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/*
* Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
*
* Portions are Copyright (C) 1998 Netscape Communications Corporation.
*
* Other contributors:
* Robert O'Callahan <roc+@cs.cmu.edu>
* David Baron <dbaron@fas.harvard.edu>
* Christian Biesinger <cbiesinger@web.de>
* Randall Jesup <rjesup@wgate.com>
* Roland Mainz <roland.mainz@informatik.med.uni-giessen.de>
* Josh Soref <timeless@mac.com>
* Boris Zbarsky <bzbarsky@mit.edu>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Alternatively, the contents of this file may be used under the terms
* of either the Mozilla Public License Version 1.1, found at
* http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
* License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
* (the "GPL"), in which case the provisions of the MPL or the GPL are
* applicable instead of those above. If you wish to allow use of your
* version of this file only under the terms of one of those two
* licenses (the MPL or the GPL) and not to allow others to use your
* version of this file under the LGPL, indicate your decision by
* deletingthe provisions above and replace them with the notice and
* other provisions required by the MPL or the GPL, as the case may be.
* If you do not delete the provisions above, a recipient may use your
* version of this file under any of the LGPL, the MPL or the GPL.
*/
#include "config.h"
#include "core/rendering/RenderLayerStackingNode.h"
#include "core/rendering/RenderLayer.h"
#include "core/rendering/RenderLayerCompositor.h"
#include "core/rendering/RenderView.h"
#include "public/platform/Platform.h"
namespace WebCore {
// FIXME: This should not require RenderLayer. There is currently a cycle where
// in order to determine if we shoulBeNormalFlowOnly() and isStackingContainer()
// we have to ask the render layer about some of its state.
RenderLayerStackingNode::RenderLayerStackingNode(RenderLayer* layer)
: m_layer(layer)
, m_descendantsAreContiguousInStackingOrder(false)
, m_descendantsAreContiguousInStackingOrderDirty(true)
, m_normalFlowListDirty(true)
, m_needsToBeStackingContainer(false)
, m_needsToBeStackingContainerHasBeenRecorded(false)
#if !ASSERT_DISABLED
, m_layerListMutationAllowed(true)
, m_stackingParent(0)
#endif
{
m_isNormalFlowOnly = shouldBeNormalFlowOnly();
// Non-stacking containers should have empty z-order lists. As this is already the case,
// there is no need to dirty / recompute these lists.
m_zOrderListsDirty = isStackingContainer();
}
RenderLayerStackingNode::~RenderLayerStackingNode()
{
#if !ASSERT_DISABLED
if (!renderer()->documentBeingDestroyed()) {
ASSERT(!isInStackingParentZOrderLists());
ASSERT(!isInStackingParentNormalFlowList());
updateStackingParentForZOrderLists(0);
updateStackingParentForNormalFlowList(0);
}
#endif
}
bool RenderLayerStackingNode::isStackingContext(const RenderStyle* style) const
{
return !style->hasAutoZIndex() || layer()->isRootLayer();
}
// Helper for the sorting of layers by z-index.
static inline bool compareZIndex(RenderLayerStackingNode* first, RenderLayerStackingNode* second)
{
return first->zIndex() < second->zIndex();
}
RenderLayerCompositor* RenderLayerStackingNode::compositor() const
{
if (!renderer()->view())
return 0;
return renderer()->view()->compositor();
}
void RenderLayerStackingNode::dirtyNormalFlowListCanBePromotedToStackingContainer()
{
m_descendantsAreContiguousInStackingOrderDirty = true;
if (m_normalFlowListDirty || !normalFlowList())
return;
for (size_t index = 0; index < normalFlowList()->size(); ++index)
normalFlowList()->at(index)->dirtyNormalFlowListCanBePromotedToStackingContainer();
}
void RenderLayerStackingNode::dirtySiblingStackingNodeCanBePromotedToStackingContainer()
{
RenderLayerStackingNode* stackingNode = ancestorStackingNode();
if (!stackingNode)
return;
if (!stackingNode->zOrderListsDirty() && stackingNode->posZOrderList()) {
for (size_t index = 0; index < stackingNode->posZOrderList()->size(); ++index)
stackingNode->posZOrderList()->at(index)->setDescendantsAreContiguousInStackingOrderDirty(true);
}
stackingNode->dirtyNormalFlowListCanBePromotedToStackingContainer();
if (!stackingNode->zOrderListsDirty() && stackingNode->negZOrderList()) {
for (size_t index = 0; index < stackingNode->negZOrderList()->size(); ++index)
stackingNode->negZOrderList()->at(index)->setDescendantsAreContiguousInStackingOrderDirty(true);
}
}
void RenderLayerStackingNode::dirtyZOrderLists()
{
ASSERT(m_layerListMutationAllowed);
ASSERT(isStackingContainer());
#if !ASSERT_DISABLED
updateStackingParentForZOrderLists(0);
#endif
if (m_posZOrderList)
m_posZOrderList->clear();
if (m_negZOrderList)
m_negZOrderList->clear();
m_zOrderListsDirty = true;
m_descendantsAreContiguousInStackingOrderDirty = true;
if (!renderer()->documentBeingDestroyed()) {
compositor()->setNeedsUpdateCompositingRequirementsState();
compositor()->setCompositingLayersNeedRebuild();
if (layer()->acceleratedCompositingForOverflowScrollEnabled())
compositor()->setShouldReevaluateCompositingAfterLayout();
}
}
void RenderLayerStackingNode::dirtyStackingContainerZOrderLists()
{
// Any siblings in the ancestor stacking context could also be affected.
// Changing z-index, for example, could cause us to stack in between a
// sibling's descendants, meaning that we have to recompute
// m_descendantsAreContiguousInStackingOrder for that sibling.
dirtySiblingStackingNodeCanBePromotedToStackingContainer();
RenderLayerStackingNode* stackingContainerNode = ancestorStackingContainerNode();
if (stackingContainerNode)
stackingContainerNode->dirtyZOrderLists();
// Any change that could affect our stacking container's z-order list could
// cause other RenderLayers in our stacking context to either opt in or out
// of composited scrolling. It is important that we make our stacking
// context aware of these z-order changes so the appropriate updating can
// happen.
RenderLayerStackingNode* stackingNode = ancestorStackingNode();
if (stackingNode && stackingNode != stackingContainerNode)
stackingNode->dirtyZOrderLists();
}
void RenderLayerStackingNode::dirtyNormalFlowList()
{
ASSERT(m_layerListMutationAllowed);
#if !ASSERT_DISABLED
updateStackingParentForNormalFlowList(0);
#endif
if (m_normalFlowList)
m_normalFlowList->clear();
m_normalFlowListDirty = true;
if (!renderer()->documentBeingDestroyed()) {
compositor()->setCompositingLayersNeedRebuild();
if (layer()->acceleratedCompositingForOverflowScrollEnabled())
compositor()->setShouldReevaluateCompositingAfterLayout();
}
}
void RenderLayerStackingNode::rebuildZOrderLists()
{
ASSERT(m_layerListMutationAllowed);
ASSERT(isDirtyStackingContainer());
rebuildZOrderLists(m_posZOrderList, m_negZOrderList);
#if !ASSERT_DISABLED
updateStackingParentForZOrderLists(this);
#endif
m_zOrderListsDirty = false;
}
void RenderLayerStackingNode::rebuildZOrderLists(OwnPtr<Vector<RenderLayerStackingNode*> >& posZOrderList,
OwnPtr<Vector<RenderLayerStackingNode*> >& negZOrderList, const RenderLayerStackingNode* nodeToForceAsStackingContainer,
CollectLayersBehavior collectLayersBehavior)
{
bool includeHiddenLayers = compositor()->inCompositingMode();
for (RenderLayer* child = layer()->firstChild(); child; child = child->nextSibling()) {
if (!layer()->reflectionInfo() || layer()->reflectionInfo()->reflectionLayer() != child)
child->stackingNode()->collectLayers(includeHiddenLayers, posZOrderList, negZOrderList, nodeToForceAsStackingContainer, collectLayersBehavior);
}
// Sort the two lists.
if (posZOrderList)
std::stable_sort(posZOrderList->begin(), posZOrderList->end(), compareZIndex);
if (negZOrderList)
std::stable_sort(negZOrderList->begin(), negZOrderList->end(), compareZIndex);
// Append layers for top layer elements after normal layer collection, to ensure they are on top regardless of z-indexes.
// The renderers of top layer elements are children of the view, sorted in top layer stacking order.
if (layer()->isRootLayer()) {
RenderObject* view = renderer()->view();
for (RenderObject* child = view->firstChild(); child; child = child->nextSibling()) {
Element* childElement = (child->node() && child->node()->isElementNode()) ? toElement(child->node()) : 0;
if (childElement && childElement->isInTopLayer()) {
RenderLayer* layer = toRenderLayerModelObject(child)->layer();
// Create the buffer if it doesn't exist yet.
if (!posZOrderList)
posZOrderList = adoptPtr(new Vector<RenderLayerStackingNode*>);
posZOrderList->append(layer->stackingNode());
}
}
}
}
void RenderLayerStackingNode::updateNormalFlowList()
{
if (!m_normalFlowListDirty)
return;
ASSERT(m_layerListMutationAllowed);
for (RenderLayer* child = layer()->firstChild(); child; child = child->nextSibling()) {
// Ignore non-overflow layers and reflections.
if (child->stackingNode()->isNormalFlowOnly() && (!layer()->reflectionInfo() || layer()->reflectionInfo()->reflectionLayer() != child)) {
if (!m_normalFlowList)
m_normalFlowList = adoptPtr(new Vector<RenderLayerStackingNode*>);
m_normalFlowList->append(child->stackingNode());
}
}
#if !ASSERT_DISABLED
updateStackingParentForNormalFlowList(this);
#endif
m_normalFlowListDirty = false;
}
void RenderLayerStackingNode::collectLayers(bool includeHiddenLayers,
OwnPtr<Vector<RenderLayerStackingNode*> >& posBuffer, OwnPtr<Vector<RenderLayerStackingNode*> >& negBuffer,
const RenderLayerStackingNode* nodeToForceAsStackingContainer, CollectLayersBehavior collectLayersBehavior)
{
if (layer()->isInTopLayer())
return;
layer()->updateDescendantDependentFlags();
bool isStacking = false;
bool isNormalFlow = false;
switch (collectLayersBehavior) {
case ForceLayerToStackingContainer:
ASSERT(nodeToForceAsStackingContainer);
if (this == nodeToForceAsStackingContainer) {
isStacking = true;
isNormalFlow = false;
} else {
isStacking = isStackingContext();
isNormalFlow = shouldBeNormalFlowOnlyIgnoringCompositedScrolling();
}
break;
case OverflowScrollCanBeStackingContainers:
ASSERT(!nodeToForceAsStackingContainer);
isStacking = isStackingContainer();
isNormalFlow = isNormalFlowOnly();
break;
case OnlyStackingContextsCanBeStackingContainers:
isStacking = isStackingContext();
isNormalFlow = shouldBeNormalFlowOnlyIgnoringCompositedScrolling();
break;
}
// Overflow layers are just painted by their enclosing layers, so they don't get put in zorder lists.
bool includeHiddenLayer = includeHiddenLayers || (layer()->hasVisibleContent() || (layer()->hasVisibleDescendant() && isStacking));
if (includeHiddenLayer && !isNormalFlow && !layer()->isOutOfFlowRenderFlowThread()) {
// Determine which buffer the child should be in.
OwnPtr<Vector<RenderLayerStackingNode*> >& buffer = (zIndex() >= 0) ? posBuffer : negBuffer;
// Create the buffer if it doesn't exist yet.
if (!buffer)
buffer = adoptPtr(new Vector<RenderLayerStackingNode*>);
// Append ourselves at the end of the appropriate buffer.
buffer->append(this);
}
// Recur into our children to collect more layers, but only if we don't establish
// a stacking context/container.
if ((includeHiddenLayers || layer()->hasVisibleDescendant()) && !isStacking) {
for (RenderLayer* child = layer()->firstChild(); child; child = child->nextSibling()) {
// Ignore reflections.
if (!layer()->reflectionInfo() || layer()->reflectionInfo()->reflectionLayer() != child)
child->stackingNode()->collectLayers(includeHiddenLayers, posBuffer, negBuffer, nodeToForceAsStackingContainer, collectLayersBehavior);
}
}
}
#if !ASSERT_DISABLED
bool RenderLayerStackingNode::isInStackingParentZOrderLists() const
{
if (!m_stackingParent || m_stackingParent->zOrderListsDirty())
return false;
if (m_stackingParent->posZOrderList() && m_stackingParent->posZOrderList()->find(this) != kNotFound)
return true;
if (m_stackingParent->negZOrderList() && m_stackingParent->negZOrderList()->find(this) != kNotFound)
return true;
return false;
}
bool RenderLayerStackingNode::isInStackingParentNormalFlowList() const
{
if (!m_stackingParent || m_stackingParent->normalFlowListDirty())
return false;
return (m_stackingParent->normalFlowList() && m_stackingParent->normalFlowList()->find(this) != kNotFound);
}
void RenderLayerStackingNode::updateStackingParentForZOrderLists(RenderLayerStackingNode* stackingParent)
{
if (m_posZOrderList) {
for (size_t i = 0; i < m_posZOrderList->size(); ++i)
m_posZOrderList->at(i)->setStackingParent(stackingParent);
}
if (m_negZOrderList) {
for (size_t i = 0; i < m_negZOrderList->size(); ++i)
m_negZOrderList->at(i)->setStackingParent(stackingParent);
}
}
void RenderLayerStackingNode::updateStackingParentForNormalFlowList(RenderLayerStackingNode* stackingParent)
{
if (m_normalFlowList) {
for (size_t i = 0; i < m_normalFlowList->size(); ++i)
m_normalFlowList->at(i)->setStackingParent(stackingParent);
}
}
#endif
void RenderLayerStackingNode::updateLayerListsIfNeeded()
{
updateZOrderLists();
updateNormalFlowList();
if (!layer()->reflectionInfo())
return;
RenderLayer* reflectionLayer = layer()->reflectionInfo()->reflectionLayer();
reflectionLayer->stackingNode()->updateZOrderLists();
reflectionLayer->stackingNode()->updateNormalFlowList();
}
void RenderLayerStackingNode::updateStackingNodesAfterStyleChange(const RenderStyle* oldStyle)
{
bool wasStackingContext = oldStyle ? isStackingContext(oldStyle) : false;
EVisibility oldVisibility = oldStyle ? oldStyle->visibility() : VISIBLE;
int oldZIndex = oldStyle ? oldStyle->zIndex() : 0;
// FIXME: RenderLayer already handles visibility changes through our visiblity dirty bits. This logic could
// likely be folded along with the rest.
bool isStackingContext = this->isStackingContext();
if (isStackingContext == wasStackingContext && oldVisibility == renderer()->style()->visibility() && oldZIndex == zIndex())
return;
dirtyStackingContainerZOrderLists();
if (isStackingContainer())
dirtyZOrderLists();
else
clearZOrderLists();
compositor()->setNeedsUpdateCompositingRequirementsState();
}
bool RenderLayerStackingNode::shouldBeNormalFlowOnly() const
{
return shouldBeNormalFlowOnlyIgnoringCompositedScrolling() && !layer()->needsCompositedScrolling();
}
bool RenderLayerStackingNode::shouldBeNormalFlowOnlyIgnoringCompositedScrolling() const
{
const bool couldBeNormalFlow = renderer()->hasOverflowClip()
|| renderer()->hasReflection()
|| renderer()->hasMask()
|| renderer()->isCanvas()
|| renderer()->isVideo()
|| renderer()->isEmbeddedObject()
|| renderer()->isRenderIFrame()
|| (renderer()->style()->specifiesColumns() && !layer()->isRootLayer());
const bool preventsElementFromBeingNormalFlow = renderer()->isPositioned()
|| renderer()->hasTransform()
|| renderer()->hasClipPath()
|| renderer()->hasFilter()
|| renderer()->hasBlendMode()
|| layer()->isTransparent()
|| renderer()->isRenderRegion();
return couldBeNormalFlow && !preventsElementFromBeingNormalFlow;
}
void RenderLayerStackingNode::updateIsNormalFlowOnly()
{
bool isNormalFlowOnly = shouldBeNormalFlowOnly();
if (isNormalFlowOnly == m_isNormalFlowOnly)
return;
m_isNormalFlowOnly = isNormalFlowOnly;
if (RenderLayer* p = layer()->parent())
p->stackingNode()->dirtyNormalFlowList();
dirtyStackingContainerZOrderLists();
}
bool RenderLayerStackingNode::needsToBeStackingContainer() const
{
return layer()->adjustForForceCompositedScrollingMode(m_needsToBeStackingContainer);
}
// Determine whether the current layer can be promoted to a stacking container.
// We do this by computing what positive and negative z-order lists would look
// like before and after promotion, and ensuring that proper stacking order is
// preserved between the two sets of lists.
void RenderLayerStackingNode::updateDescendantsAreContiguousInStackingOrder()
{
TRACE_EVENT0("blink_rendering,comp-scroll", "RenderLayerStackingNode::updateDescendantsAreContiguousInStackingOrder");
const RenderLayer* currentLayer = layer();
if (isStackingContext() || !m_descendantsAreContiguousInStackingOrderDirty || !currentLayer->acceleratedCompositingForOverflowScrollEnabled())
return;
if (!currentLayer->scrollsOverflow())
return;
RenderLayerStackingNode* stackingNode = ancestorStackingNode();
if (!stackingNode)
return;
OwnPtr<Vector<RenderLayerStackingNode*> > posZOrderListBeforePromote = adoptPtr(new Vector<RenderLayerStackingNode*>);
OwnPtr<Vector<RenderLayerStackingNode*> > negZOrderListBeforePromote = adoptPtr(new Vector<RenderLayerStackingNode*>);
OwnPtr<Vector<RenderLayerStackingNode*> > posZOrderListAfterPromote = adoptPtr(new Vector<RenderLayerStackingNode*>);
OwnPtr<Vector<RenderLayerStackingNode*> > negZOrderListAfterPromote = adoptPtr(new Vector<RenderLayerStackingNode*>);
collectBeforePromotionZOrderList(stackingNode, posZOrderListBeforePromote, negZOrderListBeforePromote);
collectAfterPromotionZOrderList(stackingNode, posZOrderListAfterPromote, negZOrderListAfterPromote);
size_t maxIndex = std::min(posZOrderListAfterPromote->size() + negZOrderListAfterPromote->size(), posZOrderListBeforePromote->size() + negZOrderListBeforePromote->size());
m_descendantsAreContiguousInStackingOrderDirty = false;
m_descendantsAreContiguousInStackingOrder = false;
const RenderLayerStackingNode* nodeAfterPromote = 0;
for (size_t i = 0; i < maxIndex && nodeAfterPromote != this; ++i) {
const RenderLayerStackingNode* nodeBeforePromote = i < negZOrderListBeforePromote->size()
? negZOrderListBeforePromote->at(i)
: posZOrderListBeforePromote->at(i - negZOrderListBeforePromote->size());
nodeAfterPromote = i < negZOrderListAfterPromote->size()
? negZOrderListAfterPromote->at(i)
: posZOrderListAfterPromote->at(i - negZOrderListAfterPromote->size());
if (nodeBeforePromote != nodeAfterPromote && (nodeAfterPromote != this || renderer()->hasBackground()))
return;
}
nodeAfterPromote = 0;
for (size_t i = 0; i < maxIndex && nodeAfterPromote != this; ++i) {
const RenderLayerStackingNode* nodeBeforePromote = i < posZOrderListBeforePromote->size()
? posZOrderListBeforePromote->at(posZOrderListBeforePromote->size() - i - 1)
: negZOrderListBeforePromote->at(negZOrderListBeforePromote->size() + posZOrderListBeforePromote->size() - i - 1);
nodeAfterPromote = i < posZOrderListAfterPromote->size()
? posZOrderListAfterPromote->at(posZOrderListAfterPromote->size() - i - 1)
: negZOrderListAfterPromote->at(negZOrderListAfterPromote->size() + posZOrderListAfterPromote->size() - i - 1);
if (nodeBeforePromote != nodeAfterPromote && nodeAfterPromote != this)
return;
}
m_descendantsAreContiguousInStackingOrder = true;
}
void RenderLayerStackingNode::collectBeforePromotionZOrderList(RenderLayerStackingNode* ancestorStackingNode,
OwnPtr<Vector<RenderLayerStackingNode*> >& posZOrderList, OwnPtr<Vector<RenderLayerStackingNode*> >& negZOrderList)
{
ancestorStackingNode->rebuildZOrderLists(posZOrderList, negZOrderList, this, OnlyStackingContextsCanBeStackingContainers);
const RenderLayer* currentLayer = layer();
const RenderLayer* positionedAncestor = currentLayer->parent();
while (positionedAncestor && !positionedAncestor->isPositionedContainer() && !positionedAncestor->stackingNode()->isStackingContext())
positionedAncestor = positionedAncestor->parent();
if (positionedAncestor && (!positionedAncestor->isPositionedContainer() || positionedAncestor->stackingNode()->isStackingContext()))
positionedAncestor = 0;
if (!posZOrderList)
posZOrderList = adoptPtr(new Vector<RenderLayerStackingNode*>());
else if (posZOrderList->find(this) != kNotFound)
return;
// The current node will appear in the z-order lists after promotion, so
// for a meaningful comparison, we must insert it in the z-order lists
// before promotion if it does not appear there already.
if (!positionedAncestor) {
posZOrderList->prepend(this);
return;
}
for (size_t index = 0; index < posZOrderList->size(); index++) {
if (posZOrderList->at(index)->layer() == positionedAncestor) {
posZOrderList->insert(index + 1, this);
return;
}
}
}
void RenderLayerStackingNode::collectAfterPromotionZOrderList(RenderLayerStackingNode* ancestorStackingNode,
OwnPtr<Vector<RenderLayerStackingNode*> >& posZOrderList, OwnPtr<Vector<RenderLayerStackingNode*> >& negZOrderList)
{
ancestorStackingNode->rebuildZOrderLists(posZOrderList, negZOrderList, this, ForceLayerToStackingContainer);
}
// Compute what positive and negative z-order lists would look like before and
// after promotion, so we can later ensure that proper stacking order is
// preserved between the two sets of lists.
//
// A few examples:
// c = currentLayer
// - = negative z-order child of currentLayer
// + = positive z-order child of currentLayer
// a = positioned ancestor of currentLayer
// x = any other RenderLayer in the list
//
// (a) xxxxx-----++a+++x
// (b) xxx-----c++++++xx
//
// Normally the current layer would be painted in the normal flow list if it
// doesn't already appear in the positive z-order list. However, in the case
// that the layer has a positioned ancestor, it will paint directly after the
// positioned ancestor. In example (a), the current layer would be painted in
// the middle of its own positive z-order children, so promoting would cause a
// change in paint order (since a promoted layer will paint all of its positive
// z-order children strictly after it paints itself).
//
// In example (b), it is ok to promote the current layer only if it does not
// have a background. If it has a background, the background gets painted before
// the layer's negative z-order children, so again, a promotion would cause a
// change in paint order (causing the background to get painted after the
// negative z-order children instead of before).
//
void RenderLayerStackingNode::computePaintOrderList(PaintOrderListType type, Vector<RefPtr<Node> >& list)
{
OwnPtr<Vector<RenderLayerStackingNode*> > posZOrderList;
OwnPtr<Vector<RenderLayerStackingNode*> > negZOrderList;
RenderLayerStackingNode* stackingNode = ancestorStackingNode();
if (!stackingNode)
return;
switch (type) {
case BeforePromote:
collectBeforePromotionZOrderList(stackingNode, posZOrderList, negZOrderList);
break;
case AfterPromote:
collectAfterPromotionZOrderList(stackingNode, posZOrderList, negZOrderList);
break;
}
if (negZOrderList) {
for (size_t index = 0; index < negZOrderList->size(); ++index)
list.append(negZOrderList->at(index)->renderer()->node());
}
if (posZOrderList) {
for (size_t index = 0; index < posZOrderList->size(); ++index)
list.append(posZOrderList->at(index)->renderer()->node());
}
}
bool RenderLayerStackingNode::descendantsAreContiguousInStackingOrder() const
{
if (isStackingContext() || !ancestorStackingContainerNode())
return true;
ASSERT(!m_descendantsAreContiguousInStackingOrderDirty);
return m_descendantsAreContiguousInStackingOrder;
}
bool RenderLayerStackingNode::setNeedsToBeStackingContainer(bool needsToBeStackingContainer)
{
if (m_needsToBeStackingContainer == needsToBeStackingContainer)
return false;
// Count the total number of RenderLayers which need to be stacking
// containers some point. This should be recorded at most once per
// RenderLayer, so we check m_needsToBeStackingContainerHasBeenRecorded.
if (layer()->acceleratedCompositingForOverflowScrollEnabled() && !m_needsToBeStackingContainerHasBeenRecorded) {
WebKit::Platform::current()->histogramEnumeration("Renderer.CompositedScrolling", RenderLayer::NeedsToBeStackingContainerBucket, RenderLayer::CompositedScrollingHistogramMax);
m_needsToBeStackingContainerHasBeenRecorded = true;
}
m_needsToBeStackingContainer = needsToBeStackingContainer;
return true;
}
RenderLayerStackingNode* RenderLayerStackingNode::ancestorStackingContainerNode() const
{
RenderLayer* ancestor = layer()->parent();
while (ancestor && !ancestor->stackingNode()->isStackingContainer())
ancestor = ancestor->parent();
if (ancestor)
return ancestor->stackingNode();
return 0;
}
RenderLayerStackingNode* RenderLayerStackingNode::ancestorStackingNode() const
{
RenderLayer* ancestor = layer()->parent();
while (ancestor && !ancestor->stackingNode()->isStackingContext())
ancestor = ancestor->parent();
if (ancestor)
return ancestor->stackingNode();
return 0;
}
RenderLayerModelObject* RenderLayerStackingNode::renderer() const
{
return m_layer->renderer();
}
} // namespace WebCore