blob: c9ecb9f064fe8909c2fea23a789f3d73a9389f5b [file] [log] [blame]
/*
* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
* (C) 1999 Antti Koivisto (koivisto@kde.org)
* (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
* (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
* Copyright (C) 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
* Copyright (C) 2010, 2012 Google Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "RenderElement.h"
#include "AXObjectCache.h"
#include "AnimationController.h"
#include "ContentData.h"
#include "CursorList.h"
#include "EventHandler.h"
#include "Frame.h"
#include "HTMLElement.h"
#include "HTMLNames.h"
#include "RenderCounter.h"
#include "RenderDeprecatedFlexibleBox.h"
#include "RenderFlexibleBox.h"
#include "RenderGrid.h"
#include "RenderImage.h"
#include "RenderImageResourceStyleImage.h"
#include "RenderIterator.h"
#include "RenderLayer.h"
#include "RenderLineBreak.h"
#include "RenderListItem.h"
#include "RenderMultiColumnBlock.h"
#include "RenderRegion.h"
#include "RenderRuby.h"
#include "RenderRubyText.h"
#include "RenderTableCaption.h"
#include "RenderTableCell.h"
#include "RenderTableCol.h"
#include "RenderTableRow.h"
#include "RenderText.h"
#include "RenderView.h"
#include "SVGRenderSupport.h"
#include "StyleResolver.h"
#include <wtf/StackStats.h>
#if USE(ACCELERATED_COMPOSITING)
#include "RenderLayerCompositor.h"
#endif
namespace WebCore {
bool RenderElement::s_affectsParentBlock = false;
bool RenderElement::s_noLongerAffectsParentBlock = false;
RenderElement::RenderElement(Element& element, PassRef<RenderStyle> style, unsigned baseTypeFlags)
: RenderObject(element)
, m_baseTypeFlags(baseTypeFlags)
, m_ancestorLineBoxDirty(false)
, m_hasInitializedStyle(false)
, m_renderInlineAlwaysCreatesLineBoxes(false)
, m_firstChild(nullptr)
, m_lastChild(nullptr)
, m_style(std::move(style))
{
}
RenderElement::RenderElement(Document& document, PassRef<RenderStyle> style, unsigned baseTypeFlags)
: RenderObject(document)
, m_baseTypeFlags(baseTypeFlags)
, m_ancestorLineBoxDirty(false)
, m_hasInitializedStyle(false)
, m_renderInlineAlwaysCreatesLineBoxes(false)
, m_firstChild(nullptr)
, m_lastChild(nullptr)
, m_style(std::move(style))
{
}
RenderElement::~RenderElement()
{
if (hasInitializedStyle()) {
for (const FillLayer* bgLayer = m_style->backgroundLayers(); bgLayer; bgLayer = bgLayer->next()) {
if (StyleImage* backgroundImage = bgLayer->image())
backgroundImage->removeClient(this);
}
for (const FillLayer* maskLayer = m_style->maskLayers(); maskLayer; maskLayer = maskLayer->next()) {
if (StyleImage* maskImage = maskLayer->image())
maskImage->removeClient(this);
}
if (StyleImage* borderImage = m_style->borderImage().image())
borderImage->removeClient(this);
if (StyleImage* maskBoxImage = m_style->maskBoxImage().image())
maskBoxImage->removeClient(this);
#if ENABLE(CSS_SHAPES)
if (auto shapeValue = m_style->shapeInside()) {
if (auto shapeImage = shapeValue->image())
shapeImage->removeClient(this);
}
if (auto shapeValue = m_style->shapeOutside()) {
if (auto shapeImage = shapeValue->image())
shapeImage->removeClient(this);
}
#endif
}
}
RenderElement* RenderElement::createFor(Element& element, PassRef<RenderStyle> style)
{
Document& document = element.document();
// Minimal support for content properties replacing an entire element.
// Works only if we have exactly one piece of content and it's a URL.
// Otherwise acts as if we didn't support this feature.
const ContentData* contentData = style.get().contentData();
if (contentData && !contentData->next() && contentData->isImage() && !element.isPseudoElement()) {
RenderImage* image = new RenderImage(element, std::move(style));
if (const StyleImage* styleImage = static_cast<const ImageContentData*>(contentData)->image()) {
image->setImageResource(RenderImageResourceStyleImage::create(const_cast<StyleImage&>(*styleImage)));
image->setIsGeneratedContent();
} else
image->setImageResource(RenderImageResource::create());
return image;
}
if (element.hasTagName(HTMLNames::rubyTag)) {
if (style.get().display() == INLINE)
return new RenderRubyAsInline(element, std::move(style));
if (style.get().display() == BLOCK)
return new RenderRubyAsBlock(element, std::move(style));
}
// treat <rt> as ruby text ONLY if it still has its default treatment of block
if (element.hasTagName(HTMLNames::rtTag) && style.get().display() == BLOCK)
return new RenderRubyText(element, std::move(style));
switch (style.get().display()) {
case NONE:
style.dropRef();
return nullptr;
case INLINE:
return new RenderInline(element, std::move(style));
case BLOCK:
case INLINE_BLOCK:
case RUN_IN:
case COMPACT:
if ((!style.get().hasAutoColumnCount() || !style.get().hasAutoColumnWidth()) && document.regionBasedColumnsEnabled())
return new RenderMultiColumnBlock(element, std::move(style));
return new RenderBlockFlow(element, std::move(style));
case LIST_ITEM:
return new RenderListItem(element, std::move(style));
case TABLE:
case INLINE_TABLE:
return new RenderTable(element, std::move(style));
case TABLE_ROW_GROUP:
case TABLE_HEADER_GROUP:
case TABLE_FOOTER_GROUP:
return new RenderTableSection(element, std::move(style));
case TABLE_ROW:
return new RenderTableRow(element, std::move(style));
case TABLE_COLUMN_GROUP:
case TABLE_COLUMN:
return new RenderTableCol(element, std::move(style));
case TABLE_CELL:
return new RenderTableCell(element, std::move(style));
case TABLE_CAPTION:
return new RenderTableCaption(element, std::move(style));
case BOX:
case INLINE_BOX:
return new RenderDeprecatedFlexibleBox(element, std::move(style));
case FLEX:
case INLINE_FLEX:
return new RenderFlexibleBox(element, std::move(style));
case GRID:
case INLINE_GRID:
return new RenderGrid(element, std::move(style));
}
ASSERT_NOT_REACHED();
return nullptr;
}
enum StyleCacheState {
Cached,
Uncached
};
static PassRefPtr<RenderStyle> firstLineStyleForCachedUncachedType(StyleCacheState type, const RenderElement& renderer, RenderStyle* style)
{
RenderElement& rendererForFirstLineStyle = renderer.isBeforeOrAfterContent() ? *renderer.parent() : const_cast<RenderElement&>(renderer);
if (rendererForFirstLineStyle.isRenderBlockFlow() || rendererForFirstLineStyle.isRenderButton()) {
if (RenderBlock* firstLineBlock = rendererForFirstLineStyle.firstLineBlock()) {
if (type == Cached)
return firstLineBlock->getCachedPseudoStyle(FIRST_LINE, style);
return firstLineBlock->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE), style, firstLineBlock == &renderer ? style : nullptr);
}
} else if (!rendererForFirstLineStyle.isAnonymous() && rendererForFirstLineStyle.isRenderInline()) {
RenderStyle& parentStyle = rendererForFirstLineStyle.parent()->firstLineStyle();
if (&parentStyle != &rendererForFirstLineStyle.parent()->style()) {
if (type == Cached) {
// A first-line style is in effect. Cache a first-line style for ourselves.
rendererForFirstLineStyle.style().setHasPseudoStyle(FIRST_LINE_INHERITED);
return rendererForFirstLineStyle.getCachedPseudoStyle(FIRST_LINE_INHERITED, &parentStyle);
}
return rendererForFirstLineStyle.getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE_INHERITED), &parentStyle, style);
}
}
return nullptr;
}
PassRefPtr<RenderStyle> RenderElement::uncachedFirstLineStyle(RenderStyle* style) const
{
if (!document().styleSheetCollection().usesFirstLineRules())
return 0;
return firstLineStyleForCachedUncachedType(Uncached, *this, style);
}
RenderStyle* RenderElement::cachedFirstLineStyle() const
{
ASSERT(document().styleSheetCollection().usesFirstLineRules());
RenderStyle& style = this->style();
if (RefPtr<RenderStyle> firstLineStyle = firstLineStyleForCachedUncachedType(Cached, *this, &style))
return firstLineStyle.get();
return &style;
}
StyleDifference RenderElement::adjustStyleDifference(StyleDifference diff, unsigned contextSensitiveProperties) const
{
#if USE(ACCELERATED_COMPOSITING)
// If transform changed, and we are not composited, need to do a layout.
if (contextSensitiveProperties & ContextSensitivePropertyTransform) {
// Text nodes share style with their parents but transforms don't apply to them,
// hence the !isText() check.
// FIXME: when transforms are taken into account for overflow, we will need to do a layout.
if (!hasLayer() || !toRenderLayerModelObject(this)->layer()->isComposited()) {
// We need to set at least SimplifiedLayout, but if PositionedMovementOnly is already set
// then we actually need SimplifiedLayoutAndPositionedMovement.
if (!hasLayer())
diff = StyleDifferenceLayout; // FIXME: Do this for now since SimplifiedLayout cannot handle updating floating objects lists.
else if (diff < StyleDifferenceLayoutPositionedMovementOnly)
diff = StyleDifferenceSimplifiedLayout;
else if (diff < StyleDifferenceSimplifiedLayout)
diff = StyleDifferenceSimplifiedLayoutAndPositionedMovement;
} else if (diff < StyleDifferenceRecompositeLayer)
diff = StyleDifferenceRecompositeLayer;
}
// If opacity changed, and we are not composited, need to repaint (also
// ignoring text nodes)
if (contextSensitiveProperties & ContextSensitivePropertyOpacity) {
if (!hasLayer() || !toRenderLayerModelObject(this)->layer()->isComposited())
diff = StyleDifferenceRepaintLayer;
else if (diff < StyleDifferenceRecompositeLayer)
diff = StyleDifferenceRecompositeLayer;
}
#if ENABLE(CSS_FILTERS)
if ((contextSensitiveProperties & ContextSensitivePropertyFilter) && hasLayer()) {
RenderLayer* layer = toRenderLayerModelObject(this)->layer();
if (!layer->isComposited() || layer->paintsWithFilters())
diff = StyleDifferenceRepaintLayer;
else if (diff < StyleDifferenceRecompositeLayer)
diff = StyleDifferenceRecompositeLayer;
}
#endif
// The answer to requiresLayer() for plugins, iframes, and canvas can change without the actual
// style changing, since it depends on whether we decide to composite these elements. When the
// layer status of one of these elements changes, we need to force a layout.
if (diff == StyleDifferenceEqual && isRenderLayerModelObject()) {
if (hasLayer() != toRenderLayerModelObject(this)->requiresLayer())
diff = StyleDifferenceLayout;
}
#else
UNUSED_PARAM(contextSensitiveProperties);
#endif
// If we have no layer(), just treat a RepaintLayer hint as a normal Repaint.
if (diff == StyleDifferenceRepaintLayer && !hasLayer())
diff = StyleDifferenceRepaint;
return diff;
}
inline bool RenderElement::hasImmediateNonWhitespaceTextChildOrBorderOrOutline() const
{
auto children = childrenOfType<RenderObject>(*this);
for (auto child = children.begin(), end = children.end(); child != end; ++child) {
if (child->isText() && !toRenderText(*child).isAllCollapsibleWhitespace())
return true;
if (child->style().hasOutline() || child->style().hasBorder())
return true;
}
return false;
}
inline bool RenderElement::shouldRepaintForStyleDifference(StyleDifference diff) const
{
return diff == StyleDifferenceRepaint || (diff == StyleDifferenceRepaintIfTextOrBorderOrOutline && hasImmediateNonWhitespaceTextChildOrBorderOrOutline());
}
void RenderElement::updateFillImages(const FillLayer* oldLayers, const FillLayer* newLayers)
{
// Optimize the common case
if (oldLayers && !oldLayers->next() && newLayers && !newLayers->next() && (oldLayers->image() == newLayers->image()))
return;
// Go through the new layers and addClients first, to avoid removing all clients of an image.
for (const FillLayer* currNew = newLayers; currNew; currNew = currNew->next()) {
if (currNew->image())
currNew->image()->addClient(this);
}
for (const FillLayer* currOld = oldLayers; currOld; currOld = currOld->next()) {
if (currOld->image())
currOld->image()->removeClient(this);
}
}
void RenderElement::updateImage(StyleImage* oldImage, StyleImage* newImage)
{
if (oldImage == newImage)
return;
if (oldImage)
oldImage->removeClient(this);
if (newImage)
newImage->addClient(this);
}
#if ENABLE(CSS_SHAPES)
void RenderElement::updateShapeImage(const ShapeValue* oldShapeValue, const ShapeValue* newShapeValue)
{
if (oldShapeValue || newShapeValue)
updateImage(oldShapeValue ? oldShapeValue->image() : 0, newShapeValue ? newShapeValue->image() : 0);
}
#endif
void RenderElement::initializeStyle()
{
#if ENABLE(SVG)
// FIXME: This logic should be in a less ridiculous place. (This is mirrored from RenderSVGBlock::setStyle().)
if (isRenderSVGBlock() && m_style->isDisplayInlineType()) {
// SVG text layout code expects us to be a block-level style element.
m_style->setDisplay(BLOCK);
}
#endif
styleWillChange(StyleDifferenceEqual, style());
m_hasInitializedStyle = true;
updateFillImages(nullptr, m_style->backgroundLayers());
updateFillImages(nullptr, m_style->maskLayers());
updateImage(nullptr, m_style->borderImage().image());
updateImage(nullptr, m_style->maskBoxImage().image());
#if ENABLE(CSS_SHAPES)
updateShapeImage(nullptr, m_style->shapeInside());
updateShapeImage(nullptr, m_style->shapeOutside());
#endif
// We need to ensure that view->maximalOutlineSize() is valid for any repaints that happen
// during styleDidChange (it's used by clippedOverflowRectForRepaint()).
if (m_style->outlineWidth() > 0 && m_style->outlineSize() > maximalOutlineSize(PaintPhaseOutline))
view().setMaximalOutlineSize(m_style->outlineSize());
styleDidChange(StyleDifferenceEqual, nullptr);
#if !ASSERT_DISABLED
// We shouldn't have any text children that would need styleDidChange at this point.
auto textChildren = childrenOfType<RenderText>(*this);
ASSERT(textChildren.begin() == textChildren.end());
#endif
// It would be nice to assert that !parent() here, but some RenderLayer subrenderers
// have their parent set before getting a call to initializeStyle() :|
}
void RenderElement::setStyle(PassRef<RenderStyle> style)
{
if (&m_style.get() == &style.get()) {
#if USE(ACCELERATED_COMPOSITING)
// We need to run through adjustStyleDifference() for iframes, plugins, and canvas so
// style sharing is disabled for them. That should ensure that we never hit this code path.
ASSERT(!isRenderIFrame() && !isEmbeddedObject() && !isCanvas());
#endif
style.dropRef();
return;
}
StyleDifference diff = StyleDifferenceEqual;
unsigned contextSensitiveProperties = ContextSensitivePropertyNone;
if (m_hasInitializedStyle)
diff = m_style->diff(&style.get(), contextSensitiveProperties);
diff = adjustStyleDifference(diff, contextSensitiveProperties);
styleWillChange(diff, style.get());
Ref<RenderStyle> oldStyle(m_style.replace(std::move(style)));
updateFillImages(oldStyle.get().backgroundLayers(), m_style->backgroundLayers());
updateFillImages(oldStyle.get().maskLayers(), m_style->maskLayers());
updateImage(oldStyle.get().borderImage().image(), m_style->borderImage().image());
updateImage(oldStyle.get().maskBoxImage().image(), m_style->maskBoxImage().image());
#if ENABLE(CSS_SHAPES)
updateShapeImage(oldStyle.get().shapeInside(), m_style->shapeInside());
updateShapeImage(oldStyle.get().shapeOutside(), m_style->shapeOutside());
#endif
// We need to ensure that view->maximalOutlineSize() is valid for any repaints that happen
// during styleDidChange (it's used by clippedOverflowRectForRepaint()).
if (m_style->outlineWidth() > 0 && m_style->outlineSize() > maximalOutlineSize(PaintPhaseOutline))
view().setMaximalOutlineSize(m_style->outlineSize());
bool doesNotNeedLayout = !parent();
styleDidChange(diff, &oldStyle.get());
// Text renderers use their parent style. Notify them about the change.
auto textChildren = childrenOfType<RenderText>(*this);
for (auto child = textChildren.begin(), end = textChildren.end(); child != end; ++child)
child->styleDidChange(diff, &oldStyle.get());
// FIXME: |this| might be destroyed here. This can currently happen for a RenderTextFragment when
// its first-letter block gets an update in RenderTextFragment::styleDidChange. For RenderTextFragment(s),
// we will safely bail out with the doesNotNeedLayout flag. We might want to broaden this condition
// in the future as we move renderer changes out of layout and into style changes.
if (doesNotNeedLayout)
return;
// Now that the layer (if any) has been updated, we need to adjust the diff again,
// check whether we should layout now, and decide if we need to repaint.
StyleDifference updatedDiff = adjustStyleDifference(diff, contextSensitiveProperties);
if (diff <= StyleDifferenceLayoutPositionedMovementOnly) {
if (updatedDiff == StyleDifferenceLayout)
setNeedsLayoutAndPrefWidthsRecalc();
else if (updatedDiff == StyleDifferenceLayoutPositionedMovementOnly)
setNeedsPositionedMovementLayout(&oldStyle.get());
else if (updatedDiff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
setNeedsPositionedMovementLayout(&oldStyle.get());
setNeedsSimplifiedNormalFlowLayout();
} else if (updatedDiff == StyleDifferenceSimplifiedLayout)
setNeedsSimplifiedNormalFlowLayout();
}
if (updatedDiff == StyleDifferenceRepaintLayer || shouldRepaintForStyleDifference(updatedDiff)) {
// Do a repaint with the new style now, e.g., for example if we go from
// not having an outline to having an outline.
repaint();
}
}
void RenderElement::setAnimatableStyle(PassRef<RenderStyle> style)
{
setStyle(animation().updateAnimations(*this, std::move(style)));
}
void RenderElement::addChild(RenderObject* newChild, RenderObject* beforeChild)
{
bool needsTable = false;
if (newChild->isRenderTableCol()) {
RenderTableCol* newTableColumn = toRenderTableCol(newChild);
bool isColumnInColumnGroup = newTableColumn->isTableColumn() && isRenderTableCol();
needsTable = !isTable() && !isColumnInColumnGroup;
} else if (newChild->isTableCaption())
needsTable = !isTable();
else if (newChild->isTableSection())
needsTable = !isTable();
else if (newChild->isTableRow())
needsTable = !isTableSection();
else if (newChild->isTableCell())
needsTable = !isTableRow();
if (needsTable) {
RenderTable* table;
RenderObject* afterChild = beforeChild ? beforeChild->previousSibling() : m_lastChild;
if (afterChild && afterChild->isAnonymous() && afterChild->isTable() && !afterChild->isBeforeContent())
table = toRenderTable(afterChild);
else {
table = RenderTable::createAnonymousWithParentRenderer(this);
addChild(table, beforeChild);
}
table->addChild(newChild);
} else
insertChildInternal(newChild, beforeChild, NotifyChildren);
if (newChild->isText())
toRenderText(newChild)->styleDidChange(StyleDifferenceEqual, nullptr);
// SVG creates renderers for <g display="none">, as SVG requires children of hidden
// <g>s to have renderers - at least that's how our implementation works. Consider:
// <g display="none"><foreignObject><body style="position: relative">FOO...
// - requiresLayer() would return true for the <body>, creating a new RenderLayer
// - when the document is painted, both layers are painted. The <body> layer doesn't
// know that it's inside a "hidden SVG subtree", and thus paints, even if it shouldn't.
// To avoid the problem alltogether, detect early if we're inside a hidden SVG subtree
// and stop creating layers at all for these cases - they're not used anyways.
if (newChild->hasLayer() && !layerCreationAllowedForSubtree())
toRenderLayerModelObject(newChild)->layer()->removeOnlyThisLayer();
#if ENABLE(SVG)
SVGRenderSupport::childAdded(*this, *newChild);
#endif
}
void RenderElement::removeChild(RenderObject& oldChild)
{
removeChildInternal(oldChild, NotifyChildren);
}
void RenderElement::destroyLeftoverChildren()
{
while (m_firstChild) {
if (m_firstChild->isListMarker() || (m_firstChild->style().styleType() == FIRST_LETTER && !m_firstChild->isText()))
m_firstChild->removeFromParent(); // List markers are owned by their enclosing list and so don't get destroyed by this container. Similarly, first letters are destroyed by their remaining text fragment.
else if (m_firstChild->isRunIn() && m_firstChild->node()) {
m_firstChild->node()->setRenderer(0);
m_firstChild->node()->setNeedsStyleRecalc();
m_firstChild->destroy();
} else {
// Destroy any anonymous children remaining in the render tree, as well as implicit (shadow) DOM elements like those used in the engine-based text fields.
if (m_firstChild->node())
m_firstChild->node()->setRenderer(0);
m_firstChild->destroy();
}
}
}
void RenderElement::insertChildInternal(RenderObject* newChild, RenderObject* beforeChild, NotifyChildrenType notifyChildren)
{
ASSERT(canHaveChildren() || canHaveGeneratedChildren());
ASSERT(!newChild->parent());
ASSERT(!isRenderBlockFlow() || (!newChild->isTableSection() && !newChild->isTableRow() && !newChild->isTableCell()));
while (beforeChild && beforeChild->parent() && beforeChild->parent() != this)
beforeChild = beforeChild->parent();
// This should never happen, but if it does prevent render tree corruption
// where child->parent() ends up being owner but child->nextSibling()->parent()
// is not owner.
if (beforeChild && beforeChild->parent() != this) {
ASSERT_NOT_REACHED();
return;
}
newChild->setParent(this);
if (m_firstChild == beforeChild)
m_firstChild = newChild;
if (beforeChild) {
RenderObject* previousSibling = beforeChild->previousSibling();
if (previousSibling)
previousSibling->setNextSibling(newChild);
newChild->setPreviousSibling(previousSibling);
newChild->setNextSibling(beforeChild);
beforeChild->setPreviousSibling(newChild);
} else {
if (lastChild())
lastChild()->setNextSibling(newChild);
newChild->setPreviousSibling(lastChild());
m_lastChild = newChild;
}
if (!documentBeingDestroyed()) {
if (notifyChildren == NotifyChildren)
newChild->insertedIntoTree();
RenderCounter::rendererSubtreeAttached(newChild);
}
newChild->setNeedsLayoutAndPrefWidthsRecalc();
setPreferredLogicalWidthsDirty(true);
if (!normalChildNeedsLayout())
setChildNeedsLayout(); // We may supply the static position for an absolute positioned child.
if (AXObjectCache* cache = document().axObjectCache())
cache->childrenChanged(this);
}
void RenderElement::removeChildInternal(RenderObject& oldChild, NotifyChildrenType notifyChildren)
{
ASSERT(canHaveChildren() || canHaveGeneratedChildren());
ASSERT(oldChild.parent() == this);
if (oldChild.isFloatingOrOutOfFlowPositioned())
toRenderBox(oldChild).removeFloatingOrPositionedChildFromBlockLists();
// So that we'll get the appropriate dirty bit set (either that a normal flow child got yanked or
// that a positioned child got yanked). We also repaint, so that the area exposed when the child
// disappears gets repainted properly.
if (!documentBeingDestroyed() && notifyChildren == NotifyChildren && oldChild.everHadLayout()) {
oldChild.setNeedsLayoutAndPrefWidthsRecalc();
// We only repaint |oldChild| if we have a RenderLayer as its visual overflow may not be tracked by its parent.
if (oldChild.isBody())
view().repaintRootContents();
else
oldChild.repaint();
}
// If we have a line box wrapper, delete it.
if (oldChild.isBox())
toRenderBox(oldChild).deleteLineBoxWrapper();
else if (oldChild.isLineBreak())
toRenderLineBreak(oldChild).deleteInlineBoxWrapper();
// If oldChild is the start or end of the selection, then clear the selection to
// avoid problems of invalid pointers.
// FIXME: The FrameSelection should be responsible for this when it
// is notified of DOM mutations.
if (!documentBeingDestroyed() && oldChild.isSelectionBorder())
view().clearSelection();
if (!documentBeingDestroyed() && notifyChildren == NotifyChildren)
oldChild.willBeRemovedFromTree();
// WARNING: There should be no code running between willBeRemovedFromTree and the actual removal below.
// This is needed to avoid race conditions where willBeRemovedFromTree would dirty the tree's structure
// and the code running here would force an untimely rebuilding, leaving |oldChild| dangling.
if (oldChild.previousSibling())
oldChild.previousSibling()->setNextSibling(oldChild.nextSibling());
if (oldChild.nextSibling())
oldChild.nextSibling()->setPreviousSibling(oldChild.previousSibling());
if (m_firstChild == &oldChild)
m_firstChild = oldChild.nextSibling();
if (m_lastChild == &oldChild)
m_lastChild = oldChild.previousSibling();
oldChild.setPreviousSibling(nullptr);
oldChild.setNextSibling(nullptr);
oldChild.setParent(nullptr);
// rendererRemovedFromTree walks the whole subtree. We can improve performance
// by skipping this step when destroying the entire tree.
if (!documentBeingDestroyed())
RenderCounter::rendererRemovedFromTree(oldChild);
if (AXObjectCache* cache = document().existingAXObjectCache())
cache->childrenChanged(this);
}
static void addLayers(RenderElement& renderer, RenderLayer* parentLayer, RenderElement*& newObject, RenderLayer*& beforeChild)
{
if (renderer.hasLayer()) {
if (!beforeChild && newObject) {
// We need to figure out the layer that follows newObject. We only do
// this the first time we find a child layer, and then we update the
// pointer values for newObject and beforeChild used by everyone else.
beforeChild = newObject->parent()->findNextLayer(parentLayer, newObject);
newObject = nullptr;
}
parentLayer->addChild(toRenderLayerModelObject(renderer).layer(), beforeChild);
return;
}
auto children = childrenOfType<RenderElement>(renderer);
for (auto child = children.begin(), end = children.end(); child != end; ++child)
addLayers(*child, parentLayer, newObject, beforeChild);
}
void RenderElement::addLayers(RenderLayer* parentLayer)
{
if (!parentLayer)
return;
RenderElement* renderer = this;
RenderLayer* beforeChild = nullptr;
WebCore::addLayers(*this, parentLayer, renderer, beforeChild);
}
void RenderElement::removeLayers(RenderLayer* parentLayer)
{
if (!parentLayer)
return;
if (hasLayer()) {
parentLayer->removeChild(toRenderLayerModelObject(this)->layer());
return;
}
auto children = childrenOfType<RenderElement>(*this);
for (auto child = children.begin(), end = children.end(); child != end; ++child)
child->removeLayers(parentLayer);
}
void RenderElement::moveLayers(RenderLayer* oldParent, RenderLayer* newParent)
{
if (!newParent)
return;
if (hasLayer()) {
RenderLayer* layer = toRenderLayerModelObject(this)->layer();
ASSERT(oldParent == layer->parent());
if (oldParent)
oldParent->removeChild(layer);
newParent->addChild(layer);
return;
}
auto children = childrenOfType<RenderElement>(*this);
for (auto child = children.begin(), end = children.end(); child != end; ++child)
child->moveLayers(oldParent, newParent);
}
RenderLayer* RenderElement::findNextLayer(RenderLayer* parentLayer, RenderObject* startPoint, bool checkParent)
{
// Error check the parent layer passed in. If it's null, we can't find anything.
if (!parentLayer)
return 0;
// Step 1: If our layer is a child of the desired parent, then return our layer.
RenderLayer* ourLayer = hasLayer() ? toRenderLayerModelObject(this)->layer() : nullptr;
if (ourLayer && ourLayer->parent() == parentLayer)
return ourLayer;
// Step 2: If we don't have a layer, or our layer is the desired parent, then descend
// into our siblings trying to find the next layer whose parent is the desired parent.
if (!ourLayer || ourLayer == parentLayer) {
for (RenderObject* child = startPoint ? startPoint->nextSibling() : firstChild(); child; child = child->nextSibling()) {
if (!child->isRenderElement())
continue;
RenderLayer* nextLayer = toRenderElement(child)->findNextLayer(parentLayer, nullptr, false);
if (nextLayer)
return nextLayer;
}
}
// Step 3: If our layer is the desired parent layer, then we're finished. We didn't
// find anything.
if (parentLayer == ourLayer)
return nullptr;
// Step 4: If |checkParent| is set, climb up to our parent and check its siblings that
// follow us to see if we can locate a layer.
if (checkParent && parent())
return parent()->findNextLayer(parentLayer, this, true);
return nullptr;
}
bool RenderElement::layerCreationAllowedForSubtree() const
{
#if ENABLE(SVG)
RenderElement* parentRenderer = parent();
while (parentRenderer) {
if (parentRenderer->isSVGHiddenContainer())
return false;
parentRenderer = parentRenderer->parent();
}
#endif
return true;
}
void RenderElement::propagateStyleToAnonymousChildren(StylePropagationType propagationType)
{
// FIXME: We could save this call when the change only affected non-inherited properties.
auto children = childrenOfType<RenderElement>(*this);
for (auto child = children.begin(), end = children.end(); child != end; ++child) {
RenderElement& elementChild = *child;
if (!elementChild.isAnonymous() || elementChild.style().styleType() != NOPSEUDO)
continue;
if (propagationType == PropagateToBlockChildrenOnly && !elementChild.isRenderBlock())
continue;
#if ENABLE(FULLSCREEN_API)
if (elementChild.isRenderFullScreen() || elementChild.isRenderFullScreenPlaceholder())
continue;
#endif
// RenderFlowThreads are updated through the RenderView::styleDidChange function.
if (elementChild.isRenderFlowThread())
continue;
auto newStyle = RenderStyle::createAnonymousStyleWithDisplay(&style(), elementChild.style().display());
if (style().specifiesColumns()) {
if (elementChild.style().specifiesColumns())
newStyle.get().inheritColumnPropertiesFrom(&style());
if (elementChild.style().columnSpan())
newStyle.get().setColumnSpan(ColumnSpanAll);
}
// Preserve the position style of anonymous block continuations as they can have relative or sticky position when
// they contain block descendants of relative or sticky positioned inlines.
if (elementChild.isInFlowPositioned() && toRenderBlock(elementChild).isAnonymousBlockContinuation())
newStyle.get().setPosition(elementChild.style().position());
elementChild.setStyle(std::move(newStyle));
}
}
// On low-powered/mobile devices, preventing blitting on a scroll can cause noticeable delays
// when scrolling a page with a fixed background image. As an optimization, assuming there are
// no fixed positoned elements on the page, we can acclerate scrolling (via blitting) if we
// ignore the CSS property "background-attachment: fixed".
static bool shouldRepaintFixedBackgroundsOnScroll()
{
#if ENABLE(FAST_MOBILE_SCROLLING)
return false;
#else
return true;
#endif
}
static inline bool rendererHasBackground(const RenderElement* renderer)
{
return renderer && renderer->hasBackground();
}
void RenderElement::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
{
RenderStyle* oldStyle = hasInitializedStyle() ? &style() : nullptr;
if (oldStyle) {
// If our z-index changes value or our visibility changes,
// we need to dirty our stacking context's z-order list.
bool visibilityChanged = m_style->visibility() != newStyle.visibility()
|| m_style->zIndex() != newStyle.zIndex()
|| m_style->hasAutoZIndex() != newStyle.hasAutoZIndex();
#if ENABLE(DASHBOARD_SUPPORT) || ENABLE(DRAGGABLE_REGION)
if (visibilityChanged)
document().setAnnotatedRegionsDirty(true);
#endif
if (visibilityChanged) {
if (AXObjectCache* cache = document().existingAXObjectCache())
cache->childrenChanged(parent());
}
// Keep layer hierarchy visibility bits up to date if visibility changes.
if (m_style->visibility() != newStyle.visibility()) {
if (RenderLayer* layer = enclosingLayer()) {
if (newStyle.visibility() == VISIBLE)
layer->setHasVisibleContent();
else if (layer->hasVisibleContent() && (this == &layer->renderer() || layer->renderer().style().visibility() != VISIBLE)) {
layer->dirtyVisibleContentStatus();
if (diff > StyleDifferenceRepaintLayer)
repaint();
}
}
}
if (m_parent && (newStyle.outlineSize() < m_style->outlineSize() || shouldRepaintForStyleDifference(diff)))
repaint();
if (isFloating() && (m_style->floating() != newStyle.floating()))
// For changes in float styles, we need to conceivably remove ourselves
// from the floating objects list.
toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
else if (isOutOfFlowPositioned() && (m_style->position() != newStyle.position()))
// For changes in positioning styles, we need to conceivably remove ourselves
// from the positioned objects list.
toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
s_affectsParentBlock = isFloatingOrOutOfFlowPositioned()
&& (!newStyle.isFloating() && !newStyle.hasOutOfFlowPosition())
&& parent() && (parent()->isRenderBlockFlow() || parent()->isRenderInline());
s_noLongerAffectsParentBlock = ((!isFloating() && newStyle.isFloating()) || (!isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition()))
&& parent() && parent()->isRenderBlock();
// reset style flags
if (diff == StyleDifferenceLayout || diff == StyleDifferenceLayoutPositionedMovementOnly) {
setFloating(false);
clearPositionedState();
}
setHorizontalWritingMode(true);
setHasBoxDecorations(false);
setHasOverflowClip(false);
setHasTransform(false);
setHasReflection(false);
} else {
s_affectsParentBlock = false;
s_noLongerAffectsParentBlock = false;
}
bool repaintFixedBackgroundsOnScroll = shouldRepaintFixedBackgroundsOnScroll();
bool newStyleSlowScroll = repaintFixedBackgroundsOnScroll && newStyle.hasFixedBackgroundImage();
bool oldStyleSlowScroll = oldStyle && repaintFixedBackgroundsOnScroll && m_style->hasFixedBackgroundImage();
#if USE(ACCELERATED_COMPOSITING)
bool drawsRootBackground = isRoot() || (isBody() && !rendererHasBackground(document().documentElement()->renderer()));
if (drawsRootBackground && repaintFixedBackgroundsOnScroll) {
if (view().compositor().supportsFixedRootBackgroundCompositing()) {
if (newStyleSlowScroll && newStyle.hasEntirelyFixedBackground())
newStyleSlowScroll = false;
if (oldStyleSlowScroll && m_style->hasEntirelyFixedBackground())
oldStyleSlowScroll = false;
}
}
#endif
if (oldStyleSlowScroll != newStyleSlowScroll) {
if (oldStyleSlowScroll)
view().frameView().removeSlowRepaintObject(this);
if (newStyleSlowScroll)
view().frameView().addSlowRepaintObject(this);
}
}
static bool areNonIdenticalCursorListsEqual(const RenderStyle* a, const RenderStyle* b)
{
ASSERT(a->cursors() != b->cursors());
return a->cursors() && b->cursors() && *a->cursors() == *b->cursors();
}
static inline bool areCursorsEqual(const RenderStyle* a, const RenderStyle* b)
{
return a->cursor() == b->cursor() && (a->cursors() == b->cursors() || areNonIdenticalCursorListsEqual(a, b));
}
void RenderElement::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
if (s_affectsParentBlock)
handleDynamicFloatPositionChange();
if (s_noLongerAffectsParentBlock)
removeAnonymousWrappersForInlinesIfNecessary();
#if ENABLE(SVG)
SVGRenderSupport::styleChanged(*this);
#endif
if (!m_parent)
return;
if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {
RenderCounter::rendererStyleChanged(this, oldStyle, &m_style.get());
// If the object already needs layout, then setNeedsLayout won't do
// any work. But if the containing block has changed, then we may need
// to mark the new containing blocks for layout. The change that can
// directly affect the containing block of this object is a change to
// the position style.
if (needsLayout() && oldStyle->position() != m_style->position())
markContainingBlocksForLayout();
if (diff == StyleDifferenceLayout)
setNeedsLayoutAndPrefWidthsRecalc();
else
setNeedsSimplifiedNormalFlowLayout();
} else if (diff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
setNeedsPositionedMovementLayout(oldStyle);
setNeedsSimplifiedNormalFlowLayout();
} else if (diff == StyleDifferenceLayoutPositionedMovementOnly)
setNeedsPositionedMovementLayout(oldStyle);
// Don't check for repaint here; we need to wait until the layer has been
// updated by subclasses before we know if we have to repaint (in setStyle()).
if (oldStyle && !areCursorsEqual(oldStyle, &style()))
frame().eventHandler().scheduleCursorUpdate();
}
void RenderElement::insertedIntoTree()
{
RenderObject::insertedIntoTree();
// Keep our layer hierarchy updated. Optimize for the common case where we don't have any children
// and don't have a layer attached to ourselves.
RenderLayer* layer = nullptr;
if (firstChild() || hasLayer()) {
layer = parent()->enclosingLayer();
addLayers(layer);
}
// If |this| is visible but this object was not, tell the layer it has some visible content
// that needs to be drawn and layer visibility optimization can't be used
if (parent()->style().visibility() != VISIBLE && style().visibility() == VISIBLE && !hasLayer()) {
if (!layer)
layer = parent()->enclosingLayer();
if (layer)
layer->setHasVisibleContent();
}
}
void RenderElement::willBeRemovedFromTree()
{
// If we remove a visible child from an invisible parent, we don't know the layer visibility any more.
RenderLayer* layer = nullptr;
if (parent()->style().visibility() != VISIBLE && style().visibility() == VISIBLE && !hasLayer()) {
if ((layer = parent()->enclosingLayer()))
layer->dirtyVisibleContentStatus();
}
// Keep our layer hierarchy updated.
if (firstChild() || hasLayer()) {
if (!layer)
layer = parent()->enclosingLayer();
removeLayers(layer);
}
bool repaintFixedBackgroundsOnScroll = shouldRepaintFixedBackgroundsOnScroll();
if (repaintFixedBackgroundsOnScroll && m_style->hasFixedBackgroundImage())
view().frameView().removeSlowRepaintObject(this);
if (isOutOfFlowPositioned() && parent()->childrenInline())
parent()->dirtyLinesFromChangedChild(this);
RenderObject::willBeRemovedFromTree();
}
void RenderElement::willBeDestroyed()
{
animation().cancelAnimations(this);
destroyLeftoverChildren();
RenderObject::willBeDestroyed();
}
void RenderElement::setNeedsPositionedMovementLayout(const RenderStyle* oldStyle)
{
ASSERT(!isSetNeedsLayoutForbidden());
if (needsPositionedMovementLayout())
return;
setNeedsPositionedMovementLayoutBit(true);
markContainingBlocksForLayout();
if (hasLayer()) {
if (oldStyle && style().diffRequiresRepaint(oldStyle))
setLayerNeedsFullRepaint();
else
setLayerNeedsFullRepaintForPositionedMovementLayout();
}
}
void RenderElement::clearChildNeedsLayout()
{
setNormalChildNeedsLayoutBit(false);
setPosChildNeedsLayoutBit(false);
setNeedsSimplifiedNormalFlowLayoutBit(false);
setNormalChildNeedsLayoutBit(false);
setNeedsPositionedMovementLayoutBit(false);
}
void RenderElement::setNeedsSimplifiedNormalFlowLayout()
{
ASSERT(!isSetNeedsLayoutForbidden());
if (needsSimplifiedNormalFlowLayout())
return;
setNeedsSimplifiedNormalFlowLayoutBit(true);
markContainingBlocksForLayout();
if (hasLayer())
setLayerNeedsFullRepaint();
}
RenderElement* RenderElement::rendererForRootBackground()
{
ASSERT(isRoot());
if (!hasBackground() && element() && element()->hasTagName(HTMLNames::htmlTag)) {
// Locate the <body> element using the DOM. This is easier than trying
// to crawl around a render tree with potential :before/:after content and
// anonymous blocks created by inline <body> tags etc. We can locate the <body>
// render object very easily via the DOM.
if (auto body = document().body()) {
if (body->hasLocalName(HTMLNames::bodyTag)) {
if (auto renderer = body->renderer())
return renderer;
}
}
}
return this;
}
RenderElement* RenderElement::hoverAncestor() const
{
// When searching for the hover ancestor and encountering a named flow thread,
// the search will continue with the DOM ancestor of the top-most element
// in the named flow thread.
// See https://bugs.webkit.org/show_bug.cgi?id=111749
RenderElement* hoverAncestor = parent();
// Skip anonymous blocks directly flowed into flow threads as it would
// prevent us from continuing the search on the DOM tree when reaching the named flow thread.
if (hoverAncestor && hoverAncestor->isAnonymousBlock() && hoverAncestor->parent() && hoverAncestor->parent()->isRenderNamedFlowThread())
hoverAncestor = hoverAncestor->parent();
if (hoverAncestor && hoverAncestor->isRenderNamedFlowThread()) {
hoverAncestor = nullptr;
if (Element* element = this->element()) {
if (auto parent = element->parentNode())
hoverAncestor = parent->renderer();
}
}
return hoverAncestor;
}
void RenderElement::layout()
{
StackStats::LayoutCheckPoint layoutCheckPoint;
ASSERT(needsLayout());
RenderObject* child = firstChild();
while (child) {
if (child->needsLayout())
toRenderElement(child)->layout();
ASSERT(!child->needsLayout());
child = child->nextSibling();
}
clearNeedsLayout();
}
}