasureAscentAndHeightForFlexItem(aItem, aPresContext, aChildReflowInput);
|
||
|
||
// Save the sizing info that we learned from this reflow
|
||
// -----------------------------------------------------
|
||
|
||
// Tentatively store the child's desired content-box cross-size.
|
||
// Note that childDesiredSize is the border-box size, so we have to
|
||
// subtract border & padding to get the content-box size.
|
||
// (Note that at this point in the code, we know our cross axis is vertical,
|
||
// so we don't bother with making aAxisTracker pick the cross-axis component
|
||
// for us.)
|
||
nscoord crossAxisBorderPadding = aItem.GetBorderPadding().TopBottom();
|
||
if (reflowResult.Height() < crossAxisBorderPadding) {
|
||
// Child's requested size isn't large enough for its border/padding!
|
||
// This is OK for the trivial nsFrame::Reflow() impl, but other frame
|
||
// classes should know better. So, if we get here, the child had better be
|
||
// an instance of nsFrame (i.e. it should return null from GetType()).
|
||
// XXXdholbert Once we've fixed bug 765861, we should upgrade this to an
|
||
// assertion that trivially passes if bug 765861's flag has been flipped.
|
||
NS_WARNING_ASSERTION(
|
||
!aItem.Frame()->GetType(),
|
||
"Child should at least request space for border/padding");
|
||
aItem.SetCrossSize(0);
|
||
} else {
|
||
// (normal case)
|
||
aItem.SetCrossSize(reflowResult.Height() - crossAxisBorderPadding);
|
||
}
|
||
|
||
aItem.SetAscent(reflowResult.Ascent());
|
||
}
|
||
|
||
void
|
||
FlexLine::PositionItemsInCrossAxis(nscoord aLineStartPosition,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
SingleLineCrossAxisPositionTracker lineCrossAxisPosnTracker(aAxisTracker);
|
||
|
||
for (FlexItem* item = mItems.getFirst(); item; item = item->getNext()) {
|
||
// First, stretch the item's cross size (if appropriate), and resolve any
|
||
// auto margins in this axis.
|
||
item->ResolveStretchedCrossSize(mLineCrossSize, aAxisTracker);
|
||
lineCrossAxisPosnTracker.ResolveAutoMarginsInCrossAxis(*this, *item);
|
||
|
||
// Compute the cross-axis position of this item
|
||
nscoord itemCrossBorderBoxSize =
|
||
item->GetCrossSize() +
|
||
item->GetBorderPaddingSizeInAxis(aAxisTracker.GetCrossAxis());
|
||
lineCrossAxisPosnTracker.EnterAlignPackingSpace(*this, *item, aAxisTracker);
|
||
lineCrossAxisPosnTracker.EnterMargin(item->GetMargin());
|
||
lineCrossAxisPosnTracker.EnterChildFrame(itemCrossBorderBoxSize);
|
||
|
||
item->SetCrossPosition(aLineStartPosition +
|
||
lineCrossAxisPosnTracker.GetPosition());
|
||
|
||
// Back out to cross-axis edge of the line.
|
||
lineCrossAxisPosnTracker.ResetPosition();
|
||
}
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::Reflow(nsPresContext* aPresContext,
|
||
ReflowOutput& aDesiredSize,
|
||
const ReflowInput& aReflowInput,
|
||
nsReflowStatus& aStatus)
|
||
{
|
||
MarkInReflow();
|
||
DO_GLOBAL_REFLOW_COUNT("nsFlexContainerFrame");
|
||
DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
|
||
MOZ_LOG(gFlexContainerLog, LogLevel::Debug,
|
||
("Reflow() for nsFlexContainerFrame %p\n", this));
|
||
|
||
if (IsFrameTreeTooDeep(aReflowInput, aDesiredSize, aStatus)) {
|
||
return;
|
||
}
|
||
|
||
// We (and our children) can only depend on our ancestor's bsize if we have
|
||
// a percent-bsize, or if we're positioned and we have "block-start" and "block-end"
|
||
// set and have block-size:auto. (There are actually other cases, too -- e.g. if
|
||
// our parent is itself a block-dir flex container and we're flexible -- but
|
||
// we'll let our ancestors handle those sorts of cases.)
|
||
WritingMode wm = aReflowInput.GetWritingMode();
|
||
const nsStylePosition* stylePos = StylePosition();
|
||
const nsStyleCoord& bsize = stylePos->BSize(wm);
|
||
if (bsize.HasPercent() ||
|
||
(StyleDisplay()->IsAbsolutelyPositionedStyle() &&
|
||
eStyleUnit_Auto == bsize.GetUnit() &&
|
||
eStyleUnit_Auto != stylePos->mOffset.GetBStartUnit(wm) &&
|
||
eStyleUnit_Auto != stylePos->mOffset.GetBEndUnit(wm))) {
|
||
AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
|
||
}
|
||
|
||
// If we've never reordered our children, then we can trust that they're
|
||
// already in DOM-order, and we only need to consider their "order" property
|
||
// when checking them for sortedness & sorting them.
|
||
//
|
||
// After we actually sort them, though, we can't trust that they're in DOM
|
||
// order anymore. So, from that point on, our sort & sorted-order-checking
|
||
// operations need to use a fancier LEQ function that also takes DOM order
|
||
// into account, so that we can honor the spec's requirement that frames w/
|
||
// equal "order" values are laid out in DOM order.
|
||
|
||
if (!HasAnyStateBits(NS_STATE_FLEX_CHILDREN_REORDERED)) {
|
||
if (SortChildrenIfNeeded<IsOrderLEQ>()) {
|
||
AddStateBits(NS_STATE_FLEX_CHILDREN_REORDERED);
|
||
}
|
||
} else {
|
||
SortChildrenIfNeeded<IsOrderLEQWithDOMFallback>();
|
||
}
|
||
|
||
RenumberList();
|
||
|
||
const FlexboxAxisTracker axisTracker(this, aReflowInput.GetWritingMode());
|
||
|
||
// If we're being fragmented into a constrained BSize, then subtract off
|
||
// borderpadding BStart from that constrained BSize, to get the available
|
||
// BSize for our content box. (No need to subtract the borderpadding BStart
|
||
// if we're already skipping it via GetLogicalSkipSides, though.)
|
||
nscoord availableBSizeForContent = aReflowInput.AvailableBSize();
|
||
if (availableBSizeForContent != NS_UNCONSTRAINEDSIZE &&
|
||
!(GetLogicalSkipSides(&aReflowInput).BStart())) {
|
||
availableBSizeForContent -=
|
||
aReflowInput.ComputedLogicalBorderPadding().BStart(wm);
|
||
// (Don't let that push availableBSizeForContent below zero, though):
|
||
availableBSizeForContent = std::max(availableBSizeForContent, 0);
|
||
}
|
||
|
||
nscoord contentBoxMainSize = GetMainSizeFromReflowInput(aReflowInput,
|
||
axisTracker);
|
||
|
||
AutoTArray<StrutInfo, 1> struts;
|
||
DoFlexLayout(aPresContext, aDesiredSize, aReflowInput, aStatus,
|
||
contentBoxMainSize, availableBSizeForContent,
|
||
struts, axisTracker);
|
||
|
||
if (!struts.IsEmpty()) {
|
||
// We're restarting flex layout, with new knowledge of collapsed items.
|
||
DoFlexLayout(aPresContext, aDesiredSize, aReflowInput, aStatus,
|
||
contentBoxMainSize, availableBSizeForContent,
|
||
struts, axisTracker);
|
||
}
|
||
}
|
||
|
||
// RAII class to clean up a list of FlexLines.
|
||
// Specifically, this removes each line from the list, deletes all the
|
||
// FlexItems in its list, and deletes the FlexLine.
|
||
class MOZ_RAII AutoFlexLineListClearer
|
||
{
|
||
public:
|
||
explicit AutoFlexLineListClearer(LinkedList<FlexLine>& aLines
|
||
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
|
||
: mLines(aLines)
|
||
{
|
||
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
|
||
}
|
||
|
||
~AutoFlexLineListClearer()
|
||
{
|
||
while (FlexLine* line = mLines.popFirst()) {
|
||
while (FlexItem* item = line->mItems.popFirst()) {
|
||
delete item;
|
||
}
|
||
delete line;
|
||
}
|
||
}
|
||
|
||
private:
|
||
LinkedList<FlexLine>& mLines;
|
||
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
|
||
};
|
||
|
||
// Class to let us temporarily provide an override value for the the main-size
|
||
// CSS property ('width' or 'height') on a flex item, for use in
|
||
// nsFrame::ComputeSizeWithIntrinsicDimensions.
|
||
// (We could use this overridden size more broadly, too, but it's probably
|
||
// better to avoid property-table accesses. So, where possible, we communicate
|
||
// the resolved main-size to the child via modifying its reflow state directly,
|
||
// instead of using this class.)
|
||
class MOZ_RAII AutoFlexItemMainSizeOverride final
|
||
{
|
||
public:
|
||
explicit AutoFlexItemMainSizeOverride(FlexItem& aItem
|
||
MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
|
||
: mItemFrame(aItem.Frame())
|
||
{
|
||
MOZ_GUARD_OBJECT_NOTIFIER_INIT;
|
||
|
||
MOZ_ASSERT(!mItemFrame->HasProperty(nsIFrame::FlexItemMainSizeOverride()),
|
||
"FlexItemMainSizeOverride prop shouldn't be set already; "
|
||
"it should only be set temporarily (& not recursively)");
|
||
NS_ASSERTION(aItem.HasIntrinsicRatio(),
|
||
"This should only be needed for items with an aspect ratio");
|
||
|
||
mItemFrame->SetProperty(nsIFrame::FlexItemMainSizeOverride(),
|
||
aItem.GetMainSize());
|
||
}
|
||
|
||
~AutoFlexItemMainSizeOverride() {
|
||
mItemFrame->RemoveProperty(nsIFrame::FlexItemMainSizeOverride());
|
||
}
|
||
|
||
private:
|
||
nsIFrame* mItemFrame;
|
||
MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
|
||
};
|
||
|
||
void
|
||
nsFlexContainerFrame::CalculatePackingSpace(uint32_t aNumThingsToPack,
|
||
uint8_t aAlignVal,
|
||
nscoord* aFirstSubjectOffset,
|
||
uint32_t* aNumPackingSpacesRemaining,
|
||
nscoord* aPackingSpaceRemaining)
|
||
{
|
||
MOZ_ASSERT(NS_STYLE_ALIGN_SPACE_BETWEEN == NS_STYLE_JUSTIFY_SPACE_BETWEEN &&
|
||
NS_STYLE_ALIGN_SPACE_AROUND == NS_STYLE_JUSTIFY_SPACE_AROUND &&
|
||
NS_STYLE_ALIGN_SPACE_EVENLY == NS_STYLE_JUSTIFY_SPACE_EVENLY,
|
||
"CalculatePackingSpace assumes that NS_STYLE_ALIGN_SPACE and "
|
||
"NS_STYLE_JUSTIFY_SPACE constants are interchangeable");
|
||
|
||
MOZ_ASSERT(aAlignVal == NS_STYLE_ALIGN_SPACE_BETWEEN ||
|
||
aAlignVal == NS_STYLE_ALIGN_SPACE_AROUND ||
|
||
aAlignVal == NS_STYLE_ALIGN_SPACE_EVENLY,
|
||
"Unexpected alignment value");
|
||
|
||
MOZ_ASSERT(*aPackingSpaceRemaining >= 0,
|
||
"Should not be called with negative packing space");
|
||
|
||
MOZ_ASSERT(aNumThingsToPack >= 1,
|
||
"Should not be called with less than 1 thing to pack");
|
||
|
||
// Packing spaces between items:
|
||
*aNumPackingSpacesRemaining = aNumThingsToPack - 1;
|
||
|
||
if (aAlignVal == NS_STYLE_ALIGN_SPACE_BETWEEN) {
|
||
// No need to reserve space at beginning/end, so we're done.
|
||
return;
|
||
}
|
||
|
||
// We need to add 1 or 2 packing spaces, split between beginning/end, for
|
||
// space-around / space-evenly:
|
||
size_t numPackingSpacesForEdges =
|
||
aAlignVal == NS_STYLE_JUSTIFY_SPACE_AROUND ? 1 : 2;
|
||
|
||
// How big will each "full" packing space be:
|
||
nscoord packingSpaceSize = *aPackingSpaceRemaining /
|
||
(*aNumPackingSpacesRemaining + numPackingSpacesForEdges);
|
||
// How much packing-space are we allocating to the edges:
|
||
nscoord totalEdgePackingSpace = numPackingSpacesForEdges * packingSpaceSize;
|
||
|
||
// Use half of that edge packing space right now:
|
||
*aFirstSubjectOffset += totalEdgePackingSpace / 2;
|
||
// ...but we need to subtract all of it right away, so that we won't
|
||
// hand out any of it to intermediate packing spaces.
|
||
*aPackingSpaceRemaining -= totalEdgePackingSpace;
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::DoFlexLayout(nsPresContext* aPresContext,
|
||
ReflowOutput& aDesiredSize,
|
||
const ReflowInput& aReflowInput,
|
||
nsReflowStatus& aStatus,
|
||
nscoord aContentBoxMainSize,
|
||
nscoord aAvailableBSizeForContent,
|
||
nsTArray<StrutInfo>& aStruts,
|
||
const FlexboxAxisTracker& aAxisTracker)
|
||
{
|
||
aStatus = NS_FRAME_COMPLETE;
|
||
|
||
LinkedList<FlexLine> lines;
|
||
nsTArray<nsIFrame*> placeholderKids;
|
||
AutoFlexLineListClearer cleanupLines(lines);
|
||
|
||
GenerateFlexLines(aPresContext, aReflowInput,
|
||
aContentBoxMainSize,
|
||
aAvailableBSizeForContent,
|
||
aStruts, aAxisTracker,
|
||
placeholderKids, lines);
|
||
|
||
if (lines.getFirst()->IsEmpty() &&
|
||
!lines.getFirst()->getNext()) {
|
||
// We have no flex items, our parent should synthesize a baseline if needed.
|
||
AddStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE);
|
||
} else {
|
||
RemoveStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE);
|
||
}
|
||
|
||
aContentBoxMainSize =
|
||
ResolveFlexContainerMainSize(aReflowInput, aAxisTracker,
|
||
aContentBoxMainSize, aAvailableBSizeForContent,
|
||
lines.getFirst(), aStatus);
|
||
|
||
for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
line->ResolveFlexibleLengths(aContentBoxMainSize);
|
||
}
|
||
|
||
// Cross Size Determination - Flexbox spec section 9.4
|
||
// ===================================================
|
||
// Calculate the hypothetical cross size of each item:
|
||
nscoord sumLineCrossSizes = 0;
|
||
for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
for (FlexItem* item = line->GetFirstItem(); item; item = item->getNext()) {
|
||
// The item may already have the correct cross-size; only recalculate
|
||
// if the item's main size resolution (flexing) could have influenced it:
|
||
if (item->CanMainSizeInfluenceCrossSize(aAxisTracker)) {
|
||
Maybe<AutoFlexItemMainSizeOverride> sizeOverride;
|
||
if (item->HasIntrinsicRatio()) {
|
||
// For flex items with an aspect ratio, we have to impose an override
|
||
// for the main-size property *before* we even instantiate the reflow
|
||
// state, in order for aspect ratio calculations to produce the right
|
||
// cross size in the reflow state. (For other flex items, it's OK
|
||
// (and cheaper) to impose our main size *after* the reflow state has
|
||
// been constructed, since the main size shouldn't influence anything
|
||
// about cross-size measurement until we actually reflow the child.)
|
||
sizeOverride.emplace(*item);
|
||
}
|
||
|
||
WritingMode wm = item->Frame()->GetWritingMode();
|
||
LogicalSize availSize = aReflowInput.ComputedSize(wm);
|
||
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
|
||
ReflowInput childReflowInput(aPresContext, aReflowInput,
|
||
item->Frame(), availSize);
|
||
if (!sizeOverride) {
|
||
// Directly override the computed main-size, by tweaking reflow state:
|
||
if (aAxisTracker.IsMainAxisHorizontal()) {
|
||
childReflowInput.SetComputedWidth(item->GetMainSize());
|
||
} else {
|
||
childReflowInput.SetComputedHeight(item->GetMainSize());
|
||
}
|
||
}
|
||
|
||
SizeItemInCrossAxis(aPresContext, aAxisTracker,
|
||
childReflowInput, *item);
|
||
}
|
||
}
|
||
// Now that we've finished with this line's items, size the line itself:
|
||
line->ComputeCrossSizeAndBaseline(aAxisTracker);
|
||
sumLineCrossSizes += line->GetLineCrossSize();
|
||
}
|
||
|
||
bool isCrossSizeDefinite;
|
||
const nscoord contentBoxCrossSize =
|
||
ComputeCrossSize(aReflowInput, aAxisTracker, sumLineCrossSizes,
|
||
aAvailableBSizeForContent, &isCrossSizeDefinite, aStatus);
|
||
|
||
// Set up state for cross-axis alignment, at a high level (outside the
|
||
// scope of a particular flex line)
|
||
CrossAxisPositionTracker
|
||
crossAxisPosnTracker(lines.getFirst(),
|
||
aReflowInput, contentBoxCrossSize,
|
||
isCrossSizeDefinite, aAxisTracker);
|
||
|
||
// Now that we know the cross size of each line (including
|
||
// "align-content:stretch" adjustments, from the CrossAxisPositionTracker
|
||
// constructor), we can create struts for any flex items with
|
||
// "visibility: collapse" (and restart flex layout).
|
||
if (aStruts.IsEmpty()) { // (Don't make struts if we already did)
|
||
BuildStrutInfoFromCollapsedItems(lines.getFirst(), aStruts);
|
||
if (!aStruts.IsEmpty()) {
|
||
// Restart flex layout, using our struts.
|
||
return;
|
||
}
|
||
}
|
||
|
||
// If the container should derive its baseline from the first FlexLine,
|
||
// do that here (while crossAxisPosnTracker is conveniently pointing
|
||
// at the cross-start edge of that line, which the line's baseline offset is
|
||
// measured from):
|
||
nscoord flexContainerAscent;
|
||
if (!aAxisTracker.AreAxesInternallyReversed()) {
|
||
nscoord firstLineBaselineOffset = lines.getFirst()->GetFirstBaselineOffset();
|
||
if (firstLineBaselineOffset == nscoord_MIN) {
|
||
// No baseline-aligned items in line. Use sentinel value to prompt us to
|
||
// get baseline from the first FlexItem after we've reflowed it.
|
||
flexContainerAscent = nscoord_MIN;
|
||
} else {
|
||
flexContainerAscent =
|
||
ComputePhysicalAscentFromFlexRelativeAscent(
|
||
crossAxisPosnTracker.GetPosition() + firstLineBaselineOffset,
|
||
contentBoxCrossSize, aReflowInput, aAxisTracker);
|
||
}
|
||
}
|
||
|
||
const auto justifyContent = IsLegacyBox(aReflowInput.mFrame) ?
|
||
ConvertLegacyStyleToJustifyContent(StyleXUL()) :
|
||
aReflowInput.mStylePosition->mJustifyContent;
|
||
|
||
for (FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
// Main-Axis Alignment - Flexbox spec section 9.5
|
||
// ==============================================
|
||
line->PositionItemsInMainAxis(justifyContent,
|
||
aContentBoxMainSize,
|
||
aAxisTracker);
|
||
|
||
// Cross-Axis Alignment - Flexbox spec section 9.6
|
||
// ===============================================
|
||
line->PositionItemsInCrossAxis(crossAxisPosnTracker.GetPosition(),
|
||
aAxisTracker);
|
||
crossAxisPosnTracker.TraverseLine(*line);
|
||
crossAxisPosnTracker.TraversePackingSpace();
|
||
}
|
||
|
||
// If the container should derive its baseline from the last FlexLine,
|
||
// do that here (while crossAxisPosnTracker is conveniently pointing
|
||
// at the cross-end edge of that line, which the line's baseline offset is
|
||
// measured from):
|
||
if (aAxisTracker.AreAxesInternallyReversed()) {
|
||
nscoord lastLineBaselineOffset = lines.getLast()->GetFirstBaselineOffset();
|
||
if (lastLineBaselineOffset == nscoord_MIN) {
|
||
// No baseline-aligned items in line. Use sentinel value to prompt us to
|
||
// get baseline from the last FlexItem after we've reflowed it.
|
||
flexContainerAscent = nscoord_MIN;
|
||
} else {
|
||
flexContainerAscent =
|
||
ComputePhysicalAscentFromFlexRelativeAscent(
|
||
crossAxisPosnTracker.GetPosition() - lastLineBaselineOffset,
|
||
contentBoxCrossSize, aReflowInput, aAxisTracker);
|
||
}
|
||
}
|
||
|
||
// Before giving each child a final reflow, calculate the origin of the
|
||
// flex container's content box (with respect to its border-box), so that
|
||
// we can compute our flex item's final positions.
|
||
WritingMode flexWM = aReflowInput.GetWritingMode();
|
||
LogicalMargin containerBP = aReflowInput.ComputedLogicalBorderPadding();
|
||
|
||
// Unconditionally skip block-end border & padding for now, regardless of
|
||
// writing-mode/GetLogicalSkipSides. We add it lower down, after we've
|
||
// established baseline and decided whether bottom border-padding fits (if
|
||
// we're fragmented).
|
||
const nscoord blockEndContainerBP = containerBP.BEnd(flexWM);
|
||
const LogicalSides skipSides =
|
||
GetLogicalSkipSides(&aReflowInput) | LogicalSides(eLogicalSideBitsBEnd);
|
||
containerBP.ApplySkipSides(skipSides);
|
||
|
||
const LogicalPoint containerContentBoxOrigin(flexWM,
|
||
containerBP.IStart(flexWM),
|
||
containerBP.BStart(flexWM));
|
||
|
||
// Determine flex container's border-box size (used in positioning children):
|
||
LogicalSize logSize =
|
||
aAxisTracker.LogicalSizeFromFlexRelativeSizes(aContentBoxMainSize,
|
||
contentBoxCrossSize);
|
||
logSize += aReflowInput.ComputedLogicalBorderPadding().Size(flexWM);
|
||
nsSize containerSize = logSize.GetPhysicalSize(flexWM);
|
||
|
||
// If the flex container has no baseline-aligned items, it will use this item
|
||
// (the first item, discounting any under-the-hood reversing that we've done)
|
||
// to determine its baseline:
|
||
const FlexItem* const firstItem =
|
||
aAxisTracker.AreAxesInternallyReversed()
|
||
? lines.getLast()->GetLastItem()
|
||
: lines.getFirst()->GetFirstItem();
|
||
|
||
// FINAL REFLOW: Give each child frame another chance to reflow, now that
|
||
// we know its final size and position.
|
||
for (const FlexLine* line = lines.getFirst(); line; line = line->getNext()) {
|
||
for (const FlexItem* item = line->GetFirstItem(); item;
|
||
item = item->getNext()) {
|
||
LogicalPoint framePos = aAxisTracker.LogicalPointFromFlexRelativePoint(
|
||
item->GetMainPosition(),
|
||
item->GetCrossPosition(),
|
||
aContentBoxMainSize,
|
||
contentBoxCrossSize);
|
||
// Adjust framePos to be relative to the container's border-box
|
||
// (i.e. its frame rect), instead of the container's content-box:
|
||
framePos += containerContentBoxOrigin;
|
||
|
||
// (Intentionally snapshotting this before ApplyRelativePositioning, to
|
||
// maybe use for setting the flex container's baseline.)
|
||
const nscoord itemNormalBPos = framePos.B(flexWM);
|
||
|
||
// Check if we actually need to reflow the item -- if we already reflowed
|
||
// it with the right size, we can just reposition it as-needed.
|
||
bool itemNeedsReflow = true; // (Start out assuming the worst.)
|
||
if (item->HadMeasuringReflow()) {
|
||
LogicalSize finalFlexItemCBSize =
|
||
aAxisTracker.LogicalSizeFromFlexRelativeSizes(item->GetMainSize(),
|
||
item->GetCrossSize());
|
||
// We've already reflowed the child once. Was the size we gave it in
|
||
// that reflow the same as its final (post-flexing/stretching) size?
|
||
if (finalFlexItemCBSize ==
|
||
LogicalSize(flexWM,
|
||
item->Frame()->GetContentRectRelativeToSelf().Size())) {
|
||
// Even if our size hasn't changed, some of our descendants might
|
||
// care that our bsize is now considered "definite" (whereas it
|
||
// wasn't in our previous "measuring" reflow), if they have a
|
||
// relative bsize.
|
||
if (!(item->Frame()->GetStateBits() &
|
||
NS_FRAME_CONTAINS_RELATIVE_BSIZE)) {
|
||
// Item has the correct size (and its children don't care that
|
||
// it's now "definite"). Let's just make sure it's at the right
|
||
// position.
|
||
itemNeedsReflow = false;
|
||
MoveFlexItemToFinalPosition(aReflowInput, *item, framePos,
|
||
containerSize);
|
||
}
|
||
}
|
||
}
|
||
if (itemNeedsReflow) {
|
||
ReflowFlexItem(aPresContext, aAxisTracker, aReflowInput,
|
||
*item, framePos, containerSize);
|
||
}
|
||
|
||
// If this is our first item and we haven't established a baseline for
|
||
// the container yet (i.e. if we don't have 'align-self: baseline' on any
|
||
// children), then use this child's first baseline as the container's
|
||
// baseline.
|
||
if (item == firstItem &&
|
||
flexContainerAscent == nscoord_MIN) {
|
||
flexContainerAscent = itemNormalBPos + item->ResolvedAscent(true);
|
||
}
|
||
}
|
||
}
|
||
|
||
if (!placeholderKids.IsEmpty()) {
|
||
ReflowPlaceholders(aPresContext, aReflowInput,
|
||
placeholderKids, containerContentBoxOrigin,
|
||
containerSize);
|
||
}
|
||
|
||
// Compute flex container's desired size (in its own writing-mode),
|
||
// starting w/ content-box size & growing from there:
|
||
LogicalSize desiredSizeInFlexWM =
|
||
aAxisTracker.LogicalSizeFromFlexRelativeSizes(aContentBoxMainSize,
|
||
contentBoxCrossSize);
|
||
// Add border/padding (w/ skipSides already applied):
|
||
desiredSizeInFlexWM.ISize(flexWM) += containerBP.IStartEnd(flexWM);
|
||
desiredSizeInFlexWM.BSize(flexWM) += containerBP.BStartEnd(flexWM);
|
||
|
||
if (flexContainerAscent == nscoord_MIN) {
|
||
// Still don't have our baseline set -- this happens if we have no
|
||
// children (or if our children are huge enough that they have nscoord_MIN
|
||
// as their baseline... in which case, we'll use the wrong baseline, but no
|
||
// big deal)
|
||
NS_WARNING_ASSERTION(
|
||
lines.getFirst()->IsEmpty(),
|
||
"Have flex items but didn't get an ascent - that's odd (or there are "
|
||
"just gigantic sizes involved)");
|
||
// Per spec, synthesize baseline from the flex container's content box
|
||
// (i.e. use block-end side of content-box)
|
||
// XXXdholbert This only makes sense if parent's writing mode is
|
||
// horizontal (& even then, really we should be using the BSize in terms
|
||
// of the parent's writing mode, not ours). Clean up in bug 1155322.
|
||
flexContainerAscent = desiredSizeInFlexWM.BSize(flexWM);
|
||
}
|
||
|
||
if (HasAnyStateBits(NS_STATE_FLEX_SYNTHESIZE_BASELINE)) {
|
||
// This will force our parent to call GetLogicalBaseline, which will
|
||
// synthesize a margin-box baseline.
|
||
aDesiredSize.SetBlockStartAscent(ReflowOutput::ASK_FOR_BASELINE);
|
||
} else {
|
||
// XXXdholbert flexContainerAscent needs to be in terms of
|
||
// our parent's writing-mode here. See bug 1155322.
|
||
aDesiredSize.SetBlockStartAscent(flexContainerAscent);
|
||
}
|
||
|
||
// Now: If we're complete, add bottom border/padding to desired height (which
|
||
// we skipped via skipSides) -- unless that pushes us over available height,
|
||
// in which case we become incomplete (unless we already weren't asking for
|
||
// any height, in which case we stay complete to avoid looping forever).
|
||
// NOTE: If we're auto-height, we allow our bottom border/padding to push us
|
||
// over the available height without requesting a continuation, for
|
||
// consistency with the behavior of "display:block" elements.
|
||
if (NS_FRAME_IS_COMPLETE(aStatus)) {
|
||
nscoord desiredBSizeWithBEndBP =
|
||
desiredSizeInFlexWM.BSize(flexWM) + blockEndContainerBP;
|
||
|
||
if (aReflowInput.AvailableBSize() == NS_UNCONSTRAINEDSIZE ||
|
||
desiredSizeInFlexWM.BSize(flexWM) == 0 ||
|
||
desiredBSizeWithBEndBP <= aReflowInput.AvailableBSize() ||
|
||
aReflowInput.ComputedBSize() == NS_INTRINSICSIZE) {
|
||
// Update desired height to include block-end border/padding
|
||
desiredSizeInFlexWM.BSize(flexWM) = desiredBSizeWithBEndBP;
|
||
} else {
|
||
// We couldn't fit bottom border/padding, so we'll need a continuation.
|
||
NS_FRAME_SET_INCOMPLETE(aStatus);
|
||
}
|
||
}
|
||
|
||
// Calculate the container baselines so that our parent can baseline-align us.
|
||
mBaselineFromLastReflow = flexContainerAscent;
|
||
mLastBaselineFromLastReflow = lines.getLast()->GetLastBaselineOffset();
|
||
if (mLastBaselineFromLastReflow == nscoord_MIN) {
|
||
// XXX we fall back to a mirrored first baseline here for now, but this
|
||
// should probably use the last baseline of the last item or something.
|
||
mLastBaselineFromLastReflow =
|
||
desiredSizeInFlexWM.BSize(flexWM) - flexContainerAscent;
|
||
}
|
||
|
||
// Convert flex container's final desired size to parent's WM, for outparam.
|
||
aDesiredSize.SetSize(flexWM, desiredSizeInFlexWM);
|
||
|
||
// Overflow area = union(my overflow area, kids' overflow areas)
|
||
aDesiredSize.SetOverflowAreasToDesiredBounds();
|
||
for (nsIFrame* childFrame : mFrames) {
|
||
ConsiderChildOverflow(aDesiredSize.mOverflowAreas, childFrame);
|
||
}
|
||
|
||
FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize,
|
||
aReflowInput, aStatus);
|
||
|
||
NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize)
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::MoveFlexItemToFinalPosition(
|
||
const ReflowInput& aReflowInput,
|
||
const FlexItem& aItem,
|
||
LogicalPoint& aFramePos,
|
||
const nsSize& aContainerSize)
|
||
{
|
||
WritingMode outerWM = aReflowInput.GetWritingMode();
|
||
|
||
// If item is relpos, look up its offsets (cached from prev reflow)
|
||
LogicalMargin logicalOffsets(outerWM);
|
||
if (NS_STYLE_POSITION_RELATIVE == aItem.Frame()->StyleDisplay()->mPosition) {
|
||
nsMargin* cachedOffsets = aItem.Frame()->GetProperty(nsIFrame::ComputedOffsetProperty());
|
||
MOZ_ASSERT(cachedOffsets,
|
||
"relpos previously-reflowed frame should've cached its offsets");
|
||
logicalOffsets = LogicalMargin(outerWM, *cachedOffsets);
|
||
}
|
||
ReflowInput::ApplyRelativePositioning(aItem.Frame(), outerWM,
|
||
logicalOffsets, &aFramePos,
|
||
aContainerSize);
|
||
aItem.Frame()->SetPosition(outerWM, aFramePos, aContainerSize);
|
||
PositionFrameView(aItem.Frame());
|
||
PositionChildViews(aItem.Frame());
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::ReflowFlexItem(nsPresContext* aPresContext,
|
||
const FlexboxAxisTracker& aAxisTracker,
|
||
const ReflowInput& aReflowInput,
|
||
const FlexItem& aItem,
|
||
LogicalPoint& aFramePos,
|
||
const nsSize& aContainerSize)
|
||
{
|
||
WritingMode outerWM = aReflowInput.GetWritingMode();
|
||
WritingMode wm = aItem.Frame()->GetWritingMode();
|
||
LogicalSize availSize = aReflowInput.ComputedSize(wm);
|
||
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
|
||
ReflowInput childReflowInput(aPresContext, aReflowInput,
|
||
aItem.Frame(), availSize);
|
||
|
||
// Keep track of whether we've overriden the child's computed height
|
||
// and/or width, so we can set its resize flags accordingly.
|
||
bool didOverrideComputedWidth = false;
|
||
bool didOverrideComputedHeight = false;
|
||
|
||
// Override computed main-size
|
||
if (aAxisTracker.IsMainAxisHorizontal()) {
|
||
childReflowInput.SetComputedWidth(aItem.GetMainSize());
|
||
didOverrideComputedWidth = true;
|
||
} else {
|
||
childReflowInput.SetComputedHeight(aItem.GetMainSize());
|
||
didOverrideComputedHeight = true;
|
||
}
|
||
|
||
// Override reflow state's computed cross-size if either:
|
||
// - the item was stretched (in which case we're imposing a cross size)
|
||
// ...or...
|
||
// - the item it has an aspect ratio (in which case the cross-size that's
|
||
// currently in the reflow state is based on arithmetic involving a stale
|
||
// main-size value that we just stomped on above). (Note that we could handle
|
||
// this case using an AutoFlexItemMainSizeOverride, as we do elsewhere; but
|
||
// given that we *already know* the correct cross size to use here, it's
|
||
// cheaper to just directly set it instead of setting a frame property.)
|
||
if (aItem.IsStretched() ||
|
||
aItem.HasIntrinsicRatio()) {
|
||
if (aAxisTracker.IsCrossAxisHorizontal()) {
|
||
childReflowInput.SetComputedWidth(aItem.GetCrossSize());
|
||
didOverrideComputedWidth = true;
|
||
} else {
|
||
childReflowInput.SetComputedHeight(aItem.GetCrossSize());
|
||
didOverrideComputedHeight = true;
|
||
}
|
||
}
|
||
if (aItem.IsStretched() && !aAxisTracker.IsCrossAxisHorizontal()) {
|
||
// If this item's height is stretched, it's a relative height.
|
||
aItem.Frame()->AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
|
||
}
|
||
|
||
// XXXdholbert Might need to actually set the correct margins in the
|
||
// reflow state at some point, so that they can be saved on the frame for
|
||
// UsedMarginProperty(). Maybe doesn't matter though...?
|
||
|
||
// If we're overriding the computed width or height, *and* we had an
|
||
// earlier "measuring" reflow, then this upcoming reflow needs to be
|
||
// treated as a resize.
|
||
if (aItem.HadMeasuringReflow()) {
|
||
if (didOverrideComputedWidth) {
|
||
// (This is somewhat redundant, since the reflow state already
|
||
// sets mHResize whenever our computed width has changed since the
|
||
// previous reflow. Still, it's nice for symmetry, and it may become
|
||
// necessary once we support orthogonal flows.)
|
||
childReflowInput.SetHResize(true);
|
||
}
|
||
if (didOverrideComputedHeight) {
|
||
childReflowInput.SetVResize(true);
|
||
}
|
||
}
|
||
// NOTE: Be very careful about doing anything else with childReflowInput
|
||
// after this point, because some of its methods (e.g. SetComputedWidth)
|
||
// internally call InitResizeFlags and stomp on mVResize & mHResize.
|
||
|
||
ReflowOutput childDesiredSize(childReflowInput);
|
||
nsReflowStatus childReflowStatus;
|
||
ReflowChild(aItem.Frame(), aPresContext,
|
||
childDesiredSize, childReflowInput,
|
||
outerWM, aFramePos, aContainerSize,
|
||
0, childReflowStatus);
|
||
|
||
// XXXdholbert Once we do pagination / splitting, we'll need to actually
|
||
// handle incomplete childReflowStatuses. But for now, we give our kids
|
||
// unconstrained available height, which means they should always
|
||
// complete.
|
||
MOZ_ASSERT(NS_FRAME_IS_COMPLETE(childReflowStatus),
|
||
"We gave flex item unconstrained available height, so it "
|
||
"should be complete");
|
||
|
||
LogicalMargin offsets =
|
||
childReflowInput.ComputedLogicalOffsets().ConvertTo(outerWM, wm);
|
||
ReflowInput::ApplyRelativePositioning(aItem.Frame(), outerWM,
|
||
offsets, &aFramePos,
|
||
aContainerSize);
|
||
|
||
FinishReflowChild(aItem.Frame(), aPresContext,
|
||
childDesiredSize, &childReflowInput,
|
||
outerWM, aFramePos, aContainerSize, 0);
|
||
|
||
aItem.SetAscent(childDesiredSize.BlockStartAscent());
|
||
}
|
||
|
||
void
|
||
nsFlexContainerFrame::ReflowPlaceholders(nsPresContext* aPresContext,
|
||
const ReflowInput& aReflowInput,
|
||
nsTArray<nsIFrame*>& aPlaceholders,
|
||
const LogicalPoint& aContentBoxOrigin,
|
||
const nsSize& aContainerSize)
|
||
{
|
||
WritingMode outerWM = aReflowInput.GetWritingMode();
|
||
|
||
// As noted in this method's documentation, we'll reflow every entry in
|
||
// |aPlaceholders| at the container's content-box origin.
|
||
for (nsIFrame* placeholder : aPlaceholders) {
|
||
MOZ_ASSERT(placeholder->GetType() == nsGkAtoms::placeholderFrame,
|
||
"placeholders array should only contain placeholder frames");
|
||
WritingMode wm = placeholder->GetWritingMode();
|
||
LogicalSize availSize = aReflowInput.ComputedSize(wm);
|
||
ReflowInput childReflowInput(aPresContext, aReflowInput,
|
||
placeholder, availSize);
|
||
ReflowOutput childDesiredSize(childReflowInput);
|
||
nsReflowStatus childReflowStatus;
|
||
ReflowChild(placeholder, aPresContext,
|
||
childDesiredSize, childReflowInput,
|
||
outerWM, aContentBoxOrigin, aContainerSize, 0,
|
||
childReflowStatus);
|
||
|
||
FinishReflowChild(placeholder, aPresContext,
|
||
childDesiredSize, &childReflowInput,
|
||
outerWM, aContentBoxOrigin, aContainerSize, 0);
|
||
|
||
// Mark the placeholder frame to indicate that it's not actually at the
|
||
// element's static position, because we need to apply CSS Alignment after
|
||
// we determine the OOF's size:
|
||
placeholder->AddStateBits(PLACEHOLDER_STATICPOS_NEEDS_CSSALIGN);
|
||
}
|
||
}
|
||
|
||
/* virtual */ nscoord
|
||
nsFlexContainerFrame::GetMinISize(nsRenderingContext* aRenderingContext)
|
||
{
|
||
nscoord minISize = 0;
|
||
DISPLAY_MIN_WIDTH(this, minISize);
|
||
|
||
RenumberList();
|
||
|
||
const nsStylePosition* stylePos = StylePosition();
|
||
const FlexboxAxisTracker axisTracker(this, GetWritingMode());
|
||
|
||
for (nsIFrame* childFrame : mFrames) {
|
||
nscoord childMinISize =
|
||
nsLayoutUtils::IntrinsicForContainer(aRenderingContext, childFrame,
|
||
nsLayoutUtils::MIN_ISIZE);
|
||
// For a horizontal single-line flex container, the intrinsic min
|
||
// isize is the sum of its items' min isizes.
|
||
// For a column-oriented flex container, or for a multi-line row-
|
||
// oriented flex container, the intrinsic min isize is the max of
|
||
// its items' min isizes.
|
||
if (axisTracker.IsRowOriented() &&
|
||
NS_STYLE_FLEX_WRAP_NOWRAP == stylePos->mFlexWrap) {
|
||
minISize += childMinISize;
|
||
} else {
|
||
minISize = std::max(minISize, childMinISize);
|
||
}
|
||
}
|
||
return minISize;
|
||
}
|
||
|
||
/* virtual */ nscoord
|
||
nsFlexContainerFrame::GetPrefISize(nsRenderingContext* aRenderingContext)
|
||
{
|
||
nscoord prefISize = 0;
|
||
DISPLAY_PREF_WIDTH(this, prefISize);
|
||
|
||
RenumberList();
|
||
|
||
// XXXdholbert Optimization: We could cache our intrinsic widths like
|
||
// nsBlockFrame does (and return it early from this function if it's set).
|
||
// Whenever anything happens that might change it, set it to
|
||
// NS_INTRINSIC_WIDTH_UNKNOWN (like nsBlockFrame::MarkIntrinsicISizesDirty
|
||
// does)
|
||
const FlexboxAxisTracker axisTracker(this, GetWritingMode());
|
||
|
||
for (nsIFrame* childFrame : mFrames) {
|
||
nscoord childPrefISize =
|
||
nsLayoutUtils::IntrinsicForContainer(aRenderingContext, childFrame,
|
||
nsLayoutUtils::PREF_ISIZE);
|
||
if (axisTracker.IsRowOriented()) {
|
||
prefISize += childPrefISize;
|
||
} else {
|
||
prefISize = std::max(prefISize, childPrefISize);
|
||
}
|
||
}
|
||
return prefISize;
|
||
}
|