Source/WebCore/rendering/RenderElement.cpp

   1 /*
   2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
   3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
   4  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
   5  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
   6  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
   7  * Copyright (C) 2010, 2012 Google Inc. All rights reserved.
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Library General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Library General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Library General Public License
  20  * along with this library; see the file COPYING.LIB.  If not, write to
  21  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22  * Boston, MA 02110-1301, USA.
  23  */
  24
  25 #include "config.h"
  26 #include "RenderElement.h"
  27
  28 #include "AXObjectCache.h"
  29 #include "ContentData.h"
  30 #include "ControlStates.h"
  31 #include "CursorList.h"
  32 #include "ElementChildIterator.h"
  33 #include "EventHandler.h"
  34 #include "Frame.h"
  35 #include "FrameSelection.h"
  36 #include "HTMLBodyElement.h"
  37 #include "HTMLHtmlElement.h"
  38 #include "HTMLNames.h"
  39 #include "FlowThreadController.h"
  40 #include "RenderBlock.h"
  41 #include "RenderCounter.h"
  42 #include "RenderDeprecatedFlexibleBox.h"
  43 #include "RenderFlexibleBox.h"
  44 #include "RenderImage.h"
  45 #include "RenderImageResourceStyleImage.h"
  46 #include "RenderInline.h"
  47 #include "RenderIterator.h"
  48 #include "RenderLayer.h"
  49 #include "RenderLayerCompositor.h"
  50 #include "RenderLineBreak.h"
  51 #include "RenderListItem.h"
  52 #include "RenderNamedFlowThread.h"
  53 #include "RenderRegion.h"
  54 #include "RenderTableCaption.h"
  55 #include "RenderTableCell.h"
  56 #include "RenderTableCol.h"
  57 #include "RenderTableRow.h"
  58 #include "RenderText.h"
  59 #include "RenderTheme.h"
  60 #include "RenderView.h"
  61 #include "SVGRenderSupport.h"
  62 #include "Settings.h"
  63 #include "ShadowRoot.h"
  64 #include "StyleResolver.h"
  65 #include <wtf/MathExtras.h>
  66 #include <wtf/StackStats.h>
  67
  68 #if ENABLE(CSS_GRID_LAYOUT)
  69 #include "RenderGrid.h"
  70 #endif
  71
  72 namespace WebCore {
  73
  74 bool RenderElement::s_affectsParentBlock = false;
  75 bool RenderElement::s_noLongerAffectsParentBlock = false;
  76
  77 static HashMap<const RenderObject*, ControlStates*>& controlStatesRendererMap()
  78 {
  79     static NeverDestroyed<HashMap<const RenderObject*, ControlStates*>> map;
  80     return map;
  81 }
  82
  83 inline RenderElement::RenderElement(ContainerNode& elementOrDocument, Ref<RenderStyle>&& style, unsigned baseTypeFlags)
  84     : RenderObject(elementOrDocument)
  85     , m_baseTypeFlags(baseTypeFlags)
  86     , m_ancestorLineBoxDirty(false)
  87     , m_hasInitializedStyle(false)
  88     , m_renderInlineAlwaysCreatesLineBoxes(false)
  89     , m_renderBoxNeedsLazyRepaint(false)
  90     , m_hasPausedImageAnimations(false)
  91     , m_hasCounterNodeMap(false)
  92     , m_isCSSAnimating(false)
  93     , m_hasContinuation(false)
  94     , m_renderBlockHasMarginBeforeQuirk(false)
  95     , m_renderBlockHasMarginAfterQuirk(false)
  96     , m_renderBlockHasBorderOrPaddingLogicalWidthChanged(false)
  97     , m_renderBlockFlowHasMarkupTruncation(false)
  98     , m_renderBlockFlowLineLayoutPath(RenderBlockFlow::UndeterminedPath)
  99     , m_firstChild(nullptr)
 100     , m_lastChild(nullptr)
 101     , m_style(WTF::move(style))
 102 {
 103 }
 104
 105 RenderElement::RenderElement(Element& element, Ref<RenderStyle>&& style, unsigned baseTypeFlags)
 106     : RenderElement(static_cast<ContainerNode&>(element), WTF::move(style), baseTypeFlags)
 107 {
 108 }
 109
 110 RenderElement::RenderElement(Document& document, Ref<RenderStyle>&& style, unsigned baseTypeFlags)
 111     : RenderElement(static_cast<ContainerNode&>(document), WTF::move(style), baseTypeFlags)
 112 {
 113 }
 114
 115 RenderElement::~RenderElement()
 116 {
 117     if (hasInitializedStyle()) {
 118         for (const FillLayer* bgLayer = m_style->backgroundLayers(); bgLayer; bgLayer = bgLayer->next()) {
 119             if (StyleImage* backgroundImage = bgLayer->image())
 120                 backgroundImage->removeClient(this);
 121         }
 122
 123         for (const FillLayer* maskLayer = m_style->maskLayers(); maskLayer; maskLayer = maskLayer->next()) {
 124             if (StyleImage* maskImage = maskLayer->image())
 125                 maskImage->removeClient(this);
 126             else if (maskLayer->maskImage().get())
 127                 maskLayer->maskImage()->removeRendererImageClient(this);
 128         }
 129
 130         if (StyleImage* borderImage = m_style->borderImage().image())
 131             borderImage->removeClient(this);
 132
 133         if (StyleImage* maskBoxImage = m_style->maskBoxImage().image())
 134             maskBoxImage->removeClient(this);
 135
 136 #if ENABLE(CSS_SHAPES)
 137         if (auto shapeValue = m_style->shapeOutside()) {
 138             if (auto shapeImage = shapeValue->image())
 139                 shapeImage->removeClient(this);
 140         }
 141 #endif
 142     }
 143     if (m_hasPausedImageAnimations)
 144         view().removeRendererWithPausedImageAnimations(*this);
 145 }
 146
 147 RenderPtr<RenderElement> RenderElement::createFor(Element& element, Ref<RenderStyle>&& style)
 148 {
 149     // Minimal support for content properties replacing an entire element.
 150     // Works only if we have exactly one piece of content and it's a URL.
 151     // Otherwise acts as if we didn't support this feature.
 152     const ContentData* contentData = style.get().contentData();
 153     if (contentData && !contentData->next() && is<ImageContentData>(*contentData) && !element.isPseudoElement()) {
 154         auto& styleImage = downcast<ImageContentData>(*contentData).image();
 155         auto image = createRenderer<RenderImage>(element, WTF::move(style), const_cast<StyleImage*>(&styleImage));
 156         image->setIsGeneratedContent();
 157         return WTF::move(image);
 158     }
 159
 160     switch (style.get().display()) {
 161     case NONE:
 162         return nullptr;
 163     case INLINE:
 164         return createRenderer<RenderInline>(element, WTF::move(style));
 165     case BLOCK:
 166     case INLINE_BLOCK:
 167     case COMPACT:
 168         return createRenderer<RenderBlockFlow>(element, WTF::move(style));
 169     case LIST_ITEM:
 170         return createRenderer<RenderListItem>(element, WTF::move(style));
 171     case TABLE:
 172     case INLINE_TABLE:
 173         return createRenderer<RenderTable>(element, WTF::move(style));
 174     case TABLE_ROW_GROUP:
 175     case TABLE_HEADER_GROUP:
 176     case TABLE_FOOTER_GROUP:
 177         return createRenderer<RenderTableSection>(element, WTF::move(style));
 178     case TABLE_ROW:
 179         return createRenderer<RenderTableRow>(element, WTF::move(style));
 180     case TABLE_COLUMN_GROUP:
 181     case TABLE_COLUMN:
 182         return createRenderer<RenderTableCol>(element, WTF::move(style));
 183     case TABLE_CELL:
 184         return createRenderer<RenderTableCell>(element, WTF::move(style));
 185     case TABLE_CAPTION:
 186         return createRenderer<RenderTableCaption>(element, WTF::move(style));
 187     case BOX:
 188     case INLINE_BOX:
 189         return createRenderer<RenderDeprecatedFlexibleBox>(element, WTF::move(style));
 190     case FLEX:
 191     case INLINE_FLEX:
 192     case WEBKIT_FLEX:
 193     case WEBKIT_INLINE_FLEX:
 194         return createRenderer<RenderFlexibleBox>(element, WTF::move(style));
 195 #if ENABLE(CSS_GRID_LAYOUT)
 196     case GRID:
 197     case INLINE_GRID:
 198         return createRenderer<RenderGrid>(element, WTF::move(style));
 199 #endif
 200     }
 201     ASSERT_NOT_REACHED();
 202     return nullptr;
 203 }
 204
 205 enum StyleCacheState {
 206     Cached,
 207     Uncached
 208 };
 209
 210 static PassRefPtr<RenderStyle> firstLineStyleForCachedUncachedType(StyleCacheState type, const RenderElement& renderer, RenderStyle* style)
 211 {
 212     RenderElement& rendererForFirstLineStyle = renderer.isBeforeOrAfterContent() ? *renderer.parent() : const_cast<RenderElement&>(renderer);
 213
 214     if (rendererForFirstLineStyle.isRenderBlockFlow() || rendererForFirstLineStyle.isRenderButton()) {
 215         if (RenderBlock* firstLineBlock = rendererForFirstLineStyle.firstLineBlock()) {
 216             if (type == Cached)
 217                 return firstLineBlock->getCachedPseudoStyle(FIRST_LINE, style);
 218             return firstLineBlock->getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE), style, firstLineBlock == &renderer ? style : nullptr);
 219         }
 220     } else if (!rendererForFirstLineStyle.isAnonymous() && rendererForFirstLineStyle.isRenderInline()) {
 221         RenderStyle& parentStyle = rendererForFirstLineStyle.parent()->firstLineStyle();
 222         if (&parentStyle != &rendererForFirstLineStyle.parent()->style()) {
 223             if (type == Cached) {
 224                 // A first-line style is in effect. Cache a first-line style for ourselves.
 225                 rendererForFirstLineStyle.style().setHasPseudoStyle(FIRST_LINE_INHERITED);
 226                 return rendererForFirstLineStyle.getCachedPseudoStyle(FIRST_LINE_INHERITED, &parentStyle);
 227             }
 228             return rendererForFirstLineStyle.getUncachedPseudoStyle(PseudoStyleRequest(FIRST_LINE_INHERITED), &parentStyle, style);
 229         }
 230     }
 231     return nullptr;
 232 }
 233
 234 PassRefPtr<RenderStyle> RenderElement::uncachedFirstLineStyle(RenderStyle* style) const
 235 {
 236     if (!document().styleSheetCollection().usesFirstLineRules())
 237         return nullptr;
 238
 239     return firstLineStyleForCachedUncachedType(Uncached, *this, style);
 240 }
 241
 242 RenderStyle* RenderElement::cachedFirstLineStyle() const
 243 {
 244     ASSERT(document().styleSheetCollection().usesFirstLineRules());
 245
 246     RenderStyle& style = this->style();
 247     if (RefPtr<RenderStyle> firstLineStyle = firstLineStyleForCachedUncachedType(Cached, *this, &style))
 248         return firstLineStyle.get();
 249
 250     return &style;
 251 }
 252
 253 StyleDifference RenderElement::adjustStyleDifference(StyleDifference diff, unsigned contextSensitiveProperties) const
 254 {
 255     // If transform changed, and we are not composited, need to do a layout.
 256     if (contextSensitiveProperties & ContextSensitivePropertyTransform) {
 257         // FIXME: when transforms are taken into account for overflow, we will need to do a layout.
 258         if (!hasLayer() || !downcast<RenderLayerModelObject>(*this).layer()->isComposited()) {
 259             if (!hasLayer())
 260                 diff = std::max(diff, StyleDifferenceLayout);
 261             else {
 262                 // We need to set at least SimplifiedLayout, but if PositionedMovementOnly is already set
 263                 // then we actually need SimplifiedLayoutAndPositionedMovement.
 264                 diff = std::max(diff, (diff == StyleDifferenceLayoutPositionedMovementOnly) ? StyleDifferenceSimplifiedLayoutAndPositionedMovement : StyleDifferenceSimplifiedLayout);
 265             }
 266
 267         } else
 268             diff = std::max(diff, StyleDifferenceRecompositeLayer);
 269     }
 270
 271     if (contextSensitiveProperties & ContextSensitivePropertyOpacity) {
 272         if (!hasLayer() || !downcast<RenderLayerModelObject>(*this).layer()->isComposited())
 273             diff = std::max(diff, StyleDifferenceRepaintLayer);
 274         else
 275             diff = std::max(diff, StyleDifferenceRecompositeLayer);
 276     }
 277
 278     if (contextSensitiveProperties & ContextSensitivePropertyClipPath) {
 279         if (hasLayer()
 280             && downcast<RenderLayerModelObject>(*this).layer()->isComposited()
 281             && hasClipPath()
 282             && RenderLayerCompositor::canCompositeClipPath(*downcast<RenderLayerModelObject>(*this).layer()))
 283             diff = std::max(diff, StyleDifferenceRecompositeLayer);
 284         else
 285             diff = std::max(diff, StyleDifferenceRepaint);
 286     }
 287
 288     if ((contextSensitiveProperties & ContextSensitivePropertyFilter) && hasLayer()) {
 289         RenderLayer* layer = downcast<RenderLayerModelObject>(*this).layer();
 290         if (!layer->isComposited() || layer->paintsWithFilters())
 291             diff = std::max(diff, StyleDifferenceRepaintLayer);
 292         else
 293             diff = std::max(diff, StyleDifferenceRecompositeLayer);
 294     }
 295
 296     // The answer to requiresLayer() for plugins, iframes, and canvas can change without the actual
 297     // style changing, since it depends on whether we decide to composite these elements. When the
 298     // layer status of one of these elements changes, we need to force a layout.
 299     if (diff < StyleDifferenceLayout && isRenderLayerModelObject()) {
 300         if (hasLayer() != downcast<RenderLayerModelObject>(*this).requiresLayer())
 301             diff = StyleDifferenceLayout;
 302     }
 303
 304     // If we have no layer(), just treat a RepaintLayer hint as a normal Repaint.
 305     if (diff == StyleDifferenceRepaintLayer && !hasLayer())
 306         diff = StyleDifferenceRepaint;
 307
 308     return diff;
 309 }
 310
 311 inline bool RenderElement::hasImmediateNonWhitespaceTextChildOrBorderOrOutline() const
 312 {
 313     for (auto& child : childrenOfType<RenderObject>(*this)) {
 314         if (is<RenderText>(child) && !downcast<RenderText>(child).isAllCollapsibleWhitespace())
 315             return true;
 316         if (child.style().hasOutline() || child.style().hasBorder())
 317             return true;
 318     }
 319     return false;
 320 }
 321
 322 inline bool RenderElement::shouldRepaintForStyleDifference(StyleDifference diff) const
 323 {
 324     return diff == StyleDifferenceRepaint || (diff == StyleDifferenceRepaintIfTextOrBorderOrOutline && hasImmediateNonWhitespaceTextChildOrBorderOrOutline());
 325 }
 326
 327 void RenderElement::updateFillImages(const FillLayer* oldLayers, const FillLayer* newLayers)
 328 {
 329     // Optimize the common case
 330     if (FillLayer::imagesIdentical(oldLayers, newLayers))
 331         return;
 332
 333     // Go through the new layers and addClients first, to avoid removing all clients of an image.
 334     for (const FillLayer* currNew = newLayers; currNew; currNew = currNew->next()) {
 335         if (StyleImage* image = currNew->image())
 336             image->addClient(this);
 337         else if (currNew->maskImage().get())
 338             currNew->maskImage()->addRendererImageClient(this);
 339     }
 340
 341     for (const FillLayer* currOld = oldLayers; currOld; currOld = currOld->next()) {
 342         if (StyleImage* image = currOld->image())
 343             image->removeClient(this);
 344         else if (currOld->maskImage().get())
 345             currOld->maskImage()->removeRendererImageClient(this);
 346     }
 347 }
 348
 349 void RenderElement::updateImage(StyleImage* oldImage, StyleImage* newImage)
 350 {
 351     if (oldImage == newImage)
 352         return;
 353     if (oldImage)
 354         oldImage->removeClient(this);
 355     if (newImage)
 356         newImage->addClient(this);
 357 }
 358
 359 #if ENABLE(CSS_SHAPES)
 360 void RenderElement::updateShapeImage(const ShapeValue* oldShapeValue, const ShapeValue* newShapeValue)
 361 {
 362     if (oldShapeValue || newShapeValue)
 363         updateImage(oldShapeValue ? oldShapeValue->image() : nullptr, newShapeValue ? newShapeValue->image() : nullptr);
 364 }
 365 #endif
 366
 367 void RenderElement::initializeStyle()
 368 {
 369     styleWillChange(StyleDifferenceNewStyle, style());
 370
 371     m_hasInitializedStyle = true;
 372
 373     updateFillImages(nullptr, m_style->backgroundLayers());
 374     updateFillImages(nullptr, m_style->maskLayers());
 375
 376     updateImage(nullptr, m_style->borderImage().image());
 377     updateImage(nullptr, m_style->maskBoxImage().image());
 378
 379 #if ENABLE(CSS_SHAPES)
 380     updateShapeImage(nullptr, m_style->shapeOutside());
 381 #endif
 382
 383     // We need to ensure that view->maximalOutlineSize() is valid for any repaints that happen
 384     // during styleDidChange (it's used by clippedOverflowRectForRepaint()).
 385     if (m_style->outlineWidth() > 0 && m_style->outlineSize() > maximalOutlineSize(PaintPhaseOutline))
 386         view().setMaximalOutlineSize(std::max(theme().platformFocusRingMaxWidth(), static_cast<int>(m_style->outlineSize())));
 387
 388     styleDidChange(StyleDifferenceNewStyle, nullptr);
 389
 390     // We shouldn't have any text children that would need styleDidChange at this point.
 391     ASSERT(!childrenOfType<RenderText>(*this).first());
 392
 393     // It would be nice to assert that !parent() here, but some RenderLayer subrenderers
 394     // have their parent set before getting a call to initializeStyle() :|
 395 }
 396
 397 void RenderElement::setStyle(Ref<RenderStyle>&& style, StyleDifference minimalStyleDifference)
 398 {
 399     // FIXME: Should change RenderView so it can use initializeStyle too.
 400     // If we do that, we can assert m_hasInitializedStyle unconditionally,
 401     // and remove the check of m_hasInitializedStyle below too.
 402     ASSERT(m_hasInitializedStyle || isRenderView());
 403
 404     if (m_style.ptr() == style.ptr()) {
 405         // FIXME: Can we change things so we never hit this code path?
 406         // We need to run through adjustStyleDifference() for iframes, plugins, and canvas so
 407         // style sharing is disabled for them. That should ensure that we never hit this code path.
 408         ASSERT(!isRenderIFrame());
 409         ASSERT(!isEmbeddedObject());
 410         ASSERT(!isCanvas());
 411         ASSERT(minimalStyleDifference == StyleDifferenceEqual);
 412         return;
 413     }
 414
 415     StyleDifference diff = StyleDifferenceEqual;
 416     unsigned contextSensitiveProperties = ContextSensitivePropertyNone;
 417     if (m_hasInitializedStyle)
 418         diff = m_style->diff(style.get(), contextSensitiveProperties);
 419
 420     diff = std::max(diff, minimalStyleDifference);
 421
 422     diff = adjustStyleDifference(diff, contextSensitiveProperties);
 423
 424     styleWillChange(diff, style.get());
 425
 426     Ref<RenderStyle> oldStyle(m_style.replace(WTF::move(style)));
 427
 428     updateFillImages(oldStyle.get().backgroundLayers(), m_style->backgroundLayers());
 429     updateFillImages(oldStyle.get().maskLayers(), m_style->maskLayers());
 430
 431     updateImage(oldStyle.get().borderImage().image(), m_style->borderImage().image());
 432     updateImage(oldStyle.get().maskBoxImage().image(), m_style->maskBoxImage().image());
 433
 434 #if ENABLE(CSS_SHAPES)
 435     updateShapeImage(oldStyle.get().shapeOutside(), m_style->shapeOutside());
 436 #endif
 437
 438     // We need to ensure that view->maximalOutlineSize() is valid for any repaints that happen
 439     // during styleDidChange (it's used by clippedOverflowRectForRepaint()).
 440     if (m_style->outlineWidth() > 0 && m_style->outlineSize() > maximalOutlineSize(PaintPhaseOutline))
 441         view().setMaximalOutlineSize(std::max(theme().platformFocusRingMaxWidth(), static_cast<int>(m_style->outlineSize())));
 442
 443     bool doesNotNeedLayout = !parent();
 444
 445     styleDidChange(diff, oldStyle.ptr());
 446
 447     // Text renderers use their parent style. Notify them about the change.
 448     for (auto& child : childrenOfType<RenderText>(*this))
 449         child.styleDidChange(diff, oldStyle.ptr());
 450
 451     // FIXME: |this| might be destroyed here. This can currently happen for a RenderTextFragment when
 452     // its first-letter block gets an update in RenderTextFragment::styleDidChange. For RenderTextFragment(s),
 453     // we will safely bail out with the doesNotNeedLayout flag. We might want to broaden this condition
 454     // in the future as we move renderer changes out of layout and into style changes.
 455     if (doesNotNeedLayout)
 456         return;
 457
 458     // Now that the layer (if any) has been updated, we need to adjust the diff again,
 459     // check whether we should layout now, and decide if we need to repaint.
 460     StyleDifference updatedDiff = adjustStyleDifference(diff, contextSensitiveProperties);
 461
 462     if (diff <= StyleDifferenceLayoutPositionedMovementOnly) {
 463         if (updatedDiff == StyleDifferenceLayout)
 464             setNeedsLayoutAndPrefWidthsRecalc();
 465         else if (updatedDiff == StyleDifferenceLayoutPositionedMovementOnly)
 466             setNeedsPositionedMovementLayout(oldStyle.ptr());
 467         else if (updatedDiff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
 468             setNeedsPositionedMovementLayout(oldStyle.ptr());
 469             setNeedsSimplifiedNormalFlowLayout();
 470         } else if (updatedDiff == StyleDifferenceSimplifiedLayout)
 471             setNeedsSimplifiedNormalFlowLayout();
 472     }
 473
 474     if (updatedDiff == StyleDifferenceRepaintLayer || shouldRepaintForStyleDifference(updatedDiff)) {
 475         // Do a repaint with the new style now, e.g., for example if we go from
 476         // not having an outline to having an outline.
 477         repaint();
 478     }
 479 }
 480
 481 void RenderElement::addChild(RenderObject* newChild, RenderObject* beforeChild)
 482 {
 483     bool needsTable = false;
 484
 485     if (is<RenderTableCol>(*newChild)) {
 486         RenderTableCol& newTableColumn = downcast<RenderTableCol>(*newChild);
 487         bool isColumnInColumnGroup = newTableColumn.isTableColumn() && is<RenderTableCol>(*this);
 488         needsTable = !is<RenderTable>(*this) && !isColumnInColumnGroup;
 489     } else if (is<RenderTableCaption>(*newChild))
 490         needsTable = !is<RenderTable>(*this);
 491     else if (is<RenderTableSection>(*newChild))
 492         needsTable = !is<RenderTable>(*this);
 493     else if (is<RenderTableRow>(*newChild))
 494         needsTable = !is<RenderTableSection>(*this);
 495     else if (is<RenderTableCell>(*newChild))
 496         needsTable = !is<RenderTableRow>(*this);
 497
 498     if (needsTable) {
 499         RenderTable* table;
 500         RenderObject* afterChild = beforeChild ? beforeChild->previousSibling() : m_lastChild;
 501         if (afterChild && afterChild->isAnonymous() && is<RenderTable>(*afterChild) && !afterChild->isBeforeContent())
 502             table = downcast<RenderTable>(afterChild);
 503         else {
 504             table = RenderTable::createAnonymousWithParentRenderer(this);
 505             addChild(table, beforeChild);
 506         }
 507         table->addChild(newChild);
 508     } else
 509         insertChildInternal(newChild, beforeChild, NotifyChildren);
 510
 511     if (is<RenderText>(*newChild))
 512         downcast<RenderText>(*newChild).styleDidChange(StyleDifferenceEqual, nullptr);
 513
 514     // SVG creates renderers for <g display="none">, as SVG requires children of hidden
 515     // <g>s to have renderers - at least that's how our implementation works. Consider:
 516     // <g display="none"><foreignObject><body style="position: relative">FOO...
 517     // - requiresLayer() would return true for the <body>, creating a new RenderLayer
 518     // - when the document is painted, both layers are painted. The <body> layer doesn't
 519     //   know that it's inside a "hidden SVG subtree", and thus paints, even if it shouldn't.
 520     // To avoid the problem alltogether, detect early if we're inside a hidden SVG subtree
 521     // and stop creating layers at all for these cases - they're not used anyways.
 522     if (newChild->hasLayer() && !layerCreationAllowedForSubtree())
 523         downcast<RenderLayerModelObject>(*newChild).layer()->removeOnlyThisLayer();
 524
 525     SVGRenderSupport::childAdded(*this, *newChild);
 526 }
 527
 528 void RenderElement::removeChild(RenderObject& oldChild)
 529 {
 530     removeChildInternal(oldChild, NotifyChildren);
 531 }
 532
 533 void RenderElement::destroyLeftoverChildren()
 534 {
 535     while (m_firstChild) {
 536         if (m_firstChild->style().styleType() == FIRST_LETTER && !m_firstChild->isText()) {
 537             m_firstChild->removeFromParent(); // :first-letter fragment renderers are destroyed by their remaining text fragment.
 538         } else {
 539             // 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.
 540             if (m_firstChild->node())
 541                 m_firstChild->node()->setRenderer(nullptr);
 542             m_firstChild->destroy();
 543         }
 544     }
 545 }
 546
 547 void RenderElement::insertChildInternal(RenderObject* newChild, RenderObject* beforeChild, NotifyChildrenType notifyChildren)
 548 {
 549     ASSERT(canHaveChildren() || canHaveGeneratedChildren());
 550     ASSERT(!newChild->parent());
 551     ASSERT(!isRenderBlockFlow() || (!newChild->isTableSection() && !newChild->isTableRow() && !newChild->isTableCell()));
 552
 553     while (beforeChild && beforeChild->parent() && beforeChild->parent() != this)
 554         beforeChild = beforeChild->parent();
 555
 556     // This should never happen, but if it does prevent render tree corruption
 557     // where child->parent() ends up being owner but child->nextSibling()->parent()
 558     // is not owner.
 559     if (beforeChild && beforeChild->parent() != this) {
 560         ASSERT_NOT_REACHED();
 561         return;
 562     }
 563
 564     newChild->setParent(this);
 565
 566     if (m_firstChild == beforeChild)
 567         m_firstChild = newChild;
 568
 569     if (beforeChild) {
 570         RenderObject* previousSibling = beforeChild->previousSibling();
 571         if (previousSibling)
 572             previousSibling->setNextSibling(newChild);
 573         newChild->setPreviousSibling(previousSibling);
 574         newChild->setNextSibling(beforeChild);
 575         beforeChild->setPreviousSibling(newChild);
 576     } else {
 577         if (lastChild())
 578             lastChild()->setNextSibling(newChild);
 579         newChild->setPreviousSibling(lastChild());
 580         m_lastChild = newChild;
 581     }
 582
 583     if (!documentBeingDestroyed()) {
 584         if (notifyChildren == NotifyChildren)
 585             newChild->insertedIntoTree();
 586         if (is<RenderElement>(*newChild))
 587             RenderCounter::rendererSubtreeAttached(downcast<RenderElement>(*newChild));
 588     }
 589
 590     newChild->setNeedsLayoutAndPrefWidthsRecalc();
 591     setPreferredLogicalWidthsDirty(true);
 592     if (!normalChildNeedsLayout())
 593         setChildNeedsLayout(); // We may supply the static position for an absolute positioned child.
 594
 595     if (AXObjectCache* cache = document().axObjectCache())
 596         cache->childrenChanged(this, newChild);
 597 }
 598
 599 void RenderElement::removeChildInternal(RenderObject& oldChild, NotifyChildrenType notifyChildren)
 600 {
 601     ASSERT(canHaveChildren() || canHaveGeneratedChildren());
 602     ASSERT(oldChild.parent() == this);
 603
 604     if (oldChild.isFloatingOrOutOfFlowPositioned())
 605         downcast<RenderBox>(oldChild).removeFloatingOrPositionedChildFromBlockLists();
 606
 607     // So that we'll get the appropriate dirty bit set (either that a normal flow child got yanked or
 608     // that a positioned child got yanked). We also repaint, so that the area exposed when the child
 609     // disappears gets repainted properly.
 610     if (!documentBeingDestroyed() && notifyChildren == NotifyChildren && oldChild.everHadLayout()) {
 611         oldChild.setNeedsLayoutAndPrefWidthsRecalc();
 612         // We only repaint |oldChild| if we have a RenderLayer as its visual overflow may not be tracked by its parent.
 613         if (oldChild.isBody())
 614             view().repaintRootContents();
 615         else
 616             oldChild.repaint();
 617     }
 618
 619     // If we have a line box wrapper, delete it.
 620     if (is<RenderBox>(oldChild))
 621         downcast<RenderBox>(oldChild).deleteLineBoxWrapper();
 622     else if (is<RenderLineBreak>(oldChild))
 623         downcast<RenderLineBreak>(oldChild).deleteInlineBoxWrapper();
 624
 625     // If oldChild is the start or end of the selection, then clear the selection to
 626     // avoid problems of invalid pointers.
 627     if (!documentBeingDestroyed() && oldChild.isSelectionBorder())
 628         frame().selection().setNeedsSelectionUpdate();
 629
 630     if (!documentBeingDestroyed() && notifyChildren == NotifyChildren)
 631         oldChild.willBeRemovedFromTree();
 632
 633     // WARNING: There should be no code running between willBeRemovedFromTree and the actual removal below.
 634     // This is needed to avoid race conditions where willBeRemovedFromTree would dirty the tree's structure
 635     // and the code running here would force an untimely rebuilding, leaving |oldChild| dangling.
 636
 637     RenderObject* nextSibling = oldChild.nextSibling();
 638
 639     if (oldChild.previousSibling())
 640         oldChild.previousSibling()->setNextSibling(nextSibling);
 641     if (nextSibling)
 642         nextSibling->setPreviousSibling(oldChild.previousSibling());
 643
 644     if (m_firstChild == &oldChild)
 645         m_firstChild = nextSibling;
 646     if (m_lastChild == &oldChild)
 647         m_lastChild = oldChild.previousSibling();
 648
 649     oldChild.setPreviousSibling(nullptr);
 650     oldChild.setNextSibling(nullptr);
 651     oldChild.setParent(nullptr);
 652
 653     // rendererRemovedFromTree walks the whole subtree. We can improve performance
 654     // by skipping this step when destroying the entire tree.
 655     if (!documentBeingDestroyed() && is<RenderElement>(oldChild))
 656         RenderCounter::rendererRemovedFromTree(downcast<RenderElement>(oldChild));
 657
 658     if (AXObjectCache* cache = document().existingAXObjectCache())
 659         cache->childrenChanged(this);
 660 }
 661
 662 static void addLayers(RenderElement& renderer, RenderLayer* parentLayer, RenderElement*& newObject, RenderLayer*& beforeChild)
 663 {
 664     if (renderer.hasLayer()) {
 665         if (!beforeChild && newObject) {
 666             // We need to figure out the layer that follows newObject. We only do
 667             // this the first time we find a child layer, and then we update the
 668             // pointer values for newObject and beforeChild used by everyone else.
 669             beforeChild = newObject->parent()->findNextLayer(parentLayer, newObject);
 670             newObject = nullptr;
 671         }
 672         parentLayer->addChild(downcast<RenderLayerModelObject>(renderer).layer(), beforeChild);
 673         return;
 674     }
 675
 676     for (auto& child : childrenOfType<RenderElement>(renderer))
 677         addLayers(child, parentLayer, newObject, beforeChild);
 678 }
 679
 680 void RenderElement::addLayers(RenderLayer* parentLayer)
 681 {
 682     if (!parentLayer)
 683         return;
 684
 685     RenderElement* renderer = this;
 686     RenderLayer* beforeChild = nullptr;
 687     WebCore::addLayers(*this, parentLayer, renderer, beforeChild);
 688 }
 689
 690 void RenderElement::removeLayers(RenderLayer* parentLayer)
 691 {
 692     if (!parentLayer)
 693         return;
 694
 695     if (hasLayer()) {
 696         parentLayer->removeChild(downcast<RenderLayerModelObject>(*this).layer());
 697         return;
 698     }
 699
 700     for (auto& child : childrenOfType<RenderElement>(*this))
 701         child.removeLayers(parentLayer);
 702 }
 703
 704 void RenderElement::moveLayers(RenderLayer* oldParent, RenderLayer* newParent)
 705 {
 706     if (!newParent)
 707         return;
 708
 709     if (hasLayer()) {
 710         RenderLayer* layer = downcast<RenderLayerModelObject>(*this).layer();
 711         ASSERT(oldParent == layer->parent());
 712         if (oldParent)
 713             oldParent->removeChild(layer);
 714         newParent->addChild(layer);
 715         return;
 716     }
 717
 718     for (auto& child : childrenOfType<RenderElement>(*this))
 719         child.moveLayers(oldParent, newParent);
 720 }
 721
 722 RenderLayer* RenderElement::findNextLayer(RenderLayer* parentLayer, RenderObject* startPoint, bool checkParent)
 723 {
 724     // Error check the parent layer passed in. If it's null, we can't find anything.
 725     if (!parentLayer)
 726         return nullptr;
 727
 728     // Step 1: If our layer is a child of the desired parent, then return our layer.
 729     RenderLayer* ourLayer = hasLayer() ? downcast<RenderLayerModelObject>(*this).layer() : nullptr;
 730     if (ourLayer && ourLayer->parent() == parentLayer)
 731         return ourLayer;
 732
 733     // Step 2: If we don't have a layer, or our layer is the desired parent, then descend
 734     // into our siblings trying to find the next layer whose parent is the desired parent.
 735     if (!ourLayer || ourLayer == parentLayer) {
 736         for (RenderObject* child = startPoint ? startPoint->nextSibling() : firstChild(); child; child = child->nextSibling()) {
 737             if (!is<RenderElement>(*child))
 738                 continue;
 739             RenderLayer* nextLayer = downcast<RenderElement>(*child).findNextLayer(parentLayer, nullptr, false);
 740             if (nextLayer)
 741                 return nextLayer;
 742         }
 743     }
 744
 745     // Step 3: If our layer is the desired parent layer, then we're finished. We didn't
 746     // find anything.
 747     if (parentLayer == ourLayer)
 748         return nullptr;
 749
 750     // Step 4: If |checkParent| is set, climb up to our parent and check its siblings that
 751     // follow us to see if we can locate a layer.
 752     if (checkParent && parent())
 753         return parent()->findNextLayer(parentLayer, this, true);
 754
 755     return nullptr;
 756 }
 757
 758 bool RenderElement::layerCreationAllowedForSubtree() const
 759 {
 760     RenderElement* parentRenderer = parent();
 761     while (parentRenderer) {
 762         if (parentRenderer->isSVGHiddenContainer())
 763             return false;
 764         parentRenderer = parentRenderer->parent();
 765     }
 766
 767     return true;
 768 }
 769
 770 void RenderElement::propagateStyleToAnonymousChildren(StylePropagationType propagationType)
 771 {
 772     // FIXME: We could save this call when the change only affected non-inherited properties.
 773     for (auto& elementChild : childrenOfType<RenderElement>(*this)) {
 774         if (!elementChild.isAnonymous() || elementChild.style().styleType() != NOPSEUDO)
 775             continue;
 776
 777         if (propagationType == PropagateToBlockChildrenOnly && !is<RenderBlock>(elementChild))
 778             continue;
 779
 780 #if ENABLE(FULLSCREEN_API)
 781         if (elementChild.isRenderFullScreen() || elementChild.isRenderFullScreenPlaceholder())
 782             continue;
 783 #endif
 784
 785         // RenderFlowThreads are updated through the RenderView::styleDidChange function.
 786         if (is<RenderFlowThread>(elementChild))
 787             continue;
 788
 789         auto newStyle = RenderStyle::createAnonymousStyleWithDisplay(&style(), elementChild.style().display());
 790         if (style().specifiesColumns()) {
 791             if (elementChild.style().specifiesColumns())
 792                 newStyle.get().inheritColumnPropertiesFrom(&style());
 793             if (elementChild.style().columnSpan())
 794                 newStyle.get().setColumnSpan(ColumnSpanAll);
 795         }
 796
 797         // Preserve the position style of anonymous block continuations as they can have relative or sticky position when
 798         // they contain block descendants of relative or sticky positioned inlines.
 799         if (elementChild.isInFlowPositioned() && downcast<RenderBlock>(elementChild).isAnonymousBlockContinuation())
 800             newStyle.get().setPosition(elementChild.style().position());
 801
 802         elementChild.setStyle(WTF::move(newStyle));
 803     }
 804 }
 805
 806 static inline bool rendererHasBackground(const RenderElement* renderer)
 807 {
 808     return renderer && renderer->hasBackground();
 809 }
 810
 811 void RenderElement::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 812 {
 813     RenderStyle* oldStyle = hasInitializedStyle() ? &style() : nullptr;
 814     if (oldStyle) {
 815         // If our z-index changes value or our visibility changes,
 816         // we need to dirty our stacking context's z-order list.
 817         bool visibilityChanged = m_style->visibility() != newStyle.visibility()
 818             || m_style->zIndex() != newStyle.zIndex()
 819             || m_style->hasAutoZIndex() != newStyle.hasAutoZIndex();
 820 #if ENABLE(DASHBOARD_SUPPORT)
 821         if (visibilityChanged)
 822             document().setAnnotatedRegionsDirty(true);
 823 #endif
 824 #if PLATFORM(IOS) && ENABLE(TOUCH_EVENTS)
 825         if (visibilityChanged)
 826             document().dirtyTouchEventRects();
 827 #endif
 828         if (visibilityChanged) {
 829             if (AXObjectCache* cache = document().existingAXObjectCache())
 830                 cache->childrenChanged(parent(), this);
 831         }
 832
 833         // Keep layer hierarchy visibility bits up to date if visibility changes.
 834         if (m_style->visibility() != newStyle.visibility()) {
 835             if (RenderLayer* layer = enclosingLayer()) {
 836                 if (newStyle.visibility() == VISIBLE)
 837                     layer->setHasVisibleContent();
 838                 else if (layer->hasVisibleContent() && (this == &layer->renderer() || layer->renderer().style().visibility() != VISIBLE)) {
 839                     layer->dirtyVisibleContentStatus();
 840                     if (diff > StyleDifferenceRepaintLayer)
 841                         repaint();
 842                 }
 843             }
 844         }
 845
 846         if (m_parent && (newStyle.outlineSize() < m_style->outlineSize() || shouldRepaintForStyleDifference(diff)))
 847             repaint();
 848         if (isFloating() && (m_style->floating() != newStyle.floating()))
 849             // For changes in float styles, we need to conceivably remove ourselves
 850             // from the floating objects list.
 851             downcast<RenderBox>(*this).removeFloatingOrPositionedChildFromBlockLists();
 852         else if (isOutOfFlowPositioned() && (m_style->position() != newStyle.position()))
 853             // For changes in positioning styles, we need to conceivably remove ourselves
 854             // from the positioned objects list.
 855             downcast<RenderBox>(*this).removeFloatingOrPositionedChildFromBlockLists();
 856
 857         s_affectsParentBlock = isFloatingOrOutOfFlowPositioned()
 858             && (!newStyle.isFloating() && !newStyle.hasOutOfFlowPosition())
 859             && parent() && (parent()->isRenderBlockFlow() || parent()->isRenderInline());
 860
 861         s_noLongerAffectsParentBlock = ((!isFloating() && newStyle.isFloating()) || (!isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition()))
 862             && parent() && parent()->isRenderBlock();
 863
 864         // reset style flags
 865         if (diff == StyleDifferenceLayout || diff == StyleDifferenceLayoutPositionedMovementOnly) {
 866             setFloating(false);
 867             clearPositionedState();
 868         }
 869         setHorizontalWritingMode(true);
 870         setHasBoxDecorations(false);
 871         setHasOverflowClip(false);
 872         setHasTransformRelatedProperty(false);
 873         setHasReflection(false);
 874     } else {
 875         s_affectsParentBlock = false;
 876         s_noLongerAffectsParentBlock = false;
 877     }
 878
 879     bool newStyleUsesFixedBackgrounds = newStyle.hasFixedBackgroundImage();
 880     bool oldStyleUsesFixedBackgrounds = m_style->hasFixedBackgroundImage();
 881     if (newStyleUsesFixedBackgrounds || oldStyleUsesFixedBackgrounds) {
 882         bool repaintFixedBackgroundsOnScroll = !frame().settings().fixedBackgroundsPaintRelativeToDocument();
 883
 884         bool newStyleSlowScroll = repaintFixedBackgroundsOnScroll && newStyleUsesFixedBackgrounds;
 885         bool oldStyleSlowScroll = oldStyle && repaintFixedBackgroundsOnScroll && oldStyleUsesFixedBackgrounds;
 886         bool drawsRootBackground = isRoot() || (isBody() && !rendererHasBackground(document().documentElement()->renderer()));
 887         if (drawsRootBackground && repaintFixedBackgroundsOnScroll) {
 888             if (view().compositor().supportsFixedRootBackgroundCompositing()) {
 889                 if (newStyleSlowScroll && newStyle.hasEntirelyFixedBackground())
 890                     newStyleSlowScroll = false;
 891
 892                 if (oldStyleSlowScroll && m_style->hasEntirelyFixedBackground())
 893                     oldStyleSlowScroll = false;
 894             }
 895         }
 896
 897         if (oldStyleSlowScroll != newStyleSlowScroll) {
 898             if (oldStyleSlowScroll)
 899                 view().frameView().removeSlowRepaintObject(this);
 900
 901             if (newStyleSlowScroll)
 902                 view().frameView().addSlowRepaintObject(this);
 903         }
 904     }
 905
 906     if (isRoot() || isBody())
 907         view().frameView().updateExtendBackgroundIfNecessary();
 908 }
 909
 910 void RenderElement::handleDynamicFloatPositionChange()
 911 {
 912     // We have gone from not affecting the inline status of the parent flow to suddenly
 913     // having an impact.  See if there is a mismatch between the parent flow's
 914     // childrenInline() state and our state.
 915     setInline(style().isDisplayInlineType());
 916     if (isInline() != parent()->childrenInline()) {
 917         if (!isInline())
 918             downcast<RenderBoxModelObject>(*parent()).childBecameNonInline(*this);
 919         else {
 920             // An anonymous block must be made to wrap this inline.
 921             RenderBlock* block = downcast<RenderBlock>(*parent()).createAnonymousBlock();
 922             parent()->insertChildInternal(block, this, RenderElement::NotifyChildren);
 923             parent()->removeChildInternal(*this, RenderElement::NotifyChildren);
 924             block->insertChildInternal(this, nullptr, RenderElement::NotifyChildren);
 925         }
 926     }
 927 }
 928
 929 void RenderElement::removeAnonymousWrappersForInlinesIfNecessary()
 930 {
 931     RenderBlock& parentBlock = downcast<RenderBlock>(*parent());
 932     if (!parentBlock.canCollapseAnonymousBlockChild())
 933         return;
 934
 935     // We have changed to floated or out-of-flow positioning so maybe all our parent's
 936     // children can be inline now. Bail if there are any block children left on the line,
 937     // otherwise we can proceed to stripping solitary anonymous wrappers from the inlines.
 938     // FIXME: We should also handle split inlines here - we exclude them at the moment by returning
 939     // if we find a continuation.
 940     RenderObject* current = parent()->firstChild();
 941     while (current && ((current->isAnonymousBlock() && !downcast<RenderBlock>(*current).isAnonymousBlockContinuation()) || current->style().isFloating() || current->style().hasOutOfFlowPosition()))
 942         current = current->nextSibling();
 943
 944     if (current)
 945         return;
 946
 947     RenderObject* next;
 948     for (current = parent()->firstChild(); current; current = next) {
 949         next = current->nextSibling();
 950         if (current->isAnonymousBlock())
 951             parentBlock.collapseAnonymousBoxChild(parentBlock, downcast<RenderBlock>(current));
 952     }
 953 }
 954
 955 #if !PLATFORM(IOS)
 956 static bool areNonIdenticalCursorListsEqual(const RenderStyle* a, const RenderStyle* b)
 957 {
 958     ASSERT(a->cursors() != b->cursors());
 959     return a->cursors() && b->cursors() && *a->cursors() == *b->cursors();
 960 }
 961
 962 static inline bool areCursorsEqual(const RenderStyle* a, const RenderStyle* b)
 963 {
 964     return a->cursor() == b->cursor() && (a->cursors() == b->cursors() || areNonIdenticalCursorListsEqual(a, b));
 965 }
 966 #endif
 967
 968 void RenderElement::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 969 {
 970     if (s_affectsParentBlock)
 971         handleDynamicFloatPositionChange();
 972
 973     if (s_noLongerAffectsParentBlock)
 974         removeAnonymousWrappersForInlinesIfNecessary();
 975
 976     SVGRenderSupport::styleChanged(*this, oldStyle);
 977
 978     if (!m_parent)
 979         return;
 980
 981     if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {
 982         RenderCounter::rendererStyleChanged(*this, oldStyle, m_style.ptr());
 983
 984         // If the object already needs layout, then setNeedsLayout won't do
 985         // any work. But if the containing block has changed, then we may need
 986         // to mark the new containing blocks for layout. The change that can
 987         // directly affect the containing block of this object is a change to
 988         // the position style.
 989         if (needsLayout() && oldStyle->position() != m_style->position())
 990             markContainingBlocksForLayout();
 991
 992         if (diff == StyleDifferenceLayout)
 993             setNeedsLayoutAndPrefWidthsRecalc();
 994         else
 995             setNeedsSimplifiedNormalFlowLayout();
 996     } else if (diff == StyleDifferenceSimplifiedLayoutAndPositionedMovement) {
 997         setNeedsPositionedMovementLayout(oldStyle);
 998         setNeedsSimplifiedNormalFlowLayout();
 999     } else if (diff == StyleDifferenceLayoutPositionedMovementOnly)
1000         setNeedsPositionedMovementLayout(oldStyle);
1001
1002     // Don't check for repaint here; we need to wait until the layer has been
1003     // updated by subclasses before we know if we have to repaint (in setStyle()).
1004
1005 #if !PLATFORM(IOS)
1006     if (oldStyle && !areCursorsEqual(oldStyle, &style()))
1007         frame().eventHandler().scheduleCursorUpdate();
1008 #endif
1009 }
1010
1011 void RenderElement::insertedIntoTree()
1012 {
1013     if (auto* containerFlowThread = parent()->renderNamedFlowThreadWrapper())
1014         containerFlowThread->addFlowChild(*this);
1015
1016     // Keep our layer hierarchy updated. Optimize for the common case where we don't have any children
1017     // and don't have a layer attached to ourselves.
1018     RenderLayer* layer = nullptr;
1019     if (firstChild() || hasLayer()) {
1020         layer = parent()->enclosingLayer();
1021         addLayers(layer);
1022     }
1023
1024     // If |this| is visible but this object was not, tell the layer it has some visible content
1025     // that needs to be drawn and layer visibility optimization can't be used
1026     if (parent()->style().visibility() != VISIBLE && style().visibility() == VISIBLE && !hasLayer()) {
1027         if (!layer)
1028             layer = parent()->enclosingLayer();
1029         if (layer)
1030             layer->setHasVisibleContent();
1031     }
1032
1033     RenderObject::insertedIntoTree();
1034 }
1035
1036 void RenderElement::willBeRemovedFromTree()
1037 {
1038     // If we remove a visible child from an invisible parent, we don't know the layer visibility any more.
1039     RenderLayer* layer = nullptr;
1040     if (parent()->style().visibility() != VISIBLE && style().visibility() == VISIBLE && !hasLayer()) {
1041         if ((layer = parent()->enclosingLayer()))
1042             layer->dirtyVisibleContentStatus();
1043     }
1044     // Keep our layer hierarchy updated.
1045     if (firstChild() || hasLayer()) {
1046         if (!layer)
1047             layer = parent()->enclosingLayer();
1048         removeLayers(layer);
1049     }
1050
1051     if (m_style->hasFixedBackgroundImage() && !frame().settings().fixedBackgroundsPaintRelativeToDocument())
1052         view().frameView().removeSlowRepaintObject(this);
1053
1054     if (isOutOfFlowPositioned() && parent()->childrenInline())
1055         parent()->dirtyLinesFromChangedChild(*this);
1056
1057     if (auto* containerFlowThread = parent()->renderNamedFlowThreadWrapper())
1058         containerFlowThread->removeFlowChild(*this);
1059
1060     RenderObject::willBeRemovedFromTree();
1061 }
1062
1063 void RenderElement::willBeDestroyed()
1064 {
1065     animation().cancelAnimations(*this);
1066
1067     destroyLeftoverChildren();
1068
1069     if (hasCounterNodeMap())
1070         RenderCounter::destroyCounterNodes(*this);
1071
1072     RenderObject::willBeDestroyed();
1073
1074 #if !ASSERT_DISABLED
1075     if (!documentBeingDestroyed() && view().hasRenderNamedFlowThreads()) {
1076         // After remove, the object and the associated information should not be in any flow thread.
1077         for (auto& flowThread : *view().flowThreadController().renderNamedFlowThreadList()) {
1078             ASSERT(!flowThread->hasChild(*this));
1079             ASSERT(!flowThread->hasChildInfo(this));
1080         }
1081     }
1082 #endif
1083 }
1084
1085 void RenderElement::setNeedsPositionedMovementLayout(const RenderStyle* oldStyle)
1086 {
1087     ASSERT(!isSetNeedsLayoutForbidden());
1088     if (needsPositionedMovementLayout())
1089         return;
1090     setNeedsPositionedMovementLayoutBit(true);
1091     markContainingBlocksForLayout();
1092     if (hasLayer()) {
1093         if (oldStyle && style().diffRequiresLayerRepaint(*oldStyle, downcast<RenderLayerModelObject>(*this).layer()->isComposited()))
1094             setLayerNeedsFullRepaint();
1095         else
1096             setLayerNeedsFullRepaintForPositionedMovementLayout();
1097     }
1098 }
1099
1100 void RenderElement::clearChildNeedsLayout()
1101 {
1102     setNormalChildNeedsLayoutBit(false);
1103     setPosChildNeedsLayoutBit(false);
1104     setNeedsSimplifiedNormalFlowLayoutBit(false);
1105     setNormalChildNeedsLayoutBit(false);
1106     setNeedsPositionedMovementLayoutBit(false);
1107 }
1108
1109 void RenderElement::setNeedsSimplifiedNormalFlowLayout()
1110 {
1111     ASSERT(!isSetNeedsLayoutForbidden());
1112     if (needsSimplifiedNormalFlowLayout())
1113         return;
1114     setNeedsSimplifiedNormalFlowLayoutBit(true);
1115     markContainingBlocksForLayout();
1116     if (hasLayer())
1117         setLayerNeedsFullRepaint();
1118 }
1119
1120 RenderElement& RenderElement::rendererForRootBackground()
1121 {
1122     ASSERT(isRoot());
1123     if (!hasBackground() && is<HTMLHtmlElement>(element())) {
1124         // Locate the <body> element using the DOM. This is easier than trying
1125         // to crawl around a render tree with potential :before/:after content and
1126         // anonymous blocks created by inline <body> tags etc. We can locate the <body>
1127         // render object very easily via the DOM.
1128         if (auto* body = document().body()) {
1129             if (auto* renderer = body->renderer())
1130                 return *renderer;
1131         }
1132     }
1133     return *this;
1134 }
1135
1136 RenderElement* RenderElement::hoverAncestor() const
1137 {
1138     // When searching for the hover ancestor and encountering a named flow thread,
1139     // the search will continue with the DOM ancestor of the top-most element
1140     // in the named flow thread.
1141     // See https://bugs.webkit.org/show_bug.cgi?id=111749
1142     RenderElement* hoverAncestor = parent();
1143
1144     // Skip anonymous blocks directly flowed into flow threads as it would
1145     // prevent us from continuing the search on the DOM tree when reaching the named flow thread.
1146     if (hoverAncestor && hoverAncestor->isAnonymousBlock() && hoverAncestor->parent() && hoverAncestor->parent()->isRenderNamedFlowThread())
1147         hoverAncestor = hoverAncestor->parent();
1148
1149     if (hoverAncestor && hoverAncestor->isRenderNamedFlowThread()) {
1150         hoverAncestor = nullptr;
1151         if (Element* element = this->element()) {
1152             if (auto parent = element->parentNode())
1153                 hoverAncestor = parent->renderer();
1154         }
1155     }
1156
1157     return hoverAncestor;
1158 }
1159
1160 static inline void paintPhase(RenderElement& element, PaintPhase phase, PaintInfo& paintInfo, const LayoutPoint& childPoint)
1161 {
1162     paintInfo.phase = phase;
1163     element.paint(paintInfo, childPoint);
1164 }
1165
1166 void RenderElement::paintAsInlineBlock(PaintInfo& paintInfo, const LayoutPoint& childPoint)
1167 {
1168     // Paint all phases atomically, as though the element established its own stacking context.
1169     // (See Appendix E.2, section 6.4 on inline block/table/replaced elements in the CSS2.1 specification.)
1170     // This is also used by other elements (e.g. flex items and grid items).
1171     if (paintInfo.phase == PaintPhaseSelection) {
1172         paint(paintInfo, childPoint);
1173     } else if (paintInfo.phase == PaintPhaseForeground) {
1174         paintPhase(*this, PaintPhaseBlockBackground, paintInfo, childPoint);
1175         paintPhase(*this, PaintPhaseChildBlockBackgrounds, paintInfo, childPoint);
1176         paintPhase(*this, PaintPhaseFloat, paintInfo, childPoint);
1177         paintPhase(*this, PaintPhaseForeground, paintInfo, childPoint);
1178         paintPhase(*this, PaintPhaseOutline, paintInfo, childPoint);
1179
1180         // Reset |paintInfo| to the original phase.
1181         paintInfo.phase = PaintPhaseForeground;
1182     }
1183 }
1184
1185 void RenderElement::layout()
1186 {
1187     StackStats::LayoutCheckPoint layoutCheckPoint;
1188     ASSERT(needsLayout());
1189     RenderObject* child = firstChild();
1190     while (child) {
1191         if (child->needsLayout())
1192             downcast<RenderElement>(*child).layout();
1193         ASSERT(!child->needsLayout());
1194         child = child->nextSibling();
1195     }
1196     clearNeedsLayout();
1197 }
1198
1199 static bool mustRepaintFillLayers(const RenderElement& renderer, const FillLayer* layer)
1200 {
1201     // Nobody will use multiple layers without wanting fancy positioning.
1202     if (layer->next())
1203         return true;
1204
1205     // Make sure we have a valid image.
1206     StyleImage* image = layer->image();
1207     if (!image || !image->canRender(&renderer, renderer.style().effectiveZoom()))
1208         return false;
1209
1210     if (!layer->xPosition().isZero() || !layer->yPosition().isZero())
1211         return true;
1212
1213     EFillSizeType sizeType = layer->sizeType();
1214
1215     if (sizeType == Contain || sizeType == Cover)
1216         return true;
1217
1218     if (sizeType == SizeLength) {
1219         LengthSize size = layer->sizeLength();
1220         if (size.width().isPercent() || size.height().isPercent())
1221             return true;
1222         // If the image has neither an intrinsic width nor an intrinsic height, its size is determined as for 'contain'.
1223         if ((size.width().isAuto() || size.height().isAuto()) && image->isGeneratedImage())
1224             return true;
1225     } else if (image->usesImageContainerSize())
1226         return true;
1227
1228     return false;
1229 }
1230
1231 static bool mustRepaintBackgroundOrBorder(const RenderElement& renderer)
1232 {
1233     if (renderer.hasMask() && mustRepaintFillLayers(renderer, renderer.style().maskLayers()))
1234         return true;
1235
1236     // If we don't have a background/border/mask, then nothing to do.
1237     if (!renderer.hasBoxDecorations())
1238         return false;
1239
1240     if (mustRepaintFillLayers(renderer, renderer.style().backgroundLayers()))
1241         return true;
1242
1243     // Our fill layers are ok. Let's check border.
1244     if (renderer.style().hasBorder() && renderer.borderImageIsLoadedAndCanBeRendered())
1245         return true;
1246
1247     return false;
1248 }
1249
1250 bool RenderElement::repaintAfterLayoutIfNeeded(const RenderLayerModelObject* repaintContainer, const LayoutRect& oldBounds, const LayoutRect& oldOutlineBox, const LayoutRect* newBoundsPtr, const LayoutRect* newOutlineBoxRectPtr)
1251 {
1252     if (view().printing())
1253         return false; // Don't repaint if we're printing.
1254
1255     // This ASSERT fails due to animations. See https://bugs.webkit.org/show_bug.cgi?id=37048
1256     // ASSERT(!newBoundsPtr || *newBoundsPtr == clippedOverflowRectForRepaint(repaintContainer));
1257     LayoutRect newBounds = newBoundsPtr ? *newBoundsPtr : clippedOverflowRectForRepaint(repaintContainer);
1258     LayoutRect newOutlineBox;
1259
1260     bool fullRepaint = selfNeedsLayout();
1261     // Presumably a background or a border exists if border-fit:lines was specified.
1262     if (!fullRepaint && style().borderFit() == BorderFitLines)
1263         fullRepaint = true;
1264     if (!fullRepaint) {
1265         // This ASSERT fails due to animations. See https://bugs.webkit.org/show_bug.cgi?id=37048
1266         // ASSERT(!newOutlineBoxRectPtr || *newOutlineBoxRectPtr == outlineBoundsForRepaint(repaintContainer));
1267         newOutlineBox = newOutlineBoxRectPtr ? *newOutlineBoxRectPtr : outlineBoundsForRepaint(repaintContainer);
1268         if (newOutlineBox.location() != oldOutlineBox.location() || (mustRepaintBackgroundOrBorder(*this) && (newBounds != oldBounds || newOutlineBox != oldOutlineBox)))
1269             fullRepaint = true;
1270     }
1271
1272     if (!repaintContainer)
1273         repaintContainer = &view();
1274
1275     if (fullRepaint) {
1276         repaintUsingContainer(repaintContainer, oldBounds);
1277         if (newBounds != oldBounds)
1278             repaintUsingContainer(repaintContainer, newBounds);
1279         return true;
1280     }
1281
1282     if (newBounds == oldBounds && newOutlineBox == oldOutlineBox)
1283         return false;
1284
1285     LayoutUnit deltaLeft = newBounds.x() - oldBounds.x();
1286     if (deltaLeft > 0)
1287         repaintUsingContainer(repaintContainer, LayoutRect(oldBounds.x(), oldBounds.y(), deltaLeft, oldBounds.height()));
1288     else if (deltaLeft < 0)
1289         repaintUsingContainer(repaintContainer, LayoutRect(newBounds.x(), newBounds.y(), -deltaLeft, newBounds.height()));
1290
1291     LayoutUnit deltaRight = newBounds.maxX() - oldBounds.maxX();
1292     if (deltaRight > 0)
1293         repaintUsingContainer(repaintContainer, LayoutRect(oldBounds.maxX(), newBounds.y(), deltaRight, newBounds.height()));
1294     else if (deltaRight < 0)
1295         repaintUsingContainer(repaintContainer, LayoutRect(newBounds.maxX(), oldBounds.y(), -deltaRight, oldBounds.height()));
1296
1297     LayoutUnit deltaTop = newBounds.y() - oldBounds.y();
1298     if (deltaTop > 0)
1299         repaintUsingContainer(repaintContainer, LayoutRect(oldBounds.x(), oldBounds.y(), oldBounds.width(), deltaTop));
1300     else if (deltaTop < 0)
1301         repaintUsingContainer(repaintContainer, LayoutRect(newBounds.x(), newBounds.y(), newBounds.width(), -deltaTop));
1302
1303     LayoutUnit deltaBottom = newBounds.maxY() - oldBounds.maxY();
1304     if (deltaBottom > 0)
1305         repaintUsingContainer(repaintContainer, LayoutRect(newBounds.x(), oldBounds.maxY(), newBounds.width(), deltaBottom));
1306     else if (deltaBottom < 0)
1307         repaintUsingContainer(repaintContainer, LayoutRect(oldBounds.x(), newBounds.maxY(), oldBounds.width(), -deltaBottom));
1308
1309     if (newOutlineBox == oldOutlineBox)
1310         return false;
1311
1312     // We didn't move, but we did change size. Invalidate the delta, which will consist of possibly
1313     // two rectangles (but typically only one).
1314     const RenderStyle& outlineStyle = outlineStyleForRepaint();
1315     LayoutUnit outlineWidth = outlineStyle.outlineSize();
1316     LayoutBoxExtent insetShadowExtent = style().getBoxShadowInsetExtent();
1317     LayoutUnit width = absoluteValue(newOutlineBox.width() - oldOutlineBox.width());
1318     if (width) {
1319         LayoutUnit shadowLeft;
1320         LayoutUnit shadowRight;
1321         style().getBoxShadowHorizontalExtent(shadowLeft, shadowRight);
1322         LayoutUnit borderRight = is<RenderBox>(*this) ? downcast<RenderBox>(*this).borderRight() : LayoutUnit::fromPixel(0);
1323         LayoutUnit boxWidth = is<RenderBox>(*this) ? downcast<RenderBox>(*this).width() : LayoutUnit();
1324         LayoutUnit minInsetRightShadowExtent = std::min<LayoutUnit>(-insetShadowExtent.right(), std::min<LayoutUnit>(newBounds.width(), oldBounds.width()));
1325         LayoutUnit borderWidth = std::max<LayoutUnit>(borderRight, std::max<LayoutUnit>(valueForLength(style().borderTopRightRadius().width(), boxWidth), valueForLength(style().borderBottomRightRadius().width(), boxWidth)));
1326         LayoutUnit decorationsWidth = std::max<LayoutUnit>(-outlineStyle.outlineOffset(), borderWidth + minInsetRightShadowExtent) + std::max<LayoutUnit>(outlineWidth, shadowRight);
1327         LayoutRect rightRect(newOutlineBox.x() + std::min(newOutlineBox.width(), oldOutlineBox.width()) - decorationsWidth,
1328             newOutlineBox.y(),
1329             width + decorationsWidth,
1330             std::max(newOutlineBox.height(), oldOutlineBox.height()));
1331         LayoutUnit right = std::min<LayoutUnit>(newBounds.maxX(), oldBounds.maxX());
1332         if (rightRect.x() < right) {
1333             rightRect.setWidth(std::min(rightRect.width(), right - rightRect.x()));
1334             repaintUsingContainer(repaintContainer, rightRect);
1335         }
1336     }
1337     LayoutUnit height = absoluteValue(newOutlineBox.height() - oldOutlineBox.height());
1338     if (height) {
1339         LayoutUnit shadowTop;
1340         LayoutUnit shadowBottom;
1341         style().getBoxShadowVerticalExtent(shadowTop, shadowBottom);
1342         LayoutUnit borderBottom = is<RenderBox>(*this) ? downcast<RenderBox>(*this).borderBottom() : LayoutUnit::fromPixel(0);
1343         LayoutUnit boxHeight = is<RenderBox>(*this) ? downcast<RenderBox>(*this).height() : LayoutUnit();
1344         LayoutUnit minInsetBottomShadowExtent = std::min<LayoutUnit>(-insetShadowExtent.bottom(), std::min<LayoutUnit>(newBounds.height(), oldBounds.height()));
1345         LayoutUnit borderHeight = std::max<LayoutUnit>(borderBottom, std::max<LayoutUnit>(valueForLength(style().borderBottomLeftRadius().height(), boxHeight),
1346             valueForLength(style().borderBottomRightRadius().height(), boxHeight)));
1347         LayoutUnit decorationsHeight = std::max<LayoutUnit>(-outlineStyle.outlineOffset(), borderHeight + minInsetBottomShadowExtent) + std::max<LayoutUnit>(outlineWidth, shadowBottom);
1348         LayoutRect bottomRect(newOutlineBox.x(),
1349             std::min(newOutlineBox.maxY(), oldOutlineBox.maxY()) - decorationsHeight,
1350             std::max(newOutlineBox.width(), oldOutlineBox.width()),
1351             height + decorationsHeight);
1352         LayoutUnit bottom = std::min(newBounds.maxY(), oldBounds.maxY());
1353         if (bottomRect.y() < bottom) {
1354             bottomRect.setHeight(std::min(bottomRect.height(), bottom - bottomRect.y()));
1355             repaintUsingContainer(repaintContainer, bottomRect);
1356         }
1357     }
1358     return false;
1359 }
1360
1361 bool RenderElement::borderImageIsLoadedAndCanBeRendered() const
1362 {
1363     ASSERT(style().hasBorder());
1364
1365     StyleImage* borderImage = style().borderImage().image();
1366     return borderImage && borderImage->canRender(this, style().effectiveZoom()) && borderImage->isLoaded();
1367 }
1368
1369 bool RenderElement::mayCauseRepaintInsideViewport(const IntRect* optionalViewportRect) const
1370 {
1371     auto& frameView = view().frameView();
1372     if (frameView.isOffscreen())
1373         return false;
1374
1375     if (!hasOverflowClip()) {
1376         // FIXME: Computing the overflow rect is expensive if any descendant has
1377         // its own self-painting layer. As a result, we prefer to abort early in
1378         // this case and assume it may cause us to repaint inside the viewport.
1379         if (!hasLayer() || downcast<RenderLayerModelObject>(*this).layer()->firstChild())
1380             return true;
1381     }
1382
1383     // Compute viewport rect if it was not provided.
1384     const IntRect& visibleRect = optionalViewportRect ? *optionalViewportRect : frameView.windowToContents(frameView.windowClipRect());
1385     return visibleRect.intersects(enclosingIntRect(absoluteClippedOverflowRect()));
1386 }
1387
1388 static bool shouldRepaintForImageAnimation(const RenderElement& renderer, const IntRect& visibleRect)
1389 {
1390     const Document& document = renderer.document();
1391     if (document.inPageCache())
1392         return false;
1393 #if PLATFORM(IOS)
1394     if (document.frame()->timersPaused())
1395         return false;
1396 #endif
1397     if (document.activeDOMObjectsAreSuspended())
1398         return false;
1399     if (renderer.style().visibility() != VISIBLE)
1400         return false;
1401     if (renderer.view().frameView().isOffscreen())
1402         return false;
1403
1404     // Use background rect if we are the root or if we are the body and the background is propagated to the root.
1405     // FIXME: This is overly conservative as the image may not be a background-image, in which case it will not
1406     // be propagated to the root. At this point, we unfortunately don't have access to the image anymore so we
1407     // can no longer check if it is a background image.
1408     bool backgroundIsPaintedByRoot = renderer.isRoot();
1409     if (renderer.isBody()) {
1410         auto& rootRenderer = *renderer.parent(); // If <body> has a renderer then <html> does too.
1411         ASSERT(rootRenderer.isRoot());
1412         ASSERT(is<HTMLHtmlElement>(rootRenderer.element()));
1413         // FIXME: Should share body background propagation code.
1414         backgroundIsPaintedByRoot = !rootRenderer.hasBackground();
1415
1416     }
1417     LayoutRect backgroundPaintingRect = backgroundIsPaintedByRoot ? renderer.view().backgroundRect(&renderer.view()) : renderer.absoluteClippedOverflowRect();
1418     if (!visibleRect.intersects(enclosingIntRect(backgroundPaintingRect)))
1419         return false;
1420
1421     return true;
1422 }
1423
1424 void RenderElement::newImageAnimationFrameAvailable(CachedImage& image)
1425 {
1426     if (document().inPageCache())
1427         return;
1428     auto& frameView = view().frameView();
1429     auto visibleRect = frameView.windowToContents(frameView.windowClipRect());
1430     if (!shouldRepaintForImageAnimation(*this, visibleRect)) {
1431         // FIXME: It would be better to pass the image along with the renderer
1432         // so that we can be smarter about detecting if the image is inside the
1433         // viewport in repaintForPausedImageAnimationsIfNeeded().
1434         view().addRendererWithPausedImageAnimations(*this);
1435         return;
1436     }
1437     imageChanged(&image);
1438 }
1439
1440 bool RenderElement::repaintForPausedImageAnimationsIfNeeded(const IntRect& visibleRect)
1441 {
1442     ASSERT(m_hasPausedImageAnimations);
1443     if (!shouldRepaintForImageAnimation(*this, visibleRect))
1444         return false;
1445     repaint();
1446     return true;
1447 }
1448
1449 RenderNamedFlowThread* RenderElement::renderNamedFlowThreadWrapper()
1450 {
1451     auto* renderer = this;
1452     while (renderer && renderer->isAnonymousBlock() && !is<RenderNamedFlowThread>(*renderer))
1453         renderer = renderer->parent();
1454     return is<RenderNamedFlowThread>(renderer) ? downcast<RenderNamedFlowThread>(renderer) : nullptr;
1455 }
1456
1457 bool RenderElement::hasControlStatesForRenderer(const RenderObject* o)
1458 {
1459     return controlStatesRendererMap().contains(o);
1460 }
1461
1462 ControlStates* RenderElement::controlStatesForRenderer(const RenderObject* o)
1463 {
1464     return controlStatesRendererMap().get(o);
1465 }
1466
1467 void RenderElement::removeControlStatesForRenderer(const RenderObject* o)
1468 {
1469     ControlStates* states = controlStatesRendererMap().get(o);
1470     if (states) {
1471         controlStatesRendererMap().remove(o);
1472         delete states;
1473     }
1474 }
1475
1476 void RenderElement::addControlStatesForRenderer(const RenderObject* o, ControlStates* states)
1477 {
1478     controlStatesRendererMap().add(o, states);
1479 }
1480
1481 RenderStyle* RenderElement::getCachedPseudoStyle(PseudoId pseudo, RenderStyle* parentStyle) const
1482 {
1483     if (pseudo < FIRST_INTERNAL_PSEUDOID && !style().hasPseudoStyle(pseudo))
1484         return nullptr;
1485
1486     RenderStyle* cachedStyle = style().getCachedPseudoStyle(pseudo);
1487     if (cachedStyle)
1488         return cachedStyle;
1489
1490     RefPtr<RenderStyle> result = getUncachedPseudoStyle(PseudoStyleRequest(pseudo), parentStyle);
1491     if (result)
1492         return style().addCachedPseudoStyle(result.release());
1493     return nullptr;
1494 }
1495
1496 PassRefPtr<RenderStyle> RenderElement::getUncachedPseudoStyle(const PseudoStyleRequest& pseudoStyleRequest, RenderStyle* parentStyle, RenderStyle* ownStyle) const
1497 {
1498     if (pseudoStyleRequest.pseudoId < FIRST_INTERNAL_PSEUDOID && !ownStyle && !style().hasPseudoStyle(pseudoStyleRequest.pseudoId))
1499         return nullptr;
1500
1501     if (!parentStyle) {
1502         ASSERT(!ownStyle);
1503         parentStyle = &style();
1504     }
1505
1506     if (isAnonymous())
1507         return nullptr;
1508
1509     if (pseudoStyleRequest.pseudoId == FIRST_LINE_INHERITED) {
1510         RefPtr<RenderStyle> result = document().ensureStyleResolver().styleForElement(element(), parentStyle, DisallowStyleSharing);
1511         result->setStyleType(FIRST_LINE_INHERITED);
1512         return result.release();
1513     }
1514
1515     return document().ensureStyleResolver().pseudoStyleForElement(element(), pseudoStyleRequest, parentStyle);
1516 }
1517
1518 RenderBlock* RenderElement::containingBlockForFixedPosition() const
1519 {
1520     const RenderElement* object = this;
1521     while (object && !object->canContainFixedPositionObjects())
1522         object = object->parent();
1523
1524     ASSERT(!object || !object->isAnonymousBlock());
1525     return const_cast<RenderBlock*>(downcast<RenderBlock>(object));
1526 }
1527
1528 RenderBlock* RenderElement::containingBlockForAbsolutePosition() const
1529 {
1530     const RenderElement* object = this;
1531     while (object && !object->canContainAbsolutelyPositionedObjects())
1532         object = object->parent();
1533
1534     // For a relatively positioned inline, return its nearest non-anonymous containing block,
1535     // not the inline itself, to avoid having a positioned objects list in all RenderInlines
1536     // and use RenderBlock* as RenderElement::containingBlock's return type.
1537     // Use RenderBlock::container() to obtain the inline.
1538     if (object && !is<RenderBlock>(*object))
1539         object = object->containingBlock();
1540
1541     while (object && object->isAnonymousBlock())
1542         object = object->containingBlock();
1543
1544     return const_cast<RenderBlock*>(downcast<RenderBlock>(object));
1545 }
1546
1547 static inline bool isNonRenderBlockInline(const RenderElement& object)
1548 {
1549     return (object.isInline() && !object.isReplaced()) || !object.isRenderBlock();
1550 }
1551
1552 RenderBlock* RenderElement::containingBlockForObjectInFlow() const
1553 {
1554     const RenderElement* object = this;
1555     while (object && isNonRenderBlockInline(*object))
1556         object = object->parent();
1557     return const_cast<RenderBlock*>(downcast<RenderBlock>(object));
1558 }
1559
1560 Color RenderElement::selectionColor(int colorProperty) const
1561 {
1562     // If the element is unselectable, or we are only painting the selection,
1563     // don't override the foreground color with the selection foreground color.
1564     if (style().userSelect() == SELECT_NONE
1565         || (view().frameView().paintBehavior() & PaintBehaviorSelectionOnly))
1566         return Color();
1567
1568     if (RefPtr<RenderStyle> pseudoStyle = selectionPseudoStyle()) {
1569         Color color = pseudoStyle->visitedDependentColor(colorProperty);
1570         if (!color.isValid())
1571             color = pseudoStyle->visitedDependentColor(CSSPropertyColor);
1572         return color;
1573     }
1574
1575     if (frame().selection().isFocusedAndActive())
1576         return theme().activeSelectionForegroundColor();
1577     return theme().inactiveSelectionForegroundColor();
1578 }
1579
1580 PassRefPtr<RenderStyle> RenderElement::selectionPseudoStyle() const
1581 {
1582     if (isAnonymous())
1583         return nullptr;
1584
1585     if (ShadowRoot* root = element()->containingShadowRoot()) {
1586         if (root->type() == ShadowRoot::UserAgentShadowRoot) {
1587             if (Element* shadowHost = element()->shadowHost())
1588                 return shadowHost->renderer()->getUncachedPseudoStyle(PseudoStyleRequest(SELECTION));
1589         }
1590     }
1591
1592     return getUncachedPseudoStyle(PseudoStyleRequest(SELECTION));
1593 }
1594
1595 Color RenderElement::selectionForegroundColor() const
1596 {
1597     return selectionColor(CSSPropertyWebkitTextFillColor);
1598 }
1599
1600 Color RenderElement::selectionEmphasisMarkColor() const
1601 {
1602     return selectionColor(CSSPropertyWebkitTextEmphasisColor);
1603 }
1604
1605 Color RenderElement::selectionBackgroundColor() const
1606 {
1607     if (style().userSelect() == SELECT_NONE)
1608         return Color();
1609
1610     if (frame().selection().shouldShowBlockCursor() && frame().selection().isCaret())
1611         return style().visitedDependentColor(CSSPropertyColor).blendWithWhite();
1612
1613     RefPtr<RenderStyle> pseudoStyle = selectionPseudoStyle();
1614     if (pseudoStyle && pseudoStyle->visitedDependentColor(CSSPropertyBackgroundColor).isValid())
1615         return pseudoStyle->visitedDependentColor(CSSPropertyBackgroundColor).blendWithWhite();
1616
1617     if (frame().selection().isFocusedAndActive())
1618         return theme().activeSelectionBackgroundColor();
1619     return theme().inactiveSelectionBackgroundColor();
1620 }
1621
1622 bool RenderElement::getLeadingCorner(FloatPoint& point) const
1623 {
1624     if (!isInline() || isReplaced()) {
1625         point = localToAbsolute(FloatPoint(), UseTransforms);
1626         return true;
1627     }
1628
1629     // find the next text/image child, to get a position
1630     const RenderObject* o = this;
1631     while (o) {
1632         const RenderObject* p = o;
1633         if (RenderObject* child = o->firstChildSlow())
1634             o = child;
1635         else if (o->nextSibling())
1636             o = o->nextSibling();
1637         else {
1638             RenderObject* next = 0;
1639             while (!next && o->parent()) {
1640                 o = o->parent();
1641                 next = o->nextSibling();
1642             }
1643             o = next;
1644
1645             if (!o)
1646                 break;
1647         }
1648         ASSERT(o);
1649
1650         if (!o->isInline() || o->isReplaced()) {
1651             point = o->localToAbsolute(FloatPoint(), UseTransforms);
1652             return true;
1653         }
1654
1655         if (p->node() && p->node() == element() && is<RenderText>(*o) && !downcast<RenderText>(*o).firstTextBox()) {
1656             // do nothing - skip unrendered whitespace that is a child or next sibling of the anchor
1657         } else if (is<RenderText>(*o) || o->isReplaced()) {
1658             point = FloatPoint();
1659             if (is<RenderText>(*o) && downcast<RenderText>(*o).firstTextBox())
1660                 point.move(downcast<RenderText>(*o).linesBoundingBox().x(), downcast<RenderText>(*o).topOfFirstText());
1661             else if (is<RenderBox>(*o))
1662                 point.moveBy(downcast<RenderBox>(*o).location());
1663             point = o->container()->localToAbsolute(point, UseTransforms);
1664             return true;
1665         }
1666     }
1667
1668     // If the target doesn't have any children or siblings that could be used to calculate the scroll position, we must be
1669     // at the end of the document. Scroll to the bottom. FIXME: who said anything about scrolling?
1670     if (!o && document().view()) {
1671         point = FloatPoint(0, document().view()->contentsHeight());
1672         return true;
1673     }
1674     return false;
1675 }
1676
1677 bool RenderElement::getTrailingCorner(FloatPoint& point) const
1678 {
1679     if (!isInline() || isReplaced()) {
1680         point = localToAbsolute(LayoutPoint(downcast<RenderBox>(*this).size()), UseTransforms);
1681         return true;
1682     }
1683
1684     // find the last text/image child, to get a position
1685     const RenderObject* o = this;
1686     while (o) {
1687         if (RenderObject* child = o->lastChildSlow())
1688             o = child;
1689         else if (o->previousSibling())
1690             o = o->previousSibling();
1691         else {
1692             RenderObject* prev = 0;
1693             while (!prev) {
1694                 o = o->parent();
1695                 if (!o)
1696                     return false;
1697                 prev = o->previousSibling();
1698             }
1699             o = prev;
1700         }
1701         ASSERT(o);
1702         if (is<RenderText>(*o) || o->isReplaced()) {
1703             point = FloatPoint();
1704             if (is<RenderText>(*o)) {
1705                 IntRect linesBox = downcast<RenderText>(*o).linesBoundingBox();
1706                 if (!linesBox.maxX() && !linesBox.maxY())
1707                     continue;
1708                 point.moveBy(linesBox.maxXMaxYCorner());
1709             } else
1710                 point.moveBy(downcast<RenderBox>(*o).frameRect().maxXMaxYCorner());
1711             point = o->container()->localToAbsolute(point, UseTransforms);
1712             return true;
1713         }
1714     }
1715     return true;
1716 }
1717
1718 LayoutRect RenderElement::anchorRect() const
1719 {
1720     FloatPoint leading, trailing;
1721     bool foundLeading = getLeadingCorner(leading);
1722     bool foundTrailing = getTrailingCorner(trailing);
1723
1724     // If we've found one corner, but not the other,
1725     // then we should just return a point at the corner that we did find.
1726     if (foundLeading != foundTrailing) {
1727         if (foundLeading)
1728             foundTrailing = foundLeading;
1729         else
1730             foundLeading = foundTrailing;
1731     }
1732
1733     FloatPoint upperLeft = leading;
1734     FloatPoint lowerRight = trailing;
1735
1736     // Vertical writing modes might mean the leading point is not in the top left
1737     if (!isInline() || isReplaced()) {
1738         upperLeft = FloatPoint(std::min(leading.x(), trailing.x()), std::min(leading.y(), trailing.y()));
1739         lowerRight = FloatPoint(std::max(leading.x(), trailing.x()), std::max(leading.y(), trailing.y()));
1740     } // Otherwise, it's not obvious what to do.
1741
1742     return enclosingLayoutRect(FloatRect(upperLeft, lowerRight.expandedTo(upperLeft) - upperLeft));
1743 }
1744
1745 const RenderElement* RenderElement::enclosingRendererWithTextDecoration(TextDecoration textDecoration, bool firstLine) const
1746 {
1747     const RenderElement* current = this;
1748     do {
1749         if (current->isRenderBlock())
1750             return current;
1751         if (!current->isRenderInline() || current->isRubyText())
1752             return nullptr;
1753
1754         const RenderStyle& styleToUse = firstLine ? current->firstLineStyle() : current->style();
1755         if (styleToUse.textDecoration() & textDecoration)
1756             return current;
1757         current = current->parent();
1758     } while (current && (!current->element() || (!is<HTMLAnchorElement>(*current->element()) && !current->element()->hasTagName(HTMLNames::fontTag))));
1759
1760     return current;
1761 }
1762
1763 }