/
RenderElement.cpp
2265 lines (1927 loc) · 93.4 KB
/
RenderElement.cpp
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/*
* 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) 2005-2021 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 "BorderPainter.h"
#include "CachedResourceLoader.h"
#include "ContentData.h"
#include "CursorList.h"
#include "DocumentInlines.h"
#include "ElementChildIterator.h"
#include "EventHandler.h"
#include "FocusController.h"
#include "Frame.h"
#include "FrameSelection.h"
#include "HTMLAnchorElement.h"
#include "HTMLBodyElement.h"
#include "HTMLHtmlElement.h"
#include "HTMLImageElement.h"
#include "HTMLNames.h"
#include "InlineIteratorLineBox.h"
#include "InlineIteratorTextBox.h"
#include "LengthFunctions.h"
#include "Logging.h"
#include "Page.h"
#include "PathUtilities.h"
#include "ReferencedSVGResources.h"
#include "RenderBlock.h"
#include "RenderChildIterator.h"
#include "RenderCounter.h"
#include "RenderDeprecatedFlexibleBox.h"
#include "RenderDescendantIterator.h"
#include "RenderFlexibleBox.h"
#include "RenderFragmentedFlow.h"
#include "RenderGrid.h"
#include "RenderImage.h"
#include "RenderImageResourceStyleImage.h"
#include "RenderInline.h"
#include "RenderIterator.h"
#include "RenderLayer.h"
#include "RenderLayerCompositor.h"
#include "RenderLineBreak.h"
#include "RenderListItem.h"
#if ASSERT_ENABLED
#include "RenderListMarker.h"
#endif
#include "RenderFragmentContainer.h"
#include "RenderSVGViewportContainer.h"
#include "RenderStyle.h"
#include "RenderTableCaption.h"
#include "RenderTableCell.h"
#include "RenderTableCol.h"
#include "RenderTableRow.h"
#include "RenderText.h"
#include "RenderTheme.h"
#include "RenderTreeBuilder.h"
#include "RenderView.h"
#include "SVGElementTypeHelpers.h"
#include "SVGImage.h"
#include "SVGLengthContext.h"
#include "SVGRenderSupport.h"
#include "SVGSVGElement.h"
#include "Settings.h"
#include "ShadowRoot.h"
#include "StylePendingResources.h"
#include "StyleResolver.h"
#include "Styleable.h"
#include "TextAutoSizing.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/MathExtras.h>
#include <wtf/StackStats.h>
#if ENABLE(CONTENT_CHANGE_OBSERVER)
#include "ContentChangeObserver.h"
#endif
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderElement);
struct SameSizeAsRenderElement : public RenderObject {
unsigned bitfields : 25;
void* firstChild;
void* lastChild;
RenderStyle style;
};
static_assert(sizeof(RenderElement) == sizeof(SameSizeAsRenderElement), "RenderElement should stay small");
inline RenderElement::RenderElement(ContainerNode& elementOrDocument, RenderStyle&& style, BaseTypeFlags baseTypeFlags)
: RenderObject(elementOrDocument)
, m_baseTypeFlags(baseTypeFlags)
, m_ancestorLineBoxDirty(false)
, m_hasInitializedStyle(false)
, m_renderBoxNeedsLazyRepaint(false)
, m_hasPausedImageAnimations(false)
, m_hasCounterNodeMap(false)
, m_hasContinuationChainNode(false)
, m_isContinuation(false)
, m_isFirstLetter(false)
, m_renderBlockHasMarginBeforeQuirk(false)
, m_renderBlockHasMarginAfterQuirk(false)
, m_renderBlockShouldForceRelayoutChildren(false)
, m_renderBlockFlowHasMarkupTruncation(false)
, m_renderBlockFlowLineLayoutPath(RenderBlockFlow::UndeterminedPath)
, m_isRegisteredForVisibleInViewportCallback(false)
, m_visibleInViewportState(static_cast<unsigned>(VisibleInViewportState::Unknown))
, m_didContributeToVisuallyNonEmptyPixelCount(false)
, m_firstChild(nullptr)
, m_lastChild(nullptr)
, m_style(WTFMove(style))
{
}
RenderElement::RenderElement(Element& element, RenderStyle&& style, BaseTypeFlags baseTypeFlags)
: RenderElement(static_cast<ContainerNode&>(element), WTFMove(style), baseTypeFlags)
{
}
RenderElement::RenderElement(Document& document, RenderStyle&& style, BaseTypeFlags baseTypeFlags)
: RenderElement(static_cast<ContainerNode&>(document), WTFMove(style), baseTypeFlags)
{
}
RenderElement::~RenderElement()
{
// Do not add any code here. Add it to willBeDestroyed() instead.
ASSERT(!m_firstChild);
}
bool RenderElement::isContentDataSupported(const ContentData& contentData)
{
// 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.
return is<ImageContentData>(contentData) && !contentData.next();
}
RenderPtr<RenderElement> RenderElement::createFor(Element& element, RenderStyle&& style, OptionSet<ConstructBlockLevelRendererFor> rendererTypeOverride)
{
const ContentData* contentData = style.contentData();
if (!rendererTypeOverride && contentData && isContentDataSupported(*contentData) && !element.isPseudoElement()) {
Style::loadPendingResources(style, element.document(), &element);
auto& styleImage = downcast<ImageContentData>(*contentData).image();
auto image = createRenderer<RenderImage>(element, WTFMove(style), const_cast<StyleImage*>(&styleImage));
image->setIsGeneratedContent();
return image;
}
switch (style.display()) {
case DisplayType::None:
case DisplayType::Contents:
return nullptr;
case DisplayType::Inline:
if (rendererTypeOverride.contains(ConstructBlockLevelRendererFor::Inline))
return createRenderer<RenderBlockFlow>(element, WTFMove(style));
return createRenderer<RenderInline>(element, WTFMove(style));
case DisplayType::Block:
case DisplayType::FlowRoot:
case DisplayType::InlineBlock:
return createRenderer<RenderBlockFlow>(element, WTFMove(style));
case DisplayType::ListItem:
if (rendererTypeOverride.contains(ConstructBlockLevelRendererFor::ListItem))
return createRenderer<RenderBlockFlow>(element, WTFMove(style));
return createRenderer<RenderListItem>(element, WTFMove(style));
case DisplayType::Flex:
case DisplayType::InlineFlex:
return createRenderer<RenderFlexibleBox>(element, WTFMove(style));
case DisplayType::Grid:
case DisplayType::InlineGrid:
return createRenderer<RenderGrid>(element, WTFMove(style));
case DisplayType::Box:
case DisplayType::InlineBox:
return createRenderer<RenderDeprecatedFlexibleBox>(element, WTFMove(style));
default: {
if (style.isDisplayTableOrTablePart() && rendererTypeOverride.contains(ConstructBlockLevelRendererFor::TableOrTablePart))
return createRenderer<RenderBlockFlow>(element, WTFMove(style));
switch (style.display()) {
case DisplayType::Table:
case DisplayType::InlineTable:
return createRenderer<RenderTable>(element, WTFMove(style));
case DisplayType::TableCell:
return createRenderer<RenderTableCell>(element, WTFMove(style));
case DisplayType::TableCaption:
return createRenderer<RenderTableCaption>(element, WTFMove(style));
case DisplayType::TableRowGroup:
case DisplayType::TableHeaderGroup:
case DisplayType::TableFooterGroup:
return createRenderer<RenderTableSection>(element, WTFMove(style));
case DisplayType::TableRow:
return createRenderer<RenderTableRow>(element, WTFMove(style));
case DisplayType::TableColumnGroup:
case DisplayType::TableColumn:
return createRenderer<RenderTableCol>(element, WTFMove(style));
default:
break;
}
break;
}
}
ASSERT_NOT_REACHED();
return nullptr;
}
const RenderStyle& RenderElement::firstLineStyle() const
{
// FIXME: It would be better to just set anonymous block first-line styles correctly.
if (isAnonymousBlock()) {
if (!previousInFlowSibling()) {
if (auto* firstLineStyle = parent()->style().getCachedPseudoStyle(PseudoId::FirstLine))
return *firstLineStyle;
}
return style();
}
if (auto* firstLineStyle = style().getCachedPseudoStyle(PseudoId::FirstLine))
return *firstLineStyle;
return style();
}
StyleDifference RenderElement::adjustStyleDifference(StyleDifference diff, OptionSet<StyleDifferenceContextSensitiveProperty> contextSensitiveProperties) const
{
// If transform changed, and we are not composited, need to do a layout.
if (contextSensitiveProperties & StyleDifferenceContextSensitiveProperty::Transform) {
// FIXME: when transforms are taken into account for overflow, we will need to do a layout.
if (!hasLayer() || !downcast<RenderLayerModelObject>(*this).layer()->isComposited()) {
if (!hasLayer())
diff = std::max(diff, StyleDifference::Layout);
else {
// We need to set at least SimplifiedLayout, but if PositionedMovementOnly is already set
// then we actually need SimplifiedLayoutAndPositionedMovement.
diff = std::max(diff, (diff == StyleDifference::LayoutPositionedMovementOnly) ? StyleDifference::SimplifiedLayoutAndPositionedMovement : StyleDifference::SimplifiedLayout);
}
} else
diff = std::max(diff, StyleDifference::RecompositeLayer);
}
if (contextSensitiveProperties & StyleDifferenceContextSensitiveProperty::Opacity) {
if (!hasLayer() || !downcast<RenderLayerModelObject>(*this).layer()->isComposited())
diff = std::max(diff, StyleDifference::RepaintLayer);
else
diff = std::max(diff, StyleDifference::RecompositeLayer);
}
if (contextSensitiveProperties & StyleDifferenceContextSensitiveProperty::ClipPath) {
if (hasLayer() && downcast<RenderLayerModelObject>(*this).layer()->willCompositeClipPath())
diff = std::max(diff, StyleDifference::RecompositeLayer);
else
diff = std::max(diff, StyleDifference::Repaint);
}
if (contextSensitiveProperties & StyleDifferenceContextSensitiveProperty::WillChange) {
if (style().willChange() && style().willChange()->canTriggerCompositing())
diff = std::max(diff, StyleDifference::RecompositeLayer);
}
if ((contextSensitiveProperties & StyleDifferenceContextSensitiveProperty::Filter) && hasLayer()) {
auto& layer = *downcast<RenderLayerModelObject>(*this).layer();
if (!layer.isComposited() || layer.paintsWithFilters())
diff = std::max(diff, StyleDifference::RepaintLayer);
else
diff = std::max(diff, StyleDifference::RecompositeLayer);
}
// 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 < StyleDifference::Layout && isRenderLayerModelObject()) {
if (hasLayer() != downcast<RenderLayerModelObject>(*this).requiresLayer())
diff = StyleDifference::Layout;
}
// If we have no layer(), just treat a RepaintLayer hint as a normal Repaint.
if (diff == StyleDifference::RepaintLayer && !hasLayer())
diff = StyleDifference::Repaint;
return diff;
}
inline bool RenderElement::shouldRepaintForStyleDifference(StyleDifference diff) const
{
auto hasImmediateNonWhitespaceTextChild = [&] {
for (auto& child : childrenOfType<RenderText>(*this)) {
if (!child.isAllCollapsibleWhitespace())
return true;
}
return false;
};
return diff == StyleDifference::Repaint || (diff == StyleDifference::RepaintIfText && hasImmediateNonWhitespaceTextChild());
}
void RenderElement::updateFillImages(const FillLayer* oldLayers, const FillLayer& newLayers)
{
auto fillImagesAreIdentical = [](const FillLayer* layer1, const FillLayer* layer2) -> bool {
if (layer1 == layer2)
return true;
for (; layer1 && layer2; layer1 = layer1->next(), layer2 = layer2->next()) {
if (!arePointingToEqualData(layer1->image(), layer2->image()))
return false;
if (layer1->image() && layer1->image()->usesDataProtocol())
return false;
if (auto styleImage = layer1->image()) {
if (styleImage->errorOccurred() || !styleImage->hasImage() || styleImage->usesDataProtocol())
return false;
}
}
return !layer1 && !layer2;
};
auto isRegisteredWithNewFillImages = [&]() -> bool {
for (auto* layer = &newLayers; layer; layer = layer->next()) {
if (layer->image() && !layer->image()->hasClient(*this))
return false;
}
return true;
};
// If images have the same characteristics and this element is already registered as a
// client to the new images, there is nothing to do.
if (fillImagesAreIdentical(oldLayers, &newLayers) && isRegisteredWithNewFillImages())
return;
// Add before removing, to avoid removing all clients of an image that is in both sets.
for (auto* layer = &newLayers; layer; layer = layer->next()) {
if (layer->image())
layer->image()->addClient(*this);
}
for (auto* layer = oldLayers; layer; layer = layer->next()) {
if (layer->image())
layer->image()->removeClient(*this);
}
}
void RenderElement::updateImage(StyleImage* oldImage, StyleImage* newImage)
{
if (oldImage == newImage)
return;
if (oldImage)
oldImage->removeClient(*this);
if (newImage)
newImage->addClient(*this);
}
void RenderElement::updateShapeImage(const ShapeValue* oldShapeValue, const ShapeValue* newShapeValue)
{
if (oldShapeValue || newShapeValue)
updateImage(oldShapeValue ? oldShapeValue->image() : nullptr, newShapeValue ? newShapeValue->image() : nullptr);
}
bool RenderElement::repaintBeforeStyleChange(StyleDifference diff, const RenderStyle& oldStyle, const RenderStyle& newStyle)
{
if (oldStyle.visibility() == Visibility::Hidden) {
// Repaint on hidden renderer is a no-op.
return false;
}
enum class RequiredRepaint { None, RendererOnly, RendererAndDescendantsRenderersWithLayers };
auto shouldRepaintBeforeStyleChange = [&]() -> RequiredRepaint {
if (!parent()) {
// Can't resolve absolute coordinates.
return RequiredRepaint::None;
}
if (is<RenderLayerModelObject>(this) && hasLayer()) {
if (diff == StyleDifference::RepaintLayer)
return RequiredRepaint::RendererAndDescendantsRenderersWithLayers;
if (diff == StyleDifference::Layout || diff == StyleDifference::SimplifiedLayout) {
// Certain style changes require layer repaint, since the layer could end up being destroyed.
auto layerMayGetDestroyed = oldStyle.position() != newStyle.position()
|| oldStyle.usedZIndex() != newStyle.usedZIndex()
|| oldStyle.hasAutoUsedZIndex() != newStyle.hasAutoUsedZIndex()
|| oldStyle.clip() != newStyle.clip()
|| oldStyle.hasClip() != newStyle.hasClip()
|| oldStyle.hasOpacity() != newStyle.hasOpacity()
|| oldStyle.hasTransform() != newStyle.hasTransform()
|| oldStyle.hasFilter() != newStyle.hasFilter();
if (layerMayGetDestroyed)
return RequiredRepaint::RendererAndDescendantsRenderersWithLayers;
}
}
if (shouldRepaintForStyleDifference(diff))
return RequiredRepaint::RendererOnly;
if (newStyle.outlineSize() < oldStyle.outlineSize())
return RequiredRepaint::RendererOnly;
if (is<RenderLayerModelObject>(*this)) {
// If we don't have a layer yet, but we are going to get one because of transform or opacity, then we need to repaint the old position of the object.
bool hasLayer = downcast<RenderLayerModelObject>(*this).hasLayer();
bool willHaveLayer = newStyle.hasTransform() || newStyle.hasOpacity() || newStyle.hasFilter() || newStyle.hasBackdropFilter();
if (!hasLayer && willHaveLayer)
return RequiredRepaint::RendererOnly;
}
if (is<RenderBox>(*this)) {
if (diff == StyleDifference::Layout && oldStyle.position() != newStyle.position() && oldStyle.position() == PositionType::Static)
return RequiredRepaint::RendererOnly;
}
if (diff > StyleDifference::RepaintLayer && oldStyle.visibility() != newStyle.visibility()) {
if (auto* enclosingLayer = this->enclosingLayer()) {
auto rendererWillBeHidden = newStyle.visibility() != Visibility::Visible;
if (rendererWillBeHidden && enclosingLayer->hasVisibleContent() && (this == &enclosingLayer->renderer() || enclosingLayer->renderer().style().visibility() != Visibility::Visible))
return RequiredRepaint::RendererOnly;
}
}
return RequiredRepaint::None;
}();
if (shouldRepaintBeforeStyleChange == RequiredRepaint::RendererAndDescendantsRenderersWithLayers) {
ASSERT(hasLayer());
downcast<RenderLayerModelObject>(*this).layer()->repaintIncludingDescendants();
return true;
}
if (shouldRepaintBeforeStyleChange == RequiredRepaint::RendererOnly) {
repaint();
return true;
}
return false;
}
void RenderElement::initializeStyle()
{
Style::loadPendingResources(m_style, document(), element());
styleWillChange(StyleDifference::NewStyle, style());
m_hasInitializedStyle = true;
styleDidChange(StyleDifference::NewStyle, nullptr);
// We shouldn't have any text children that would need styleDidChange at this point.
ASSERT(!childrenOfType<RenderText>(*this).first());
// 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(RenderStyle&& style, StyleDifference minimalStyleDifference)
{
// FIXME: Should change RenderView so it can use initializeStyle too.
// If we do that, we can assert m_hasInitializedStyle unconditionally,
// and remove the check of m_hasInitializedStyle below too.
ASSERT(m_hasInitializedStyle || isRenderView());
StyleDifference diff = StyleDifference::Equal;
OptionSet<StyleDifferenceContextSensitiveProperty> contextSensitiveProperties;
if (m_hasInitializedStyle)
diff = m_style.diff(style, contextSensitiveProperties);
diff = std::max(diff, minimalStyleDifference);
diff = adjustStyleDifference(diff, contextSensitiveProperties);
Style::loadPendingResources(style, document(), element());
auto didRepaint = repaintBeforeStyleChange(diff, m_style, style);
styleWillChange(diff, style);
auto oldStyle = m_style.replace(WTFMove(style));
bool detachedFromParent = !parent();
adjustFragmentedFlowStateOnContainingBlockChangeIfNeeded(oldStyle, m_style);
styleDidChange(diff, &oldStyle);
// Text renderers use their parent style. Notify them about the change.
for (auto& child : childrenOfType<RenderText>(*this))
child.styleDidChange(diff, &oldStyle);
// 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 detachedFromParent flag. We might want to broaden this condition
// in the future as we move renderer changes out of layout and into style changes.
if (detachedFromParent)
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 <= StyleDifference::LayoutPositionedMovementOnly) {
if (updatedDiff == StyleDifference::Layout)
setNeedsLayoutAndPrefWidthsRecalc();
else if (updatedDiff == StyleDifference::LayoutPositionedMovementOnly)
setNeedsPositionedMovementLayout(&oldStyle);
else if (updatedDiff == StyleDifference::SimplifiedLayoutAndPositionedMovement) {
setNeedsPositionedMovementLayout(&oldStyle);
setNeedsSimplifiedNormalFlowLayout();
} else if (updatedDiff == StyleDifference::SimplifiedLayout)
setNeedsSimplifiedNormalFlowLayout();
}
if (!didRepaint && (updatedDiff == StyleDifference::RepaintLayer || 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::didAttachChild(RenderObject& child, RenderObject*)
{
if (is<RenderText>(child))
downcast<RenderText>(child).styleDidChange(StyleDifference::Equal, nullptr);
// The following only applies to the legacy SVG engine -- LBSE always creates layers
// independant of the position in the render tree, see comment in layerCreationAllowedForSubtree().
// 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 (child.hasLayer() && !layerCreationAllowedForSubtree())
downcast<RenderLayerModelObject>(child).layer()->removeOnlyThisLayer(RenderLayer::LayerChangeTiming::RenderTreeConstruction);
}
RenderObject* RenderElement::attachRendererInternal(RenderPtr<RenderObject> child, RenderObject* beforeChild)
{
child->setParent(this);
if (m_firstChild == beforeChild)
m_firstChild = child.get();
if (beforeChild) {
auto* previousSibling = beforeChild->previousSibling();
if (previousSibling)
previousSibling->setNextSibling(child.get());
child->setPreviousSibling(previousSibling);
child->setNextSibling(beforeChild);
beforeChild->setPreviousSibling(child.get());
return child.release();
}
if (m_lastChild)
m_lastChild->setNextSibling(child.get());
child->setPreviousSibling(m_lastChild);
m_lastChild = child.get();
return child.release();
}
RenderPtr<RenderObject> RenderElement::detachRendererInternal(RenderObject& renderer)
{
auto* parent = renderer.parent();
ASSERT(parent);
auto* nextSibling = renderer.nextSibling();
if (renderer.previousSibling())
renderer.previousSibling()->setNextSibling(nextSibling);
if (nextSibling)
nextSibling->setPreviousSibling(renderer.previousSibling());
if (parent->firstChild() == &renderer)
parent->m_firstChild = nextSibling;
if (parent->lastChild() == &renderer)
parent->m_lastChild = renderer.previousSibling();
renderer.setPreviousSibling(nullptr);
renderer.setNextSibling(nullptr);
renderer.setParent(nullptr);
return RenderPtr<RenderObject>(&renderer);
}
static RenderLayer* findNextLayer(const RenderElement& currRenderer, const RenderLayer& parentLayer, const RenderObject* siblingToTraverseFrom, bool checkParent = true)
{
// Step 1: If our layer is a child of the desired parent, then return our layer.
auto* ourLayer = currRenderer.hasLayer() ? downcast<RenderLayerModelObject>(currRenderer).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 (auto* child = siblingToTraverseFrom ? siblingToTraverseFrom->nextSibling() : currRenderer.firstChild(); child; child = child->nextSibling()) {
if (!is<RenderElement>(*child))
continue;
if (auto* nextLayer = findNextLayer(downcast<RenderElement>(*child), parentLayer, nullptr, false))
return nextLayer;
}
}
// Step 3: If our layer is the desired parent layer, then we're finished. We didn't
// find anything.
if (ourLayer == &parentLayer)
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 && currRenderer.parent())
return findNextLayer(*currRenderer.parent(), parentLayer, &currRenderer, true);
return nullptr;
}
static RenderLayer* layerNextSiblingRespectingTopLayer(const RenderElement& renderer, const RenderLayer& parentLayer)
{
ASSERT_IMPLIES(isInTopLayerOrBackdrop(renderer.style(), renderer.element()), renderer.hasLayer());
if (is<RenderLayerModelObject>(renderer) && isInTopLayerOrBackdrop(renderer.style(), renderer.element())) {
auto& layerModelObject = downcast<RenderLayerModelObject>(renderer);
ASSERT(layerModelObject.hasLayer());
auto topLayerLayers = RenderLayer::topLayerRenderLayers(renderer.view());
auto layerIndex = topLayerLayers.find(layerModelObject.layer());
if (layerIndex != notFound && layerIndex < topLayerLayers.size() - 1)
return topLayerLayers[layerIndex + 1];
return nullptr;
}
return findNextLayer(*renderer.parent(), parentLayer, &renderer);
}
static void addLayers(const RenderElement& insertedRenderer, RenderElement& currentRenderer, RenderLayer& parentLayer)
{
if (currentRenderer.hasLayer()) {
auto* layerToUse = &parentLayer;
if (isInTopLayerOrBackdrop(currentRenderer.style(), currentRenderer.element())) {
// The special handling of a toplayer/backdrop content may result in trying to insert the associated
// layer twice as we connect subtrees.
if (auto* parentLayer = downcast<RenderLayerModelObject>(currentRenderer).layer()->parent()) {
ASSERT_UNUSED(parentLayer, parentLayer == currentRenderer.view().layer());
return;
}
layerToUse = insertedRenderer.view().layer();
}
auto* beforeChild = layerNextSiblingRespectingTopLayer(insertedRenderer, *layerToUse);
layerToUse->addChild(*downcast<RenderLayerModelObject>(currentRenderer).layer(), beforeChild);
return;
}
for (auto& child : childrenOfType<RenderElement>(currentRenderer))
addLayers(insertedRenderer, child, parentLayer);
}
void RenderElement::removeLayers()
{
RenderLayer* parentLayer = layerParent();
if (!parentLayer)
return;
if (hasLayer()) {
parentLayer->removeChild(*downcast<RenderLayerModelObject>(*this).layer());
return;
}
for (auto& child : childrenOfType<RenderElement>(*this))
child.removeLayers();
}
void RenderElement::moveLayers(RenderLayer& newParent)
{
if (hasLayer()) {
if (isInTopLayerOrBackdrop(style(), element()))
return;
RenderLayer* layer = downcast<RenderLayerModelObject>(*this).layer();
auto* layerParent = layer->parent();
if (layerParent)
layerParent->removeChild(*layer);
newParent.addChild(*layer);
return;
}
for (auto& child : childrenOfType<RenderElement>(*this))
child.moveLayers(newParent);
}
RenderLayer* RenderElement::layerParent() const
{
ASSERT_IMPLIES(isInTopLayerOrBackdrop(style(), element()), hasLayer());
if (hasLayer() && isInTopLayerOrBackdrop(style(), element()))
return view().layer();
return parent()->enclosingLayer();
}
// This answers the question "if this renderer had a layer, what would its next sibling layer be".
RenderLayer* RenderElement::layerNextSibling(RenderLayer& parentLayer) const
{
return WebCore::layerNextSiblingRespectingTopLayer(*this, parentLayer);
}
bool RenderElement::layerCreationAllowedForSubtree() const
{
#if ENABLE(LAYER_BASED_SVG_ENGINE)
// In LBSE layers are always created regardless of there position in the render tree.
// Consider the SVG document fragment: "<defs><mask><rect transform="scale(2)".../>"
// To paint the <rect> into the mask image, the rect needs to be transformed -
// which is handled via RenderLayer in LBSE, unlike as in the legacy engine where no
// layers are involved for any SVG painting features. In the legacy engine we could
// simply omit the layer creation for any children of a <defs> element (or in general
// any "hidden container"). For LBSE layers are needed for painting, even if a
// RenderSVGHiddenContainer is in the render tree ancestor chain -- however they are
// never painted directly, only indirectly through the "RenderSVGResourceContainer
// elements (such as RenderSVGResourceClipper, RenderSVGResourceMasker, etc.)
if (document().settings().layerBasedSVGEngineEnabled())
return true;
#endif
RenderElement* parentRenderer = parent();
while (parentRenderer) {
if (parentRenderer->isLegacySVGHiddenContainer())
return false;
parentRenderer = parentRenderer->parent();
}
return true;
}
void RenderElement::propagateStyleToAnonymousChildren(StylePropagationType propagationType)
{
// FIXME: We could save this call when the change only affected non-inherited properties.
for (auto& elementChild : childrenOfType<RenderElement>(*this)) {
if (!elementChild.isAnonymous() || elementChild.style().styleType() != PseudoId::None)
continue;
if (propagationType == PropagateToBlockChildrenOnly && !is<RenderBlock>(elementChild))
continue;
#if ENABLE(FULLSCREEN_API)
if (elementChild.isRenderFullScreen() || elementChild.isRenderFullScreenPlaceholder())
continue;
#endif
// RenderFragmentedFlows are updated through the RenderView::styleDidChange function.
if (is<RenderFragmentedFlow>(elementChild))
continue;
auto newStyle = RenderStyle::createAnonymousStyleWithDisplay(style(), elementChild.style().display());
if (style().specifiesColumns()) {
if (elementChild.style().specifiesColumns())
newStyle.inheritColumnPropertiesFrom(style());
if (elementChild.style().columnSpan() == ColumnSpan::All)
newStyle.setColumnSpan(ColumnSpan::All);
}
// 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() && elementChild.isContinuation())
newStyle.setPosition(elementChild.style().position());
updateAnonymousChildStyle(newStyle);
elementChild.setStyle(WTFMove(newStyle));
}
}
static inline bool rendererHasBackground(const RenderElement* renderer)
{
return renderer && renderer->hasBackground();
}
void RenderElement::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
{
ASSERT(settings().shouldAllowUserInstalledFonts() || newStyle.fontDescription().shouldAllowUserInstalledFonts() == AllowUserInstalledFonts::No);
auto* 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.usedZIndex() != newStyle.usedZIndex()
|| m_style.hasAutoUsedZIndex() != newStyle.hasAutoUsedZIndex();
if (visibilityChanged)
document().invalidateRenderingDependentRegions();
if (visibilityChanged) {
if (AXObjectCache* cache = document().existingAXObjectCache())
cache->childrenChanged(parent(), this);
}
// Keep layer hierarchy visibility bits up to date if visibility changes.
if (m_style.visibility() != newStyle.visibility()) {
if (RenderLayer* layer = enclosingLayer()) {
if (newStyle.visibility() == Visibility::Visible)
layer->setHasVisibleContent();
else if (layer->hasVisibleContent() && (this == &layer->renderer() || layer->renderer().style().visibility() != Visibility::Visible))
layer->dirtyVisibleContentStatus();
}
}
auto needsInvalidateEventRegion = [&] {
if (m_style.effectivePointerEvents() != newStyle.effectivePointerEvents())
return true;
#if ENABLE(TOUCH_ACTION_REGIONS)
if (m_style.effectiveTouchActions() != newStyle.effectiveTouchActions())
return true;
#endif
if (m_style.eventListenerRegionTypes() != newStyle.eventListenerRegionTypes())
return true;
#if ENABLE(EDITABLE_REGION)
bool wasEditable = m_style.effectiveUserModify() != UserModify::ReadOnly;
bool isEditable = newStyle.effectiveUserModify() != UserModify::ReadOnly;
if (wasEditable != isEditable)
return page().shouldBuildEditableRegion();
#endif
return false;
};
if (needsInvalidateEventRegion()) {
// Usually the event region gets updated as a result of paint invalidation. Here we need to request an update explicitly.
if (auto* layer = enclosingLayer())
layer->invalidateEventRegion(RenderLayer::EventRegionInvalidationReason::Style);
}
if (isFloating() && m_style.floating() != newStyle.floating()) {
// For changes in float styles, we need to conceivably remove ourselves
// from the floating objects list.
downcast<RenderBox>(*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.
downcast<RenderBox>(*this).removeFloatingOrPositionedChildFromBlockLists();
}
// reset style flags
if (diff == StyleDifference::Layout || diff == StyleDifference::LayoutPositionedMovementOnly) {
setFloating(false);
clearPositionedState();
}
setHorizontalWritingMode(true);
setHasVisibleBoxDecorations(false);
setHasNonVisibleOverflow(false);
setHasTransformRelatedProperty(false);
setHasReflection(false);
}
bool hadOutline = oldStyle && oldStyle->hasOutline();
bool hasOutline = newStyle.hasOutline();
if (hadOutline != hasOutline) {
if (hasOutline)
view().incrementRendersWithOutline();
else
view().decrementRendersWithOutline();
}
bool newStyleSlowScroll = false;
if (newStyle.hasAnyFixedBackground() && !settings().fixedBackgroundsPaintRelativeToDocument()) {
newStyleSlowScroll = true;
bool drawsRootBackground = isDocumentElementRenderer() || (isBody() && !rendererHasBackground(document().documentElement()->renderer()));
if (drawsRootBackground && newStyle.hasEntirelyFixedBackground() && view().compositor().supportsFixedRootBackgroundCompositing())
newStyleSlowScroll = false;
}
if (view().frameView().hasSlowRepaintObject(*this)) {
if (!newStyleSlowScroll)
view().frameView().removeSlowRepaintObject(*this);
} else if (newStyleSlowScroll)
view().frameView().addSlowRepaintObject(*this);
if (isDocumentElementRenderer() || isBody())
view().frameView().updateExtendBackgroundIfNecessary();
}
#if !PLATFORM(IOS_FAMILY)
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));
}
#endif
void RenderElement::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
auto registerImages = [this](auto& style, auto* oldStyle) {
updateFillImages(oldStyle ? &oldStyle->backgroundLayers() : nullptr, style.backgroundLayers());
updateFillImages(oldStyle ? &oldStyle->maskLayers() : nullptr, style.maskLayers());
updateImage(oldStyle ? oldStyle->borderImage().image() : nullptr, style.borderImage().image());
updateImage(oldStyle ? oldStyle->maskBoxImage().image() : nullptr, style.maskBoxImage().image());
updateShapeImage(oldStyle ? oldStyle->shapeOutside() : nullptr, style.shapeOutside());
};
registerImages(style(), oldStyle);
// Are there other pseudo-elements that need the resources to be registered?
if (auto* firstLineStyle = style().getCachedPseudoStyle(PseudoId::FirstLine))
registerImages(*firstLineStyle, oldStyle ? oldStyle->getCachedPseudoStyle(PseudoId::FirstLine) : nullptr);
SVGRenderSupport::styleChanged(*this, oldStyle);
if (diff >= StyleDifference::Repaint)
updateReferencedSVGResources();
if (!m_parent)
return;
if (diff == StyleDifference::Layout || diff == StyleDifference::SimplifiedLayout) {
RenderCounter::rendererStyleChanged(*this, oldStyle, m_style);
// 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 && oldStyle->position() != m_style.position())
markContainingBlocksForLayout();
if (diff == StyleDifference::Layout)
setNeedsLayoutAndPrefWidthsRecalc();
else
setNeedsSimplifiedNormalFlowLayout();
} else if (diff == StyleDifference::SimplifiedLayoutAndPositionedMovement) {
setNeedsPositionedMovementLayout(oldStyle);
setNeedsSimplifiedNormalFlowLayout();
} else if (diff == StyleDifference::LayoutPositionedMovementOnly)
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 !PLATFORM(IOS_FAMILY)
if (oldStyle && !areCursorsEqual(oldStyle, &style()))
frame().eventHandler().scheduleCursorUpdate();
#endif
bool hadOutlineAuto = oldStyle && oldStyle->outlineStyleIsAuto() == OutlineIsAuto::On;
bool hasOutlineAuto = outlineStyleForRepaint().outlineStyleIsAuto() == OutlineIsAuto::On;
if (hasOutlineAuto != hadOutlineAuto) {
updateOutlineAutoAncestor(hasOutlineAuto);
issueRepaintForOutlineAuto(hasOutlineAuto ? outlineStyleForRepaint().outlineSize() : oldStyle->outlineSize());
}
}
void RenderElement::insertedIntoTree(IsInternalMove isInternalMove)
{
// 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* parentLayer = nullptr;
if (firstChild() || hasLayer()) {
if (auto* parentLayer = layerParent())
addLayers(*this, *this, *parentLayer);
}
// 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() != Visibility::Visible && style().visibility() == Visibility::Visible && !hasLayer()) {
if (!parentLayer)
parentLayer = layerParent();
if (parentLayer)
parentLayer->dirtyVisibleContentStatus();
}
RenderObject::insertedIntoTree(isInternalMove);
}
void RenderElement::willBeRemovedFromTree(IsInternalMove isInternalMove)
{
// If we remove a visible child from an invisible parent, we don't know the layer visibility any more.
if (parent()->style().visibility() != Visibility::Visible && style().visibility() == Visibility::Visible && !hasLayer()) {
// FIXME: should get parent layer. Necessary?
if (auto* enclosingLayer = parent()->enclosingLayer())
enclosingLayer->dirtyVisibleContentStatus();
}
// Keep our layer hierarchy updated.
if (firstChild() || hasLayer())
removeLayers();
if (isOutOfFlowPositioned() && parent()->childrenInline())
parent()->dirtyLinesFromChangedChild(*this);