Source/WebCore/rendering/RenderBox.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, 2010 Apple Inc. All rights reserved.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Library General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Library General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Library General Public License
  19  * along with this library; see the file COPYING.LIB.  If not, write to
  20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  * Boston, MA 02110-1301, USA.
  22  *
  23  */
  24
  25 #include "config.h"
  26 #include "RenderBox.h"
  27
  28 #include "Chrome.h"
  29 #include "ChromeClient.h"
  30 #include "Document.h"
  31 #include "EventHandler.h"
  32 #include "FloatQuad.h"
  33 #include "FloatRoundedRect.h"
  34 #include "Frame.h"
  35 #include "FrameView.h"
  36 #include "GraphicsContext.h"
  37 #include "HTMLBodyElement.h"
  38 #include "HTMLButtonElement.h"
  39 #include "HTMLElement.h"
  40 #include "HTMLFrameOwnerElement.h"
  41 #include "HTMLInputElement.h"
  42 #include "HTMLNames.h"
  43 #include "HTMLTextAreaElement.h"
  44 #include "HitTestResult.h"
  45 #include "InlineElementBox.h"
  46 #include "Page.h"
  47 #include "PaintInfo.h"
  48 #include "RenderBoxRegionInfo.h"
  49 #include "RenderDeprecatedFlexibleBox.h"
  50 #include "RenderFlexibleBox.h"
  51 #include "RenderGeometryMap.h"
  52 #include "RenderInline.h"
  53 #include "RenderIterator.h"
  54 #include "RenderLayer.h"
  55 #include "RenderLayerBacking.h"
  56 #include "RenderLayerCompositor.h"
  57 #include "RenderNamedFlowFragment.h"
  58 #include "RenderNamedFlowThread.h"
  59 #include "RenderTableCell.h"
  60 #include "RenderTheme.h"
  61 #include "RenderView.h"
  62 #include "ScrollbarTheme.h"
  63 #include "TransformState.h"
  64 #include "htmlediting.h"
  65 #include <algorithm>
  66 #include <math.h>
  67 #include <wtf/StackStats.h>
  68
  69 #if PLATFORM(IOS)
  70 #include "Settings.h"
  71 #endif
  72
  73 namespace WebCore {
  74
  75 struct SameSizeAsRenderBox : public RenderBoxModelObject {
  76     virtual ~SameSizeAsRenderBox() { }
  77     LayoutRect frameRect;
  78     LayoutBoxExtent marginBox;
  79     LayoutUnit preferredLogicalWidths[2];
  80     void* pointers[2];
  81 };
  82
  83 COMPILE_ASSERT(sizeof(RenderBox) == sizeof(SameSizeAsRenderBox), RenderBox_should_stay_small);
  84
  85 using namespace HTMLNames;
  86
  87 // Used by flexible boxes when flexing this element and by table cells.
  88 typedef WTF::HashMap<const RenderBox*, LayoutUnit> OverrideSizeMap;
  89 static OverrideSizeMap* gOverrideHeightMap = nullptr;
  90 static OverrideSizeMap* gOverrideWidthMap = nullptr;
  91
  92 #if ENABLE(CSS_GRID_LAYOUT)
  93 // Used by grid elements to properly size their grid items.
  94 static OverrideSizeMap* gOverrideContainingBlockLogicalHeightMap = nullptr;
  95 static OverrideSizeMap* gOverrideContainingBlockLogicalWidthMap = nullptr;
  96 #endif
  97
  98 // Size of border belt for autoscroll. When mouse pointer in border belt,
  99 // autoscroll is started.
 100 static const int autoscrollBeltSize = 20;
 101 static const unsigned backgroundObscurationTestMaxDepth = 4;
 102
 103 bool RenderBox::s_hadOverflowClip = false;
 104
 105 static bool skipBodyBackground(const RenderBox* bodyElementRenderer)
 106 {
 107     ASSERT(bodyElementRenderer->isBody());
 108     // The <body> only paints its background if the root element has defined a background independent of the body,
 109     // or if the <body>'s parent is not the document element's renderer (e.g. inside SVG foreignObject).
 110     auto documentElementRenderer = bodyElementRenderer->document().documentElement()->renderer();
 111
 112     if (!documentElementRenderer)
 113         return false;
 114
 115     if (documentElementRenderer->hasBackground())
 116         return false;
 117
 118     if (documentElementRenderer != bodyElementRenderer->parent())
 119         return false;
 120
 121     if (bodyElementRenderer->isComposited() && documentElementRenderer->isComposited())
 122         return downcast<RenderLayerModelObject>(documentElementRenderer)->layer()->backing()->graphicsLayer()->drawsContent();
 123
 124     return true;
 125 }
 126
 127 RenderBox::RenderBox(Element& element, Ref<RenderStyle>&& style, unsigned baseTypeFlags)
 128     : RenderBoxModelObject(element, WTF::move(style), baseTypeFlags)
 129     , m_minPreferredLogicalWidth(-1)
 130     , m_maxPreferredLogicalWidth(-1)
 131     , m_inlineBoxWrapper(nullptr)
 132 {
 133     setIsBox();
 134 }
 135
 136 RenderBox::RenderBox(Document& document, Ref<RenderStyle>&& style, unsigned baseTypeFlags)
 137     : RenderBoxModelObject(document, WTF::move(style), baseTypeFlags)
 138     , m_minPreferredLogicalWidth(-1)
 139     , m_maxPreferredLogicalWidth(-1)
 140     , m_inlineBoxWrapper(nullptr)
 141 {
 142     setIsBox();
 143 }
 144
 145 RenderBox::~RenderBox()
 146 {
 147     if (frame().eventHandler().autoscrollRenderer() == this)
 148         frame().eventHandler().stopAutoscrollTimer(true);
 149
 150     clearOverrideSize();
 151 #if ENABLE(CSS_GRID_LAYOUT)
 152     clearContainingBlockOverrideSize();
 153 #endif
 154
 155     RenderBlock::removePercentHeightDescendantIfNeeded(*this);
 156
 157 #if ENABLE(CSS_SHAPES)
 158     ShapeOutsideInfo::removeInfo(*this);
 159 #endif
 160
 161     view().unscheduleLazyRepaint(*this);
 162     if (hasControlStatesForRenderer(this))
 163         removeControlStatesForRenderer(this);
 164 }
 165
 166 RenderRegion* RenderBox::clampToStartAndEndRegions(RenderRegion* region) const
 167 {
 168     RenderFlowThread* flowThread = flowThreadContainingBlock();
 169
 170     ASSERT(isRenderView() || (region && flowThread));
 171     if (isRenderView())
 172         return region;
 173
 174     // We need to clamp to the block, since we want any lines or blocks that overflow out of the
 175     // logical top or logical bottom of the block to size as though the border box in the first and
 176     // last regions extended infinitely. Otherwise the lines are going to size according to the regions
 177     // they overflow into, which makes no sense when this block doesn't exist in |region| at all.
 178     RenderRegion* startRegion = nullptr;
 179     RenderRegion* endRegion = nullptr;
 180     if (!flowThread->getRegionRangeForBox(this, startRegion, endRegion))
 181         return region;
 182
 183     if (region->logicalTopForFlowThreadContent() < startRegion->logicalTopForFlowThreadContent())
 184         return startRegion;
 185     if (region->logicalTopForFlowThreadContent() > endRegion->logicalTopForFlowThreadContent())
 186         return endRegion;
 187
 188     return region;
 189 }
 190
 191 bool RenderBox::hasRegionRangeInFlowThread() const
 192 {
 193     RenderFlowThread* flowThread = flowThreadContainingBlock();
 194     if (!flowThread || !flowThread->hasValidRegionInfo())
 195         return false;
 196
 197     return flowThread->hasCachedRegionRangeForBox(this);
 198 }
 199
 200 LayoutRect RenderBox::clientBoxRectInRegion(RenderRegion* region) const
 201 {
 202     if (!region)
 203         return clientBoxRect();
 204
 205     LayoutRect clientBox = borderBoxRectInRegion(region);
 206     clientBox.setLocation(clientBox.location() + LayoutSize(borderLeft(), borderTop()));
 207     clientBox.setSize(clientBox.size() - LayoutSize(borderLeft() + borderRight() + verticalScrollbarWidth(), borderTop() + borderBottom() + horizontalScrollbarHeight()));
 208
 209     return clientBox;
 210 }
 211
 212 LayoutRect RenderBox::borderBoxRectInRegion(RenderRegion* region, RenderBoxRegionInfoFlags cacheFlag) const
 213 {
 214     if (!region)
 215         return borderBoxRect();
 216
 217     RenderFlowThread* flowThread = flowThreadContainingBlock();
 218     if (!flowThread)
 219         return borderBoxRect();
 220
 221     RenderRegion* startRegion = nullptr;
 222     RenderRegion* endRegion = nullptr;
 223     if (!flowThread->getRegionRangeForBox(this, startRegion, endRegion)) {
 224         // FIXME: In a perfect world this condition should never happen.
 225         return borderBoxRect();
 226     }
 227
 228     ASSERT(flowThread->regionInRange(region, startRegion, endRegion));
 229
 230     // Compute the logical width and placement in this region.
 231     RenderBoxRegionInfo* boxInfo = renderBoxRegionInfo(region, cacheFlag);
 232     if (!boxInfo)
 233         return borderBoxRect();
 234
 235     // We have cached insets.
 236     LayoutUnit logicalWidth = boxInfo->logicalWidth();
 237     LayoutUnit logicalLeft = boxInfo->logicalLeft();
 238
 239     // Now apply the parent inset since it is cumulative whenever anything in the containing block chain shifts.
 240     // FIXME: Doesn't work right with perpendicular writing modes.
 241     const RenderBlock* currentBox = containingBlock();
 242     RenderBoxRegionInfo* currentBoxInfo = isRenderFlowThread() ? nullptr : currentBox->renderBoxRegionInfo(region);
 243     while (currentBoxInfo && currentBoxInfo->isShifted()) {
 244         if (currentBox->style().direction() == LTR)
 245             logicalLeft += currentBoxInfo->logicalLeft();
 246         else
 247             logicalLeft -= (currentBox->logicalWidth() - currentBoxInfo->logicalWidth()) - currentBoxInfo->logicalLeft();
 248
 249         // Once we reach the fragmentation container we should stop.
 250         if (currentBox->isRenderFlowThread())
 251             break;
 252
 253         currentBox = currentBox->containingBlock();
 254         region = currentBox->clampToStartAndEndRegions(region);
 255         currentBoxInfo = currentBox->renderBoxRegionInfo(region);
 256     }
 257
 258     if (cacheFlag == DoNotCacheRenderBoxRegionInfo)
 259         delete boxInfo;
 260
 261     if (isHorizontalWritingMode())
 262         return LayoutRect(logicalLeft, 0, logicalWidth, height());
 263     return LayoutRect(0, logicalLeft, width(), logicalWidth);
 264 }
 265
 266 RenderBlockFlow* RenderBox::outermostBlockContainingFloatingObject()
 267 {
 268     ASSERT(isFloating());
 269     RenderBlockFlow* parentBlock = nullptr;
 270     for (auto& ancestor : ancestorsOfType<RenderBlockFlow>(*this)) {
 271         if (ancestor.isRenderView())
 272             break;
 273         if (!parentBlock || ancestor.containsFloat(*this))
 274             parentBlock = &ancestor;
 275     }
 276     return parentBlock;
 277 }
 278
 279 void RenderBox::removeFloatingOrPositionedChildFromBlockLists()
 280 {
 281     ASSERT(isFloatingOrOutOfFlowPositioned());
 282
 283     if (documentBeingDestroyed())
 284         return;
 285
 286     if (isFloating()) {
 287         if (RenderBlockFlow* parentBlock = outermostBlockContainingFloatingObject()) {
 288             parentBlock->markSiblingsWithFloatsForLayout(this);
 289             parentBlock->markAllDescendantsWithFloatsForLayout(this, false);
 290         }
 291     }
 292
 293     if (isOutOfFlowPositioned())
 294         RenderBlock::removePositionedObject(*this);
 295 }
 296
 297 void RenderBox::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 298 {
 299     s_hadOverflowClip = hasOverflowClip();
 300
 301     const RenderStyle* oldStyle = hasInitializedStyle() ? &style() : nullptr;
 302     if (oldStyle) {
 303         // The background of the root element or the body element could propagate up to
 304         // the canvas. Issue full repaint, when our style changes substantially.
 305         if (diff >= StyleDifferenceRepaint && (isRoot() || isBody())) {
 306             view().repaintRootContents();
 307             if (oldStyle->hasEntirelyFixedBackground() != newStyle.hasEntirelyFixedBackground())
 308                 view().compositor().rootFixedBackgroundsChanged();
 309         }
 310
 311         // When a layout hint happens and an object's position style changes, we have to do a layout
 312         // to dirty the render tree using the old position value now.
 313         if (diff == StyleDifferenceLayout && parent() && oldStyle->position() != newStyle.position()) {
 314             markContainingBlocksForLayout();
 315             if (oldStyle->position() == StaticPosition)
 316                 repaint();
 317             else if (newStyle.hasOutOfFlowPosition())
 318                 parent()->setChildNeedsLayout();
 319             if (isFloating() && !isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition())
 320                 removeFloatingOrPositionedChildFromBlockLists();
 321         }
 322     } else if (isBody())
 323         view().repaintRootContents();
 324
 325     RenderBoxModelObject::styleWillChange(diff, newStyle);
 326 }
 327
 328 void RenderBox::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 329 {
 330     // Horizontal writing mode definition is updated in RenderBoxModelObject::updateFromStyle,
 331     // (as part of the RenderBoxModelObject::styleDidChange call below). So, we can safely cache the horizontal
 332     // writing mode value before style change here.
 333     bool oldHorizontalWritingMode = isHorizontalWritingMode();
 334
 335     RenderBoxModelObject::styleDidChange(diff, oldStyle);
 336
 337     const RenderStyle& newStyle = style();
 338     if (needsLayout() && oldStyle) {
 339         RenderBlock::removePercentHeightDescendantIfNeeded(*this);
 340
 341         // Normally we can do optimized positioning layout for absolute/fixed positioned objects. There is one special case, however, which is
 342         // when the positioned object's margin-before is changed. In this case the parent has to get a layout in order to run margin collapsing
 343         // to determine the new static position.
 344         if (isOutOfFlowPositioned() && newStyle.hasStaticBlockPosition(isHorizontalWritingMode()) && oldStyle->marginBefore() != newStyle.marginBefore()
 345             && parent() && !parent()->normalChildNeedsLayout())
 346             parent()->setChildNeedsLayout();
 347     }
 348
 349     if (RenderBlock::hasPercentHeightContainerMap() && firstChild()
 350         && oldHorizontalWritingMode != isHorizontalWritingMode())
 351         RenderBlock::clearPercentHeightDescendantsFrom(*this);
 352
 353     // If our zoom factor changes and we have a defined scrollLeft/Top, we need to adjust that value into the
 354     // new zoomed coordinate space.
 355     if (hasOverflowClip() && oldStyle && oldStyle->effectiveZoom() != newStyle.effectiveZoom()) {
 356         if (int left = layer()->scrollXOffset()) {
 357             left = (left / oldStyle->effectiveZoom()) * newStyle.effectiveZoom();
 358             layer()->scrollToXOffset(left);
 359         }
 360         if (int top = layer()->scrollYOffset()) {
 361             top = (top / oldStyle->effectiveZoom()) * newStyle.effectiveZoom();
 362             layer()->scrollToYOffset(top);
 363         }
 364     }
 365
 366     // Our opaqueness might have changed without triggering layout.
 367     if (diff >= StyleDifferenceRepaint && diff <= StyleDifferenceRepaintLayer) {
 368         auto parentToInvalidate = parent();
 369         for (unsigned i = 0; i < backgroundObscurationTestMaxDepth && parentToInvalidate; ++i) {
 370             parentToInvalidate->invalidateBackgroundObscurationStatus();
 371             parentToInvalidate = parentToInvalidate->parent();
 372         }
 373     }
 374
 375     bool isBodyRenderer = isBody();
 376     bool isRootRenderer = isRoot();
 377
 378     // Set the text color if we're the body.
 379     if (isBodyRenderer)
 380         document().setTextColor(newStyle.visitedDependentColor(CSSPropertyColor));
 381
 382     if (isRootRenderer || isBodyRenderer) {
 383         // Propagate the new writing mode and direction up to the RenderView.
 384         RenderStyle& viewStyle = view().style();
 385         bool viewChangedWritingMode = false;
 386         bool rootStyleChanged = false;
 387         bool viewStyleChanged = false;
 388         RenderObject* rootRenderer = isBodyRenderer ? document().documentElement()->renderer() : nullptr;
 389         if (viewStyle.direction() != newStyle.direction() && (isRootRenderer || !document().directionSetOnDocumentElement())) {
 390             viewStyle.setDirection(newStyle.direction());
 391             viewStyleChanged = true;
 392             if (isBodyRenderer) {
 393                 rootRenderer->style().setDirection(newStyle.direction());
 394                 rootStyleChanged = true;
 395             }
 396             setNeedsLayoutAndPrefWidthsRecalc();
 397         }
 398
 399         if (viewStyle.writingMode() != newStyle.writingMode() && (isRootRenderer || !document().writingModeSetOnDocumentElement())) {
 400             viewStyle.setWritingMode(newStyle.writingMode());
 401             viewChangedWritingMode = true;
 402             viewStyleChanged = true;
 403             view().setHorizontalWritingMode(newStyle.isHorizontalWritingMode());
 404             view().markAllDescendantsWithFloatsForLayout();
 405             if (isBodyRenderer) {
 406                 rootStyleChanged = true;
 407                 rootRenderer->style().setWritingMode(newStyle.writingMode());
 408                 rootRenderer->setHorizontalWritingMode(newStyle.isHorizontalWritingMode());
 409             }
 410             setNeedsLayoutAndPrefWidthsRecalc();
 411         }
 412
 413         view().frameView().recalculateScrollbarOverlayStyle();
 414
 415         const Pagination& pagination = view().frameView().pagination();
 416         if (viewChangedWritingMode && pagination.mode != Pagination::Unpaginated) {
 417             viewStyle.setColumnStylesFromPaginationMode(pagination.mode);
 418             if (view().multiColumnFlowThread())
 419                 view().updateColumnProgressionFromStyle(viewStyle);
 420         }
 421
 422         if (viewStyleChanged && view().multiColumnFlowThread())
 423             view().updateStylesForColumnChildren();
 424
 425         if (rootStyleChanged && is<RenderBlockFlow>(rootRenderer) && downcast<RenderBlockFlow>(*rootRenderer).multiColumnFlowThread())
 426             downcast<RenderBlockFlow>(*rootRenderer).updateStylesForColumnChildren();
 427     }
 428
 429 #if ENABLE(CSS_SHAPES)
 430     if ((oldStyle && oldStyle->shapeOutside()) || style().shapeOutside())
 431         updateShapeOutsideInfoAfterStyleChange(style(), oldStyle);
 432 #endif
 433 }
 434
 435 #if ENABLE(CSS_SHAPES)
 436 void RenderBox::updateShapeOutsideInfoAfterStyleChange(const RenderStyle& style, const RenderStyle* oldStyle)
 437 {
 438     const ShapeValue* shapeOutside = style.shapeOutside();
 439     const ShapeValue* oldShapeOutside = oldStyle ? oldStyle->shapeOutside() : nullptr;
 440
 441     Length shapeMargin = style.shapeMargin();
 442     Length oldShapeMargin = oldStyle ? oldStyle->shapeMargin() : RenderStyle::initialShapeMargin();
 443
 444     float shapeImageThreshold = style.shapeImageThreshold();
 445     float oldShapeImageThreshold = oldStyle ? oldStyle->shapeImageThreshold() : RenderStyle::initialShapeImageThreshold();
 446
 447     // FIXME: A future optimization would do a deep comparison for equality. (bug 100811)
 448     if (shapeOutside == oldShapeOutside && shapeMargin == oldShapeMargin && shapeImageThreshold == oldShapeImageThreshold)
 449         return;
 450
 451     if (!shapeOutside)
 452         ShapeOutsideInfo::removeInfo(*this);
 453     else
 454         ShapeOutsideInfo::ensureInfo(*this).markShapeAsDirty();
 455
 456     if (shapeOutside || shapeOutside != oldShapeOutside)
 457         markShapeOutsideDependentsForLayout();
 458 }
 459 #endif
 460
 461 void RenderBox::updateFromStyle()
 462 {
 463     RenderBoxModelObject::updateFromStyle();
 464
 465     const RenderStyle& styleToUse = style();
 466     bool isRootObject = isRoot();
 467     bool isViewObject = isRenderView();
 468
 469     // The root and the RenderView always paint their backgrounds/borders.
 470     if (isRootObject || isViewObject)
 471         setHasBoxDecorations(true);
 472
 473     setFloating(!isOutOfFlowPositioned() && styleToUse.isFloating());
 474
 475     // We also handle <body> and <html>, whose overflow applies to the viewport.
 476     if (styleToUse.overflowX() != OVISIBLE && !isRootObject && isRenderBlock()) {
 477         bool boxHasOverflowClip = true;
 478         if (isBody()) {
 479             // Overflow on the body can propagate to the viewport under the following conditions.
 480             // (1) The root element is <html>.
 481             // (2) We are the primary <body> (can be checked by looking at document.body).
 482             // (3) The root element has visible overflow.
 483             if (is<HTMLHtmlElement>(*document().documentElement())
 484                 && document().body() == element()
 485                 && document().documentElement()->renderer()->style().overflowX() == OVISIBLE) {
 486                 boxHasOverflowClip = false;
 487             }
 488         }
 489
 490         // Check for overflow clip.
 491         // It's sufficient to just check one direction, since it's illegal to have visible on only one overflow value.
 492         if (boxHasOverflowClip) {
 493             if (!s_hadOverflowClip)
 494                 // Erase the overflow
 495                 repaint();
 496             setHasOverflowClip();
 497         }
 498     }
 499
 500     setHasTransformRelatedProperty(styleToUse.hasTransformRelatedProperty());
 501     setHasReflection(styleToUse.boxReflect());
 502 }
 503
 504 void RenderBox::layout()
 505 {
 506     StackStats::LayoutCheckPoint layoutCheckPoint;
 507     ASSERT(needsLayout());
 508
 509     RenderObject* child = firstChild();
 510     if (!child) {
 511         clearNeedsLayout();
 512         return;
 513     }
 514
 515     LayoutStateMaintainer statePusher(view(), *this, locationOffset(), style().isFlippedBlocksWritingMode());
 516     while (child) {
 517         if (child->needsLayout())
 518             downcast<RenderElement>(*child).layout();
 519         ASSERT(!child->needsLayout());
 520         child = child->nextSibling();
 521     }
 522     statePusher.pop();
 523     invalidateBackgroundObscurationStatus();
 524     clearNeedsLayout();
 525 }
 526
 527 // More IE extensions.  clientWidth and clientHeight represent the interior of an object
 528 // excluding border and scrollbar.
 529 LayoutUnit RenderBox::clientWidth() const
 530 {
 531     return width() - borderLeft() - borderRight() - verticalScrollbarWidth();
 532 }
 533
 534 LayoutUnit RenderBox::clientHeight() const
 535 {
 536     return height() - borderTop() - borderBottom() - horizontalScrollbarHeight();
 537 }
 538
 539 int RenderBox::pixelSnappedClientWidth() const
 540 {
 541     // FIXME: This should use snappedIntSize() instead with absolute coordinates.
 542     return roundToInt(clientWidth());
 543 }
 544
 545 int RenderBox::pixelSnappedClientHeight() const
 546 {
 547     // FIXME: This should use snappedIntSize() instead with absolute coordinates.
 548     return roundToInt(clientHeight());
 549 }
 550
 551 int RenderBox::pixelSnappedOffsetWidth() const
 552 {
 553     // FIXME: This should use snappedIntSize() instead with absolute coordinates.
 554     return roundToInt(offsetWidth());
 555 }
 556
 557 int RenderBox::pixelSnappedOffsetHeight() const
 558 {
 559     // FIXME: This should use snappedIntSize() instead with absolute coordinates.
 560     return roundToInt(offsetHeight());
 561 }
 562
 563 int RenderBox::scrollWidth() const
 564 {
 565     if (hasOverflowClip())
 566         return layer()->scrollWidth();
 567     // For objects with visible overflow, this matches IE.
 568     // FIXME: Need to work right with writing modes.
 569     if (style().isLeftToRightDirection()) {
 570         // FIXME: This should use snappedIntSize() instead with absolute coordinates.
 571         return roundToInt(std::max(clientWidth(), layoutOverflowRect().maxX() - borderLeft()));
 572     }
 573     return clientWidth() - std::min<LayoutUnit>(0, layoutOverflowRect().x() - borderLeft());
 574 }
 575
 576 int RenderBox::scrollHeight() const
 577 {
 578     if (hasOverflowClip())
 579         return layer()->scrollHeight();
 580     // For objects with visible overflow, this matches IE.
 581     // FIXME: Need to work right with writing modes.
 582     // FIXME: This should use snappedIntSize() instead with absolute coordinates.
 583     return roundToInt(std::max(clientHeight(), layoutOverflowRect().maxY() - borderTop()));
 584 }
 585
 586 int RenderBox::scrollLeft() const
 587 {
 588     return hasOverflowClip() ? layer()->scrollXOffset() : 0;
 589 }
 590
 591 int RenderBox::scrollTop() const
 592 {
 593     return hasOverflowClip() ? layer()->scrollYOffset() : 0;
 594 }
 595
 596 void RenderBox::setScrollLeft(int newLeft)
 597 {
 598     if (hasOverflowClip())
 599         layer()->scrollToXOffset(newLeft, RenderLayer::ScrollOffsetClamped);
 600 }
 601
 602 void RenderBox::setScrollTop(int newTop)
 603 {
 604     if (hasOverflowClip())
 605         layer()->scrollToYOffset(newTop, RenderLayer::ScrollOffsetClamped);
 606 }
 607
 608 void RenderBox::absoluteRects(Vector<IntRect>& rects, const LayoutPoint& accumulatedOffset) const
 609 {
 610     rects.append(snappedIntRect(accumulatedOffset, size()));
 611 }
 612
 613 void RenderBox::absoluteQuads(Vector<FloatQuad>& quads, bool* wasFixed) const
 614 {
 615     FloatRect localRect(0, 0, width(), height());
 616
 617     RenderFlowThread* flowThread = flowThreadContainingBlock();
 618     if (flowThread && flowThread->absoluteQuadsForBox(quads, wasFixed, this, localRect.y(), localRect.maxY()))
 619         return;
 620
 621     quads.append(localToAbsoluteQuad(localRect, UseTransforms, wasFixed));
 622 }
 623
 624 void RenderBox::updateLayerTransform()
 625 {
 626     // Transform-origin depends on box size, so we need to update the layer transform after layout.
 627     if (hasLayer())
 628         layer()->updateTransform();
 629 }
 630
 631 LayoutUnit RenderBox::constrainLogicalWidthInRegionByMinMax(LayoutUnit logicalWidth, LayoutUnit availableWidth, RenderBlock* cb, RenderRegion* region) const
 632 {
 633     const RenderStyle& styleToUse = style();
 634     if (!styleToUse.logicalMaxWidth().isUndefined())
 635         logicalWidth = std::min(logicalWidth, computeLogicalWidthInRegionUsing(MaxSize, styleToUse.logicalMaxWidth(), availableWidth, cb, region));
 636     return std::max(logicalWidth, computeLogicalWidthInRegionUsing(MinSize, styleToUse.logicalMinWidth(), availableWidth, cb, region));
 637 }
 638
 639 LayoutUnit RenderBox::constrainLogicalHeightByMinMax(LayoutUnit logicalHeight) const
 640 {
 641     const RenderStyle& styleToUse = style();
 642     if (!styleToUse.logicalMaxHeight().isUndefined()) {
 643         LayoutUnit maxH = computeLogicalHeightUsing(styleToUse.logicalMaxHeight());
 644         if (maxH != -1)
 645             logicalHeight = std::min(logicalHeight, maxH);
 646     }
 647     return std::max(logicalHeight, computeLogicalHeightUsing(styleToUse.logicalMinHeight()));
 648 }
 649
 650 LayoutUnit RenderBox::constrainContentBoxLogicalHeightByMinMax(LayoutUnit logicalHeight) const
 651 {
 652     const RenderStyle& styleToUse = style();
 653     if (!styleToUse.logicalMaxHeight().isUndefined()) {
 654         LayoutUnit maxH = computeContentLogicalHeight(styleToUse.logicalMaxHeight());
 655         if (maxH != -1)
 656             logicalHeight = std::min(logicalHeight, maxH);
 657     }
 658     return std::max(logicalHeight, computeContentLogicalHeight(styleToUse.logicalMinHeight()));
 659 }
 660
 661 RoundedRect::Radii RenderBox::borderRadii() const
 662 {
 663     RenderStyle& style = this->style();
 664     LayoutRect bounds = frameRect();
 665
 666     unsigned borderLeft = style.borderLeftWidth();
 667     unsigned borderTop = style.borderTopWidth();
 668     bounds.moveBy(LayoutPoint(borderLeft, borderTop));
 669     bounds.contract(borderLeft + style.borderRightWidth(), borderTop + style.borderBottomWidth());
 670     return style.getRoundedBorderFor(bounds).radii();
 671 }
 672
 673 IntRect RenderBox::absoluteContentBox() const
 674 {
 675     // This is wrong with transforms and flipped writing modes.
 676     IntRect rect = snappedIntRect(contentBoxRect());
 677     FloatPoint absPos = localToAbsolute();
 678     rect.move(absPos.x(), absPos.y());
 679     return rect;
 680 }
 681
 682 FloatQuad RenderBox::absoluteContentQuad() const
 683 {
 684     LayoutRect rect = contentBoxRect();
 685     return localToAbsoluteQuad(FloatRect(rect));
 686 }
 687
 688 LayoutRect RenderBox::outlineBoundsForRepaint(const RenderLayerModelObject* repaintContainer, const RenderGeometryMap* geometryMap) const
 689 {
 690     LayoutRect box = borderBoundingBox();
 691     adjustRectForOutlineAndShadow(box);
 692
 693     if (repaintContainer != this) {
 694         FloatQuad containerRelativeQuad;
 695         if (geometryMap)
 696             containerRelativeQuad = geometryMap->mapToContainer(box, repaintContainer);
 697         else
 698             containerRelativeQuad = localToContainerQuad(FloatRect(box), repaintContainer);
 699
 700         box = LayoutRect(containerRelativeQuad.boundingBox());
 701     }
 702
 703     // FIXME: layoutDelta needs to be applied in parts before/after transforms and
 704     // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
 705     box.move(view().layoutDelta());
 706
 707     return LayoutRect(snapRectToDevicePixels(box, document().deviceScaleFactor()));
 708 }
 709
 710 void RenderBox::addFocusRingRects(Vector<IntRect>& rects, const LayoutPoint& additionalOffset, const RenderLayerModelObject*)
 711 {
 712     if (!size().isEmpty())
 713         rects.append(snappedIntRect(additionalOffset, size()));
 714 }
 715
 716 int RenderBox::reflectionOffset() const
 717 {
 718     if (!style().boxReflect())
 719         return 0;
 720     if (style().boxReflect()->direction() == ReflectionLeft || style().boxReflect()->direction() == ReflectionRight)
 721         return valueForLength(style().boxReflect()->offset(), borderBoxRect().width());
 722     return valueForLength(style().boxReflect()->offset(), borderBoxRect().height());
 723 }
 724
 725 LayoutRect RenderBox::reflectedRect(const LayoutRect& r) const
 726 {
 727     if (!style().boxReflect())
 728         return LayoutRect();
 729
 730     LayoutRect box = borderBoxRect();
 731     LayoutRect result = r;
 732     switch (style().boxReflect()->direction()) {
 733         case ReflectionBelow:
 734             result.setY(box.maxY() + reflectionOffset() + (box.maxY() - r.maxY()));
 735             break;
 736         case ReflectionAbove:
 737             result.setY(box.y() - reflectionOffset() - box.height() + (box.maxY() - r.maxY()));
 738             break;
 739         case ReflectionLeft:
 740             result.setX(box.x() - reflectionOffset() - box.width() + (box.maxX() - r.maxX()));
 741             break;
 742         case ReflectionRight:
 743             result.setX(box.maxX() + reflectionOffset() + (box.maxX() - r.maxX()));
 744             break;
 745     }
 746     return result;
 747 }
 748
 749 bool RenderBox::fixedElementLaysOutRelativeToFrame(const FrameView& frameView) const
 750 {
 751     return style().position() == FixedPosition && container()->isRenderView() && frameView.fixedElementsLayoutRelativeToFrame();
 752 }
 753
 754 bool RenderBox::includeVerticalScrollbarSize() const
 755 {
 756     return hasOverflowClip() && !layer()->hasOverlayScrollbars()
 757         && (style().overflowY() == OSCROLL || style().overflowY() == OAUTO);
 758 }
 759
 760 bool RenderBox::includeHorizontalScrollbarSize() const
 761 {
 762     return hasOverflowClip() && !layer()->hasOverlayScrollbars()
 763         && (style().overflowX() == OSCROLL || style().overflowX() == OAUTO);
 764 }
 765
 766 int RenderBox::verticalScrollbarWidth() const
 767 {
 768     return includeVerticalScrollbarSize() ? layer()->verticalScrollbarWidth() : 0;
 769 }
 770
 771 int RenderBox::horizontalScrollbarHeight() const
 772 {
 773     return includeHorizontalScrollbarSize() ? layer()->horizontalScrollbarHeight() : 0;
 774 }
 775
 776 int RenderBox::instrinsicScrollbarLogicalWidth() const
 777 {
 778     if (!hasOverflowClip())
 779         return 0;
 780
 781     if (isHorizontalWritingMode() && (style().overflowY() == OSCROLL && !hasVerticalScrollbarWithAutoBehavior())) {
 782         ASSERT(layer()->hasVerticalScrollbar());
 783         return verticalScrollbarWidth();
 784     }
 785
 786     if (!isHorizontalWritingMode() && (style().overflowX() == OSCROLL && !hasHorizontalScrollbarWithAutoBehavior())) {
 787         ASSERT(layer()->hasHorizontalScrollbar());
 788         return horizontalScrollbarHeight();
 789     }
 790
 791     return 0;
 792 }
 793
 794 bool RenderBox::scrollLayer(ScrollDirection direction, ScrollGranularity granularity, float multiplier, Element** stopElement)
 795 {
 796     RenderLayer* boxLayer = layer();
 797     if (boxLayer && boxLayer->scroll(direction, granularity, multiplier)) {
 798         if (stopElement)
 799             *stopElement = element();
 800
 801         return true;
 802     }
 803
 804     return false;
 805 }
 806
 807 bool RenderBox::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier, Element** stopElement, RenderBox* startBox, const IntPoint& wheelEventAbsolutePoint)
 808 {
 809     if (scrollLayer(direction, granularity, multiplier, stopElement))
 810         return true;
 811
 812     if (stopElement && *stopElement && *stopElement == element())
 813         return true;
 814
 815     RenderBlock* nextScrollBlock = containingBlock();
 816     if (is<RenderNamedFlowThread>(nextScrollBlock)) {
 817         ASSERT(startBox);
 818         nextScrollBlock = downcast<RenderNamedFlowThread>(*nextScrollBlock).fragmentFromAbsolutePointAndBox(wheelEventAbsolutePoint, *startBox);
 819     }
 820
 821     if (nextScrollBlock && !nextScrollBlock->isRenderView())
 822         return nextScrollBlock->scroll(direction, granularity, multiplier, stopElement, startBox, wheelEventAbsolutePoint);
 823
 824     return false;
 825 }
 826
 827 bool RenderBox::logicalScroll(ScrollLogicalDirection direction, ScrollGranularity granularity, float multiplier, Element** stopElement)
 828 {
 829     bool scrolled = false;
 830
 831     RenderLayer* l = layer();
 832     if (l) {
 833 #if PLATFORM(COCOA)
 834         // On Mac only we reset the inline direction position when doing a document scroll (e.g., hitting Home/End).
 835         if (granularity == ScrollByDocument)
 836             scrolled = l->scroll(logicalToPhysical(ScrollInlineDirectionBackward, isHorizontalWritingMode(), style().isFlippedBlocksWritingMode()), ScrollByDocument, multiplier);
 837 #endif
 838         if (l->scroll(logicalToPhysical(direction, isHorizontalWritingMode(), style().isFlippedBlocksWritingMode()), granularity, multiplier))
 839             scrolled = true;
 840
 841         if (scrolled) {
 842             if (stopElement)
 843                 *stopElement = element();
 844             return true;
 845         }
 846     }
 847
 848     if (stopElement && *stopElement && *stopElement == element())
 849         return true;
 850
 851     RenderBlock* b = containingBlock();
 852     if (b && !b->isRenderView())
 853         return b->logicalScroll(direction, granularity, multiplier, stopElement);
 854     return false;
 855 }
 856
 857 bool RenderBox::canBeScrolledAndHasScrollableArea() const
 858 {
 859     return canBeProgramaticallyScrolled() && (scrollHeight() != clientHeight() || scrollWidth() != clientWidth());
 860 }
 861
 862 bool RenderBox::isScrollableOrRubberbandableBox() const
 863 {
 864     return canBeScrolledAndHasScrollableArea();
 865 }
 866
 867 bool RenderBox::canBeProgramaticallyScrolled() const
 868 {
 869     if (isRenderView())
 870         return true;
 871
 872     if (!hasOverflowClip())
 873         return false;
 874
 875     bool hasScrollableOverflow = hasScrollableOverflowX() || hasScrollableOverflowY();
 876     if (scrollsOverflow() && hasScrollableOverflow)
 877         return true;
 878
 879     return element() && element()->hasEditableStyle();
 880 }
 881
 882 bool RenderBox::usesCompositedScrolling() const
 883 {
 884     return hasOverflowClip() && hasLayer() && layer()->usesCompositedScrolling();
 885 }
 886
 887 void RenderBox::autoscroll(const IntPoint& position)
 888 {
 889     if (layer())
 890         layer()->autoscroll(position);
 891 }
 892
 893 // There are two kinds of renderer that can autoscroll.
 894 bool RenderBox::canAutoscroll() const
 895 {
 896     if (isRenderView())
 897         return view().frameView().isScrollable();
 898
 899     // Check for a box that can be scrolled in its own right.
 900     if (canBeScrolledAndHasScrollableArea())
 901         return true;
 902
 903     return false;
 904 }
 905
 906 // If specified point is in border belt, returned offset denotes direction of
 907 // scrolling.
 908 IntSize RenderBox::calculateAutoscrollDirection(const IntPoint& windowPoint) const
 909 {
 910     IntRect box(absoluteBoundingBoxRect());
 911     box.move(view().frameView().scrollOffset());
 912     IntRect windowBox = view().frameView().contentsToWindow(box);
 913
 914     IntPoint windowAutoscrollPoint = windowPoint;
 915
 916     if (windowAutoscrollPoint.x() < windowBox.x() + autoscrollBeltSize)
 917         windowAutoscrollPoint.move(-autoscrollBeltSize, 0);
 918     else if (windowAutoscrollPoint.x() > windowBox.maxX() - autoscrollBeltSize)
 919         windowAutoscrollPoint.move(autoscrollBeltSize, 0);
 920
 921     if (windowAutoscrollPoint.y() < windowBox.y() + autoscrollBeltSize)
 922         windowAutoscrollPoint.move(0, -autoscrollBeltSize);
 923     else if (windowAutoscrollPoint.y() > windowBox.maxY() - autoscrollBeltSize)
 924         windowAutoscrollPoint.move(0, autoscrollBeltSize);
 925
 926     return windowAutoscrollPoint - windowPoint;
 927 }
 928
 929 RenderBox* RenderBox::findAutoscrollable(RenderObject* renderer)
 930 {
 931     while (renderer && !(is<RenderBox>(*renderer) && downcast<RenderBox>(*renderer).canAutoscroll())) {
 932         if (is<RenderView>(*renderer) && renderer->document().ownerElement())
 933             renderer = renderer->document().ownerElement()->renderer();
 934         else
 935             renderer = renderer->parent();
 936     }
 937
 938     return is<RenderBox>(renderer) ? downcast<RenderBox>(renderer) : nullptr;
 939 }
 940
 941 void RenderBox::panScroll(const IntPoint& source)
 942 {
 943     if (layer())
 944         layer()->panScrollFromPoint(source);
 945 }
 946
 947 bool RenderBox::hasVerticalScrollbarWithAutoBehavior() const
 948 {
 949     bool overflowScrollActsLikeAuto = style().overflowY() == OSCROLL && !style().hasPseudoStyle(SCROLLBAR) && ScrollbarTheme::theme()->usesOverlayScrollbars();
 950     return hasOverflowClip() && (style().overflowY() == OAUTO || style().overflowY() == OOVERLAY || overflowScrollActsLikeAuto);
 951 }
 952
 953 bool RenderBox::hasHorizontalScrollbarWithAutoBehavior() const
 954 {
 955     bool overflowScrollActsLikeAuto = style().overflowX() == OSCROLL && !style().hasPseudoStyle(SCROLLBAR) && ScrollbarTheme::theme()->usesOverlayScrollbars();
 956     return hasOverflowClip() && (style().overflowX() == OAUTO || style().overflowX() == OOVERLAY || overflowScrollActsLikeAuto);
 957 }
 958
 959 bool RenderBox::needsPreferredWidthsRecalculation() const
 960 {
 961     return style().paddingStart().isPercent() || style().paddingEnd().isPercent();
 962 }
 963
 964 IntSize RenderBox::scrolledContentOffset() const
 965 {
 966     if (!hasOverflowClip())
 967         return IntSize();
 968
 969     ASSERT(hasLayer());
 970     return layer()->scrolledContentOffset();
 971 }
 972
 973 LayoutSize RenderBox::cachedSizeForOverflowClip() const
 974 {
 975     ASSERT(hasOverflowClip());
 976     ASSERT(hasLayer());
 977     return layer()->size();
 978 }
 979
 980 void RenderBox::applyCachedClipAndScrollOffsetForRepaint(LayoutRect& paintRect) const
 981 {
 982     flipForWritingMode(paintRect);
 983     paintRect.move(-scrolledContentOffset()); // For overflow:auto/scroll/hidden.
 984
 985     // Do not clip scroll layer contents to reduce the number of repaints while scrolling.
 986     if (usesCompositedScrolling()) {
 987         flipForWritingMode(paintRect);
 988         return;
 989     }
 990
 991     // height() is inaccurate if we're in the middle of a layout of this RenderBox, so use the
 992     // layer's size instead. Even if the layer's size is wrong, the layer itself will repaint
 993     // anyway if its size does change.
 994     LayoutRect clipRect(LayoutPoint(), cachedSizeForOverflowClip());
 995     paintRect = intersection(paintRect, clipRect);
 996     flipForWritingMode(paintRect);
 997 }
 998
 999 void RenderBox::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
1000 {
1001     minLogicalWidth = minPreferredLogicalWidth() - borderAndPaddingLogicalWidth();
1002     maxLogicalWidth = maxPreferredLogicalWidth() - borderAndPaddingLogicalWidth();
1003 }
1004
1005 LayoutUnit RenderBox::minPreferredLogicalWidth() const
1006 {
1007     if (preferredLogicalWidthsDirty()) {
1008 #ifndef NDEBUG
1009         SetLayoutNeededForbiddenScope layoutForbiddenScope(const_cast<RenderBox*>(this));
1010 #endif
1011         const_cast<RenderBox*>(this)->computePreferredLogicalWidths();
1012     }
1013
1014     return m_minPreferredLogicalWidth;
1015 }
1016
1017 LayoutUnit RenderBox::maxPreferredLogicalWidth() const
1018 {
1019     if (preferredLogicalWidthsDirty()) {
1020 #ifndef NDEBUG
1021         SetLayoutNeededForbiddenScope layoutForbiddenScope(const_cast<RenderBox*>(this));
1022 #endif
1023         const_cast<RenderBox*>(this)->computePreferredLogicalWidths();
1024     }
1025
1026     return m_maxPreferredLogicalWidth;
1027 }
1028
1029 bool RenderBox::hasOverrideLogicalContentHeight() const
1030 {
1031     return gOverrideHeightMap && gOverrideHeightMap->contains(this);
1032 }
1033
1034 bool RenderBox::hasOverrideLogicalContentWidth() const
1035 {
1036     return gOverrideWidthMap && gOverrideWidthMap->contains(this);
1037 }
1038
1039 void RenderBox::setOverrideLogicalContentHeight(LayoutUnit height)
1040 {
1041     if (!gOverrideHeightMap)
1042         gOverrideHeightMap = new OverrideSizeMap();
1043     gOverrideHeightMap->set(this, height);
1044 }
1045
1046 void RenderBox::setOverrideLogicalContentWidth(LayoutUnit width)
1047 {
1048     if (!gOverrideWidthMap)
1049         gOverrideWidthMap = new OverrideSizeMap();
1050     gOverrideWidthMap->set(this, width);
1051 }
1052
1053 void RenderBox::clearOverrideLogicalContentHeight()
1054 {
1055     if (gOverrideHeightMap)
1056         gOverrideHeightMap->remove(this);
1057 }
1058
1059 void RenderBox::clearOverrideLogicalContentWidth()
1060 {
1061     if (gOverrideWidthMap)
1062         gOverrideWidthMap->remove(this);
1063 }
1064
1065 void RenderBox::clearOverrideSize()
1066 {
1067     clearOverrideLogicalContentHeight();
1068     clearOverrideLogicalContentWidth();
1069 }
1070
1071 LayoutUnit RenderBox::overrideLogicalContentWidth() const
1072 {
1073     ASSERT(hasOverrideLogicalContentWidth());
1074     return gOverrideWidthMap->get(this);
1075 }
1076
1077 LayoutUnit RenderBox::overrideLogicalContentHeight() const
1078 {
1079     ASSERT(hasOverrideLogicalContentHeight());
1080     return gOverrideHeightMap->get(this);
1081 }
1082
1083 #if ENABLE(CSS_GRID_LAYOUT)
1084 LayoutUnit RenderBox::overrideContainingBlockContentLogicalWidth() const
1085 {
1086     ASSERT(hasOverrideContainingBlockLogicalWidth());
1087     return gOverrideContainingBlockLogicalWidthMap->get(this);
1088 }
1089
1090 LayoutUnit RenderBox::overrideContainingBlockContentLogicalHeight() const
1091 {
1092     ASSERT(hasOverrideContainingBlockLogicalHeight());
1093     return gOverrideContainingBlockLogicalHeightMap->get(this);
1094 }
1095
1096 bool RenderBox::hasOverrideContainingBlockLogicalWidth() const
1097 {
1098     return gOverrideContainingBlockLogicalWidthMap && gOverrideContainingBlockLogicalWidthMap->contains(this);
1099 }
1100
1101 bool RenderBox::hasOverrideContainingBlockLogicalHeight() const
1102 {
1103     return gOverrideContainingBlockLogicalHeightMap && gOverrideContainingBlockLogicalHeightMap->contains(this);
1104 }
1105
1106 void RenderBox::setOverrideContainingBlockContentLogicalWidth(LayoutUnit logicalWidth)
1107 {
1108     if (!gOverrideContainingBlockLogicalWidthMap)
1109         gOverrideContainingBlockLogicalWidthMap = new OverrideSizeMap;
1110     gOverrideContainingBlockLogicalWidthMap->set(this, logicalWidth);
1111 }
1112
1113 void RenderBox::setOverrideContainingBlockContentLogicalHeight(LayoutUnit logicalHeight)
1114 {
1115     if (!gOverrideContainingBlockLogicalHeightMap)
1116         gOverrideContainingBlockLogicalHeightMap = new OverrideSizeMap;
1117     gOverrideContainingBlockLogicalHeightMap->set(this, logicalHeight);
1118 }
1119
1120 void RenderBox::clearContainingBlockOverrideSize()
1121 {
1122     if (gOverrideContainingBlockLogicalWidthMap)
1123         gOverrideContainingBlockLogicalWidthMap->remove(this);
1124     clearOverrideContainingBlockContentLogicalHeight();
1125 }
1126
1127 void RenderBox::clearOverrideContainingBlockContentLogicalHeight()
1128 {
1129     if (gOverrideContainingBlockLogicalHeightMap)
1130         gOverrideContainingBlockLogicalHeightMap->remove(this);
1131 }
1132 #endif // ENABLE(CSS_GRID_LAYOUT)
1133
1134 LayoutUnit RenderBox::adjustBorderBoxLogicalWidthForBoxSizing(LayoutUnit width) const
1135 {
1136     LayoutUnit bordersPlusPadding = borderAndPaddingLogicalWidth();
1137     if (style().boxSizing() == CONTENT_BOX)
1138         return width + bordersPlusPadding;
1139     return std::max(width, bordersPlusPadding);
1140 }
1141
1142 LayoutUnit RenderBox::adjustBorderBoxLogicalHeightForBoxSizing(LayoutUnit height) const
1143 {
1144     LayoutUnit bordersPlusPadding = borderAndPaddingLogicalHeight();
1145     if (style().boxSizing() == CONTENT_BOX)
1146         return height + bordersPlusPadding;
1147     return std::max(height, bordersPlusPadding);
1148 }
1149
1150 LayoutUnit RenderBox::adjustContentBoxLogicalWidthForBoxSizing(LayoutUnit width) const
1151 {
1152     if (style().boxSizing() == BORDER_BOX)
1153         width -= borderAndPaddingLogicalWidth();
1154     return std::max<LayoutUnit>(0, width);
1155 }
1156
1157 LayoutUnit RenderBox::adjustContentBoxLogicalHeightForBoxSizing(LayoutUnit height) const
1158 {
1159     if (style().boxSizing() == BORDER_BOX)
1160         height -= borderAndPaddingLogicalHeight();
1161     return std::max<LayoutUnit>(0, height);
1162 }
1163
1164 // Hit Testing
1165 bool RenderBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
1166 {
1167     LayoutPoint adjustedLocation = accumulatedOffset + location();
1168
1169     // Check kids first.
1170     for (RenderObject* child = lastChild(); child; child = child->previousSibling()) {
1171         if (!child->hasLayer() && child->nodeAtPoint(request, result, locationInContainer, adjustedLocation, action)) {
1172             updateHitTestResult(result, locationInContainer.point() - toLayoutSize(adjustedLocation));
1173             return true;
1174         }
1175     }
1176
1177     RenderFlowThread* flowThread = flowThreadContainingBlock();
1178     RenderRegion* regionToUse = flowThread ? downcast<RenderNamedFlowFragment>(flowThread->currentRegion()) : nullptr;
1179
1180     // If the box is not contained by this region there's no point in going further.
1181     if (regionToUse && !flowThread->objectShouldFragmentInFlowRegion(this, regionToUse))
1182         return false;
1183
1184     // Check our bounds next. For this purpose always assume that we can only be hit in the
1185     // foreground phase (which is true for replaced elements like images).
1186     LayoutRect boundsRect = borderBoxRectInRegion(regionToUse);
1187     boundsRect.moveBy(adjustedLocation);
1188     if (visibleToHitTesting() && action == HitTestForeground && locationInContainer.intersects(boundsRect)) {
1189         updateHitTestResult(result, locationInContainer.point() - toLayoutSize(adjustedLocation));
1190         if (!result.addNodeToRectBasedTestResult(element(), request, locationInContainer, boundsRect))
1191             return true;
1192     }
1193
1194     return false;
1195 }
1196
1197 // --------------------- painting stuff -------------------------------
1198
1199 void RenderBox::paintRootBoxFillLayers(const PaintInfo& paintInfo)
1200 {
1201     if (paintInfo.skipRootBackground())
1202         return;
1203
1204     auto& rootBackgroundRenderer = rendererForRootBackground();
1205
1206     const FillLayer* bgLayer = rootBackgroundRenderer.style().backgroundLayers();
1207     Color bgColor = rootBackgroundRenderer.style().visitedDependentColor(CSSPropertyBackgroundColor);
1208
1209     paintFillLayers(paintInfo, bgColor, bgLayer, view().backgroundRect(this), BackgroundBleedNone, CompositeSourceOver, &rootBackgroundRenderer);
1210 }
1211
1212 BackgroundBleedAvoidance RenderBox::determineBackgroundBleedAvoidance(GraphicsContext* context) const
1213 {
1214     if (context->paintingDisabled())
1215         return BackgroundBleedNone;
1216
1217     const RenderStyle& style = this->style();
1218
1219     if (!style.hasBackground() || !style.hasBorder() || !style.hasBorderRadius() || borderImageIsLoadedAndCanBeRendered())
1220         return BackgroundBleedNone;
1221
1222     AffineTransform ctm = context->getCTM();
1223     FloatSize contextScaling(static_cast<float>(ctm.xScale()), static_cast<float>(ctm.yScale()));
1224
1225     // Because RoundedRect uses IntRect internally the inset applied by the
1226     // BackgroundBleedShrinkBackground strategy cannot be less than one integer
1227     // layout coordinate, even with subpixel layout enabled. To take that into
1228     // account, we clamp the contextScaling to 1.0 for the following test so
1229     // that borderObscuresBackgroundEdge can only return true if the border
1230     // widths are greater than 2 in both layout coordinates and screen
1231     // coordinates.
1232     // This precaution will become obsolete if RoundedRect is ever promoted to
1233     // a sub-pixel representation.
1234     if (contextScaling.width() > 1)
1235         contextScaling.setWidth(1);
1236     if (contextScaling.height() > 1)
1237         contextScaling.setHeight(1);
1238
1239     if (borderObscuresBackgroundEdge(contextScaling))
1240         return BackgroundBleedShrinkBackground;
1241     if (!style.hasAppearance() && borderObscuresBackground() && backgroundHasOpaqueTopLayer())
1242         return BackgroundBleedBackgroundOverBorder;
1243
1244     return BackgroundBleedUseTransparencyLayer;
1245 }
1246
1247 void RenderBox::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
1248 {
1249     if (!paintInfo.shouldPaintWithinRoot(*this))
1250         return;
1251
1252     LayoutRect paintRect = borderBoxRectInRegion(currentRenderNamedFlowFragment());
1253     paintRect.moveBy(paintOffset);
1254
1255 #if PLATFORM(IOS)
1256     // Workaround for <rdar://problem/6209763>. Force the painting bounds of checkboxes and radio controls to be square.
1257     if (style().appearance() == CheckboxPart || style().appearance() == RadioPart) {
1258         int width = std::min(paintRect.width(), paintRect.height());
1259         int height = width;
1260         paintRect = IntRect(paintRect.x(), paintRect.y() + (this->height() - height) / 2, width, height); // Vertically center the checkbox, like on desktop
1261     }
1262 #endif
1263     BackgroundBleedAvoidance bleedAvoidance = determineBackgroundBleedAvoidance(paintInfo.context);
1264
1265     // FIXME: Should eventually give the theme control over whether the box shadow should paint, since controls could have
1266     // custom shadows of their own.
1267     if (!boxShadowShouldBeAppliedToBackground(bleedAvoidance))
1268         paintBoxShadow(paintInfo, paintRect, style(), Normal);
1269
1270     GraphicsContextStateSaver stateSaver(*paintInfo.context, false);
1271     if (bleedAvoidance == BackgroundBleedUseTransparencyLayer) {
1272         // To avoid the background color bleeding out behind the border, we'll render background and border
1273         // into a transparency layer, and then clip that in one go (which requires setting up the clip before
1274         // beginning the layer).
1275         stateSaver.save();
1276         paintInfo.context->clipRoundedRect(style().getRoundedBorderFor(paintRect).pixelSnappedRoundedRectForPainting(document().deviceScaleFactor()));
1277         paintInfo.context->beginTransparencyLayer(1);
1278     }
1279
1280     // If we have a native theme appearance, paint that before painting our background.
1281     // The theme will tell us whether or not we should also paint the CSS background.
1282     ControlStates* controlStates = nullptr;
1283     if (style().hasAppearance()) {
1284         if (hasControlStatesForRenderer(this))
1285             controlStates = controlStatesForRenderer(this);
1286         else {
1287             controlStates = new ControlStates();
1288             addControlStatesForRenderer(this, controlStates);
1289         }
1290     }
1291
1292     bool themePainted = style().hasAppearance() && !theme().paint(*this, controlStates, paintInfo, paintRect);
1293
1294     if (controlStates && controlStates->needsRepaint())
1295         view().scheduleLazyRepaint(*this);
1296
1297     if (!themePainted) {
1298         if (bleedAvoidance == BackgroundBleedBackgroundOverBorder)
1299             paintBorder(paintInfo, paintRect, style(), bleedAvoidance);
1300
1301         paintBackground(paintInfo, paintRect, bleedAvoidance);
1302
1303         if (style().hasAppearance())
1304             theme().paintDecorations(*this, paintInfo, paintRect);
1305     }
1306     paintBoxShadow(paintInfo, paintRect, style(), Inset);
1307
1308     // The theme will tell us whether or not we should also paint the CSS border.
1309     if (bleedAvoidance != BackgroundBleedBackgroundOverBorder && (!style().hasAppearance() || (!themePainted && theme().paintBorderOnly(*this, paintInfo, paintRect))) && style().hasBorderDecoration())
1310         paintBorder(paintInfo, paintRect, style(), bleedAvoidance);
1311
1312     if (bleedAvoidance == BackgroundBleedUseTransparencyLayer)
1313         paintInfo.context->endTransparencyLayer();
1314 }
1315
1316 void RenderBox::paintBackground(const PaintInfo& paintInfo, const LayoutRect& paintRect, BackgroundBleedAvoidance bleedAvoidance)
1317 {
1318     if (isRoot()) {
1319         paintRootBoxFillLayers(paintInfo);
1320         return;
1321     }
1322     if (isBody() && skipBodyBackground(this))
1323         return;
1324     if (backgroundIsKnownToBeObscured() && !boxShadowShouldBeAppliedToBackground(bleedAvoidance))
1325         return;
1326     paintFillLayers(paintInfo, style().visitedDependentColor(CSSPropertyBackgroundColor), style().backgroundLayers(), paintRect, bleedAvoidance);
1327 }
1328
1329 bool RenderBox::getBackgroundPaintedExtent(LayoutRect& paintedExtent) const
1330 {
1331     ASSERT(hasBackground());
1332     LayoutRect backgroundRect = snappedIntRect(borderBoxRect());
1333
1334     Color backgroundColor = style().visitedDependentColor(CSSPropertyBackgroundColor);
1335     if (backgroundColor.isValid() && backgroundColor.alpha()) {
1336         paintedExtent = backgroundRect;
1337         return true;
1338     }
1339
1340     if (!style().backgroundLayers()->image() || style().backgroundLayers()->next()) {
1341         paintedExtent =  backgroundRect;
1342         return true;
1343     }
1344
1345     BackgroundImageGeometry geometry = calculateBackgroundImageGeometry(nullptr, *style().backgroundLayers(), backgroundRect);
1346     paintedExtent = geometry.destRect();
1347     return !geometry.hasNonLocalGeometry();
1348 }
1349
1350 bool RenderBox::backgroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect) const
1351 {
1352     if (isBody() && skipBodyBackground(this))
1353         return false;
1354
1355     Color backgroundColor = style().visitedDependentColor(CSSPropertyBackgroundColor);
1356     if (!backgroundColor.isValid() || backgroundColor.hasAlpha())
1357         return false;
1358
1359     // If the element has appearance, it might be painted by theme.
1360     // We cannot be sure if theme paints the background opaque.
1361     // In this case it is safe to not assume opaqueness.
1362     // FIXME: May be ask theme if it paints opaque.
1363     if (style().hasAppearance())
1364         return false;
1365     // FIXME: Check the opaqueness of background images.
1366
1367     if (hasClip() || hasClipPath())
1368         return false;
1369
1370     // FIXME: Use rounded rect if border radius is present.
1371     if (style().hasBorderRadius())
1372         return false;
1373
1374     // FIXME: The background color clip is defined by the last layer.
1375     if (style().backgroundLayers()->next())
1376         return false;
1377     LayoutRect backgroundRect;
1378     switch (style().backgroundClip()) {
1379     case BorderFillBox:
1380         backgroundRect = borderBoxRect();
1381         break;
1382     case PaddingFillBox:
1383         backgroundRect = paddingBoxRect();
1384         break;
1385     case ContentFillBox:
1386         backgroundRect = contentBoxRect();
1387         break;
1388     default:
1389         break;
1390     }
1391     return backgroundRect.contains(localRect);
1392 }
1393
1394 static bool isCandidateForOpaquenessTest(const RenderBox& childBox)
1395 {
1396     const RenderStyle& childStyle = childBox.style();
1397     if (childStyle.position() != StaticPosition && childBox.containingBlock() != childBox.parent())
1398         return false;
1399     if (childStyle.visibility() != VISIBLE)
1400         return false;
1401 #if ENABLE(CSS_SHAPES)
1402     if (childStyle.shapeOutside())
1403         return false;
1404 #endif
1405     if (!childBox.width() || !childBox.height())
1406         return false;
1407     if (RenderLayer* childLayer = childBox.layer()) {
1408         if (childLayer->isComposited())
1409             return false;
1410         // FIXME: Deal with z-index.
1411         if (!childStyle.hasAutoZIndex())
1412             return false;
1413         if (childLayer->hasTransform() || childLayer->isTransparent() || childLayer->hasFilter())
1414             return false;
1415         if (!childBox.scrolledContentOffset().isZero())
1416             return false;
1417     }
1418     return true;
1419 }
1420
1421 bool RenderBox::foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned maxDepthToTest) const
1422 {
1423     if (!maxDepthToTest)
1424         return false;
1425     for (auto& childBox : childrenOfType<RenderBox>(*this)) {
1426         if (!isCandidateForOpaquenessTest(childBox))
1427             continue;
1428         LayoutPoint childLocation = childBox.location();
1429         if (childBox.isRelPositioned())
1430             childLocation.move(childBox.relativePositionOffset());
1431         LayoutRect childLocalRect = localRect;
1432         childLocalRect.moveBy(-childLocation);
1433         if (childLocalRect.y() < 0 || childLocalRect.x() < 0) {
1434             // If there is unobscured area above/left of a static positioned box then the rect is probably not covered.
1435             if (childBox.style().position() == StaticPosition)
1436                 return false;
1437             continue;
1438         }
1439         if (childLocalRect.maxY() > childBox.height() || childLocalRect.maxX() > childBox.width())
1440             continue;
1441         if (childBox.backgroundIsKnownToBeOpaqueInRect(childLocalRect))
1442             return true;
1443         if (childBox.foregroundIsKnownToBeOpaqueInRect(childLocalRect, maxDepthToTest - 1))
1444             return true;
1445     }
1446     return false;
1447 }
1448
1449 bool RenderBox::computeBackgroundIsKnownToBeObscured()
1450 {
1451     // Test to see if the children trivially obscure the background.
1452     // FIXME: This test can be much more comprehensive.
1453     if (!hasBackground())
1454         return false;
1455     // Table and root background painting is special.
1456     if (isTable() || isRoot())
1457         return false;
1458
1459     LayoutRect backgroundRect;
1460     if (!getBackgroundPaintedExtent(backgroundRect))
1461         return false;
1462     return foregroundIsKnownToBeOpaqueInRect(backgroundRect, backgroundObscurationTestMaxDepth);
1463 }
1464
1465 bool RenderBox::backgroundHasOpaqueTopLayer() const
1466 {
1467     const FillLayer* fillLayer = style().backgroundLayers();
1468     if (!fillLayer || fillLayer->clip() != BorderFillBox)
1469         return false;
1470
1471     // Clipped with local scrolling
1472     if (hasOverflowClip() && fillLayer->attachment() == LocalBackgroundAttachment)
1473         return false;
1474
1475     if (fillLayer->hasOpaqueImage(*this) && fillLayer->hasRepeatXY() && fillLayer->image()->canRender(this, style().effectiveZoom()))
1476         return true;
1477
1478     // If there is only one layer and no image, check whether the background color is opaque
1479     if (!fillLayer->next() && !fillLayer->hasImage()) {
1480         Color bgColor = style().visitedDependentColor(CSSPropertyBackgroundColor);
1481         if (bgColor.isValid() && bgColor.alpha() == 255)
1482             return true;
1483     }
1484
1485     return false;
1486 }
1487
1488 void RenderBox::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
1489 {
1490     if (!paintInfo.shouldPaintWithinRoot(*this) || style().visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask || paintInfo.context->paintingDisabled())
1491         return;
1492
1493     LayoutRect paintRect = LayoutRect(paintOffset, size());
1494     paintMaskImages(paintInfo, paintRect);
1495 }
1496
1497 void RenderBox::paintClippingMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
1498 {
1499     if (!paintInfo.shouldPaintWithinRoot(*this) || style().visibility() != VISIBLE || paintInfo.phase != PaintPhaseClippingMask || paintInfo.context->paintingDisabled())
1500         return;
1501
1502     LayoutRect paintRect = LayoutRect(paintOffset, size());
1503     paintInfo.context->fillRect(snappedIntRect(paintRect), Color::black, style().colorSpace());
1504 }
1505
1506 void RenderBox::paintMaskImages(const PaintInfo& paintInfo, const LayoutRect& paintRect)
1507 {
1508     // Figure out if we need to push a transparency layer to render our mask.
1509     bool pushTransparencyLayer = false;
1510     bool compositedMask = hasLayer() && layer()->hasCompositedMask();
1511     bool flattenCompositingLayers = view().frameView().paintBehavior() & PaintBehaviorFlattenCompositingLayers;
1512     CompositeOperator compositeOp = CompositeSourceOver;
1513
1514     bool allMaskImagesLoaded = true;
1515
1516     if (!compositedMask || flattenCompositingLayers) {
1517         pushTransparencyLayer = true;
1518         StyleImage* maskBoxImage = style().maskBoxImage().image();
1519         const FillLayer* maskLayers = style().maskLayers();
1520
1521         // Don't render a masked element until all the mask images have loaded, to prevent a flash of unmasked content.
1522         if (maskBoxImage)
1523             allMaskImagesLoaded &= maskBoxImage->isLoaded();
1524
1525         if (maskLayers)
1526             allMaskImagesLoaded &= maskLayers->imagesAreLoaded();
1527
1528         paintInfo.context->setCompositeOperation(CompositeDestinationIn);
1529         paintInfo.context->beginTransparencyLayer(1);
1530         compositeOp = CompositeSourceOver;
1531     }
1532
1533     if (allMaskImagesLoaded) {
1534         paintFillLayers(paintInfo, Color(), style().maskLayers(), paintRect, BackgroundBleedNone, compositeOp);
1535         paintNinePieceImage(paintInfo.context, paintRect, style(), style().maskBoxImage(), compositeOp);
1536     }
1537
1538     if (pushTransparencyLayer)
1539         paintInfo.context->endTransparencyLayer();
1540 }
1541
1542 LayoutRect RenderBox::maskClipRect()
1543 {
1544     const NinePieceImage& maskBoxImage = style().maskBoxImage();
1545     if (maskBoxImage.image()) {
1546         LayoutRect borderImageRect = borderBoxRect();
1547
1548         // Apply outsets to the border box.
1549         borderImageRect.expand(style().maskBoxImageOutsets());
1550         return borderImageRect;
1551     }
1552
1553     LayoutRect result;
1554     LayoutRect borderBox = borderBoxRect();
1555     for (const FillLayer* maskLayer = style().maskLayers(); maskLayer; maskLayer = maskLayer->next()) {
1556         if (maskLayer->maskImage()) {
1557             // Masks should never have fixed attachment, so it's OK for paintContainer to be null.
1558             BackgroundImageGeometry geometry = calculateBackgroundImageGeometry(nullptr, *maskLayer, borderBox);
1559             result.unite(geometry.destRect());
1560         }
1561     }
1562     return result;
1563 }
1564
1565 void RenderBox::paintFillLayers(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect,
1566     BackgroundBleedAvoidance bleedAvoidance, CompositeOperator op, RenderElement* backgroundObject)
1567 {
1568     Vector<const FillLayer*, 8> layers;
1569     const FillLayer* curLayer = fillLayer;
1570     bool shouldDrawBackgroundInSeparateBuffer = false;
1571     while (curLayer) {
1572         layers.append(curLayer);
1573         // Stop traversal when an opaque layer is encountered.
1574         // FIXME : It would be possible for the following occlusion culling test to be more aggressive
1575         // on layers with no repeat by testing whether the image covers the layout rect.
1576         // Testing that here would imply duplicating a lot of calculations that are currently done in
1577         // RenderBoxModelObject::paintFillLayerExtended. A more efficient solution might be to move
1578         // the layer recursion into paintFillLayerExtended, or to compute the layer geometry here
1579         // and pass it down.
1580
1581         if (!shouldDrawBackgroundInSeparateBuffer && curLayer->blendMode() != BlendModeNormal)
1582             shouldDrawBackgroundInSeparateBuffer = true;
1583
1584         // The clipOccludesNextLayers condition must be evaluated first to avoid short-circuiting.
1585         if (curLayer->clipOccludesNextLayers(curLayer == fillLayer) && curLayer->hasOpaqueImage(*this) && curLayer->image()->canRender(this, style().effectiveZoom()) && curLayer->hasRepeatXY() && curLayer->blendMode() == BlendModeNormal)
1586             break;
1587         curLayer = curLayer->next();
1588     }
1589
1590     GraphicsContext* context = paintInfo.context;
1591     if (!context)
1592         shouldDrawBackgroundInSeparateBuffer = false;
1593
1594     BaseBackgroundColorUsage baseBgColorUsage = BaseBackgroundColorUse;
1595
1596     if (shouldDrawBackgroundInSeparateBuffer) {
1597         paintFillLayer(paintInfo, c, *layers.rbegin(), rect, bleedAvoidance, op, backgroundObject, BaseBackgroundColorOnly);
1598         baseBgColorUsage = BaseBackgroundColorSkip;
1599         context->beginTransparencyLayer(1);
1600     }
1601
1602     Vector<const FillLayer*>::const_reverse_iterator topLayer = layers.rend();
1603     for (Vector<const FillLayer*>::const_reverse_iterator it = layers.rbegin(); it != topLayer; ++it)
1604         paintFillLayer(paintInfo, c, *it, rect, bleedAvoidance, op, backgroundObject, baseBgColorUsage);
1605
1606     if (shouldDrawBackgroundInSeparateBuffer)
1607         context->endTransparencyLayer();
1608 }
1609
1610 void RenderBox::paintFillLayer(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect,
1611     BackgroundBleedAvoidance bleedAvoidance, CompositeOperator op, RenderElement* backgroundObject, BaseBackgroundColorUsage baseBgColorUsage)
1612 {
1613     paintFillLayerExtended(paintInfo, c, fillLayer, rect, bleedAvoidance, nullptr, LayoutSize(), op, backgroundObject, baseBgColorUsage);
1614 }
1615
1616 static bool layersUseImage(WrappedImagePtr image, const FillLayer* layers)
1617 {
1618     for (const FillLayer* curLayer = layers; curLayer; curLayer = curLayer->next()) {
1619         if (curLayer->image() && image == curLayer->image()->data())
1620             return true;
1621     }
1622
1623     return false;
1624 }
1625
1626 void RenderBox::imageChanged(WrappedImagePtr image, const IntRect*)
1627 {
1628     if (!parent())
1629         return;
1630
1631     if ((style().borderImage().image() && style().borderImage().image()->data() == image) ||
1632         (style().maskBoxImage().image() && style().maskBoxImage().image()->data() == image)) {
1633         repaint();
1634         return;
1635     }
1636
1637 #if ENABLE(CSS_SHAPES)
1638     ShapeValue* shapeOutsideValue = style().shapeOutside();
1639     if (!view().frameView().isInLayout() && isFloating() && shapeOutsideValue && shapeOutsideValue->image() && shapeOutsideValue->image()->data() == image) {
1640         ShapeOutsideInfo::ensureInfo(*this).markShapeAsDirty();
1641         markShapeOutsideDependentsForLayout();
1642     }
1643 #endif
1644
1645     bool didFullRepaint = repaintLayerRectsForImage(image, style().backgroundLayers(), true);
1646     if (!didFullRepaint)
1647         repaintLayerRectsForImage(image, style().maskLayers(), false);
1648
1649     if (!isComposited())
1650         return;
1651
1652     if (layer()->hasCompositedMask() && layersUseImage(image, style().maskLayers()))
1653         layer()->contentChanged(MaskImageChanged);
1654     if (layersUseImage(image, style().backgroundLayers()))
1655         layer()->contentChanged(BackgroundImageChanged);
1656 }
1657
1658 bool RenderBox::repaintLayerRectsForImage(WrappedImagePtr image, const FillLayer* layers, bool drawingBackground)
1659 {
1660     LayoutRect rendererRect;
1661     RenderBox* layerRenderer = nullptr;
1662
1663     for (const FillLayer* curLayer = layers; curLayer; curLayer = curLayer->next()) {
1664         if (curLayer->image() && image == curLayer->image()->data() && curLayer->image()->canRender(this, style().effectiveZoom())) {
1665             // Now that we know this image is being used, compute the renderer and the rect if we haven't already.
1666             bool drawingRootBackground = drawingBackground && (isRoot() || (isBody() && !document().documentElement()->renderer()->hasBackground()));
1667             if (!layerRenderer) {
1668                 if (drawingRootBackground) {
1669                     layerRenderer = &view();
1670
1671                     LayoutUnit rw = downcast<RenderView>(*layerRenderer).frameView().contentsWidth();
1672                     LayoutUnit rh = downcast<RenderView>(*layerRenderer).frameView().contentsHeight();
1673
1674                     rendererRect = LayoutRect(-layerRenderer->marginLeft(),
1675                         -layerRenderer->marginTop(),
1676                         std::max(layerRenderer->width() + layerRenderer->horizontalMarginExtent() + layerRenderer->borderLeft() + layerRenderer->borderRight(), rw),
1677                         std::max(layerRenderer->height() + layerRenderer->verticalMarginExtent() + layerRenderer->borderTop() + layerRenderer->borderBottom(), rh));
1678                 } else {
1679                     layerRenderer = this;
1680                     rendererRect = borderBoxRect();
1681                 }
1682             }
1683
1684             BackgroundImageGeometry geometry = layerRenderer->calculateBackgroundImageGeometry(nullptr, *curLayer, rendererRect);
1685             if (geometry.hasNonLocalGeometry()) {
1686                 // Rather than incur the costs of computing the paintContainer for renderers with fixed backgrounds
1687                 // in order to get the right destRect, just repaint the entire renderer.
1688                 layerRenderer->repaint();
1689                 return true;
1690             }
1691
1692             LayoutRect rectToRepaint = geometry.destRect();
1693             bool shouldClipToLayer = true;
1694
1695             // If this is the root background layer, we may need to extend the repaintRect if the FrameView has an
1696             // extendedBackground. We should only extend the rect if it is already extending the full width or height
1697             // of the rendererRect.
1698             if (drawingRootBackground && view().frameView().hasExtendedBackgroundRectForPainting()) {
1699                 shouldClipToLayer = false;
1700                 IntRect extendedBackgroundRect = view().frameView().extendedBackgroundRectForPainting();
1701                 if (rectToRepaint.width() == rendererRect.width()) {
1702                     rectToRepaint.move(extendedBackgroundRect.x(), 0);
1703                     rectToRepaint.setWidth(extendedBackgroundRect.width());
1704                 }
1705                 if (rectToRepaint.height() == rendererRect.height()) {
1706                     rectToRepaint.move(0, extendedBackgroundRect.y());
1707                     rectToRepaint.setHeight(extendedBackgroundRect.height());
1708                 }
1709             }
1710
1711             layerRenderer->repaintRectangle(rectToRepaint, shouldClipToLayer);
1712             if (geometry.destRect() == rendererRect)
1713                 return true;
1714         }
1715     }
1716     return false;
1717 }
1718
1719 bool RenderBox::pushContentsClip(PaintInfo& paintInfo, const LayoutPoint& accumulatedOffset)
1720 {
1721     if (paintInfo.phase == PaintPhaseBlockBackground || paintInfo.phase == PaintPhaseSelfOutline || paintInfo.phase == PaintPhaseMask)
1722         return false;
1723
1724     bool isControlClip = hasControlClip();
1725     bool isOverflowClip = hasOverflowClip() && !layer()->isSelfPaintingLayer();
1726
1727     if (!isControlClip && !isOverflowClip)
1728         return false;
1729
1730     if (paintInfo.phase == PaintPhaseOutline)
1731         paintInfo.phase = PaintPhaseChildOutlines;
1732     else if (paintInfo.phase == PaintPhaseChildBlockBackground) {
1733         paintInfo.phase = PaintPhaseBlockBackground;
1734         paintObject(paintInfo, accumulatedOffset);
1735         paintInfo.phase = PaintPhaseChildBlockBackgrounds;
1736     }
1737     float deviceScaleFactor = document().deviceScaleFactor();
1738     FloatRect clipRect = snapRectToDevicePixels((isControlClip ? controlClipRect(accumulatedOffset) : overflowClipRect(accumulatedOffset, currentRenderNamedFlowFragment(), IgnoreOverlayScrollbarSize, paintInfo.phase)), deviceScaleFactor);
1739     paintInfo.context->save();
1740     if (style().hasBorderRadius())
1741         paintInfo.context->clipRoundedRect(style().getRoundedInnerBorderFor(LayoutRect(accumulatedOffset, size())).pixelSnappedRoundedRectForPainting(deviceScaleFactor));
1742     paintInfo.context->clip(clipRect);
1743     return true;
1744 }
1745
1746 void RenderBox::popContentsClip(PaintInfo& paintInfo, PaintPhase originalPhase, const LayoutPoint& accumulatedOffset)
1747 {
1748     ASSERT(hasControlClip() || (hasOverflowClip() && !layer()->isSelfPaintingLayer()));
1749
1750     paintInfo.context->restore();
1751     if (originalPhase == PaintPhaseOutline) {
1752         paintInfo.phase = PaintPhaseSelfOutline;
1753         paintObject(paintInfo, accumulatedOffset);
1754         paintInfo.phase = originalPhase;
1755     } else if (originalPhase == PaintPhaseChildBlockBackground)
1756         paintInfo.phase = originalPhase;
1757 }
1758
1759 LayoutRect RenderBox::overflowClipRect(const LayoutPoint& location, RenderRegion* region, OverlayScrollbarSizeRelevancy relevancy, PaintPhase)
1760 {
1761     // FIXME: When overflow-clip (CSS3) is implemented, we'll obtain the property
1762     // here.
1763     LayoutRect clipRect = borderBoxRectInRegion(region);
1764     clipRect.setLocation(location + clipRect.location() + LayoutSize(borderLeft(), borderTop()));
1765     clipRect.setSize(clipRect.size() - LayoutSize(borderLeft() + borderRight(), borderTop() + borderBottom()));
1766
1767     // Subtract out scrollbars if we have them.
1768      if (layer()) {
1769         if (style().shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
1770             clipRect.move(layer()->verticalScrollbarWidth(relevancy), 0);
1771         clipRect.contract(layer()->verticalScrollbarWidth(relevancy), layer()->horizontalScrollbarHeight(relevancy));
1772      }
1773
1774     return clipRect;
1775 }
1776
1777 LayoutRect RenderBox::clipRect(const LayoutPoint& location, RenderRegion* region)
1778 {
1779     LayoutRect borderBoxRect = borderBoxRectInRegion(region);
1780     LayoutRect clipRect = LayoutRect(borderBoxRect.location() + location, borderBoxRect.size());
1781
1782     if (!style().clipLeft().isAuto()) {
1783         LayoutUnit c = valueForLength(style().clipLeft(), borderBoxRect.width());
1784         clipRect.move(c, 0);
1785         clipRect.contract(c, 0);
1786     }
1787
1788     // We don't use the region-specific border box's width and height since clip offsets are (stupidly) specified
1789     // from the left and top edges. Therefore it's better to avoid constraining to smaller widths and heights.
1790
1791     if (!style().clipRight().isAuto())
1792         clipRect.contract(width() - valueForLength(style().clipRight(), width()), 0);
1793
1794     if (!style().clipTop().isAuto()) {
1795         LayoutUnit c = valueForLength(style().clipTop(), borderBoxRect.height());
1796         clipRect.move(0, c);
1797         clipRect.contract(0, c);
1798     }
1799
1800     if (!style().clipBottom().isAuto())
1801         clipRect.contract(0, height() - valueForLength(style().clipBottom(), height()));
1802
1803     return clipRect;
1804 }
1805
1806 LayoutUnit RenderBox::shrinkLogicalWidthToAvoidFloats(LayoutUnit childMarginStart, LayoutUnit childMarginEnd, const RenderBlock* cb, RenderRegion* region) const
1807 {
1808     RenderRegion* containingBlockRegion = nullptr;
1809     LayoutUnit logicalTopPosition = logicalTop();
1810     if (region) {
1811         LayoutUnit offsetFromLogicalTopOfRegion = region ? region->logicalTopForFlowThreadContent() - offsetFromLogicalTopOfFirstPage() : LayoutUnit();
1812         logicalTopPosition = std::max(logicalTopPosition, logicalTopPosition + offsetFromLogicalTopOfRegion);
1813         containingBlockRegion = cb->clampToStartAndEndRegions(region);
1814     }
1815
1816     LayoutUnit logicalHeight = cb->logicalHeightForChild(*this);
1817     LayoutUnit result = cb->availableLogicalWidthForLineInRegion(logicalTopPosition, false, containingBlockRegion, logicalHeight) - childMarginStart - childMarginEnd;
1818
1819     // We need to see if margins on either the start side or the end side can contain the floats in question. If they can,
1820     // then just using the line width is inaccurate. In the case where a float completely fits, we don't need to use the line
1821     // offset at all, but can instead push all the way to the content edge of the containing block. In the case where the float
1822     // doesn't fit, we can use the line offset, but we need to grow it by the margin to reflect the fact that the margin was
1823     // "consumed" by the float. Negative margins aren't consumed by the float, and so we ignore them.
1824     if (childMarginStart > 0) {
1825         LayoutUnit startContentSide = cb->startOffsetForContent(containingBlockRegion);
1826         LayoutUnit startContentSideWithMargin = startContentSide + childMarginStart;
1827         LayoutUnit startOffset = cb->startOffsetForLineInRegion(logicalTopPosition, false, containingBlockRegion, logicalHeight);
1828         if (startOffset > startContentSideWithMargin)
1829             result += childMarginStart;
1830         else
1831             result += startOffset - startContentSide;
1832     }
1833
1834     if (childMarginEnd > 0) {
1835         LayoutUnit endContentSide = cb->endOffsetForContent(containingBlockRegion);
1836         LayoutUnit endContentSideWithMargin = endContentSide + childMarginEnd;
1837         LayoutUnit endOffset = cb->endOffsetForLineInRegion(logicalTopPosition, false, containingBlockRegion, logicalHeight);
1838         if (endOffset > endContentSideWithMargin)
1839             result += childMarginEnd;
1840         else
1841             result += endOffset - endContentSide;
1842     }
1843
1844     return result;
1845 }
1846
1847 LayoutUnit RenderBox::containingBlockLogicalWidthForContent() const
1848 {
1849 #if ENABLE(CSS_GRID_LAYOUT)
1850     if (hasOverrideContainingBlockLogicalWidth())
1851         return overrideContainingBlockContentLogicalWidth();
1852 #endif
1853
1854     RenderBlock* cb = containingBlock();
1855     if (!cb)
1856         return LayoutUnit();
1857     return cb->availableLogicalWidth();
1858 }
1859
1860 LayoutUnit RenderBox::containingBlockLogicalHeightForContent(AvailableLogicalHeightType heightType) const
1861 {
1862 #if ENABLE(CSS_GRID_LAYOUT)
1863     if (hasOverrideContainingBlockLogicalHeight())
1864         return overrideContainingBlockContentLogicalHeight();
1865 #endif
1866
1867     RenderBlock* cb = containingBlock();
1868     if (!cb)
1869         return LayoutUnit();
1870     return cb->availableLogicalHeight(heightType);
1871 }
1872
1873 LayoutUnit RenderBox::containingBlockLogicalWidthForContentInRegion(RenderRegion* region) const
1874 {
1875     if (!region)
1876         return containingBlockLogicalWidthForContent();
1877
1878     RenderBlock* cb = containingBlock();
1879     RenderRegion* containingBlockRegion = cb->clampToStartAndEndRegions(region);
1880     // FIXME: It's unclear if a region's content should use the containing block's override logical width.
1881     // If it should, the following line should call containingBlockLogicalWidthForContent.
1882     LayoutUnit result = cb->availableLogicalWidth();
1883     RenderBoxRegionInfo* boxInfo = cb->renderBoxRegionInfo(containingBlockRegion);
1884     if (!boxInfo)
1885         return result;
1886     return std::max<LayoutUnit>(0, result - (cb->logicalWidth() - boxInfo->logicalWidth()));
1887 }
1888
1889 LayoutUnit RenderBox::containingBlockAvailableLineWidthInRegion(RenderRegion* region) const
1890 {
1891     RenderBlock* cb = containingBlock();
1892     RenderRegion* containingBlockRegion = nullptr;
1893     LayoutUnit logicalTopPosition = logicalTop();
1894     if (region) {
1895         LayoutUnit offsetFromLogicalTopOfRegion = region ? region->logicalTopForFlowThreadContent() - offsetFromLogicalTopOfFirstPage() : LayoutUnit();
1896         logicalTopPosition = std::max(logicalTopPosition, logicalTopPosition + offsetFromLogicalTopOfRegion);
1897         containingBlockRegion = cb->clampToStartAndEndRegions(region);
1898     }
1899     return cb->availableLogicalWidthForLineInRegion(logicalTopPosition, false, containingBlockRegion, availableLogicalHeight(IncludeMarginBorderPadding));
1900 }
1901
1902 LayoutUnit RenderBox::perpendicularContainingBlockLogicalHeight() const
1903 {
1904 #if ENABLE(CSS_GRID_LAYOUT)
1905     if (hasOverrideContainingBlockLogicalHeight())
1906         return overrideContainingBlockContentLogicalHeight();
1907 #endif
1908
1909     RenderBlock* cb = containingBlock();
1910     if (cb->hasOverrideLogicalContentHeight())
1911         return cb->overrideLogicalContentHeight();
1912
1913     const RenderStyle& containingBlockStyle = cb->style();
1914     Length logicalHeightLength = containingBlockStyle.logicalHeight();
1915
1916     // FIXME: For now just support fixed heights.  Eventually should support percentage heights as well.
1917     if (!logicalHeightLength.isFixed()) {
1918         LayoutUnit fillFallbackExtent = containingBlockStyle.isHorizontalWritingMode() ? view().frameView().visibleHeight() : view().frameView().visibleWidth();
1919         LayoutUnit fillAvailableExtent = containingBlock()->availableLogicalHeight(ExcludeMarginBorderPadding);
1920         return std::min(fillAvailableExtent, fillFallbackExtent);
1921     }
1922
1923     // Use the content box logical height as specified by the style.
1924     return cb->adjustContentBoxLogicalHeightForBoxSizing(logicalHeightLength.value());
1925 }
1926
1927 void RenderBox::mapLocalToContainer(const RenderLayerModelObject* repaintContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed) const
1928 {
1929     if (repaintContainer == this)
1930         return;
1931
1932     if (view().layoutStateEnabled() && !repaintContainer) {
1933         LayoutState* layoutState = view().layoutState();
1934         LayoutSize offset = layoutState->m_paintOffset + locationOffset();
1935         if (style().hasInFlowPosition() && layer())
1936             offset += layer()->offsetForInFlowPosition();
1937         transformState.move(offset);
1938         return;
1939     }
1940
1941     bool containerSkipped;
1942     RenderElement* container = this->container(repaintContainer, &containerSkipped);
1943     if (!container)
1944         return;
1945
1946     bool isFixedPos = style().position() == FixedPosition;
1947     // If this box has a transform, it acts as a fixed position container for fixed descendants,
1948     // and may itself also be fixed position. So propagate 'fixed' up only if this box is fixed position.
1949     if (hasTransform() && !isFixedPos)
1950         mode &= ~IsFixed;
1951     else if (isFixedPos)
1952         mode |= IsFixed;
1953
1954     if (wasFixed)
1955         *wasFixed = mode & IsFixed;
1956
1957     LayoutSize containerOffset = offsetFromContainer(*container, LayoutPoint(transformState.mappedPoint()));
1958
1959     bool preserve3D = mode & UseTransforms && (container->style().preserves3D() || style().preserves3D());
1960     if (mode & UseTransforms && shouldUseTransformFromContainer(container)) {
1961         TransformationMatrix t;
1962         getTransformFromContainer(container, containerOffset, t);
1963         transformState.applyTransform(t, preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
1964     } else
1965         transformState.move(containerOffset.width(), containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
1966
1967     if (containerSkipped) {
1968         // There can't be a transform between repaintContainer and o, because transforms create containers, so it should be safe
1969         // to just subtract the delta between the repaintContainer and o.
1970         LayoutSize containerOffset = repaintContainer->offsetFromAncestorContainer(*container);
1971         transformState.move(-containerOffset.width(), -containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
1972         return;
1973     }
1974
1975     mode &= ~ApplyContainerFlip;
1976
1977     // For fixed positioned elements inside out-of-flow named flows, we do not want to
1978     // map their position further to regions based on their coordinates inside the named flows.
1979     if (!container->isOutOfFlowRenderFlowThread() || !fixedPositionedWithNamedFlowContainingBlock())
1980         container->mapLocalToContainer(repaintContainer, transformState, mode, wasFixed);
1981     else
1982         container->mapLocalToContainer(downcast<RenderLayerModelObject>(container), transformState, mode, wasFixed);
1983 }
1984
1985 const RenderObject* RenderBox::pushMappingToContainer(const RenderLayerModelObject* ancestorToStopAt, RenderGeometryMap& geometryMap) const
1986 {
1987     ASSERT(ancestorToStopAt != this);
1988
1989     bool ancestorSkipped;
1990     RenderElement* container = this->container(ancestorToStopAt, &ancestorSkipped);
1991     if (!container)
1992         return nullptr;
1993
1994     bool isFixedPos = style().position() == FixedPosition;
1995     LayoutSize adjustmentForSkippedAncestor;
1996     if (ancestorSkipped) {
1997         // There can't be a transform between repaintContainer and container, because transforms create containers, so it should be safe
1998         // to just subtract the delta between the ancestor and container.
1999         adjustmentForSkippedAncestor = -ancestorToStopAt->offsetFromAncestorContainer(*container);
2000     }
2001
2002     bool offsetDependsOnPoint = false;
2003     LayoutSize containerOffset = offsetFromContainer(*container, LayoutPoint(), &offsetDependsOnPoint);
2004
2005     bool preserve3D = container->style().preserves3D() || style().preserves3D();
2006     if (shouldUseTransformFromContainer(container) && (geometryMap.mapCoordinatesFlags() & UseTransforms)) {
2007         TransformationMatrix t;
2008         getTransformFromContainer(container, containerOffset, t);
2009         t.translateRight(adjustmentForSkippedAncestor.width(), adjustmentForSkippedAncestor.height());
2010
2011         geometryMap.push(this, t, preserve3D, offsetDependsOnPoint, isFixedPos, hasTransform());
2012     } else {
2013         containerOffset += adjustmentForSkippedAncestor;
2014         geometryMap.push(this, containerOffset, preserve3D, offsetDependsOnPoint, isFixedPos, hasTransform());
2015     }
2016
2017     return ancestorSkipped ? ancestorToStopAt : container;
2018 }
2019
2020 void RenderBox::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
2021 {
2022     bool isFixedPos = style().position() == FixedPosition;
2023     if (hasTransform() && !isFixedPos) {
2024         // If this box has a transform, it acts as a fixed position container for fixed descendants,
2025         // and may itself also be fixed position. So propagate 'fixed' up only if this box is fixed position.
2026         mode &= ~IsFixed;
2027     } else if (isFixedPos)
2028         mode |= IsFixed;
2029
2030     RenderBoxModelObject::mapAbsoluteToLocalPoint(mode, transformState);
2031 }
2032
2033 LayoutSize RenderBox::offsetFromContainer(RenderElement& renderer, const LayoutPoint&, bool* offsetDependsOnPoint) const
2034 {
2035     // A region "has" boxes inside it without being their container.
2036     ASSERT(&renderer == container() || is<RenderRegion>(renderer));
2037
2038     LayoutSize offset;
2039     if (isInFlowPositioned())
2040         offset += offsetForInFlowPosition();
2041
2042     if (!isInline() || isReplaced())
2043         offset += topLeftLocationOffset();
2044
2045     if (is<RenderBox>(renderer))
2046         offset -= downcast<RenderBox>(renderer).scrolledContentOffset();
2047
2048     if (style().position() == AbsolutePosition && renderer.isInFlowPositioned() && is<RenderInline>(renderer))
2049         offset += downcast<RenderInline>(renderer).offsetForInFlowPositionedInline(this);
2050
2051     if (offsetDependsOnPoint)
2052         *offsetDependsOnPoint |= is<RenderFlowThread>(renderer);
2053
2054     return offset;
2055 }
2056
2057 std::unique_ptr<InlineElementBox> RenderBox::createInlineBox()
2058 {
2059     return std::make_unique<InlineElementBox>(*this);
2060 }
2061
2062 void RenderBox::dirtyLineBoxes(bool fullLayout)
2063 {
2064     if (m_inlineBoxWrapper) {
2065         if (fullLayout) {
2066             delete m_inlineBoxWrapper;
2067             m_inlineBoxWrapper = nullptr;
2068         } else
2069             m_inlineBoxWrapper->dirtyLineBoxes();
2070     }
2071 }
2072
2073 void RenderBox::positionLineBox(InlineElementBox& box)
2074 {
2075     if (isOutOfFlowPositioned()) {
2076         // Cache the x position only if we were an INLINE type originally.
2077         bool wasInline = style().isOriginalDisplayInlineType();
2078         if (wasInline) {
2079             // The value is cached in the xPos of the box.  We only need this value if
2080             // our object was inline originally, since otherwise it would have ended up underneath
2081             // the inlines.
2082             RootInlineBox& rootBox = box.root();
2083             rootBox.blockFlow().setStaticInlinePositionForChild(*this, rootBox.lineTopWithLeading(), LayoutUnit::fromFloatRound(box.logicalLeft()));
2084             if (style().hasStaticInlinePosition(box.isHorizontal()))
2085                 setChildNeedsLayout(MarkOnlyThis); // Just mark the positioned object as needing layout, so it will update its position properly.
2086         } else {
2087             // Our object was a block originally, so we make our normal flow position be
2088             // just below the line box (as though all the inlines that came before us got
2089             // wrapped in an anonymous block, which is what would have happened had we been
2090             // in flow).  This value was cached in the y() of the box.
2091             layer()->setStaticBlockPosition(box.logicalTop());
2092             if (style().hasStaticBlockPosition(box.isHorizontal()))
2093                 setChildNeedsLayout(MarkOnlyThis); // Just mark the positioned object as needing layout, so it will update its position properly.
2094         }
2095
2096         // Nuke the box.
2097         box.removeFromParent();
2098         delete &box;
2099         return;
2100     }
2101
2102     if (isReplaced()) {
2103         setLocation(LayoutPoint(box.topLeft()));
2104         setInlineBoxWrapper(&box);
2105     }
2106 }
2107
2108 void RenderBox::deleteLineBoxWrapper()
2109 {
2110     if (m_inlineBoxWrapper) {
2111         if (!documentBeingDestroyed())
2112             m_inlineBoxWrapper->removeFromParent();
2113         delete m_inlineBoxWrapper;
2114         m_inlineBoxWrapper = nullptr;
2115     }
2116 }
2117
2118 LayoutRect RenderBox::clippedOverflowRectForRepaint(const RenderLayerModelObject* repaintContainer) const
2119 {
2120     if (style().visibility() != VISIBLE && !enclosingLayer()->hasVisibleContent())
2121         return LayoutRect();
2122
2123     LayoutRect r = visualOverflowRect();
2124
2125     // FIXME: layoutDelta needs to be applied in parts before/after transforms and
2126     // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
2127     r.move(view().layoutDelta());
2128
2129     // We have to use maximalOutlineSize() because a child might have an outline
2130     // that projects outside of our overflowRect.
2131     ASSERT(style().outlineSize() <= view().maximalOutlineSize());
2132     r.inflate(view().maximalOutlineSize());
2133
2134     computeRectForRepaint(repaintContainer, r);
2135     return r;
2136 }
2137
2138 static inline bool shouldApplyContainersClipAndOffset(const RenderLayerModelObject* repaintContainer, RenderBox* containerBox)
2139 {
2140 #if PLATFORM(IOS)
2141     if (!repaintContainer || repaintContainer != containerBox)
2142         return true;
2143
2144     return !containerBox->hasLayer() || !containerBox->layer()->usesCompositedScrolling();
2145 #else
2146     UNUSED_PARAM(repaintContainer);
2147     UNUSED_PARAM(containerBox);
2148     return true;
2149 #endif
2150 }
2151
2152 void RenderBox::computeRectForRepaint(const RenderLayerModelObject* repaintContainer, LayoutRect& rect, bool fixed) const
2153 {
2154     // The rect we compute at each step is shifted by our x/y offset in the parent container's coordinate space.
2155     // Only when we cross a writing mode boundary will we have to possibly flipForWritingMode (to convert into a more appropriate
2156     // offset corner for the enclosing container).  This allows for a fully RL or BT document to repaint
2157     // properly even during layout, since the rect remains flipped all the way until the end.
2158     //
2159     // RenderView::computeRectForRepaint then converts the rect to physical coordinates.  We also convert to
2160     // physical when we hit a repaintContainer boundary.  Therefore the final rect returned is always in the
2161     // physical coordinate space of the repaintContainer.
2162     const RenderStyle& styleToUse = style();
2163     // LayoutState is only valid for root-relative, non-fixed position repainting
2164     if (view().layoutStateEnabled() && !repaintContainer && styleToUse.position() != FixedPosition) {
2165         LayoutState* layoutState = view().layoutState();
2166
2167         if (layer() && layer()->transform())
2168             rect = LayoutRect(encloseRectToDevicePixels(layer()->transform()->mapRect(rect), document().deviceScaleFactor()));
2169
2170         // We can't trust the bits on RenderObject, because this might be called while re-resolving style.
2171         if (styleToUse.hasInFlowPosition() && layer())
2172             rect.move(layer()->offsetForInFlowPosition());
2173
2174         rect.moveBy(location());
2175         rect.move(layoutState->m_paintOffset);
2176         if (layoutState->m_clipped)
2177             rect.intersect(layoutState->m_clipRect);
2178         return;
2179     }
2180
2181     if (hasReflection())
2182         rect.unite(reflectedRect(rect));
2183
2184     if (repaintContainer == this) {
2185         if (repaintContainer->style().isFlippedBlocksWritingMode())
2186             flipForWritingMode(rect);
2187         return;
2188     }
2189
2190     bool containerSkipped;
2191     auto* renderer = container(repaintContainer, &containerSkipped);
2192     if (!renderer)
2193         return;
2194
2195     EPosition position = styleToUse.position();
2196
2197     // This code isn't necessary for in-flow RenderFlowThreads.
2198     // Don't add the location of the region in the flow thread for absolute positioned
2199     // elements because their absolute position already pushes them down through
2200     // the regions so adding this here and then adding the topLeft again would cause
2201     // us to add the height twice.
2202     // The same logic applies for elements flowed directly into the flow thread. Their topLeft member
2203     // will already contain the portion rect of the region.
2204     if (renderer->isOutOfFlowRenderFlowThread() && position != AbsolutePosition && containingBlock() != flowThreadContainingBlock()) {
2205         RenderRegion* firstRegion = nullptr;
2206         RenderRegion* lastRegion = nullptr;
2207         if (downcast<RenderFlowThread>(*renderer).getRegionRangeForBox(this, firstRegion, lastRegion))
2208             rect.moveBy(firstRegion->flowThreadPortionRect().location());
2209     }
2210
2211     if (isWritingModeRoot() && !isOutOfFlowPositioned())
2212         flipForWritingMode(rect);
2213
2214     LayoutSize locationOffset = this->locationOffset();
2215     // FIXME: This is needed as long as RenderWidget snaps to integral size/position.
2216     if (isRenderReplaced() && isWidget())
2217         locationOffset = toIntSize(flooredIntPoint(locationOffset));
2218     LayoutPoint topLeft = rect.location();
2219     topLeft.move(locationOffset);
2220
2221     // We are now in our parent container's coordinate space.  Apply our transform to obtain a bounding box
2222     // in the parent's coordinate space that encloses us.
2223     if (hasLayer() && layer()->transform()) {
2224         fixed = position == FixedPosition;
2225         rect = LayoutRect(encloseRectToDevicePixels(layer()->transform()->mapRect(rect), document().deviceScaleFactor()));
2226         topLeft = rect.location();
2227         topLeft.move(locationOffset);
2228     } else if (position == FixedPosition)
2229         fixed = true;
2230
2231     if (position == AbsolutePosition && renderer->isInFlowPositioned() && is<RenderInline>(*renderer))
2232         topLeft += downcast<RenderInline>(*renderer).offsetForInFlowPositionedInline(this);
2233     else if (styleToUse.hasInFlowPosition() && layer()) {
2234         // Apply the relative position offset when invalidating a rectangle.  The layer
2235         // is translated, but the render box isn't, so we need to do this to get the
2236         // right dirty rect.  Since this is called from RenderObject::setStyle, the relative position
2237         // flag on the RenderObject has been cleared, so use the one on the style().
2238         topLeft += layer()->offsetForInFlowPosition();
2239     }
2240
2241     // FIXME: We ignore the lightweight clipping rect that controls use, since if |o| is in mid-layout,
2242     // its controlClipRect will be wrong. For overflow clip we use the values cached by the layer.
2243     rect.setLocation(topLeft);
2244     if (renderer->hasOverflowClip()) {
2245         RenderBox& containerBox = downcast<RenderBox>(*renderer);
2246         if (shouldApplyContainersClipAndOffset(repaintContainer, &containerBox)) {
2247             containerBox.applyCachedClipAndScrollOffsetForRepaint(rect);
2248             if (rect.isEmpty())
2249                 return;
2250         }
2251     }
2252
2253     if (containerSkipped) {
2254         // If the repaintContainer is below o, then we need to map the rect into repaintContainer's coordinates.
2255         LayoutSize containerOffset = repaintContainer->offsetFromAncestorContainer(*renderer);
2256         rect.move(-containerOffset);
2257         return;
2258     }
2259
2260     renderer->computeRectForRepaint(repaintContainer, rect, fixed);
2261 }
2262
2263 void RenderBox::repaintDuringLayoutIfMoved(const LayoutRect& oldRect)
2264 {
2265     if (oldRect.location() != m_frameRect.location()) {
2266         LayoutRect newRect = m_frameRect;
2267         // The child moved.  Invalidate the object's old and new positions.  We have to do this
2268         // since the object may not have gotten a layout.
2269         m_frameRect = oldRect;
2270         repaint();
2271         repaintOverhangingFloats(true);
2272         m_frameRect = newRect;
2273         repaint();
2274         repaintOverhangingFloats(true);
2275     }
2276 }
2277
2278 void RenderBox::repaintOverhangingFloats(bool)
2279 {
2280 }
2281
2282 void RenderBox::updateLogicalWidth()
2283 {
2284     LogicalExtentComputedValues computedValues;
2285     computeLogicalWidthInRegion(computedValues);
2286
2287     setLogicalWidth(computedValues.m_extent);
2288     setLogicalLeft(computedValues.m_position);
2289     setMarginStart(computedValues.m_margins.m_start);
2290     setMarginEnd(computedValues.m_margins.m_end);
2291 }
2292
2293 void RenderBox::computeLogicalWidthInRegion(LogicalExtentComputedValues& computedValues, RenderRegion* region) const
2294 {
2295     computedValues.m_extent = logicalWidth();
2296     computedValues.m_position = logicalLeft();
2297     computedValues.m_margins.m_start = marginStart();
2298     computedValues.m_margins.m_end = marginEnd();
2299
2300     if (isOutOfFlowPositioned()) {
2301         // FIXME: This calculation is not patched for block-flow yet.
2302         // https://bugs.webkit.org/show_bug.cgi?id=46500
2303         computePositionedLogicalWidth(computedValues, region);
2304         return;
2305     }
2306
2307     // If layout is limited to a subtree, the subtree root's logical width does not change.
2308     if (element() && view().frameView().layoutRoot(true) == this)
2309         return;
2310
2311     // The parent box is flexing us, so it has increased or decreased our
2312     // width.  Use the width from the style context.
2313     // FIXME: Account for block-flow in flexible boxes.
2314     // https://bugs.webkit.org/show_bug.cgi?id=46418
2315     if (hasOverrideLogicalContentWidth() && (isRubyRun() || style().borderFit() == BorderFitLines || parent()->isFlexibleBoxIncludingDeprecated())) {
2316         computedValues.m_extent = overrideLogicalContentWidth() + borderAndPaddingLogicalWidth();
2317         return;
2318     }
2319
2320     // FIXME: Account for block-flow in flexible boxes.
2321     // https://bugs.webkit.org/show_bug.cgi?id=46418
2322     bool inVerticalBox = parent()->isDeprecatedFlexibleBox() && (parent()->style().boxOrient() == VERTICAL);
2323     bool stretching = (parent()->style().boxAlign() == BSTRETCH);
2324     bool treatAsReplaced = shouldComputeSizeAsReplaced() && (!inVerticalBox || !stretching);
2325
2326     const RenderStyle& styleToUse = style();
2327     Length logicalWidthLength = treatAsReplaced ? Length(computeReplacedLogicalWidth(), Fixed) : styleToUse.logicalWidth();
2328
2329     RenderBlock* cb = containingBlock();
2330     LayoutUnit containerLogicalWidth = std::max<LayoutUnit>(0, containingBlockLogicalWidthForContentInRegion(region));
2331     bool hasPerpendicularContainingBlock = cb->isHorizontalWritingMode() != isHorizontalWritingMode();
2332
2333     if (isInline() && !isInlineBlockOrInlineTable()) {
2334         // just calculate margins
2335         computedValues.m_margins.m_start = minimumValueForLength(styleToUse.marginStart(), containerLogicalWidth);
2336         computedValues.m_margins.m_end = minimumValueForLength(styleToUse.marginEnd(), containerLogicalWidth);
2337         if (treatAsReplaced)
2338             computedValues.m_extent = std::max<LayoutUnit>(floatValueForLength(logicalWidthLength, 0) + borderAndPaddingLogicalWidth(), minPreferredLogicalWidth());
2339         return;
2340     }
2341
2342     // Width calculations
2343     if (treatAsReplaced)
2344         computedValues.m_extent = logicalWidthLength.value() + borderAndPaddingLogicalWidth();
2345     else {
2346         LayoutUnit containerWidthInInlineDirection = containerLogicalWidth;
2347         if (hasPerpendicularContainingBlock)
2348             containerWidthInInlineDirection = perpendicularContainingBlockLogicalHeight();
2349         LayoutUnit preferredWidth = computeLogicalWidthInRegionUsing(MainOrPreferredSize, styleToUse.logicalWidth(), containerWidthInInlineDirection, cb, region);
2350         computedValues.m_extent = constrainLogicalWidthInRegionByMinMax(preferredWidth, containerWidthInInlineDirection, cb, region);
2351     }
2352
2353     // Margin calculations.
2354     if (hasPerpendicularContainingBlock || isFloating() || isInline()) {
2355         computedValues.m_margins.m_start = minimumValueForLength(styleToUse.marginStart(), containerLogicalWidth);
2356         computedValues.m_margins.m_end = minimumValueForLength(styleToUse.marginEnd(), containerLogicalWidth);
2357     } else {
2358         LayoutUnit containerLogicalWidthForAutoMargins = containerLogicalWidth;
2359         if (avoidsFloats() && cb->containsFloats())
2360             containerLogicalWidthForAutoMargins = containingBlockAvailableLineWidthInRegion(region);
2361         bool hasInvertedDirection = cb->style().isLeftToRightDirection() != style().isLeftToRightDirection();
2362         computeInlineDirectionMargins(cb, containerLogicalWidthForAutoMargins, computedValues.m_extent,
2363             hasInvertedDirection ? computedValues.m_margins.m_end : computedValues.m_margins.m_start,
2364             hasInvertedDirection ? computedValues.m_margins.m_start : computedValues.m_margins.m_end);
2365     }
2366
2367     if (!hasPerpendicularContainingBlock && containerLogicalWidth && containerLogicalWidth != (computedValues.m_extent + computedValues.m_margins.m_start + computedValues.m_margins.m_end)
2368         && !isFloating() && !isInline() && !cb->isFlexibleBoxIncludingDeprecated()
2369 #if ENABLE(CSS_GRID_LAYOUT)
2370         && !cb->isRenderGrid()
2371 #endif
2372         ) {
2373         LayoutUnit newMargin = containerLogicalWidth - computedValues.m_extent - cb->marginStartForChild(*this);
2374         bool hasInvertedDirection = cb->style().isLeftToRightDirection() != style().isLeftToRightDirection();
2375         if (hasInvertedDirection)
2376             computedValues.m_margins.m_start = newMargin;
2377         else
2378             computedValues.m_margins.m_end = newMargin;
2379     }
2380 }
2381
2382 LayoutUnit RenderBox::fillAvailableMeasure(LayoutUnit availableLogicalWidth) const
2383 {
2384     LayoutUnit marginStart = 0;
2385     LayoutUnit marginEnd = 0;
2386     return fillAvailableMeasure(availableLogicalWidth, marginStart, marginEnd);
2387 }
2388
2389 LayoutUnit RenderBox::fillAvailableMeasure(LayoutUnit availableLogicalWidth, LayoutUnit& marginStart, LayoutUnit& marginEnd) const
2390 {
2391     marginStart = minimumValueForLength(style().marginStart(), availableLogicalWidth);
2392     marginEnd = minimumValueForLength(style().marginEnd(), availableLogicalWidth);
2393     return availableLogicalWidth - marginStart - marginEnd;
2394 }
2395
2396 LayoutUnit RenderBox::computeIntrinsicLogicalWidthUsing(Length logicalWidthLength, LayoutUnit availableLogicalWidth, LayoutUnit borderAndPadding) const
2397 {
2398     if (logicalWidthLength.type() == FillAvailable)
2399         return fillAvailableMeasure(availableLogicalWidth);
2400
2401     LayoutUnit minLogicalWidth = 0;
2402     LayoutUnit maxLogicalWidth = 0;
2403     computeIntrinsicLogicalWidths(minLogicalWidth, maxLogicalWidth);
2404
2405     if (logicalWidthLength.type() == MinContent)
2406         return minLogicalWidth + borderAndPadding;
2407
2408     if (logicalWidthLength.type() == MaxContent)
2409         return maxLogicalWidth + borderAndPadding;
2410
2411     if (logicalWidthLength.type() == FitContent) {
2412         minLogicalWidth += borderAndPadding;
2413         maxLogicalWidth += borderAndPadding;
2414         return std::max(minLogicalWidth, std::min(maxLogicalWidth, fillAvailableMeasure(availableLogicalWidth)));
2415     }
2416
2417     ASSERT_NOT_REACHED();
2418     return 0;
2419 }
2420
2421 LayoutUnit RenderBox::computeLogicalWidthInRegionUsing(SizeType widthType, Length logicalWidth, LayoutUnit availableLogicalWidth,
2422     const RenderBlock* cb, RenderRegion* region) const
2423 {
2424     if (!logicalWidth.isIntrinsicOrAuto()) {
2425         // FIXME: If the containing block flow is perpendicular to our direction we need to use the available logical height instead.
2426         return adjustBorderBoxLogicalWidthForBoxSizing(valueForLength(logicalWidth, availableLogicalWidth));
2427     }
2428
2429     if (logicalWidth.isIntrinsic())
2430         return computeIntrinsicLogicalWidthUsing(logicalWidth, availableLogicalWidth, borderAndPaddingLogicalWidth());
2431
2432     LayoutUnit marginStart = 0;
2433     LayoutUnit marginEnd = 0;
2434     LayoutUnit logicalWidthResult = fillAvailableMeasure(availableLogicalWidth, marginStart, marginEnd);
2435
2436     if (shrinkToAvoidFloats() && cb->containsFloats())
2437         logicalWidthResult = std::min(logicalWidthResult, shrinkLogicalWidthToAvoidFloats(marginStart, marginEnd, cb, region));
2438
2439     if (widthType == MainOrPreferredSize && sizesLogicalWidthToFitContent(widthType))
2440         return std::max(minPreferredLogicalWidth(), std::min(maxPreferredLogicalWidth(), logicalWidthResult));
2441     return logicalWidthResult;
2442 }
2443
2444 static bool flexItemHasStretchAlignment(const RenderBox& flexitem)
2445 {
2446     auto parent = flexitem.parent();
2447     return RenderStyle::resolveAlignment(parent->style(), flexitem.style(), ItemPositionStretch) == ItemPositionStretch;
2448 }
2449
2450 static bool isStretchingColumnFlexItem(const RenderBox& flexitem)
2451 {
2452     auto parent = flexitem.parent();
2453     if (parent->isDeprecatedFlexibleBox() && parent->style().boxOrient() == VERTICAL && parent->style().boxAlign() == BSTRETCH)
2454         return true;
2455
2456     // We don't stretch multiline flexboxes because they need to apply line spacing (align-content) first.
2457     if (parent->isFlexibleBox() && parent->style().flexWrap() == FlexNoWrap && parent->style().isColumnFlexDirection() && flexItemHasStretchAlignment(flexitem))
2458         return true;
2459     return false;
2460 }
2461
2462 bool RenderBox::sizesLogicalWidthToFitContent(SizeType widthType) const
2463 {
2464     // Anonymous inline blocks always fill the width of their containing block.
2465     if (isAnonymousInlineBlock())
2466         return false;
2467
2468     // Marquees in WinIE are like a mixture of blocks and inline-blocks.  They size as though they're blocks,
2469     // but they allow text to sit on the same line as the marquee.
2470     if (isFloating() || (isInlineBlockOrInlineTable() && !isHTMLMarquee()))
2471         return true;
2472
2473     // This code may look a bit strange.  Basically width:intrinsic should clamp the size when testing both
2474     // min-width and width.  max-width is only clamped if it is also intrinsic.
2475     Length logicalWidth = (widthType == MaxSize) ? style().logicalMaxWidth() : style().logicalWidth();
2476     if (logicalWidth.type() == Intrinsic)
2477         return true;
2478
2479     // Children of a horizontal marquee do not fill the container by default.
2480     // FIXME: Need to deal with MAUTO value properly.  It could be vertical.
2481     // FIXME: Think about block-flow here.  Need to find out how marquee direction relates to
2482     // block-flow (as well as how marquee overflow should relate to block flow).
2483     // https://bugs.webkit.org/show_bug.cgi?id=46472
2484     if (parent()->style().overflowX() == OMARQUEE) {
2485         EMarqueeDirection dir = parent()->style().marqueeDirection();
2486         if (dir == MAUTO || dir == MFORWARD || dir == MBACKWARD || dir == MLEFT || dir == MRIGHT)
2487             return true;
2488     }
2489
2490     // Flexible box items should shrink wrap, so we lay them out at their intrinsic widths.
2491     // In the case of columns that have a stretch alignment, we layout at the stretched size
2492     // to avoid an extra layout when applying alignment.
2493     if (parent()->isFlexibleBox()) {
2494         // For multiline columns, we need to apply align-content first, so we can't stretch now.
2495         if (!parent()->style().isColumnFlexDirection() || parent()->style().flexWrap() != FlexNoWrap)
2496             return true;
2497         if (!flexItemHasStretchAlignment(*this))
2498             return true;
2499     }
2500
2501     // Flexible horizontal boxes lay out children at their intrinsic widths.  Also vertical boxes
2502     // that don't stretch their kids lay out their children at their intrinsic widths.
2503     // FIXME: Think about block-flow here.
2504     // https://bugs.webkit.org/show_bug.cgi?id=46473
2505     if (parent()->isDeprecatedFlexibleBox() && (parent()->style().boxOrient() == HORIZONTAL || parent()->style().boxAlign() != BSTRETCH))
2506         return true;
2507
2508     // Button, input, select, textarea, and legend treat width value of 'auto' as 'intrinsic' unless it's in a
2509     // stretching column flexbox.
2510     // FIXME: Think about block-flow here.
2511     // https://bugs.webkit.org/show_bug.cgi?id=46473
2512     if (logicalWidth.type() == Auto && !isStretchingColumnFlexItem(*this) && element() && (is<HTMLInputElement>(*element()) || is<HTMLSelectElement>(*element()) || is<HTMLButtonElement>(*element()) || is<HTMLTextAreaElement>(*element()) || is<HTMLLegendElement>(*element())))
2513         return true;
2514
2515     if (isHorizontalWritingMode() != containingBlock()->isHorizontalWritingMode())
2516         return true;
2517
2518     return false;
2519 }
2520
2521 void RenderBox::computeInlineDirectionMargins(RenderBlock* containingBlock, LayoutUnit containerWidth, LayoutUnit childWidth, LayoutUnit& marginStart, LayoutUnit& marginEnd) const
2522 {
2523     const RenderStyle& containingBlockStyle = containingBlock->style();
2524     Length marginStartLength = style().marginStartUsing(&containingBlockStyle);
2525     Length marginEndLength = style().marginEndUsing(&containingBlockStyle);
2526
2527     if (isFloating() || isInline()) {
2528         // Inline blocks/tables and floats don't have their margins increased.
2529         marginStart = minimumValueForLength(marginStartLength, containerWidth);
2530         marginEnd = minimumValueForLength(marginEndLength, containerWidth);
2531         return;
2532     }
2533
2534     // Case One: The object is being centered in the containing block's available logical width.
2535     if ((marginStartLength.isAuto() && marginEndLength.isAuto() && childWidth < containerWidth)
2536         || (!marginStartLength.isAuto() && !marginEndLength.isAuto() && containingBlock->style().textAlign() == WEBKIT_CENTER)) {
2537         // Other browsers center the margin box for align=center elements so we match them here.
2538         LayoutUnit marginStartWidth = minimumValueForLength(marginStartLength, containerWidth);
2539         LayoutUnit marginEndWidth = minimumValueForLength(marginEndLength, containerWidth);
2540         LayoutUnit centeredMarginBoxStart = std::max<LayoutUnit>(0, (containerWidth - childWidth - marginStartWidth - marginEndWidth) / 2);
2541         marginStart = centeredMarginBoxStart + marginStartWidth;
2542         marginEnd = containerWidth - childWidth - marginStart + marginEndWidth;
2543         return;
2544     }
2545
2546     // Case Two: The object is being pushed to the start of the containing block's available logical width.
2547     if (marginEndLength.isAuto() && childWidth < containerWidth) {
2548         marginStart = valueForLength(marginStartLength, containerWidth);
2549         marginEnd = containerWidth - childWidth - marginStart;
2550         return;
2551     }
2552
2553     // Case Three: The object is being pushed to the end of the containing block's available logical width.
2554     bool pushToEndFromTextAlign = !marginEndLength.isAuto() && ((!containingBlockStyle.isLeftToRightDirection() && containingBlockStyle.textAlign() == WEBKIT_LEFT)
2555         || (containingBlockStyle.isLeftToRightDirection() && containingBlockStyle.textAlign() == WEBKIT_RIGHT));
2556     if ((marginStartLength.isAuto() && childWidth < containerWidth) || pushToEndFromTextAlign) {
2557         marginEnd = valueForLength(marginEndLength, containerWidth);
2558         marginStart = containerWidth - childWidth - marginEnd;
2559         return;
2560     }
2561
2562     // Case Four: Either no auto margins, or our width is >= the container width (css2.1, 10.3.3).  In that case
2563     // auto margins will just turn into 0.
2564     marginStart = minimumValueForLength(marginStartLength, containerWidth);
2565     marginEnd = minimumValueForLength(marginEndLength, containerWidth);
2566 }
2567
2568 RenderBoxRegionInfo* RenderBox::renderBoxRegionInfo(RenderRegion* region, RenderBoxRegionInfoFlags cacheFlag) const
2569 {
2570     // Make sure nobody is trying to call this with a null region.
2571     if (!region)
2572         return nullptr;
2573
2574     // If we have computed our width in this region already, it will be cached, and we can
2575     // just return it.
2576     RenderBoxRegionInfo* boxInfo = region->renderBoxRegionInfo(this);
2577     if (boxInfo && cacheFlag == CacheRenderBoxRegionInfo)
2578         return boxInfo;
2579
2580     // No cached value was found, so we have to compute our insets in this region.
2581     // FIXME: For now we limit this computation to normal RenderBlocks. Future patches will expand
2582     // support to cover all boxes.
2583     RenderFlowThread* flowThread = flowThreadContainingBlock();
2584     if (isRenderFlowThread() || !flowThread || !canHaveBoxInfoInRegion() || flowThread->style().writingMode() != style().writingMode())
2585         return nullptr;
2586
2587     LogicalExtentComputedValues computedValues;
2588     computeLogicalWidthInRegion(computedValues, region);
2589
2590     // Now determine the insets based off where this object is supposed to be positioned.
2591     RenderBlock* cb = containingBlock();
2592     RenderRegion* clampedContainingBlockRegion = cb->clampToStartAndEndRegions(region);
2593     RenderBoxRegionInfo* containingBlockInfo = cb->renderBoxRegionInfo(clampedContainingBlockRegion);
2594     LayoutUnit containingBlockLogicalWidth = cb->logicalWidth();
2595     LayoutUnit containingBlockLogicalWidthInRegion = containingBlockInfo ? containingBlockInfo->logicalWidth() : containingBlockLogicalWidth;
2596
2597     LayoutUnit marginStartInRegion = computedValues.m_margins.m_start;
2598     LayoutUnit startMarginDelta = marginStartInRegion - marginStart();
2599     LayoutUnit logicalWidthInRegion = computedValues.m_extent;
2600     LayoutUnit logicalLeftInRegion = computedValues.m_position;
2601     LayoutUnit widthDelta = logicalWidthInRegion - logicalWidth();
2602     LayoutUnit logicalLeftDelta = isOutOfFlowPositioned() ? logicalLeftInRegion - logicalLeft() : startMarginDelta;
2603     LayoutUnit logicalRightInRegion = containingBlockLogicalWidthInRegion - (logicalLeftInRegion + logicalWidthInRegion);
2604     LayoutUnit oldLogicalRight = containingBlockLogicalWidth - (logicalLeft() + logicalWidth());
2605     LayoutUnit logicalRightDelta = isOutOfFlowPositioned() ? logicalRightInRegion - oldLogicalRight : startMarginDelta;
2606
2607     LayoutUnit logicalLeftOffset = 0;
2608
2609     if (!isOutOfFlowPositioned() && avoidsFloats() && cb->containsFloats()) {
2610         LayoutUnit startPositionDelta = cb->computeStartPositionDeltaForChildAvoidingFloats(*this, marginStartInRegion, region);
2611         if (cb->style().isLeftToRightDirection())
2612             logicalLeftDelta += startPositionDelta;
2613         else
2614             logicalRightDelta += startPositionDelta;
2615     }
2616
2617     if (cb->style().isLeftToRightDirection())
2618         logicalLeftOffset += logicalLeftDelta;
2619     else
2620         logicalLeftOffset -= (widthDelta + logicalRightDelta);
2621
2622     LayoutUnit logicalRightOffset = logicalWidth() - (logicalLeftOffset + logicalWidthInRegion);
2623     bool isShifted = (containingBlockInfo && containingBlockInfo->isShifted())
2624             || (style().isLeftToRightDirection() && logicalLeftOffset)
2625             || (!style().isLeftToRightDirection() && logicalRightOffset);
2626
2627     // FIXME: Although it's unlikely, these boxes can go outside our bounds, and so we will need to incorporate them into overflow.
2628     if (cacheFlag == CacheRenderBoxRegionInfo)
2629         return region->setRenderBoxRegionInfo(this, logicalLeftOffset, logicalWidthInRegion, isShifted);
2630     return new RenderBoxRegionInfo(logicalLeftOffset, logicalWidthInRegion, isShifted);
2631 }
2632
2633 static bool shouldFlipBeforeAfterMargins(const RenderStyle& containingBlockStyle, const RenderStyle* childStyle)
2634 {
2635     ASSERT(containingBlockStyle.isHorizontalWritingMode() != childStyle->isHorizontalWritingMode());
2636     WritingMode childWritingMode = childStyle->writingMode();
2637     bool shouldFlip = false;
2638     switch (containingBlockStyle.writingMode()) {
2639     case TopToBottomWritingMode:
2640         shouldFlip = (childWritingMode == RightToLeftWritingMode);
2641         break;
2642     case BottomToTopWritingMode:
2643         shouldFlip = (childWritingMode == RightToLeftWritingMode);
2644         break;
2645     case RightToLeftWritingMode:
2646         shouldFlip = (childWritingMode == BottomToTopWritingMode);
2647         break;
2648     case LeftToRightWritingMode:
2649         shouldFlip = (childWritingMode == BottomToTopWritingMode);
2650         break;
2651     }
2652
2653     if (!containingBlockStyle.isLeftToRightDirection())
2654         shouldFlip = !shouldFlip;
2655
2656     return shouldFlip;
2657 }
2658
2659 void RenderBox::updateLogicalHeight()
2660 {
2661     LogicalExtentComputedValues computedValues;
2662     computeLogicalHeight(logicalHeight(), logicalTop(), computedValues);
2663
2664     setLogicalHeight(computedValues.m_extent);
2665     setLogicalTop(computedValues.m_position);
2666     setMarginBefore(computedValues.m_margins.m_before);
2667     setMarginAfter(computedValues.m_margins.m_after);
2668 }
2669
2670 void RenderBox::computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues& computedValues) const
2671 {
2672     computedValues.m_extent = logicalHeight;
2673     computedValues.m_position = logicalTop;
2674
2675     // Cell height is managed by the table and inline non-replaced elements do not support a height property.
2676     if (isTableCell() || (isInline() && !isReplaced()))
2677         return;
2678
2679     Length h;
2680     if (isOutOfFlowPositioned())
2681         computePositionedLogicalHeight(computedValues);
2682     else {
2683         RenderBlock* cb = containingBlock();
2684         bool hasPerpendicularContainingBlock = cb->isHorizontalWritingMode() != isHorizontalWritingMode();
2685
2686         if (!hasPerpendicularContainingBlock) {
2687             bool shouldFlipBeforeAfter = cb->style().writingMode() != style().writingMode();
2688             computeBlockDirectionMargins(cb,
2689                 shouldFlipBeforeAfter ? computedValues.m_margins.m_after : computedValues.m_margins.m_before,
2690                 shouldFlipBeforeAfter ? computedValues.m_margins.m_before : computedValues.m_margins.m_after);
2691         }
2692
2693         // For tables, calculate margins only.
2694         if (isTable()) {
2695             if (hasPerpendicularContainingBlock) {
2696                 bool shouldFlipBeforeAfter = shouldFlipBeforeAfterMargins(cb->style(), &style());
2697                 computeInlineDirectionMargins(cb, containingBlockLogicalWidthForContent(), computedValues.m_extent,
2698                     shouldFlipBeforeAfter ? computedValues.m_margins.m_after : computedValues.m_margins.m_before,
2699                     shouldFlipBeforeAfter ? computedValues.m_margins.m_before : computedValues.m_margins.m_after);
2700             }
2701             return;
2702         }
2703
2704         // FIXME: Account for block-flow in flexible boxes.
2705         // https://bugs.webkit.org/show_bug.cgi?id=46418
2706         bool inHorizontalBox = parent()->isDeprecatedFlexibleBox() && parent()->style().boxOrient() == HORIZONTAL;
2707         bool stretching = parent()->style().boxAlign() == BSTRETCH;
2708         bool treatAsReplaced = shouldComputeSizeAsReplaced() && (!inHorizontalBox || !stretching);
2709         bool checkMinMaxHeight = false;
2710
2711         // The parent box is flexing us, so it has increased or decreased our height.  We have to
2712         // grab our cached flexible height.
2713         // FIXME: Account for block-flow in flexible boxes.
2714         // https://bugs.webkit.org/show_bug.cgi?id=46418
2715         if (hasOverrideLogicalContentHeight() && (parent()->isFlexibleBoxIncludingDeprecated() || parent()->isRenderGrid()))
2716             h = Length(overrideLogicalContentHeight(), Fixed);
2717         else if (treatAsReplaced)
2718             h = Length(computeReplacedLogicalHeight(), Fixed);
2719         else {
2720             h = style().logicalHeight();
2721             checkMinMaxHeight = true;
2722         }
2723
2724         // Block children of horizontal flexible boxes fill the height of the box.
2725         // FIXME: Account for block-flow in flexible boxes.
2726         // https://bugs.webkit.org/show_bug.cgi?id=46418
2727         if (h.isAuto() && is<RenderDeprecatedFlexibleBox>(*parent()) && parent()->style().boxOrient() == HORIZONTAL
2728                 && downcast<RenderDeprecatedFlexibleBox>(*parent()).isStretchingChildren()) {
2729             h = Length(parentBox()->contentLogicalHeight() - marginBefore() - marginAfter() - borderAndPaddingLogicalHeight(), Fixed);
2730             checkMinMaxHeight = false;
2731         }
2732
2733         LayoutUnit heightResult;
2734         if (checkMinMaxHeight) {
2735             heightResult = computeLogicalHeightUsing(style().logicalHeight());
2736             if (heightResult == -1)
2737                 heightResult = computedValues.m_extent;
2738             heightResult = constrainLogicalHeightByMinMax(heightResult);
2739         } else {
2740             // The only times we don't check min/max height are when a fixed length has
2741             // been given as an override.  Just use that.  The value has already been adjusted
2742             // for box-sizing.
2743             heightResult = h.value() + borderAndPaddingLogicalHeight();
2744         }
2745
2746         computedValues.m_extent = heightResult;
2747
2748         if (hasPerpendicularContainingBlock) {
2749             bool shouldFlipBeforeAfter = shouldFlipBeforeAfterMargins(cb->style(), &style());
2750             computeInlineDirectionMargins(cb, containingBlockLogicalWidthForContent(), heightResult,
2751                     shouldFlipBeforeAfter ? computedValues.m_margins.m_after : computedValues.m_margins.m_before,
2752                     shouldFlipBeforeAfter ? computedValues.m_margins.m_before : computedValues.m_margins.m_after);
2753         }
2754     }
2755
2756     // WinIE quirk: The <html> block always fills the entire canvas in quirks mode.  The <body> always fills the
2757     // <html> block in quirks mode.  Only apply this quirk if the block is normal flow and no height
2758     // is specified. When we're printing, we also need this quirk if the body or root has a percentage
2759     // height since we don't set a height in RenderView when we're printing. So without this quirk, the
2760     // height has nothing to be a percentage of, and it ends up being 0. That is bad.
2761     bool paginatedContentNeedsBaseHeight = document().printing() && h.isPercent()
2762         && (isRoot() || (isBody() && document().documentElement()->renderer()->style().logicalHeight().isPercent())) && !isInline();
2763     if (stretchesToViewport() || paginatedContentNeedsBaseHeight) {
2764         LayoutUnit margins = collapsedMarginBefore() + collapsedMarginAfter();
2765         LayoutUnit visibleHeight = view().pageOrViewLogicalHeight();
2766         if (isRoot())
2767             computedValues.m_extent = std::max(computedValues.m_extent, visibleHeight - margins);
2768         else {
2769             LayoutUnit marginsBordersPadding = margins + parentBox()->marginBefore() + parentBox()->marginAfter() + parentBox()->borderAndPaddingLogicalHeight();
2770             computedValues.m_extent = std::max(computedValues.m_extent, visibleHeight - marginsBordersPadding);
2771         }
2772     }
2773 }
2774
2775 LayoutUnit RenderBox::computeLogicalHeightUsing(const Length& height) const
2776 {
2777     LayoutUnit logicalHeight = computeContentAndScrollbarLogicalHeightUsing(height);
2778     if (logicalHeight != -1)
2779         logicalHeight = adjustBorderBoxLogicalHeightForBoxSizing(logicalHeight);
2780     return logicalHeight;
2781 }
2782
2783 LayoutUnit RenderBox::computeContentLogicalHeight(const Length& height) const
2784 {
2785     LayoutUnit heightIncludingScrollbar = computeContentAndScrollbarLogicalHeightUsing(height);
2786     if (heightIncludingScrollbar == -1)
2787         return -1;
2788     return std::max<LayoutUnit>(0, adjustContentBoxLogicalHeightForBoxSizing(heightIncludingScrollbar) - scrollbarLogicalHeight());
2789 }
2790
2791 LayoutUnit RenderBox::computeContentAndScrollbarLogicalHeightUsing(const Length& height) const
2792 {
2793     if (height.isFixed())
2794         return height.value();
2795     if (height.isPercent())
2796         return computePercentageLogicalHeight(height);
2797     return -1;
2798 }
2799
2800 bool RenderBox::skipContainingBlockForPercentHeightCalculation(const RenderBox* containingBlock, bool isPerpendicularWritingMode) const
2801 {
2802     // Flow threads for multicol or paged overflow should be skipped. They are invisible to the DOM,
2803     // and percent heights of children should be resolved against the multicol or paged container.
2804     if (containingBlock->isInFlowRenderFlowThread() && !isPerpendicularWritingMode)
2805         return true;
2806
2807     // For quirks mode and anonymous blocks, we skip auto-height containingBlocks when computing percentages.
2808     // For standards mode, we treat the percentage as auto if it has an auto-height containing block.
2809     if (!document().inQuirksMode() && !containingBlock->isAnonymousBlock())
2810         return false;
2811     return !containingBlock->isTableCell() && !containingBlock->isOutOfFlowPositioned() && containingBlock->style().logicalHeight().isAuto() && isHorizontalWritingMode() == containingBlock->isHorizontalWritingMode();
2812 }
2813
2814 LayoutUnit RenderBox::computePercentageLogicalHeight(const Length& height) const
2815 {
2816     LayoutUnit availableHeight = -1;
2817
2818     bool skippedAutoHeightContainingBlock = false;
2819     RenderBlock* cb = containingBlock();
2820     const RenderBox* containingBlockChild = this;
2821     LayoutUnit rootMarginBorderPaddingHeight = 0;
2822     bool isHorizontal = isHorizontalWritingMode();
2823     while (!cb->isRenderView() && skipContainingBlockForPercentHeightCalculation(cb, isHorizontal != cb->isHorizontalWritingMode())) {
2824         if (cb->isBody() || cb->isRoot())
2825             rootMarginBorderPaddingHeight += cb->marginBefore() + cb->marginAfter() + cb->borderAndPaddingLogicalHeight();
2826         skippedAutoHeightContainingBlock = true;
2827         containingBlockChild = cb;
2828         cb = cb->containingBlock();
2829         cb->addPercentHeightDescendant(const_cast<RenderBox&>(*this));
2830     }
2831
2832     const RenderStyle& cbstyle = cb->style();
2833
2834     // A positioned element that specified both top/bottom or that specifies height should be treated as though it has a height
2835     // explicitly specified that can be used for any percentage computations.
2836     bool isOutOfFlowPositionedWithSpecifiedHeight = cb->isOutOfFlowPositioned() && (!cbstyle.logicalHeight().isAuto() || (!cbstyle.logicalTop().isAuto() && !cbstyle.logicalBottom().isAuto()));
2837
2838     bool includeBorderPadding = isTable();
2839
2840     if (isHorizontal != cb->isHorizontalWritingMode())
2841         availableHeight = containingBlockChild->containingBlockLogicalWidthForContent();
2842 #if ENABLE(CSS_GRID_LAYOUT)
2843     else if (hasOverrideContainingBlockLogicalHeight())
2844         availableHeight = overrideContainingBlockContentLogicalHeight();
2845 #endif
2846     else if (is<RenderTableCell>(*cb)) {
2847         if (!skippedAutoHeightContainingBlock) {
2848             // Table cells violate what the CSS spec says to do with heights. Basically we
2849             // don't care if the cell specified a height or not. We just always make ourselves
2850             // be a percentage of the cell's current content height.
2851             if (!cb->hasOverrideLogicalContentHeight()) {
2852                 // Normally we would let the cell size intrinsically, but scrolling overflow has to be
2853                 // treated differently, since WinIE lets scrolled overflow regions shrink as needed.
2854                 // While we can't get all cases right, we can at least detect when the cell has a specified
2855                 // height or when the table has a specified height. In these cases we want to initially have
2856                 // no size and allow the flexing of the table or the cell to its specified height to cause us
2857                 // to grow to fill the space. This could end up being wrong in some cases, but it is
2858                 // preferable to the alternative (sizing intrinsically and making the row end up too big).
2859                 RenderTableCell& cell = downcast<RenderTableCell>(*cb);
2860                 if (scrollsOverflowY() && (!cell.style().logicalHeight().isAuto() || !cell.table()->style().logicalHeight().isAuto()))
2861                     return 0;
2862                 return -1;
2863             }
2864             availableHeight = cb->overrideLogicalContentHeight();
2865             includeBorderPadding = true;
2866         }
2867     } else if (cbstyle.logicalHeight().isFixed()) {
2868         LayoutUnit contentBoxHeight = cb->adjustContentBoxLogicalHeightForBoxSizing(cbstyle.logicalHeight().value());
2869         availableHeight = std::max<LayoutUnit>(0, cb->constrainContentBoxLogicalHeightByMinMax(contentBoxHeight - cb->scrollbarLogicalHeight()));
2870     } else if (cbstyle.logicalHeight().isPercent() && !isOutOfFlowPositionedWithSpecifiedHeight) {
2871         // We need to recur and compute the percentage height for our containing block.
2872         LayoutUnit heightWithScrollbar = cb->computePercentageLogicalHeight(cbstyle.logicalHeight());
2873         if (heightWithScrollbar != -1) {
2874             LayoutUnit contentBoxHeightWithScrollbar = cb->adjustContentBoxLogicalHeightForBoxSizing(heightWithScrollbar);
2875             // We need to adjust for min/max height because this method does not
2876             // handle the min/max of the current block, its caller does. So the
2877             // return value from the recursive call will not have been adjusted
2878             // yet.
2879             LayoutUnit contentBoxHeight = cb->constrainContentBoxLogicalHeightByMinMax(contentBoxHeightWithScrollbar - cb->scrollbarLogicalHeight());
2880             availableHeight = std::max<LayoutUnit>(0, contentBoxHeight);
2881         }
2882     } else if (isOutOfFlowPositionedWithSpecifiedHeight) {
2883         // Don't allow this to affect the block' height() member variable, since this
2884         // can get called while the block is still laying out its kids.
2885         LogicalExtentComputedValues computedValues;
2886         cb->computeLogicalHeight(cb->logicalHeight(), 0, computedValues);
2887         availableHeight = computedValues.m_extent - cb->borderAndPaddingLogicalHeight() - cb->scrollbarLogicalHeight();
2888     } else if (cb->isRenderView())
2889         availableHeight = view().pageOrViewLogicalHeight();
2890
2891     if (availableHeight == -1)
2892         return availableHeight;
2893
2894     availableHeight -= rootMarginBorderPaddingHeight;
2895
2896     LayoutUnit result = valueForLength(height, availableHeight);
2897     if (includeBorderPadding) {
2898         // FIXME: Table cells should default to box-sizing: border-box so we can avoid this hack.
2899         // It is necessary to use the border-box to match WinIE's broken
2900         // box model. This is essential for sizing inside
2901         // table cells using percentage heights.
2902         result -= borderAndPaddingLogicalHeight();
2903         return std::max<LayoutUnit>(0, result);
2904     }
2905     return result;
2906 }
2907
2908 LayoutUnit RenderBox::computeReplacedLogicalWidth(ShouldComputePreferred shouldComputePreferred) const
2909 {
2910     return computeReplacedLogicalWidthRespectingMinMaxWidth(computeReplacedLogicalWidthUsing(style().logicalWidth()), shouldComputePreferred);
2911 }
2912
2913 LayoutUnit RenderBox::computeReplacedLogicalWidthRespectingMinMaxWidth(LayoutUnit logicalWidth, ShouldComputePreferred shouldComputePreferred) const
2914 {
2915     LayoutUnit minLogicalWidth = (shouldComputePreferred == ComputePreferred && style().logicalMinWidth().isPercent()) || style().logicalMinWidth().isUndefined() ? logicalWidth : computeReplacedLogicalWidthUsing(style().logicalMinWidth());
2916     LayoutUnit maxLogicalWidth = (shouldComputePreferred == ComputePreferred && style().logicalMaxWidth().isPercent()) || style().logicalMaxWidth().isUndefined() ? logicalWidth : computeReplacedLogicalWidthUsing(style().logicalMaxWidth());
2917     return std::max(minLogicalWidth, std::min(logicalWidth, maxLogicalWidth));
2918 }
2919
2920 LayoutUnit RenderBox::computeReplacedLogicalWidthUsing(Length logicalWidth) const
2921 {
2922     switch (logicalWidth.type()) {
2923         case Fixed:
2924             return adjustContentBoxLogicalWidthForBoxSizing(logicalWidth.value());
2925         case MinContent:
2926         case MaxContent: {
2927             // MinContent/MaxContent don't need the availableLogicalWidth argument.
2928             LayoutUnit availableLogicalWidth = 0;
2929             return computeIntrinsicLogicalWidthUsing(logicalWidth, availableLogicalWidth, borderAndPaddingLogicalWidth()) - borderAndPaddingLogicalWidth();
2930         }
2931         case FitContent:
2932         case FillAvailable:
2933         case Percent:
2934         case Calculated: {
2935             // FIXME: containingBlockLogicalWidthForContent() is wrong if the replaced element's block-flow is perpendicular to the
2936             // containing block's block-flow.
2937             // https://bugs.webkit.org/show_bug.cgi?id=46496
2938             const LayoutUnit cw = isOutOfFlowPositioned() ? containingBlockLogicalWidthForPositioned(downcast<RenderBoxModelObject>(container())) : containingBlockLogicalWidthForContent();
2939             Length containerLogicalWidth = containingBlock()->style().logicalWidth();
2940             // FIXME: Handle cases when containing block width is calculated or viewport percent.
2941             // https://bugs.webkit.org/show_bug.cgi?id=91071
2942             if (logicalWidth.isIntrinsic())
2943                 return computeIntrinsicLogicalWidthUsing(logicalWidth, cw, borderAndPaddingLogicalWidth()) - borderAndPaddingLogicalWidth();
2944             if (cw > 0 || (!cw && (containerLogicalWidth.isFixed() || containerLogicalWidth.isPercent())))
2945                 return adjustContentBoxLogicalWidthForBoxSizing(minimumValueForLength(logicalWidth, cw));
2946         }
2947         FALLTHROUGH;
2948         case Intrinsic:
2949         case MinIntrinsic:
2950         case Auto:
2951         case Relative:
2952         case Undefined:
2953             return intrinsicLogicalWidth();
2954     }
2955
2956     ASSERT_NOT_REACHED();
2957     return 0;
2958 }
2959
2960 LayoutUnit RenderBox::computeReplacedLogicalHeight() const
2961 {
2962     return computeReplacedLogicalHeightRespectingMinMaxHeight(computeReplacedLogicalHeightUsing(style().logicalHeight()));
2963 }
2964
2965 LayoutUnit RenderBox::computeReplacedLogicalHeightRespectingMinMaxHeight(LayoutUnit logicalHeight) const
2966 {
2967     LayoutUnit minLogicalHeight = computeReplacedLogicalHeightUsing(style().logicalMinHeight());
2968     LayoutUnit maxLogicalHeight = style().logicalMaxHeight().isUndefined() ? logicalHeight : computeReplacedLogicalHeightUsing(style().logicalMaxHeight());
2969     return std::max(minLogicalHeight, std::min(logicalHeight, maxLogicalHeight));
2970 }
2971
2972 LayoutUnit RenderBox::computeReplacedLogicalHeightUsing(Length logicalHeight) const
2973 {
2974     switch (logicalHeight.type()) {
2975         case Fixed:
2976             return adjustContentBoxLogicalHeightForBoxSizing(logicalHeight.value());
2977         case Percent:
2978         case Calculated:
2979         {
2980             auto cb = isOutOfFlowPositioned() ? container() : containingBlock();
2981             while (cb->isAnonymous() && !is<RenderView>(*cb)) {
2982                 cb = cb->containingBlock();
2983                 downcast<RenderBlock>(*cb).addPercentHeightDescendant(const_cast<RenderBox&>(*this));
2984             }
2985
2986             // FIXME: This calculation is not patched for block-flow yet.
2987             // https://bugs.webkit.org/show_bug.cgi?id=46500
2988             if (cb->isOutOfFlowPositioned() && cb->style().height().isAuto() && !(cb->style().top().isAuto() || cb->style().bottom().isAuto())) {
2989                 ASSERT_WITH_SECURITY_IMPLICATION(cb->isRenderBlock());
2990                 RenderBlock& block = downcast<RenderBlock>(*cb);
2991                 LogicalExtentComputedValues computedValues;
2992                 block.computeLogicalHeight(block.logicalHeight(), 0, computedValues);
2993                 LayoutUnit newContentHeight = computedValues.m_extent - block.borderAndPaddingLogicalHeight() - block.scrollbarLogicalHeight();
2994                 LayoutUnit newHeight = block.adjustContentBoxLogicalHeightForBoxSizing(newContentHeight);
2995                 return adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeight, newHeight));
2996             }
2997
2998             // FIXME: availableLogicalHeight() is wrong if the replaced element's block-flow is perpendicular to the
2999             // containing block's block-flow.
3000             // https://bugs.webkit.org/show_bug.cgi?id=46496
3001             LayoutUnit availableHeight;
3002             if (isOutOfFlowPositioned())
3003                 availableHeight = containingBlockLogicalHeightForPositioned(downcast<RenderBoxModelObject>(cb));
3004             else {
3005                 availableHeight = containingBlockLogicalHeightForContent(IncludeMarginBorderPadding);
3006                 // It is necessary to use the border-box to match WinIE's broken
3007                 // box model.  This is essential for sizing inside
3008                 // table cells using percentage heights.
3009                 // FIXME: This needs to be made block-flow-aware.  If the cell and image are perpendicular block-flows, this isn't right.
3010                 // https://bugs.webkit.org/show_bug.cgi?id=46997
3011                 while (cb && !cb->isRenderView() && (cb->style().logicalHeight().isAuto() || cb->style().logicalHeight().isPercent())) {
3012                     if (cb->isTableCell()) {
3013                         // Don't let table cells squeeze percent-height replaced elements
3014                         // <http://bugs.webkit.org/show_bug.cgi?id=15359>
3015                         availableHeight = std::max(availableHeight, intrinsicLogicalHeight());
3016                         return valueForLength(logicalHeight, availableHeight - borderAndPaddingLogicalHeight());
3017                     }
3018                     downcast<RenderBlock>(*cb).addPercentHeightDescendant(const_cast<RenderBox&>(*this));
3019                     cb = cb->containingBlock();
3020                 }
3021             }
3022             return adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeight, availableHeight));
3023         }
3024         default:
3025             return intrinsicLogicalHeight();
3026     }
3027 }
3028
3029 LayoutUnit RenderBox::availableLogicalHeight(AvailableLogicalHeightType heightType) const
3030 {
3031     return constrainLogicalHeightByMinMax(availableLogicalHeightUsing(style().logicalHeight(), heightType));
3032 }
3033
3034 LayoutUnit RenderBox::availableLogicalHeightUsing(const Length& h, AvailableLogicalHeightType heightType) const
3035 {
3036     // We need to stop here, since we don't want to increase the height of the table
3037     // artificially.  We're going to rely on this cell getting expanded to some new
3038     // height, and then when we lay out again we'll use the calculation below.
3039     if (isTableCell() && (h.isAuto() || h.isPercent())) {
3040         if (hasOverrideLogicalContentHeight())
3041             return overrideLogicalContentHeight();
3042         return logicalHeight() - borderAndPaddingLogicalHeight();
3043     }
3044
3045     if (h.isPercent() && isOutOfFlowPositioned() && !isRenderFlowThread()) {
3046         // FIXME: This is wrong if the containingBlock has a perpendicular writing mode.
3047         LayoutUnit availableHeight = containingBlockLogicalHeightForPositioned(containingBlock());
3048         return adjustContentBoxLogicalHeightForBoxSizing(valueForLength(h, availableHeight));
3049     }
3050
3051     LayoutUnit heightIncludingScrollbar = computeContentAndScrollbarLogicalHeightUsing(h);
3052     if (heightIncludingScrollbar != -1)
3053         return std::max<LayoutUnit>(0, adjustContentBoxLogicalHeightForBoxSizing(heightIncludingScrollbar) - scrollbarLogicalHeight());
3054
3055     // FIXME: Check logicalTop/logicalBottom here to correctly handle vertical writing-mode.
3056     // https://bugs.webkit.org/show_bug.cgi?id=46500
3057     if (is<RenderBlock>(*this) && isOutOfFlowPositioned() && style().height().isAuto() && !(style().top().isAuto() || style().bottom().isAuto())) {
3058         RenderBlock& block = const_cast<RenderBlock&>(downcast<RenderBlock>(*this));
3059         LogicalExtentComputedValues computedValues;
3060         block.computeLogicalHeight(block.logicalHeight(), 0, computedValues);
3061         LayoutUnit newContentHeight = computedValues.m_extent - block.borderAndPaddingLogicalHeight() - block.scrollbarLogicalHeight();
3062         return adjustContentBoxLogicalHeightForBoxSizing(newContentHeight);
3063     }
3064
3065     // FIXME: This is wrong if the containingBlock has a perpendicular writing mode.
3066     LayoutUnit availableHeight = containingBlockLogicalHeightForContent(heightType);
3067     if (heightType == ExcludeMarginBorderPadding) {
3068         // FIXME: Margin collapsing hasn't happened yet, so this incorrectly removes collapsed margins.
3069         availableHeight -= marginBefore() + marginAfter() + borderAndPaddingLogicalHeight();
3070     }
3071     return availableHeight;
3072 }
3073
3074 void RenderBox::computeBlockDirectionMargins(const RenderBlock* containingBlock, LayoutUnit& marginBefore, LayoutUnit& marginAfter) const
3075 {
3076     if (isTableCell()) {
3077         // FIXME: Not right if we allow cells to have different directionality than the table.  If we do allow this, though,
3078         // we may just do it with an extra anonymous block inside the cell.
3079         marginBefore = 0;
3080         marginAfter = 0;
3081         return;
3082     }
3083
3084     // Margins are calculated with respect to the logical width of
3085     // the containing block (8.3)
3086     LayoutUnit cw = containingBlockLogicalWidthForContent();
3087     const RenderStyle& containingBlockStyle = containingBlock->style();
3088     marginBefore = minimumValueForLength(style().marginBeforeUsing(&containingBlockStyle), cw);
3089     marginAfter = minimumValueForLength(style().marginAfterUsing(&containingBlockStyle), cw);
3090 }
3091
3092 void RenderBox::computeAndSetBlockDirectionMargins(const RenderBlock* containingBlock)
3093 {
3094     LayoutUnit marginBefore;
3095     LayoutUnit marginAfter;
3096     computeBlockDirectionMargins(containingBlock, marginBefore, marginAfter);
3097     containingBlock->setMarginBeforeForChild(*this, marginBefore);
3098     containingBlock->setMarginAfterForChild(*this, marginAfter);
3099 }
3100
3101 LayoutUnit RenderBox::containingBlockLogicalWidthForPositioned(const RenderBoxModelObject* containingBlock, RenderRegion* region, bool checkForPerpendicularWritingMode) const
3102 {
3103     if (checkForPerpendicularWritingMode && containingBlock->isHorizontalWritingMode() != isHorizontalWritingMode())
3104         return containingBlockLogicalHeightForPositioned(containingBlock, false);
3105
3106     if (is<RenderBox>(*containingBlock)) {
3107         bool isFixedPosition = style().position() == FixedPosition;
3108
3109         RenderFlowThread* flowThread = flowThreadContainingBlock();
3110         if (!flowThread) {
3111             if (isFixedPosition && is<RenderView>(*containingBlock))
3112                 return downcast<RenderView>(*containingBlock).clientLogicalWidthForFixedPosition();
3113
3114             return downcast<RenderBox>(*containingBlock).clientLogicalWidth();
3115         }
3116
3117         if (isFixedPosition && is<RenderNamedFlowThread>(*containingBlock))
3118             return containingBlock->view().clientLogicalWidth();
3119
3120         if (!is<RenderBlock>(*containingBlock))
3121             return downcast<RenderBox>(*containingBlock).clientLogicalWidth();
3122
3123         const RenderBlock& cb = downcast<RenderBlock>(*containingBlock);
3124         RenderBoxRegionInfo* boxInfo = nullptr;
3125         if (!region) {
3126             if (is<RenderFlowThread>(*containingBlock) && !checkForPerpendicularWritingMode)
3127                 return downcast<RenderFlowThread>(*containingBlock).contentLogicalWidthOfFirstRegion();
3128             if (isWritingModeRoot()) {
3129                 LayoutUnit cbPageOffset = cb.offsetFromLogicalTopOfFirstPage();
3130                 RenderRegion* cbRegion = cb.regionAtBlockOffset(cbPageOffset);
3131                 if (cbRegion)
3132                     boxInfo = cb.renderBoxRegionInfo(cbRegion);
3133             }
3134         } else if (flowThread->isHorizontalWritingMode() == containingBlock->isHorizontalWritingMode()) {
3135             RenderRegion* containingBlockRegion = cb.clampToStartAndEndRegions(region);
3136             boxInfo = cb.renderBoxRegionInfo(containingBlockRegion);
3137         }
3138         return (boxInfo) ? std::max<LayoutUnit>(0, cb.clientLogicalWidth() - (cb.logicalWidth() - boxInfo->logicalWidth())) : cb.clientLogicalWidth();
3139     }
3140
3141     ASSERT(containingBlock->isInFlowPositioned());
3142
3143     const auto& flow = downcast<RenderInline>(*containingBlock);
3144     InlineFlowBox* first = flow.firstLineBox();
3145     InlineFlowBox* last = flow.lastLineBox();
3146
3147     // If the containing block is empty, return a width of 0.
3148     if (!first || !last)
3149         return 0;
3150
3151     LayoutUnit fromLeft;
3152     LayoutUnit fromRight;
3153     if (containingBlock->style().isLeftToRightDirection()) {
3154         fromLeft = first->logicalLeft() + first->borderLogicalLeft();
3155         fromRight = last->logicalLeft() + last->logicalWidth() - last->borderLogicalRight();
3156     } else {
3157         fromRight = first->logicalLeft() + first->logicalWidth() - first->borderLogicalRight();
3158         fromLeft = last->logicalLeft() + last->borderLogicalLeft();
3159     }
3160
3161     return std::max<LayoutUnit>(0, fromRight - fromLeft);
3162 }
3163
3164 LayoutUnit RenderBox::containingBlockLogicalHeightForPositioned(const RenderBoxModelObject* containingBlock, bool checkForPerpendicularWritingMode) const
3165 {
3166     if (checkForPerpendicularWritingMode && containingBlock->isHorizontalWritingMode() != isHorizontalWritingMode())
3167         return containingBlockLogicalWidthForPositioned(containingBlock, nullptr, false);
3168
3169     if (containingBlock->isBox()) {
3170         bool isFixedPosition = style().position() == FixedPosition;
3171
3172         if (isFixedPosition && is<RenderView>(*containingBlock))
3173             return downcast<RenderView>(*containingBlock).clientLogicalHeightForFixedPosition();
3174
3175         const RenderBlock* cb = is<RenderBlock>(*containingBlock) ? downcast<RenderBlock>(containingBlock) : containingBlock->containingBlock();
3176         LayoutUnit result = cb->clientLogicalHeight();
3177         RenderFlowThread* flowThread = flowThreadContainingBlock();
3178         if (flowThread && is<RenderFlowThread>(*containingBlock) && flowThread->isHorizontalWritingMode() == containingBlock->isHorizontalWritingMode()) {
3179             if (is<RenderNamedFlowThread>(*containingBlock) && isFixedPosition)
3180                 return containingBlock->view().clientLogicalHeight();
3181             return downcast<RenderFlowThread>(*containingBlock).contentLogicalHeightOfFirstRegion();
3182         }
3183         return result;
3184     }
3185
3186     ASSERT(containingBlock->isInFlowPositioned());
3187
3188     const auto& flow = downcast<RenderInline>(*containingBlock);
3189     InlineFlowBox* first = flow.firstLineBox();
3190     InlineFlowBox* last = flow.lastLineBox();
3191
3192     // If the containing block is empty, return a height of 0.
3193     if (!first || !last)
3194         return 0;
3195
3196     LayoutUnit heightResult;
3197     LayoutRect boundingBox = flow.linesBoundingBox();
3198     if (containingBlock->isHorizontalWritingMode())
3199         heightResult = boundingBox.height();
3200     else
3201         heightResult = boundingBox.width();
3202     heightResult -= (containingBlock->borderBefore() + containingBlock->borderAfter());
3203     return heightResult;
3204 }
3205
3206 static void computeInlineStaticDistance(Length& logicalLeft, Length& logicalRight, const RenderBox* child, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalWidth, RenderRegion* region)
3207 {
3208     if (!logicalLeft.isAuto() || !logicalRight.isAuto())
3209         return;
3210
3211     // FIXME: The static distance computation has not been patched for mixed writing modes yet.
3212     if (child->parent()->style().direction() == LTR) {
3213         LayoutUnit staticPosition = child->layer()->staticInlinePosition() - containerBlock->borderLogicalLeft();
3214         for (auto current = child->parent(); current && current != containerBlock; current = current->container()) {
3215             if (is<RenderBox>(*current)) {
3216                 staticPosition += downcast<RenderBox>(*current).logicalLeft();
3217                 if (region && is<RenderBlock>(*current)) {
3218                     const RenderBlock& currentBlock = downcast<RenderBlock>(*current);
3219                     region = currentBlock.clampToStartAndEndRegions(region);
3220                     RenderBoxRegionInfo* boxInfo = currentBlock.renderBoxRegionInfo(region);
3221                     if (boxInfo)
3222                         staticPosition += boxInfo->logicalLeft();
3223                 }
3224             }
3225         }
3226         logicalLeft.setValue(Fixed, staticPosition);
3227     } else {
3228         RenderBox& enclosingBox = child->parent()->enclosingBox();
3229         LayoutUnit staticPosition = child->layer()->staticInlinePosition() + containerLogicalWidth + containerBlock->borderLogicalLeft();
3230         for (RenderElement* current = &enclosingBox; current; current = current->container()) {
3231             if (is<RenderBox>(*current)) {
3232                 if (current != containerBlock)
3233                     staticPosition -= downcast<RenderBox>(*current).logicalLeft();
3234                 if (current == &enclosingBox)
3235                     staticPosition -= enclosingBox.logicalWidth();
3236                 if (region && is<RenderBlock>(*current)) {
3237                     const RenderBlock& currentBlock = downcast<RenderBlock>(*current);
3238                     region = currentBlock.clampToStartAndEndRegions(region);
3239                     RenderBoxRegionInfo* boxInfo = currentBlock.renderBoxRegionInfo(region);
3240                     if (boxInfo) {
3241                         if (current != containerBlock)
3242                             staticPosition -= currentBlock.logicalWidth() - (boxInfo->logicalLeft() + boxInfo->logicalWidth());
3243                         if (current == &enclosingBox)
3244                             staticPosition += enclosingBox.logicalWidth() - boxInfo->logicalWidth();
3245                     }
3246                 }
3247             }
3248             if (current == containerBlock)
3249                 break;
3250         }
3251         logicalRight.setValue(Fixed, staticPosition);
3252     }
3253 }
3254
3255 void RenderBox::computePositionedLogicalWidth(LogicalExtentComputedValues& computedValues, RenderRegion* region) const
3256 {
3257     if (isReplaced()) {
3258         // FIXME: Positioned replaced elements inside a flow thread are not working properly
3259         // with variable width regions (see https://bugs.webkit.org/show_bug.cgi?id=69896 ).
3260         computePositionedLogicalWidthReplaced(computedValues);
3261         return;
3262     }
3263
3264     // QUESTIONS
3265     // FIXME 1: Should we still deal with these the cases of 'left' or 'right' having
3266     // the type 'static' in determining whether to calculate the static distance?
3267     // NOTE: 'static' is not a legal value for 'left' or 'right' as of CSS 2.1.
3268
3269     // FIXME 2: Can perhaps optimize out cases when max-width/min-width are greater
3270     // than or less than the computed width().  Be careful of box-sizing and
3271     // percentage issues.
3272
3273     // The following is based off of the W3C Working Draft from April 11, 2006 of
3274     // CSS 2.1: Section 10.3.7 "Absolutely positioned, non-replaced elements"
3275     // <http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width>
3276     // (block-style-comments in this function and in computePositionedLogicalWidthUsing()
3277     // correspond to text from the spec)
3278
3279
3280     // We don't use containingBlock(), since we may be positioned by an enclosing
3281     // relative positioned inline.
3282     const RenderBoxModelObject* containerBlock = downcast<RenderBoxModelObject>(container());
3283
3284     const LayoutUnit containerLogicalWidth = containingBlockLogicalWidthForPositioned(containerBlock, region);
3285
3286     // Use the container block's direction except when calculating the static distance
3287     // This conforms with the reference results for abspos-replaced-width-margin-000.htm
3288     // of the CSS 2.1 test suite
3289     TextDirection containerDirection = containerBlock->style().direction();
3290
3291     bool isHorizontal = isHorizontalWritingMode();
3292     const LayoutUnit bordersPlusPadding = borderAndPaddingLogicalWidth();
3293     const Length marginLogicalLeft = isHorizontal ? style().marginLeft() : style().marginTop();
3294     const Length marginLogicalRight = isHorizontal ? style().marginRight() : style().marginBottom();
3295
3296     Length logicalLeftLength = style().logicalLeft();
3297     Length logicalRightLength = style().logicalRight();
3298
3299     /*---------------------------------------------------------------------------*\
3300      * For the purposes of this section and the next, the term "static position"
3301      * (of an element) refers, roughly, to the position an element would have had
3302      * in the normal flow. More precisely:
3303      *
3304      * * The static position for 'left' is the distance from the left edge of the
3305      *   containing block to the left margin edge of a hypothetical box that would
3306      *   have been the first box of the element if its 'position' property had
3307      *   been 'static' and 'float' had been 'none'. The value is negative if the
3308      *   hypothetical box is to the left of the containing block.
3309      * * The static position for 'right' is the distance from the right edge of the
3310      *   containing block to the right margin edge of the same hypothetical box as
3311      *   above. The value is positive if the hypothetical box is to the left of the
3312      *   containing block's edge.
3313      *
3314      * But rather than actually calculating the dimensions of that hypothetical box,
3315      * user agents are free to make a guess at its probable position.
3316      *
3317      * For the purposes of calculating the static position, the containing block of
3318      * fixed positioned elements is the initial containing block instead of the
3319      * viewport, and all scrollable boxes should be assumed to be scrolled to their
3320      * origin.
3321     \*---------------------------------------------------------------------------*/
3322
3323     // see FIXME 1
3324     // Calculate the static distance if needed.
3325     computeInlineStaticDistance(logicalLeftLength, logicalRightLength, this, containerBlock, containerLogicalWidth, region);
3326
3327     // Calculate constraint equation values for 'width' case.
3328     computePositionedLogicalWidthUsing(style().logicalWidth(), containerBlock, containerDirection,
3329                                        containerLogicalWidth, bordersPlusPadding,
3330                                        logicalLeftLength, logicalRightLength, marginLogicalLeft, marginLogicalRight,
3331                                        computedValues);
3332
3333     // Calculate constraint equation values for 'max-width' case.
3334     if (!style().logicalMaxWidth().isUndefined()) {
3335         LogicalExtentComputedValues maxValues;