gecko/gfx/layers/basic/BasicContainerLayer.cpp

/* -*- 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 "BasicContainerLayer.h"
#include <sys/types.h>                  // for int32_t
#include "BasicLayersImpl.h"            // for ToData
#include "basic/BasicImplData.h"        // for BasicImplData
#include "basic/BasicLayers.h"          // for BasicLayerManager
#include "mozilla/gfx/BaseRect.h"       // for BaseRect
#include "mozilla/mozalloc.h"           // for operator new
#include "nsAutoPtr.h"                  // for nsRefPtr
#include "nsCOMPtr.h"                   // for already_AddRefed
#include "nsISupportsImpl.h"            // for Layer::AddRef, etc
#include "nsPoint.h"                    // for nsIntPoint
#include "nsRect.h"                     // for nsIntRect

using namespace mozilla::gfx;

namespace mozilla {
namespace layers {

BasicContainerLayer::~BasicContainerLayer()
{
  while (mFirstChild) {
    ContainerRemoveChild(mFirstChild, this);
  }

  MOZ_COUNT_DTOR(BasicContainerLayer);
}

bool
BasicContainerLayer::ChildrenPartitionVisibleRegion(const nsIntRect& aInRect)
{
  gfxMatrix transform;
  if (!GetEffectiveTransform().CanDraw2D(&transform) ||
      transform.HasNonIntegerTranslation())
    return false;

  nsIntPoint offset(int32_t(transform.x0), int32_t(transform.y0));
  nsIntRect rect = aInRect.Intersect(GetEffectiveVisibleRegion().GetBounds() + offset);
  nsIntRegion covered;

  for (Layer* l = mFirstChild; l; l = l->GetNextSibling()) {
    if (ToData(l)->IsHidden())
      continue;

    gfxMatrix childTransform;
    if (!l->GetEffectiveTransform().CanDraw2D(&childTransform) ||
        childTransform.HasNonIntegerTranslation() ||
        l->GetEffectiveOpacity() != 1.0)
      return false;
    nsIntRegion childRegion = l->GetEffectiveVisibleRegion();
    childRegion.MoveBy(int32_t(childTransform.x0), int32_t(childTransform.y0));
    childRegion.And(childRegion, rect);
    if (l->GetClipRect()) {
      childRegion.And(childRegion, *l->GetClipRect() + offset);
    }
    nsIntRegion intersection;
    intersection.And(covered, childRegion);
    if (!intersection.IsEmpty())
      return false;
    covered.Or(covered, childRegion);
  }

  return covered.Contains(rect);
}

already_AddRefed<ContainerLayer>
BasicLayerManager::CreateContainerLayer()
{
  NS_ASSERTION(InConstruction(), "Only allowed in construction phase");
  nsRefPtr<ContainerLayer> layer = new BasicContainerLayer(this);
  return layer.forget();
}

}
}