/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim:expandtab:shiftwidth=2:tabstop=2: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "nsTextEquivUtils.h" #include "Accessible-inl.h" #include "AccIterator.h" #include "nsCoreUtils.h" #include "nsStyleConsts.h" #include "nsIDOMXULLabeledControlEl.h" using namespace mozilla::a11y; using namespace mozilla; /** * The accessible for which we are computing a text equivalent. It is useful * for bailing out during recursive text computation, or for special cases * like step f. of the ARIA implementation guide. */ static Accessible* sInitiatorAcc = nullptr; //////////////////////////////////////////////////////////////////////////////// // nsTextEquivUtils. Public. nsresult nsTextEquivUtils::GetNameFromSubtree(Accessible* aAccessible, nsAString& aName) { aName.Truncate(); if (sInitiatorAcc) return NS_OK; sInitiatorAcc = aAccessible; if (GetRoleRule(aAccessible->Role()) == eNameFromSubtreeRule) { //XXX: is it necessary to care the accessible is not a document? if (aAccessible->IsContent()) { nsAutoString name; AppendFromAccessibleChildren(aAccessible, &name); name.CompressWhitespace(); if (!nsCoreUtils::IsWhitespaceString(name)) aName = name; } } sInitiatorAcc = nullptr; return NS_OK; } nsresult nsTextEquivUtils::GetTextEquivFromIDRefs(Accessible* aAccessible, nsIAtom *aIDRefsAttr, nsAString& aTextEquiv) { aTextEquiv.Truncate(); nsIContent* content = aAccessible->GetContent(); if (!content) return NS_OK; nsIContent* refContent = nullptr; IDRefsIterator iter(aAccessible->Document(), content, aIDRefsAttr); while ((refContent = iter.NextElem())) { if (!aTextEquiv.IsEmpty()) aTextEquiv += ' '; nsresult rv = AppendTextEquivFromContent(aAccessible, refContent, &aTextEquiv); NS_ENSURE_SUCCESS(rv, rv); } return NS_OK; } nsresult nsTextEquivUtils::AppendTextEquivFromContent(Accessible* aInitiatorAcc, nsIContent *aContent, nsAString *aString) { // Prevent recursion which can cause infinite loops. if (sInitiatorAcc) return NS_OK; sInitiatorAcc = aInitiatorAcc; // If the given content is not visible or isn't accessible then go down // through the DOM subtree otherwise go down through accessible subtree and // calculate the flat string. nsIFrame *frame = aContent->GetPrimaryFrame(); bool isVisible = frame && frame->StyleVisibility()->IsVisible(); nsresult rv = NS_ERROR_FAILURE; bool goThroughDOMSubtree = true; if (isVisible) { Accessible* accessible = sInitiatorAcc->Document()->GetAccessible(aContent); if (accessible) { rv = AppendFromAccessible(accessible, aString); goThroughDOMSubtree = false; } } if (goThroughDOMSubtree) rv = AppendFromDOMNode(aContent, aString); sInitiatorAcc = nullptr; return rv; } nsresult nsTextEquivUtils::AppendTextEquivFromTextContent(nsIContent *aContent, nsAString *aString) { if (aContent->IsNodeOfType(nsINode::eTEXT)) { bool isHTMLBlock = false; nsIContent *parentContent = aContent->GetFlattenedTreeParent(); if (parentContent) { nsIFrame *frame = parentContent->GetPrimaryFrame(); if (frame) { // If this text is inside a block level frame (as opposed to span // level), we need to add spaces around that block's text, so we don't // get words jammed together in final name. const nsStyleDisplay* display = frame->StyleDisplay(); if (display->IsBlockOutsideStyle() || display->mDisplay == StyleDisplay::TableCell) { isHTMLBlock = true; if (!aString->IsEmpty()) { aString->Append(char16_t(' ')); } } } } if (aContent->TextLength() > 0) { nsIFrame *frame = aContent->GetPrimaryFrame(); if (frame) { nsIFrame::RenderedText text = frame->GetRenderedText(0, UINT32_MAX, nsIFrame::TextOffsetType::OFFSETS_IN_CONTENT_TEXT, nsIFrame::TrailingWhitespace::DONT_TRIM_TRAILING_WHITESPACE); aString->Append(text.mString); } else { // If aContent is an object that is display: none, we have no a frame. aContent->AppendTextTo(*aString); } if (isHTMLBlock && !aString->IsEmpty()) { aString->Append(char16_t(' ')); } } return NS_OK; } if (aContent->IsHTMLElement() && aContent->NodeInfo()->Equals(nsGkAtoms::br)) { aString->AppendLiteral("\r\n"); return NS_OK; } return NS_OK_NO_NAME_CLAUSE_HANDLED; } //////////////////////////////////////////////////////////////////////////////// // nsTextEquivUtils. Private. nsresult nsTextEquivUtils::AppendFromAccessibleChildren(Accessible* aAccessible, nsAString *aString) { nsresult rv = NS_OK_NO_NAME_CLAUSE_HANDLED; uint32_t childCount = aAccessible->ChildCount(); for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) { Accessible* child = aAccessible->GetChildAt(childIdx); rv = AppendFromAccessible(child, aString); NS_ENSURE_SUCCESS(rv, rv); } return rv; } nsresult nsTextEquivUtils::AppendFromAccessible(Accessible* aAccessible, nsAString *aString) { //XXX: is it necessary to care the accessible is not a document? if (aAccessible->IsContent()) { nsresult rv = AppendTextEquivFromTextContent(aAccessible->GetContent(), aString); if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED) return rv; } bool isEmptyTextEquiv = true; // If the name is from tooltip then append it to result string in the end // (see h. step of name computation guide). nsAutoString text; if (aAccessible->Name(text) != eNameFromTooltip) isEmptyTextEquiv = !AppendString(aString, text); // Implementation of f. step. nsresult rv = AppendFromValue(aAccessible, aString); NS_ENSURE_SUCCESS(rv, rv); if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED) isEmptyTextEquiv = false; // Implementation of g) step of text equivalent computation guide. Go down // into subtree if accessible allows "text equivalent from subtree rule" or // it's not root and not control. if (isEmptyTextEquiv) { uint32_t nameRule = GetRoleRule(aAccessible->Role()); if (nameRule & eNameFromSubtreeIfReqRule) { rv = AppendFromAccessibleChildren(aAccessible, aString); NS_ENSURE_SUCCESS(rv, rv); if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED) isEmptyTextEquiv = false; } } // Implementation of h. step if (isEmptyTextEquiv && !text.IsEmpty()) { AppendString(aString, text); return NS_OK; } return rv; } nsresult nsTextEquivUtils::AppendFromValue(Accessible* aAccessible, nsAString *aString) { if (GetRoleRule(aAccessible->Role()) != eNameFromValueRule) return NS_OK_NO_NAME_CLAUSE_HANDLED; // Implementation of step f. of text equivalent computation. If the given // accessible is not root accessible (the accessible the text equivalent is // computed for in the end) then append accessible value. Otherwise append // value if and only if the given accessible is in the middle of its parent. nsAutoString text; if (aAccessible != sInitiatorAcc) { aAccessible->Value(text); return AppendString(aString, text) ? NS_OK : NS_OK_NO_NAME_CLAUSE_HANDLED; } //XXX: is it necessary to care the accessible is not a document? if (aAccessible->IsDoc()) return NS_ERROR_UNEXPECTED; nsIContent *content = aAccessible->GetContent(); for (nsIContent* childContent = content->GetPreviousSibling(); childContent; childContent = childContent->GetPreviousSibling()) { // check for preceding text... if (!childContent->TextIsOnlyWhitespace()) { for (nsIContent* siblingContent = content->GetNextSibling(); siblingContent; siblingContent = siblingContent->GetNextSibling()) { // .. and subsequent text if (!siblingContent->TextIsOnlyWhitespace()) { aAccessible->Value(text); return AppendString(aString, text) ? NS_OK : NS_OK_NO_NAME_CLAUSE_HANDLED; break; } } break; } } return NS_OK_NO_NAME_CLAUSE_HANDLED; } nsresult nsTextEquivUtils::AppendFromDOMChildren(nsIContent *aContent, nsAString *aString) { for (nsIContent* childContent = aContent->GetFirstChild(); childContent; childContent = childContent->GetNextSibling()) { nsresult rv = AppendFromDOMNode(childContent, aString); NS_ENSURE_SUCCESS(rv, rv); } return NS_OK; } nsresult nsTextEquivUtils::AppendFromDOMNode(nsIContent *aContent, nsAString *aString) { nsresult rv = AppendTextEquivFromTextContent(aContent, aString); NS_ENSURE_SUCCESS(rv, rv); if (rv != NS_OK_NO_NAME_CLAUSE_HANDLED) return NS_OK; if (aContent->IsXULElement()) { nsAutoString textEquivalent; nsCOMPtr labeledEl = do_QueryInterface(aContent); if (labeledEl) { labeledEl->GetLabel(textEquivalent); } else { if (aContent->NodeInfo()->Equals(nsGkAtoms::label, kNameSpaceID_XUL)) aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::value, textEquivalent); if (textEquivalent.IsEmpty()) aContent->GetAttr(kNameSpaceID_None, nsGkAtoms::tooltiptext, textEquivalent); } AppendString(aString, textEquivalent); } return AppendFromDOMChildren(aContent, aString); } bool nsTextEquivUtils::AppendString(nsAString *aString, const nsAString& aTextEquivalent) { if (aTextEquivalent.IsEmpty()) return false; // Insert spaces to insure that words from controls aren't jammed together. if (!aString->IsEmpty() && !nsCoreUtils::IsWhitespace(aString->Last())) aString->Append(char16_t(' ')); aString->Append(aTextEquivalent); if (!nsCoreUtils::IsWhitespace(aString->Last())) aString->Append(char16_t(' ')); return true; } uint32_t nsTextEquivUtils::GetRoleRule(role aRole) { #define ROLE(geckoRole, stringRole, atkRole, \ macRole, msaaRole, ia2Role, nameRule) \ case roles::geckoRole: \ return nameRule; switch (aRole) { #include "RoleMap.h" default: MOZ_CRASH("Unknown role."); } #undef ROLE }