/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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 "InterfaceInitFuncs.h"

#include "AccessibleWrap.h"
#include "nsAccUtils.h"
#include "nsCoreUtils.h"
#include "nsMai.h"
#include "mozilla/Likely.h"
#include "mozilla/a11y/ProxyAccessible.h"

using namespace mozilla::a11y;

extern "C" {

static AtkObject*
refAccessibleAtPointCB(AtkComponent* aComponent, gint aAccX, gint aAccY,
                       AtkCoordType aCoordType)
{
  return refAccessibleAtPointHelper(ATK_OBJECT(aComponent),
                                    aAccX, aAccY, aCoordType);
}

static void
getExtentsCB(AtkComponent* aComponent, gint* aX, gint* aY,
             gint* aWidth, gint* aHeight, AtkCoordType aCoordType)
{
  getExtentsHelper(ATK_OBJECT(aComponent),
                   aX, aY, aWidth, aHeight, aCoordType);
}

static gboolean
grabFocusCB(AtkComponent* aComponent)
{
  AtkObject* atkObject = ATK_OBJECT(aComponent);
  AccessibleWrap* accWrap = GetAccessibleWrap(atkObject);
  if (accWrap) {
    accWrap->TakeFocus();
    return TRUE;
  }

  ProxyAccessible* proxy = GetProxy(atkObject);
  if (proxy) {
    proxy->TakeFocus();
    return TRUE;
  }

  return FALSE;
}
}

AtkObject*
refAccessibleAtPointHelper(AtkObject* aAtkObj, gint aX, gint aY,
                           AtkCoordType aCoordType)
{
  AccessibleWrap* accWrap = GetAccessibleWrap(aAtkObj);
  if (accWrap) {
    if (accWrap->IsDefunct() || nsAccUtils::MustPrune(accWrap)) {
      return nullptr;
    }

    // Accessible::ChildAtPoint(x,y) is in screen pixels.
    if (aCoordType == ATK_XY_WINDOW) {
      nsIntPoint winCoords =
        nsCoreUtils::GetScreenCoordsForWindow(accWrap->GetNode());
      aX += winCoords.x;
      aY += winCoords.y;
    }

    Accessible* accAtPoint = accWrap->ChildAtPoint(aX, aY,
                                                   Accessible::eDirectChild);
    if (!accAtPoint) {
      return nullptr;
    }

    AtkObject* atkObj = AccessibleWrap::GetAtkObject(accAtPoint);
    if (atkObj) {
      g_object_ref(atkObj);
    }

    return atkObj;
  }

  if (ProxyAccessible* proxy = GetProxy(aAtkObj)) {
    ProxyAccessible* result =
      proxy->AccessibleAtPoint(aX, aY, aCoordType == ATK_XY_WINDOW);
    AtkObject* atkObj = result ? GetWrapperFor(result) : nullptr;
    if (atkObj) {
      g_object_ref(atkObj);
    }
    return atkObj;
  }

  return nullptr;
}

void
getExtentsHelper(AtkObject* aAtkObj,
                 gint* aX, gint* aY, gint* aWidth, gint* aHeight,
                 AtkCoordType aCoordType)
{
  AccessibleWrap* accWrap = GetAccessibleWrap(aAtkObj);
  *aX = *aY = *aWidth = *aHeight = 0;

  if (accWrap) {
    if (accWrap->IsDefunct()) {
      return;
    }

    nsIntRect screenRect = accWrap->Bounds();
    if (screenRect.IsEmpty())
      return;

    if (aCoordType == ATK_XY_WINDOW) {
      nsIntPoint winCoords =
        nsCoreUtils::GetScreenCoordsForWindow(accWrap->GetNode());
      screenRect.x -= winCoords.x;
      screenRect.y -= winCoords.y;
    }

    *aX = screenRect.x;
    *aY = screenRect.y;
    *aWidth = screenRect.width;
    *aHeight = screenRect.height;
    return;
  }

  if (ProxyAccessible* proxy = GetProxy(aAtkObj)) {
    proxy->Extents(aCoordType == ATK_XY_WINDOW, aX, aY, aWidth, aHeight);
  }
}

void
componentInterfaceInitCB(AtkComponentIface* aIface)
{
  NS_ASSERTION(aIface, "Invalid Interface");
  if(MOZ_UNLIKELY(!aIface))
    return;

  /*
   * Use default implementation in atk for contains, get_position,
   * and get_size
   */
  aIface->ref_accessible_at_point = refAccessibleAtPointCB;
  aIface->get_extents = getExtentsCB;
  aIface->grab_focus = grabFocusCB;
}