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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2000 Dirk Mueller (mueller (at) kde.org)
      5  *           (C) 2004 Allan Sandfeld Jensen (kde (at) carewolf.com)
      6  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
      7  * Copyright (C) 2009 Google Inc. All rights reserved.
      8  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
      9  *
     10  * This library is free software; you can redistribute it and/or
     11  * modify it under the terms of the GNU Library General Public
     12  * License as published by the Free Software Foundation; either
     13  * version 2 of the License, or (at your option) any later version.
     14  *
     15  * This library is distributed in the hope that it will be useful,
     16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     18  * Library General Public License for more details.
     19  *
     20  * You should have received a copy of the GNU Library General Public License
     21  * along with this library; see the file COPYING.LIB.  If not, write to
     22  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     23  * Boston, MA 02110-1301, USA.
     24  *
     25  */
     26 
     27 #include "config.h"
     28 #include "RenderObject.h"
     29 
     30 #include "AXObjectCache.h"
     31 #include "CSSStyleSelector.h"
     32 #include "Chrome.h"
     33 #include "ContentData.h"
     34 #include "CursorList.h"
     35 #include "DashArray.h"
     36 #include "EditingBoundary.h"
     37 #include "FloatQuad.h"
     38 #include "Frame.h"
     39 #include "FrameView.h"
     40 #include "GraphicsContext.h"
     41 #include "HTMLNames.h"
     42 #include "HitTestResult.h"
     43 #include "Page.h"
     44 #include "RenderArena.h"
     45 #include "RenderCounter.h"
     46 #include "RenderFlexibleBox.h"
     47 #include "RenderImage.h"
     48 #include "RenderImageResourceStyleImage.h"
     49 #include "RenderInline.h"
     50 #include "RenderLayer.h"
     51 #include "RenderListItem.h"
     52 #include "RenderRuby.h"
     53 #include "RenderRubyText.h"
     54 #include "RenderTableCell.h"
     55 #include "RenderTableCol.h"
     56 #include "RenderTableRow.h"
     57 #include "RenderTheme.h"
     58 #include "RenderView.h"
     59 #include "TransformState.h"
     60 #include "htmlediting.h"
     61 #include <algorithm>
     62 #ifdef ANDROID_LAYOUT
     63 #include "Settings.h"
     64 #endif
     65 #include <stdio.h>
     66 #include <wtf/RefCountedLeakCounter.h>
     67 #include <wtf/UnusedParam.h>
     68 
     69 #if USE(ACCELERATED_COMPOSITING)
     70 #include "RenderLayerCompositor.h"
     71 #endif
     72 
     73 #if ENABLE(WML)
     74 #include "WMLNames.h"
     75 #endif
     76 
     77 #if ENABLE(SVG)
     78 #include "RenderSVGResourceContainer.h"
     79 #include "SVGRenderSupport.h"
     80 #endif
     81 
     82 using namespace std;
     83 
     84 namespace WebCore {
     85 
     86 using namespace HTMLNames;
     87 
     88 #ifndef NDEBUG
     89 static void* baseOfRenderObjectBeingDeleted;
     90 #endif
     91 
     92 bool RenderObject::s_affectsParentBlock = false;
     93 
     94 void* RenderObject::operator new(size_t sz, RenderArena* renderArena) throw()
     95 {
     96     return renderArena->allocate(sz);
     97 }
     98 
     99 void RenderObject::operator delete(void* ptr, size_t sz)
    100 {
    101     ASSERT(baseOfRenderObjectBeingDeleted == ptr);
    102 
    103     // Stash size where destroy can find it.
    104     *(size_t *)ptr = sz;
    105 }
    106 
    107 RenderObject* RenderObject::createObject(Node* node, RenderStyle* style)
    108 {
    109     Document* doc = node->document();
    110     RenderArena* arena = doc->renderArena();
    111 
    112     // Minimal support for content properties replacing an entire element.
    113     // Works only if we have exactly one piece of content and it's a URL.
    114     // Otherwise acts as if we didn't support this feature.
    115     const ContentData* contentData = style->contentData();
    116     if (contentData && !contentData->next() && contentData->isImage() && doc != node) {
    117         RenderImage* image = new (arena) RenderImage(node);
    118         image->setStyle(style);
    119         if (StyleImage* styleImage = contentData->image())
    120             image->setImageResource(RenderImageResourceStyleImage::create(styleImage));
    121         else
    122             image->setImageResource(RenderImageResource::create());
    123         return image;
    124     }
    125 
    126     if (node->hasTagName(rubyTag)) {
    127         if (style->display() == INLINE)
    128             return new (arena) RenderRubyAsInline(node);
    129         else if (style->display() == BLOCK)
    130             return new (arena) RenderRubyAsBlock(node);
    131     }
    132     // treat <rt> as ruby text ONLY if it still has its default treatment of block
    133     if (node->hasTagName(rtTag) && style->display() == BLOCK)
    134         return new (arena) RenderRubyText(node);
    135 
    136     switch (style->display()) {
    137         case NONE:
    138             return 0;
    139         case INLINE:
    140             return new (arena) RenderInline(node);
    141         case BLOCK:
    142         case INLINE_BLOCK:
    143         case RUN_IN:
    144         case COMPACT:
    145             return new (arena) RenderBlock(node);
    146         case LIST_ITEM:
    147             return new (arena) RenderListItem(node);
    148         case TABLE:
    149         case INLINE_TABLE:
    150             return new (arena) RenderTable(node);
    151         case TABLE_ROW_GROUP:
    152         case TABLE_HEADER_GROUP:
    153         case TABLE_FOOTER_GROUP:
    154             return new (arena) RenderTableSection(node);
    155         case TABLE_ROW:
    156             return new (arena) RenderTableRow(node);
    157         case TABLE_COLUMN_GROUP:
    158         case TABLE_COLUMN:
    159             return new (arena) RenderTableCol(node);
    160         case TABLE_CELL:
    161             return new (arena) RenderTableCell(node);
    162         case TABLE_CAPTION:
    163 #if ENABLE(WCSS)
    164         // As per the section 17.1 of the spec WAP-239-WCSS-20011026-a.pdf,
    165         // the marquee box inherits and extends the characteristics of the
    166         // principal block box ([CSS2] section 9.2.1).
    167         case WAP_MARQUEE:
    168 #endif
    169             return new (arena) RenderBlock(node);
    170         case BOX:
    171         case INLINE_BOX:
    172             return new (arena) RenderFlexibleBox(node);
    173     }
    174 
    175     return 0;
    176 }
    177 
    178 #ifndef NDEBUG
    179 static WTF::RefCountedLeakCounter renderObjectCounter("RenderObject");
    180 #endif
    181 
    182 RenderObject::RenderObject(Node* node)
    183     : CachedResourceClient()
    184     , m_style(0)
    185     , m_node(node)
    186     , m_parent(0)
    187     , m_previous(0)
    188     , m_next(0)
    189 #ifndef NDEBUG
    190     , m_hasAXObject(false)
    191     , m_setNeedsLayoutForbidden(false)
    192 #endif
    193     , m_needsLayout(false)
    194     , m_needsPositionedMovementLayout(false)
    195     , m_normalChildNeedsLayout(false)
    196     , m_posChildNeedsLayout(false)
    197     , m_needsSimplifiedNormalFlowLayout(false)
    198     , m_preferredLogicalWidthsDirty(false)
    199     , m_floating(false)
    200     , m_positioned(false)
    201     , m_relPositioned(false)
    202     , m_paintBackground(false)
    203     , m_isAnonymous(node == node->document())
    204     , m_isText(false)
    205     , m_isBox(false)
    206     , m_inline(true)
    207     , m_replaced(false)
    208     , m_horizontalWritingMode(true)
    209     , m_isDragging(false)
    210     , m_hasLayer(false)
    211     , m_hasOverflowClip(false)
    212     , m_hasTransform(false)
    213     , m_hasReflection(false)
    214     , m_hasOverrideSize(false)
    215     , m_hasCounterNodeMap(false)
    216     , m_everHadLayout(false)
    217     , m_childrenInline(false)
    218     , m_marginBeforeQuirk(false)
    219     , m_marginAfterQuirk(false)
    220     , m_hasMarkupTruncation(false)
    221     , m_selectionState(SelectionNone)
    222     , m_hasColumns(false)
    223 {
    224 #ifndef NDEBUG
    225     renderObjectCounter.increment();
    226 #endif
    227     ASSERT(node);
    228 }
    229 
    230 RenderObject::~RenderObject()
    231 {
    232     ASSERT(!node() || documentBeingDestroyed() || !frame()->view() || frame()->view()->layoutRoot() != this);
    233 #ifndef NDEBUG
    234     ASSERT(!m_hasAXObject);
    235     renderObjectCounter.decrement();
    236 #endif
    237 }
    238 
    239 RenderTheme* RenderObject::theme() const
    240 {
    241     ASSERT(document()->page());
    242 
    243     return document()->page()->theme();
    244 }
    245 
    246 bool RenderObject::isDescendantOf(const RenderObject* obj) const
    247 {
    248     for (const RenderObject* r = this; r; r = r->m_parent) {
    249         if (r == obj)
    250             return true;
    251     }
    252     return false;
    253 }
    254 
    255 bool RenderObject::isBody() const
    256 {
    257     return node() && node()->hasTagName(bodyTag);
    258 }
    259 
    260 bool RenderObject::isHR() const
    261 {
    262     return node() && node()->hasTagName(hrTag);
    263 }
    264 
    265 bool RenderObject::isLegend() const
    266 {
    267     return node() && (node()->hasTagName(legendTag)
    268 #if ENABLE(WML)
    269                       || node()->hasTagName(WMLNames::insertedLegendTag)
    270 #endif
    271                      );
    272 }
    273 
    274 bool RenderObject::isHTMLMarquee() const
    275 {
    276     return node() && node()->renderer() == this && node()->hasTagName(marqueeTag);
    277 }
    278 
    279 void RenderObject::addChild(RenderObject* newChild, RenderObject* beforeChild)
    280 {
    281     RenderObjectChildList* children = virtualChildren();
    282     ASSERT(children);
    283     if (!children)
    284         return;
    285 
    286     bool needsTable = false;
    287 
    288     if (newChild->isTableCol() && newChild->style()->display() == TABLE_COLUMN_GROUP)
    289         needsTable = !isTable();
    290     else if (newChild->isRenderBlock() && newChild->style()->display() == TABLE_CAPTION)
    291         needsTable = !isTable();
    292     else if (newChild->isTableSection())
    293         needsTable = !isTable();
    294     else if (newChild->isTableRow())
    295         needsTable = !isTableSection();
    296     else if (newChild->isTableCell()) {
    297         needsTable = !isTableRow();
    298         // I'm not 100% sure this is the best way to fix this, but without this
    299         // change we recurse infinitely when trying to render the CSS2 test page:
    300         // http://www.bath.ac.uk/%7Epy8ieh/internet/eviltests/htmlbodyheadrendering2.html.
    301         // See Radar 2925291.
    302         if (needsTable && isTableCell() && !children->firstChild() && !newChild->isTableCell())
    303             needsTable = false;
    304     }
    305 
    306     if (needsTable) {
    307         RenderTable* table;
    308         RenderObject* afterChild = beforeChild ? beforeChild->previousSibling() : children->lastChild();
    309         if (afterChild && afterChild->isAnonymous() && afterChild->isTable())
    310             table = toRenderTable(afterChild);
    311         else {
    312             table = new (renderArena()) RenderTable(document() /* is anonymous */);
    313             RefPtr<RenderStyle> newStyle = RenderStyle::create();
    314             newStyle->inheritFrom(style());
    315             newStyle->setDisplay(TABLE);
    316             table->setStyle(newStyle.release());
    317             addChild(table, beforeChild);
    318         }
    319         table->addChild(newChild);
    320     } else {
    321         // Just add it...
    322         children->insertChildNode(this, newChild, beforeChild);
    323     }
    324     if (newChild->isText() && newChild->style()->textTransform() == CAPITALIZE) {
    325         RefPtr<StringImpl> textToTransform = toRenderText(newChild)->originalText();
    326         if (textToTransform)
    327             toRenderText(newChild)->setText(textToTransform.release(), true);
    328     }
    329 }
    330 
    331 void RenderObject::removeChild(RenderObject* oldChild)
    332 {
    333     RenderObjectChildList* children = virtualChildren();
    334     ASSERT(children);
    335     if (!children)
    336         return;
    337 
    338     // We do this here instead of in removeChildNode, since the only extremely low-level uses of remove/appendChildNode
    339     // cannot affect the positioned object list, and the floating object list is irrelevant (since the list gets cleared on
    340     // layout anyway).
    341     if (oldChild->isFloatingOrPositioned())
    342         toRenderBox(oldChild)->removeFloatingOrPositionedChildFromBlockLists();
    343 
    344     children->removeChildNode(this, oldChild);
    345 }
    346 
    347 RenderObject* RenderObject::nextInPreOrder() const
    348 {
    349     if (RenderObject* o = firstChild())
    350         return o;
    351 
    352     return nextInPreOrderAfterChildren();
    353 }
    354 
    355 RenderObject* RenderObject::nextInPreOrderAfterChildren() const
    356 {
    357     RenderObject* o;
    358     if (!(o = nextSibling())) {
    359         o = parent();
    360         while (o && !o->nextSibling())
    361             o = o->parent();
    362         if (o)
    363             o = o->nextSibling();
    364     }
    365 
    366     return o;
    367 }
    368 
    369 RenderObject* RenderObject::nextInPreOrder(const RenderObject* stayWithin) const
    370 {
    371     if (RenderObject* o = firstChild())
    372         return o;
    373 
    374     return nextInPreOrderAfterChildren(stayWithin);
    375 }
    376 
    377 RenderObject* RenderObject::nextInPreOrderAfterChildren(const RenderObject* stayWithin) const
    378 {
    379     if (this == stayWithin)
    380         return 0;
    381 
    382     const RenderObject* current = this;
    383     RenderObject* next;
    384     while (!(next = current->nextSibling())) {
    385         current = current->parent();
    386         if (!current || current == stayWithin)
    387             return 0;
    388     }
    389     return next;
    390 }
    391 
    392 RenderObject* RenderObject::previousInPreOrder() const
    393 {
    394     if (RenderObject* o = previousSibling()) {
    395         while (o->lastChild())
    396             o = o->lastChild();
    397         return o;
    398     }
    399 
    400     return parent();
    401 }
    402 
    403 RenderObject* RenderObject::childAt(unsigned index) const
    404 {
    405     RenderObject* child = firstChild();
    406     for (unsigned i = 0; child && i < index; i++)
    407         child = child->nextSibling();
    408     return child;
    409 }
    410 
    411 RenderObject* RenderObject::firstLeafChild() const
    412 {
    413     RenderObject* r = firstChild();
    414     while (r) {
    415         RenderObject* n = 0;
    416         n = r->firstChild();
    417         if (!n)
    418             break;
    419         r = n;
    420     }
    421     return r;
    422 }
    423 
    424 RenderObject* RenderObject::lastLeafChild() const
    425 {
    426     RenderObject* r = lastChild();
    427     while (r) {
    428         RenderObject* n = 0;
    429         n = r->lastChild();
    430         if (!n)
    431             break;
    432         r = n;
    433     }
    434     return r;
    435 }
    436 
    437 static void addLayers(RenderObject* obj, RenderLayer* parentLayer, RenderObject*& newObject,
    438                       RenderLayer*& beforeChild)
    439 {
    440     if (obj->hasLayer()) {
    441         if (!beforeChild && newObject) {
    442             // We need to figure out the layer that follows newObject.  We only do
    443             // this the first time we find a child layer, and then we update the
    444             // pointer values for newObject and beforeChild used by everyone else.
    445             beforeChild = newObject->parent()->findNextLayer(parentLayer, newObject);
    446             newObject = 0;
    447         }
    448         parentLayer->addChild(toRenderBoxModelObject(obj)->layer(), beforeChild);
    449         return;
    450     }
    451 
    452     for (RenderObject* curr = obj->firstChild(); curr; curr = curr->nextSibling())
    453         addLayers(curr, parentLayer, newObject, beforeChild);
    454 }
    455 
    456 void RenderObject::addLayers(RenderLayer* parentLayer, RenderObject* newObject)
    457 {
    458     if (!parentLayer)
    459         return;
    460 
    461     RenderObject* object = newObject;
    462     RenderLayer* beforeChild = 0;
    463     WebCore::addLayers(this, parentLayer, object, beforeChild);
    464 }
    465 
    466 void RenderObject::removeLayers(RenderLayer* parentLayer)
    467 {
    468     if (!parentLayer)
    469         return;
    470 
    471     if (hasLayer()) {
    472         parentLayer->removeChild(toRenderBoxModelObject(this)->layer());
    473         return;
    474     }
    475 
    476     for (RenderObject* curr = firstChild(); curr; curr = curr->nextSibling())
    477         curr->removeLayers(parentLayer);
    478 }
    479 
    480 void RenderObject::moveLayers(RenderLayer* oldParent, RenderLayer* newParent)
    481 {
    482     if (!newParent)
    483         return;
    484 
    485     if (hasLayer()) {
    486         RenderLayer* layer = toRenderBoxModelObject(this)->layer();
    487         ASSERT(oldParent == layer->parent());
    488         if (oldParent)
    489             oldParent->removeChild(layer);
    490         newParent->addChild(layer);
    491         return;
    492     }
    493 
    494     for (RenderObject* curr = firstChild(); curr; curr = curr->nextSibling())
    495         curr->moveLayers(oldParent, newParent);
    496 }
    497 
    498 RenderLayer* RenderObject::findNextLayer(RenderLayer* parentLayer, RenderObject* startPoint,
    499                                          bool checkParent)
    500 {
    501     // Error check the parent layer passed in.  If it's null, we can't find anything.
    502     if (!parentLayer)
    503         return 0;
    504 
    505     // Step 1: If our layer is a child of the desired parent, then return our layer.
    506     RenderLayer* ourLayer = hasLayer() ? toRenderBoxModelObject(this)->layer() : 0;
    507     if (ourLayer && ourLayer->parent() == parentLayer)
    508         return ourLayer;
    509 
    510     // Step 2: If we don't have a layer, or our layer is the desired parent, then descend
    511     // into our siblings trying to find the next layer whose parent is the desired parent.
    512     if (!ourLayer || ourLayer == parentLayer) {
    513         for (RenderObject* curr = startPoint ? startPoint->nextSibling() : firstChild();
    514              curr; curr = curr->nextSibling()) {
    515             RenderLayer* nextLayer = curr->findNextLayer(parentLayer, 0, false);
    516             if (nextLayer)
    517                 return nextLayer;
    518         }
    519     }
    520 
    521     // Step 3: If our layer is the desired parent layer, then we're finished.  We didn't
    522     // find anything.
    523     if (parentLayer == ourLayer)
    524         return 0;
    525 
    526     // Step 4: If |checkParent| is set, climb up to our parent and check its siblings that
    527     // follow us to see if we can locate a layer.
    528     if (checkParent && parent())
    529         return parent()->findNextLayer(parentLayer, this, true);
    530 
    531     return 0;
    532 }
    533 
    534 RenderLayer* RenderObject::enclosingLayer() const
    535 {
    536     const RenderObject* curr = this;
    537     while (curr) {
    538         RenderLayer* layer = curr->hasLayer() ? toRenderBoxModelObject(curr)->layer() : 0;
    539         if (layer)
    540             return layer;
    541         curr = curr->parent();
    542     }
    543     return 0;
    544 }
    545 
    546 RenderBox* RenderObject::enclosingBox() const
    547 {
    548     RenderObject* curr = const_cast<RenderObject*>(this);
    549     while (curr) {
    550         if (curr->isBox())
    551             return toRenderBox(curr);
    552         curr = curr->parent();
    553     }
    554 
    555     ASSERT_NOT_REACHED();
    556     return 0;
    557 }
    558 
    559 RenderBoxModelObject* RenderObject::enclosingBoxModelObject() const
    560 {
    561     RenderObject* curr = const_cast<RenderObject*>(this);
    562     while (curr) {
    563         if (curr->isBoxModelObject())
    564             return toRenderBoxModelObject(curr);
    565         curr = curr->parent();
    566     }
    567 
    568     ASSERT_NOT_REACHED();
    569     return 0;
    570 }
    571 
    572 RenderBlock* RenderObject::firstLineBlock() const
    573 {
    574     return 0;
    575 }
    576 
    577 void RenderObject::setPreferredLogicalWidthsDirty(bool b, bool markParents)
    578 {
    579     bool alreadyDirty = m_preferredLogicalWidthsDirty;
    580     m_preferredLogicalWidthsDirty = b;
    581     if (b && !alreadyDirty && markParents && (isText() || (style()->position() != FixedPosition && style()->position() != AbsolutePosition)))
    582         invalidateContainerPreferredLogicalWidths();
    583 }
    584 
    585 void RenderObject::invalidateContainerPreferredLogicalWidths()
    586 {
    587     // In order to avoid pathological behavior when inlines are deeply nested, we do include them
    588     // in the chain that we mark dirty (even though they're kind of irrelevant).
    589     RenderObject* o = isTableCell() ? containingBlock() : container();
    590     while (o && !o->m_preferredLogicalWidthsDirty) {
    591         // Don't invalidate the outermost object of an unrooted subtree. That object will be
    592         // invalidated when the subtree is added to the document.
    593         RenderObject* container = o->isTableCell() ? o->containingBlock() : o->container();
    594         if (!container && !o->isRenderView())
    595             break;
    596 
    597         o->m_preferredLogicalWidthsDirty = true;
    598         if (o->style()->position() == FixedPosition || o->style()->position() == AbsolutePosition)
    599             // A positioned object has no effect on the min/max width of its containing block ever.
    600             // We can optimize this case and not go up any further.
    601             break;
    602         o = container;
    603     }
    604 }
    605 
    606 void RenderObject::setLayerNeedsFullRepaint()
    607 {
    608     ASSERT(hasLayer());
    609     toRenderBoxModelObject(this)->layer()->setNeedsFullRepaint(true);
    610 }
    611 
    612 RenderBlock* RenderObject::containingBlock() const
    613 {
    614     if (isTableCell()) {
    615         const RenderTableCell* cell = toRenderTableCell(this);
    616         if (parent() && cell->section())
    617             return cell->table();
    618         return 0;
    619     }
    620 
    621     if (isRenderView())
    622         return const_cast<RenderView*>(toRenderView(this));
    623 
    624     RenderObject* o = parent();
    625     if (!isText() && m_style->position() == FixedPosition) {
    626         while (o && !o->isRenderView() && !(o->hasTransform() && o->isRenderBlock()))
    627             o = o->parent();
    628     } else if (!isText() && m_style->position() == AbsolutePosition) {
    629         while (o && (o->style()->position() == StaticPosition || (o->isInline() && !o->isReplaced())) && !o->isRenderView() && !(o->hasTransform() && o->isRenderBlock())) {
    630             // For relpositioned inlines, we return the nearest enclosing block.  We don't try
    631             // to return the inline itself.  This allows us to avoid having a positioned objects
    632             // list in all RenderInlines and lets us return a strongly-typed RenderBlock* result
    633             // from this method.  The container() method can actually be used to obtain the
    634             // inline directly.
    635             if (o->style()->position() == RelativePosition && o->isInline() && !o->isReplaced())
    636                 return o->containingBlock();
    637 #if ENABLE(SVG)
    638             if (o->isSVGForeignObject()) //foreignObject is the containing block for contents inside it
    639                 break;
    640 #endif
    641 
    642             o = o->parent();
    643         }
    644     } else {
    645         while (o && ((o->isInline() && !o->isReplaced()) || o->isTableRow() || o->isTableSection()
    646                      || o->isTableCol() || o->isFrameSet() || o->isMedia()
    647 #if ENABLE(SVG)
    648                      || o->isSVGContainer() || o->isSVGRoot()
    649 #endif
    650                      ))
    651             o = o->parent();
    652     }
    653 
    654     if (!o || !o->isRenderBlock())
    655         return 0; // This can still happen in case of an orphaned tree
    656 
    657     return toRenderBlock(o);
    658 }
    659 
    660 static bool mustRepaintFillLayers(const RenderObject* renderer, const FillLayer* layer)
    661 {
    662     // Nobody will use multiple layers without wanting fancy positioning.
    663     if (layer->next())
    664         return true;
    665 
    666     // Make sure we have a valid image.
    667     StyleImage* img = layer->image();
    668     if (!img || !img->canRender(renderer->style()->effectiveZoom()))
    669         return false;
    670 
    671     if (!layer->xPosition().isZero() || !layer->yPosition().isZero())
    672         return true;
    673 
    674     if (layer->size().type == SizeLength) {
    675         if (layer->size().size.width().isPercent() || layer->size().size.height().isPercent())
    676             return true;
    677     } else if (layer->size().type == Contain || layer->size().type == Cover || img->usesImageContainerSize())
    678         return true;
    679 
    680     return false;
    681 }
    682 
    683 bool RenderObject::mustRepaintBackgroundOrBorder() const
    684 {
    685     if (hasMask() && mustRepaintFillLayers(this, style()->maskLayers()))
    686         return true;
    687 
    688     // If we don't have a background/border/mask, then nothing to do.
    689     if (!hasBoxDecorations())
    690         return false;
    691 
    692     if (mustRepaintFillLayers(this, style()->backgroundLayers()))
    693         return true;
    694 
    695     // Our fill layers are ok.  Let's check border.
    696     if (style()->hasBorder()) {
    697         // Border images are not ok.
    698         StyleImage* borderImage = style()->borderImage().image();
    699         bool shouldPaintBorderImage = borderImage && borderImage->canRender(style()->effectiveZoom());
    700 
    701         // If the image hasn't loaded, we're still using the normal border style.
    702         if (shouldPaintBorderImage && borderImage->isLoaded())
    703             return true;
    704     }
    705 
    706     return false;
    707 }
    708 
    709 void RenderObject::drawLineForBoxSide(GraphicsContext* graphicsContext, int x1, int y1, int x2, int y2,
    710                                       BoxSide side, Color color, EBorderStyle style,
    711                                       int adjacentWidth1, int adjacentWidth2, bool antialias)
    712 {
    713     int width = (side == BSTop || side == BSBottom ? y2 - y1 : x2 - x1);
    714 
    715     if (style == DOUBLE && width < 3)
    716         style = SOLID;
    717 
    718     switch (style) {
    719         case BNONE:
    720         case BHIDDEN:
    721             return;
    722         case DOTTED:
    723         case DASHED:
    724             graphicsContext->setStrokeColor(color, m_style->colorSpace());
    725             graphicsContext->setStrokeThickness(width);
    726             graphicsContext->setStrokeStyle(style == DASHED ? DashedStroke : DottedStroke);
    727 
    728             if (width > 0) {
    729                 bool wasAntialiased = graphicsContext->shouldAntialias();
    730                 graphicsContext->setShouldAntialias(antialias);
    731 
    732                 switch (side) {
    733                     case BSBottom:
    734                     case BSTop:
    735                         graphicsContext->drawLine(IntPoint(x1, (y1 + y2) / 2), IntPoint(x2, (y1 + y2) / 2));
    736                         break;
    737                     case BSRight:
    738                     case BSLeft:
    739                         graphicsContext->drawLine(IntPoint((x1 + x2) / 2, y1), IntPoint((x1 + x2) / 2, y2));
    740                         break;
    741                 }
    742                 graphicsContext->setShouldAntialias(wasAntialiased);
    743             }
    744             break;
    745         case DOUBLE: {
    746             int third = (width + 1) / 3;
    747 
    748             if (adjacentWidth1 == 0 && adjacentWidth2 == 0) {
    749                 graphicsContext->setStrokeStyle(NoStroke);
    750                 graphicsContext->setFillColor(color, m_style->colorSpace());
    751 
    752                 bool wasAntialiased = graphicsContext->shouldAntialias();
    753                 graphicsContext->setShouldAntialias(antialias);
    754 
    755                 switch (side) {
    756                     case BSTop:
    757                     case BSBottom:
    758                         graphicsContext->drawRect(IntRect(x1, y1, x2 - x1, third));
    759                         graphicsContext->drawRect(IntRect(x1, y2 - third, x2 - x1, third));
    760                         break;
    761                     case BSLeft:
    762                         graphicsContext->drawRect(IntRect(x1, y1 + 1, third, y2 - y1 - 1));
    763                         graphicsContext->drawRect(IntRect(x2 - third, y1 + 1, third, y2 - y1 - 1));
    764                         break;
    765                     case BSRight:
    766                         graphicsContext->drawRect(IntRect(x1, y1 + 1, third, y2 - y1 - 1));
    767                         graphicsContext->drawRect(IntRect(x2 - third, y1 + 1, third, y2 - y1 - 1));
    768                         break;
    769                 }
    770 
    771                 graphicsContext->setShouldAntialias(wasAntialiased);
    772             } else {
    773                 int adjacent1BigThird = ((adjacentWidth1 > 0) ? adjacentWidth1 + 1 : adjacentWidth1 - 1) / 3;
    774                 int adjacent2BigThird = ((adjacentWidth2 > 0) ? adjacentWidth2 + 1 : adjacentWidth2 - 1) / 3;
    775 
    776                 switch (side) {
    777                     case BSTop:
    778                         drawLineForBoxSide(graphicsContext, x1 + max((-adjacentWidth1 * 2 + 1) / 3, 0),
    779                                    y1, x2 - max((-adjacentWidth2 * 2 + 1) / 3, 0), y1 + third,
    780                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    781                         drawLineForBoxSide(graphicsContext, x1 + max((adjacentWidth1 * 2 + 1) / 3, 0),
    782                                    y2 - third, x2 - max((adjacentWidth2 * 2 + 1) / 3, 0), y2,
    783                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    784                         break;
    785                     case BSLeft:
    786                         drawLineForBoxSide(graphicsContext, x1, y1 + max((-adjacentWidth1 * 2 + 1) / 3, 0),
    787                                    x1 + third, y2 - max((-adjacentWidth2 * 2 + 1) / 3, 0),
    788                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    789                         drawLineForBoxSide(graphicsContext, x2 - third, y1 + max((adjacentWidth1 * 2 + 1) / 3, 0),
    790                                    x2, y2 - max((adjacentWidth2 * 2 + 1) / 3, 0),
    791                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    792                         break;
    793                     case BSBottom:
    794                         drawLineForBoxSide(graphicsContext, x1 + max((adjacentWidth1 * 2 + 1) / 3, 0),
    795                                    y1, x2 - max((adjacentWidth2 * 2 + 1) / 3, 0), y1 + third,
    796                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    797                         drawLineForBoxSide(graphicsContext, x1 + max((-adjacentWidth1 * 2 + 1) / 3, 0),
    798                                    y2 - third, x2 - max((-adjacentWidth2 * 2 + 1) / 3, 0), y2,
    799                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    800                         break;
    801                     case BSRight:
    802                         drawLineForBoxSide(graphicsContext, x1, y1 + max((adjacentWidth1 * 2 + 1) / 3, 0),
    803                                    x1 + third, y2 - max((adjacentWidth2 * 2 + 1) / 3, 0),
    804                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    805                         drawLineForBoxSide(graphicsContext, x2 - third, y1 + max((-adjacentWidth1 * 2 + 1) / 3, 0),
    806                                    x2, y2 - max((-adjacentWidth2 * 2 + 1) / 3, 0),
    807                                    side, color, SOLID, adjacent1BigThird, adjacent2BigThird, antialias);
    808                         break;
    809                     default:
    810                         break;
    811                 }
    812             }
    813             break;
    814         }
    815         case RIDGE:
    816         case GROOVE: {
    817             EBorderStyle s1;
    818             EBorderStyle s2;
    819             if (style == GROOVE) {
    820                 s1 = INSET;
    821                 s2 = OUTSET;
    822             } else {
    823                 s1 = OUTSET;
    824                 s2 = INSET;
    825             }
    826 
    827             int adjacent1BigHalf = ((adjacentWidth1 > 0) ? adjacentWidth1 + 1 : adjacentWidth1 - 1) / 2;
    828             int adjacent2BigHalf = ((adjacentWidth2 > 0) ? adjacentWidth2 + 1 : adjacentWidth2 - 1) / 2;
    829 
    830             switch (side) {
    831                 case BSTop:
    832                     drawLineForBoxSide(graphicsContext, x1 + max(-adjacentWidth1, 0) / 2, y1, x2 - max(-adjacentWidth2, 0) / 2, (y1 + y2 + 1) / 2,
    833                                side, color, s1, adjacent1BigHalf, adjacent2BigHalf, antialias);
    834                     drawLineForBoxSide(graphicsContext, x1 + max(adjacentWidth1 + 1, 0) / 2, (y1 + y2 + 1) / 2, x2 - max(adjacentWidth2 + 1, 0) / 2, y2,
    835                                side, color, s2, adjacentWidth1 / 2, adjacentWidth2 / 2, antialias);
    836                     break;
    837                 case BSLeft:
    838                     drawLineForBoxSide(graphicsContext, x1, y1 + max(-adjacentWidth1, 0) / 2, (x1 + x2 + 1) / 2, y2 - max(-adjacentWidth2, 0) / 2,
    839                                side, color, s1, adjacent1BigHalf, adjacent2BigHalf, antialias);
    840                     drawLineForBoxSide(graphicsContext, (x1 + x2 + 1) / 2, y1 + max(adjacentWidth1 + 1, 0) / 2, x2, y2 - max(adjacentWidth2 + 1, 0) / 2,
    841                                side, color, s2, adjacentWidth1 / 2, adjacentWidth2 / 2, antialias);
    842                     break;
    843                 case BSBottom:
    844                     drawLineForBoxSide(graphicsContext, x1 + max(adjacentWidth1, 0) / 2, y1, x2 - max(adjacentWidth2, 0) / 2, (y1 + y2 + 1) / 2,
    845                                side, color, s2, adjacent1BigHalf, adjacent2BigHalf, antialias);
    846                     drawLineForBoxSide(graphicsContext, x1 + max(-adjacentWidth1 + 1, 0) / 2, (y1 + y2 + 1) / 2, x2 - max(-adjacentWidth2 + 1, 0) / 2, y2,
    847                                side, color, s1, adjacentWidth1 / 2, adjacentWidth2 / 2, antialias);
    848                     break;
    849                 case BSRight:
    850                     drawLineForBoxSide(graphicsContext, x1, y1 + max(adjacentWidth1, 0) / 2, (x1 + x2 + 1) / 2, y2 - max(adjacentWidth2, 0) / 2,
    851                                side, color, s2, adjacent1BigHalf, adjacent2BigHalf, antialias);
    852                     drawLineForBoxSide(graphicsContext, (x1 + x2 + 1) / 2, y1 + max(-adjacentWidth1 + 1, 0) / 2, x2, y2 - max(-adjacentWidth2 + 1, 0) / 2,
    853                                side, color, s1, adjacentWidth1 / 2, adjacentWidth2 / 2, antialias);
    854                     break;
    855             }
    856             break;
    857         }
    858         case INSET:
    859             // FIXME: Maybe we should lighten the colors on one side like Firefox.
    860             // https://bugs.webkit.org/show_bug.cgi?id=58608
    861             if (side == BSTop || side == BSLeft)
    862                 color = color.dark();
    863             // fall through
    864         case OUTSET:
    865             if (style == OUTSET && (side == BSBottom || side == BSRight))
    866                 color = color.dark();
    867             // fall through
    868         case SOLID: {
    869             graphicsContext->setStrokeStyle(NoStroke);
    870             graphicsContext->setFillColor(color, m_style->colorSpace());
    871             ASSERT(x2 >= x1);
    872             ASSERT(y2 >= y1);
    873             if (!adjacentWidth1 && !adjacentWidth2) {
    874                 // Turn off antialiasing to match the behavior of drawConvexPolygon();
    875                 // this matters for rects in transformed contexts.
    876                 bool wasAntialiased = graphicsContext->shouldAntialias();
    877                 graphicsContext->setShouldAntialias(antialias);
    878                 graphicsContext->drawRect(IntRect(x1, y1, x2 - x1, y2 - y1));
    879                 graphicsContext->setShouldAntialias(wasAntialiased);
    880                 return;
    881             }
    882             FloatPoint quad[4];
    883             switch (side) {
    884                 case BSTop:
    885                     quad[0] = FloatPoint(x1 + max(-adjacentWidth1, 0), y1);
    886                     quad[1] = FloatPoint(x1 + max(adjacentWidth1, 0), y2);
    887                     quad[2] = FloatPoint(x2 - max(adjacentWidth2, 0), y2);
    888                     quad[3] = FloatPoint(x2 - max(-adjacentWidth2, 0), y1);
    889                     break;
    890                 case BSBottom:
    891                     quad[0] = FloatPoint(x1 + max(adjacentWidth1, 0), y1);
    892                     quad[1] = FloatPoint(x1 + max(-adjacentWidth1, 0), y2);
    893                     quad[2] = FloatPoint(x2 - max(-adjacentWidth2, 0), y2);
    894                     quad[3] = FloatPoint(x2 - max(adjacentWidth2, 0), y1);
    895                     break;
    896                 case BSLeft:
    897                     quad[0] = FloatPoint(x1, y1 + max(-adjacentWidth1, 0));
    898                     quad[1] = FloatPoint(x1, y2 - max(-adjacentWidth2, 0));
    899                     quad[2] = FloatPoint(x2, y2 - max(adjacentWidth2, 0));
    900                     quad[3] = FloatPoint(x2, y1 + max(adjacentWidth1, 0));
    901                     break;
    902                 case BSRight:
    903                     quad[0] = FloatPoint(x1, y1 + max(adjacentWidth1, 0));
    904                     quad[1] = FloatPoint(x1, y2 - max(adjacentWidth2, 0));
    905                     quad[2] = FloatPoint(x2, y2 - max(-adjacentWidth2, 0));
    906                     quad[3] = FloatPoint(x2, y1 + max(-adjacentWidth1, 0));
    907                     break;
    908             }
    909 
    910             graphicsContext->drawConvexPolygon(4, quad, antialias);
    911             break;
    912         }
    913     }
    914 }
    915 
    916 IntRect RenderObject::borderInnerRect(const IntRect& borderRect, unsigned short topWidth, unsigned short bottomWidth, unsigned short leftWidth, unsigned short rightWidth) const
    917 {
    918     return IntRect(
    919             borderRect.x() + leftWidth,
    920             borderRect.y() + topWidth,
    921             borderRect.width() - leftWidth - rightWidth,
    922             borderRect.height() - topWidth - bottomWidth);
    923 }
    924 
    925 #if !HAVE(PATH_BASED_BORDER_RADIUS_DRAWING)
    926 void RenderObject::drawArcForBoxSide(GraphicsContext* graphicsContext, int x, int y, float thickness, const IntSize& radius,
    927                                      int angleStart, int angleSpan, BoxSide s, Color color,
    928                                      EBorderStyle style, bool firstCorner)
    929 {
    930     // FIXME: This function should be removed when all ports implement GraphicsContext::clipConvexPolygon()!!
    931     // At that time, everyone can use RenderObject::drawBoxSideFromPath() instead. This should happen soon.
    932     if ((style == DOUBLE && thickness / 2 < 3) || ((style == RIDGE || style == GROOVE) && thickness / 2 < 2))
    933         style = SOLID;
    934 
    935     switch (style) {
    936         case BNONE:
    937         case BHIDDEN:
    938             return;
    939         case DOTTED:
    940         case DASHED:
    941             graphicsContext->setStrokeColor(color, m_style->colorSpace());
    942             graphicsContext->setStrokeStyle(style == DOTTED ? DottedStroke : DashedStroke);
    943             graphicsContext->setStrokeThickness(thickness);
    944             graphicsContext->strokeArc(IntRect(x, y, radius.width() * 2, radius.height() * 2), angleStart, angleSpan);
    945             break;
    946         case DOUBLE: {
    947             float third = thickness / 3.0f;
    948             float innerThird = (thickness + 1.0f) / 6.0f;
    949             int shiftForInner = static_cast<int>(innerThird * 2.5f);
    950 
    951             int outerY = y;
    952             int outerHeight = radius.height() * 2;
    953             int innerX = x + shiftForInner;
    954             int innerY = y + shiftForInner;
    955             int innerWidth = (radius.width() - shiftForInner) * 2;
    956             int innerHeight = (radius.height() - shiftForInner) * 2;
    957             if (innerThird > 1 && (s == BSTop || (firstCorner && (s == BSLeft || s == BSRight)))) {
    958                 outerHeight += 2;
    959                 innerHeight += 2;
    960             }
    961 
    962             graphicsContext->setStrokeStyle(SolidStroke);
    963             graphicsContext->setStrokeColor(color, m_style->colorSpace());
    964             graphicsContext->setStrokeThickness(third);
    965             graphicsContext->strokeArc(IntRect(x, outerY, radius.width() * 2, outerHeight), angleStart, angleSpan);
    966             graphicsContext->setStrokeThickness(innerThird > 2 ? innerThird - 1 : innerThird);
    967             graphicsContext->strokeArc(IntRect(innerX, innerY, innerWidth, innerHeight), angleStart, angleSpan);
    968             break;
    969         }
    970         case GROOVE:
    971         case RIDGE: {
    972             Color c2;
    973             if ((style == RIDGE && (s == BSTop || s == BSLeft)) ||
    974                     (style == GROOVE && (s == BSBottom || s == BSRight)))
    975                 c2 = color.dark();
    976             else {
    977                 c2 = color;
    978                 color = color.dark();
    979             }
    980 
    981             graphicsContext->setStrokeStyle(SolidStroke);
    982             graphicsContext->setStrokeColor(color, m_style->colorSpace());
    983             graphicsContext->setStrokeThickness(thickness);
    984             graphicsContext->strokeArc(IntRect(x, y, radius.width() * 2, radius.height() * 2), angleStart, angleSpan);
    985 
    986             float halfThickness = (thickness + 1.0f) / 4.0f;
    987             int shiftForInner = static_cast<int>(halfThickness * 1.5f);
    988             graphicsContext->setStrokeColor(c2, m_style->colorSpace());
    989             graphicsContext->setStrokeThickness(halfThickness > 2 ? halfThickness - 1 : halfThickness);
    990             graphicsContext->strokeArc(IntRect(x + shiftForInner, y + shiftForInner, (radius.width() - shiftForInner) * 2,
    991                                        (radius.height() - shiftForInner) * 2), angleStart, angleSpan);
    992             break;
    993         }
    994         case INSET:
    995             if (s == BSTop || s == BSLeft)
    996                 color = color.dark();
    997         case OUTSET:
    998             if (style == OUTSET && (s == BSBottom || s == BSRight))
    999                 color = color.dark();
   1000         case SOLID:
   1001             graphicsContext->setStrokeStyle(SolidStroke);
   1002             graphicsContext->setStrokeColor(color, m_style->colorSpace());
   1003             graphicsContext->setStrokeThickness(thickness);
   1004             graphicsContext->strokeArc(IntRect(x, y, radius.width() * 2, radius.height() * 2), angleStart, angleSpan);
   1005             break;
   1006     }
   1007 }
   1008 #endif
   1009 
   1010 void RenderObject::paintFocusRing(GraphicsContext* context, int tx, int ty, RenderStyle* style)
   1011 {
   1012     Vector<IntRect> focusRingRects;
   1013     addFocusRingRects(focusRingRects, tx, ty);
   1014     if (style->outlineStyleIsAuto())
   1015         context->drawFocusRing(focusRingRects, style->outlineWidth(), style->outlineOffset(), style->visitedDependentColor(CSSPropertyOutlineColor));
   1016     else
   1017         addPDFURLRect(context, unionRect(focusRingRects));
   1018 }
   1019 
   1020 void RenderObject::addPDFURLRect(GraphicsContext* context, const IntRect& rect)
   1021 {
   1022     if (rect.isEmpty())
   1023         return;
   1024     Node* n = node();
   1025     if (!n || !n->isLink() || !n->isElementNode())
   1026         return;
   1027     const AtomicString& href = static_cast<Element*>(n)->getAttribute(hrefAttr);
   1028     if (href.isNull())
   1029         return;
   1030     context->setURLForRect(n->document()->completeURL(href), rect);
   1031 }
   1032 
   1033 void RenderObject::paintOutline(GraphicsContext* graphicsContext, int tx, int ty, int w, int h)
   1034 {
   1035     if (!hasOutline())
   1036         return;
   1037 
   1038     RenderStyle* styleToUse = style();
   1039     int ow = styleToUse->outlineWidth();
   1040     EBorderStyle os = styleToUse->outlineStyle();
   1041 
   1042     Color oc = styleToUse->visitedDependentColor(CSSPropertyOutlineColor);
   1043 
   1044     int offset = styleToUse->outlineOffset();
   1045 
   1046     if (styleToUse->outlineStyleIsAuto() || hasOutlineAnnotation()) {
   1047         if (!theme()->supportsFocusRing(styleToUse)) {
   1048             // Only paint the focus ring by hand if the theme isn't able to draw the focus ring.
   1049             paintFocusRing(graphicsContext, tx, ty, styleToUse);
   1050         }
   1051     }
   1052 
   1053     if (styleToUse->outlineStyleIsAuto() || styleToUse->outlineStyle() == BNONE)
   1054         return;
   1055 
   1056     tx -= offset;
   1057     ty -= offset;
   1058     w += 2 * offset;
   1059     h += 2 * offset;
   1060 
   1061     if (h < 0 || w < 0)
   1062         return;
   1063 
   1064     drawLineForBoxSide(graphicsContext, tx - ow, ty - ow, tx, ty + h + ow, BSLeft, oc, os, ow, ow);
   1065     drawLineForBoxSide(graphicsContext, tx - ow, ty - ow, tx + w + ow, ty, BSTop, oc, os, ow, ow);
   1066     drawLineForBoxSide(graphicsContext, tx + w, ty - ow, tx + w + ow, ty + h + ow, BSRight, oc, os, ow, ow);
   1067     drawLineForBoxSide(graphicsContext, tx - ow, ty + h, tx + w + ow, ty + h + ow, BSBottom, oc, os, ow, ow);
   1068 }
   1069 
   1070 IntRect RenderObject::absoluteBoundingBoxRect(bool useTransforms)
   1071 {
   1072     if (useTransforms) {
   1073         Vector<FloatQuad> quads;
   1074         absoluteQuads(quads);
   1075 
   1076         size_t n = quads.size();
   1077         if (!n)
   1078             return IntRect();
   1079 
   1080         IntRect result = quads[0].enclosingBoundingBox();
   1081         for (size_t i = 1; i < n; ++i)
   1082             result.unite(quads[i].enclosingBoundingBox());
   1083         return result;
   1084     }
   1085 
   1086     FloatPoint absPos = localToAbsolute();
   1087     Vector<IntRect> rects;
   1088     absoluteRects(rects, absPos.x(), absPos.y());
   1089 
   1090     size_t n = rects.size();
   1091     if (!n)
   1092         return IntRect();
   1093 
   1094     IntRect result = rects[0];
   1095     for (size_t i = 1; i < n; ++i)
   1096         result.unite(rects[i]);
   1097     return result;
   1098 }
   1099 
   1100 void RenderObject::absoluteFocusRingQuads(Vector<FloatQuad>& quads)
   1101 {
   1102     Vector<IntRect> rects;
   1103     // FIXME: addFocusRingRects() needs to be passed this transform-unaware
   1104     // localToAbsolute() offset here because RenderInline::addFocusRingRects()
   1105     // implicitly assumes that. This doesn't work correctly with transformed
   1106     // descendants.
   1107     FloatPoint absolutePoint = localToAbsolute();
   1108     addFocusRingRects(rects, absolutePoint.x(), absolutePoint.y());
   1109     size_t count = rects.size();
   1110     for (size_t i = 0; i < count; ++i) {
   1111         IntRect rect = rects[i];
   1112         rect.move(-absolutePoint.x(), -absolutePoint.y());
   1113         quads.append(localToAbsoluteQuad(FloatQuad(rect)));
   1114     }
   1115 }
   1116 
   1117 void RenderObject::addAbsoluteRectForLayer(IntRect& result)
   1118 {
   1119     if (hasLayer())
   1120         result.unite(absoluteBoundingBoxRect());
   1121     for (RenderObject* current = firstChild(); current; current = current->nextSibling())
   1122         current->addAbsoluteRectForLayer(result);
   1123 }
   1124 
   1125 IntRect RenderObject::paintingRootRect(IntRect& topLevelRect)
   1126 {
   1127     IntRect result = absoluteBoundingBoxRect();
   1128     topLevelRect = result;
   1129     for (RenderObject* current = firstChild(); current; current = current->nextSibling())
   1130         current->addAbsoluteRectForLayer(result);
   1131     return result;
   1132 }
   1133 
   1134 void RenderObject::paint(PaintInfo& /*paintInfo*/, int /*tx*/, int /*ty*/)
   1135 {
   1136 }
   1137 
   1138 RenderBoxModelObject* RenderObject::containerForRepaint() const
   1139 {
   1140 #if USE(ACCELERATED_COMPOSITING)
   1141     if (RenderView* v = view()) {
   1142         if (v->usesCompositing()) {
   1143             RenderLayer* compLayer = enclosingLayer()->enclosingCompositingLayer();
   1144             return compLayer ? compLayer->renderer() : 0;
   1145         }
   1146     }
   1147 #endif
   1148     // Do root-relative repaint.
   1149     return 0;
   1150 }
   1151 
   1152 void RenderObject::repaintUsingContainer(RenderBoxModelObject* repaintContainer, const IntRect& r, bool immediate)
   1153 {
   1154     if (!repaintContainer) {
   1155         view()->repaintViewRectangle(r, immediate);
   1156         return;
   1157     }
   1158 
   1159 #if USE(ACCELERATED_COMPOSITING)
   1160     RenderView* v = view();
   1161     if (repaintContainer->isRenderView()) {
   1162         ASSERT(repaintContainer == v);
   1163         if (!v->hasLayer() || !v->layer()->isComposited() || v->layer()->backing()->paintingGoesToWindow()) {
   1164             v->repaintViewRectangle(r, immediate);
   1165             return;
   1166         }
   1167     }
   1168 
   1169     if (v->usesCompositing()) {
   1170         ASSERT(repaintContainer->hasLayer() && repaintContainer->layer()->isComposited());
   1171         repaintContainer->layer()->setBackingNeedsRepaintInRect(r);
   1172     }
   1173 #else
   1174     if (repaintContainer->isRenderView())
   1175         toRenderView(repaintContainer)->repaintViewRectangle(r, immediate);
   1176 #endif
   1177 }
   1178 
   1179 void RenderObject::repaint(bool immediate)
   1180 {
   1181     // Don't repaint if we're unrooted (note that view() still returns the view when unrooted)
   1182     RenderView* view;
   1183     if (!isRooted(&view))
   1184         return;
   1185 
   1186     if (view->printing())
   1187         return; // Don't repaint if we're printing.
   1188 
   1189     RenderBoxModelObject* repaintContainer = containerForRepaint();
   1190     repaintUsingContainer(repaintContainer ? repaintContainer : view, clippedOverflowRectForRepaint(repaintContainer), immediate);
   1191 }
   1192 
   1193 void RenderObject::repaintRectangle(const IntRect& r, bool immediate)
   1194 {
   1195     // Don't repaint if we're unrooted (note that view() still returns the view when unrooted)
   1196     RenderView* view;
   1197     if (!isRooted(&view))
   1198         return;
   1199 
   1200     if (view->printing())
   1201         return; // Don't repaint if we're printing.
   1202 
   1203     IntRect dirtyRect(r);
   1204 
   1205     // FIXME: layoutDelta needs to be applied in parts before/after transforms and
   1206     // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
   1207     dirtyRect.move(view->layoutDelta());
   1208 
   1209     RenderBoxModelObject* repaintContainer = containerForRepaint();
   1210     computeRectForRepaint(repaintContainer, dirtyRect);
   1211     repaintUsingContainer(repaintContainer ? repaintContainer : view, dirtyRect, immediate);
   1212 }
   1213 
   1214 bool RenderObject::repaintAfterLayoutIfNeeded(RenderBoxModelObject* repaintContainer, const IntRect& oldBounds, const IntRect& oldOutlineBox, const IntRect* newBoundsPtr, const IntRect* newOutlineBoxRectPtr)
   1215 {
   1216     RenderView* v = view();
   1217     if (v->printing())
   1218         return false; // Don't repaint if we're printing.
   1219 
   1220     // This ASSERT fails due to animations.  See https://bugs.webkit.org/show_bug.cgi?id=37048
   1221     // ASSERT(!newBoundsPtr || *newBoundsPtr == clippedOverflowRectForRepaint(repaintContainer));
   1222     IntRect newBounds = newBoundsPtr ? *newBoundsPtr : clippedOverflowRectForRepaint(repaintContainer);
   1223     IntRect newOutlineBox;
   1224 
   1225     bool fullRepaint = selfNeedsLayout();
   1226     // Presumably a background or a border exists if border-fit:lines was specified.
   1227     if (!fullRepaint && style()->borderFit() == BorderFitLines)
   1228         fullRepaint = true;
   1229     if (!fullRepaint) {
   1230         // This ASSERT fails due to animations.  See https://bugs.webkit.org/show_bug.cgi?id=37048
   1231         // ASSERT(!newOutlineBoxRectPtr || *newOutlineBoxRectPtr == outlineBoundsForRepaint(repaintContainer));
   1232         newOutlineBox = newOutlineBoxRectPtr ? *newOutlineBoxRectPtr : outlineBoundsForRepaint(repaintContainer);
   1233         if (newOutlineBox.location() != oldOutlineBox.location() || (mustRepaintBackgroundOrBorder() && (newBounds != oldBounds || newOutlineBox != oldOutlineBox)))
   1234             fullRepaint = true;
   1235     }
   1236 
   1237     if (!repaintContainer)
   1238         repaintContainer = v;
   1239 
   1240     if (fullRepaint) {
   1241         repaintUsingContainer(repaintContainer, oldBounds);
   1242         if (newBounds != oldBounds)
   1243             repaintUsingContainer(repaintContainer, newBounds);
   1244         return true;
   1245     }
   1246 
   1247     if (newBounds == oldBounds && newOutlineBox == oldOutlineBox)
   1248         return false;
   1249 
   1250     int deltaLeft = newBounds.x() - oldBounds.x();
   1251     if (deltaLeft > 0)
   1252         repaintUsingContainer(repaintContainer, IntRect(oldBounds.x(), oldBounds.y(), deltaLeft, oldBounds.height()));
   1253     else if (deltaLeft < 0)
   1254         repaintUsingContainer(repaintContainer, IntRect(newBounds.x(), newBounds.y(), -deltaLeft, newBounds.height()));
   1255 
   1256     int deltaRight = newBounds.maxX() - oldBounds.maxX();
   1257     if (deltaRight > 0)
   1258         repaintUsingContainer(repaintContainer, IntRect(oldBounds.maxX(), newBounds.y(), deltaRight, newBounds.height()));
   1259     else if (deltaRight < 0)
   1260         repaintUsingContainer(repaintContainer, IntRect(newBounds.maxX(), oldBounds.y(), -deltaRight, oldBounds.height()));
   1261 
   1262     int deltaTop = newBounds.y() - oldBounds.y();
   1263     if (deltaTop > 0)
   1264         repaintUsingContainer(repaintContainer, IntRect(oldBounds.x(), oldBounds.y(), oldBounds.width(), deltaTop));
   1265     else if (deltaTop < 0)
   1266         repaintUsingContainer(repaintContainer, IntRect(newBounds.x(), newBounds.y(), newBounds.width(), -deltaTop));
   1267 
   1268     int deltaBottom = newBounds.maxY() - oldBounds.maxY();
   1269     if (deltaBottom > 0)
   1270         repaintUsingContainer(repaintContainer, IntRect(newBounds.x(), oldBounds.maxY(), newBounds.width(), deltaBottom));
   1271     else if (deltaBottom < 0)
   1272         repaintUsingContainer(repaintContainer, IntRect(oldBounds.x(), newBounds.maxY(), oldBounds.width(), -deltaBottom));
   1273 
   1274     if (newOutlineBox == oldOutlineBox)
   1275         return false;
   1276 
   1277     // We didn't move, but we did change size.  Invalidate the delta, which will consist of possibly
   1278     // two rectangles (but typically only one).
   1279     RenderStyle* outlineStyle = outlineStyleForRepaint();
   1280     int ow = outlineStyle->outlineSize();
   1281     int width = abs(newOutlineBox.width() - oldOutlineBox.width());
   1282     if (width) {
   1283         int shadowLeft;
   1284         int shadowRight;
   1285         style()->getBoxShadowHorizontalExtent(shadowLeft, shadowRight);
   1286 
   1287         int borderRight = isBox() ? toRenderBox(this)->borderRight() : 0;
   1288         int boxWidth = isBox() ? toRenderBox(this)->width() : 0;
   1289         int borderWidth = max(-outlineStyle->outlineOffset(), max(borderRight, max(style()->borderTopRightRadius().width().calcValue(boxWidth), style()->borderBottomRightRadius().width().calcValue(boxWidth)))) + max(ow, shadowRight);
   1290         IntRect rightRect(newOutlineBox.x() + min(newOutlineBox.width(), oldOutlineBox.width()) - borderWidth,
   1291             newOutlineBox.y(),
   1292             width + borderWidth,
   1293             max(newOutlineBox.height(), oldOutlineBox.height()));
   1294         int right = min(newBounds.maxX(), oldBounds.maxX());
   1295         if (rightRect.x() < right) {
   1296             rightRect.setWidth(min(rightRect.width(), right - rightRect.x()));
   1297             repaintUsingContainer(repaintContainer, rightRect);
   1298         }
   1299     }
   1300     int height = abs(newOutlineBox.height() - oldOutlineBox.height());
   1301     if (height) {
   1302         int shadowTop;
   1303         int shadowBottom;
   1304         style()->getBoxShadowVerticalExtent(shadowTop, shadowBottom);
   1305 
   1306         int borderBottom = isBox() ? toRenderBox(this)->borderBottom() : 0;
   1307         int boxHeight = isBox() ? toRenderBox(this)->height() : 0;
   1308         int borderHeight = max(-outlineStyle->outlineOffset(), max(borderBottom, max(style()->borderBottomLeftRadius().height().calcValue(boxHeight), style()->borderBottomRightRadius().height().calcValue(boxHeight)))) + max(ow, shadowBottom);
   1309         IntRect bottomRect(newOutlineBox.x(),
   1310             min(newOutlineBox.maxY(), oldOutlineBox.maxY()) - borderHeight,
   1311             max(newOutlineBox.width(), oldOutlineBox.width()),
   1312             height + borderHeight);
   1313         int bottom = min(newBounds.maxY(), oldBounds.maxY());
   1314         if (bottomRect.y() < bottom) {
   1315             bottomRect.setHeight(min(bottomRect.height(), bottom - bottomRect.y()));
   1316             repaintUsingContainer(repaintContainer, bottomRect);
   1317         }
   1318     }
   1319     return false;
   1320 }
   1321 
   1322 void RenderObject::repaintDuringLayoutIfMoved(const IntRect&)
   1323 {
   1324 }
   1325 
   1326 void RenderObject::repaintOverhangingFloats(bool)
   1327 {
   1328 }
   1329 
   1330 bool RenderObject::checkForRepaintDuringLayout() const
   1331 {
   1332     // FIXME: <https://bugs.webkit.org/show_bug.cgi?id=20885> It is probably safe to also require
   1333     // m_everHadLayout. Currently, only RenderBlock::layoutBlock() adds this condition. See also
   1334     // <https://bugs.webkit.org/show_bug.cgi?id=15129>.
   1335     return !document()->view()->needsFullRepaint() && !hasLayer();
   1336 }
   1337 
   1338 IntRect RenderObject::rectWithOutlineForRepaint(RenderBoxModelObject* repaintContainer, int outlineWidth)
   1339 {
   1340     IntRect r(clippedOverflowRectForRepaint(repaintContainer));
   1341     r.inflate(outlineWidth);
   1342     return r;
   1343 }
   1344 
   1345 IntRect RenderObject::clippedOverflowRectForRepaint(RenderBoxModelObject*)
   1346 {
   1347     ASSERT_NOT_REACHED();
   1348     return IntRect();
   1349 }
   1350 
   1351 void RenderObject::computeRectForRepaint(RenderBoxModelObject* repaintContainer, IntRect& rect, bool fixed)
   1352 {
   1353     if (repaintContainer == this)
   1354         return;
   1355 
   1356     if (RenderObject* o = parent()) {
   1357         if (o->isBlockFlow()) {
   1358             RenderBlock* cb = toRenderBlock(o);
   1359             if (cb->hasColumns())
   1360                 cb->adjustRectForColumns(rect);
   1361         }
   1362 
   1363         if (o->hasOverflowClip()) {
   1364             // o->height() is inaccurate if we're in the middle of a layout of |o|, so use the
   1365             // layer's size instead.  Even if the layer's size is wrong, the layer itself will repaint
   1366             // anyway if its size does change.
   1367             RenderBox* boxParent = toRenderBox(o);
   1368 
   1369             IntRect repaintRect(rect);
   1370             repaintRect.move(-boxParent->layer()->scrolledContentOffset()); // For overflow:auto/scroll/hidden.
   1371 
   1372             IntRect boxRect(0, 0, boxParent->layer()->width(), boxParent->layer()->height());
   1373             rect = intersection(repaintRect, boxRect);
   1374             if (rect.isEmpty())
   1375                 return;
   1376         }
   1377 
   1378         o->computeRectForRepaint(repaintContainer, rect, fixed);
   1379     }
   1380 }
   1381 
   1382 void RenderObject::dirtyLinesFromChangedChild(RenderObject*)
   1383 {
   1384 }
   1385 
   1386 #ifndef NDEBUG
   1387 
   1388 void RenderObject::showTreeForThis() const
   1389 {
   1390     if (node())
   1391         node()->showTreeForThis();
   1392 }
   1393 
   1394 void RenderObject::showRenderObject() const
   1395 {
   1396     showRenderObject(0);
   1397 }
   1398 
   1399 void RenderObject::showRenderObject(int printedCharacters) const
   1400 {
   1401     // As this function is intended to be used when debugging, the
   1402     // this pointer may be 0.
   1403     if (!this) {
   1404         fputs("(null)\n", stderr);
   1405         return;
   1406     }
   1407 
   1408     printedCharacters += fprintf(stderr, "%s %p", renderName(), this);
   1409 
   1410     if (node()) {
   1411         if (printedCharacters)
   1412             for (; printedCharacters < 39; printedCharacters++)
   1413                 fputc(' ', stderr);
   1414         fputc('\t', stderr);
   1415         node()->showNode();
   1416     } else
   1417         fputc('\n', stderr);
   1418 }
   1419 
   1420 void RenderObject::showRenderTreeAndMark(const RenderObject* markedObject1, const char* markedLabel1, const RenderObject* markedObject2, const char* markedLabel2, int depth) const
   1421 {
   1422     int printedCharacters = 0;
   1423     if (markedObject1 == this && markedLabel1)
   1424         printedCharacters += fprintf(stderr, "%s", markedLabel1);
   1425     if (markedObject2 == this && markedLabel2)
   1426         printedCharacters += fprintf(stderr, "%s", markedLabel2);
   1427     for (; printedCharacters < depth * 2; printedCharacters++)
   1428         fputc(' ', stderr);
   1429 
   1430     showRenderObject(printedCharacters);
   1431     if (!this)
   1432         return;
   1433 
   1434     for (const RenderObject* child = firstChild(); child; child = child->nextSibling())
   1435         child->showRenderTreeAndMark(markedObject1, markedLabel1, markedObject2, markedLabel2, depth + 1);
   1436 }
   1437 
   1438 #endif // NDEBUG
   1439 
   1440 Color RenderObject::selectionBackgroundColor() const
   1441 {
   1442     Color color;
   1443     if (style()->userSelect() != SELECT_NONE) {
   1444         RefPtr<RenderStyle> pseudoStyle = getUncachedPseudoStyle(SELECTION);
   1445         if (pseudoStyle && pseudoStyle->visitedDependentColor(CSSPropertyBackgroundColor).isValid())
   1446             color = pseudoStyle->visitedDependentColor(CSSPropertyBackgroundColor).blendWithWhite();
   1447         else
   1448             color = frame()->selection()->isFocusedAndActive() ?
   1449                     theme()->activeSelectionBackgroundColor() :
   1450                     theme()->inactiveSelectionBackgroundColor();
   1451     }
   1452 
   1453     return color;
   1454 }
   1455 
   1456 Color RenderObject::selectionColor(int colorProperty) const
   1457 {
   1458     Color color;
   1459     // If the element is unselectable, or we are only painting the selection,
   1460     // don't override the foreground color with the selection foreground color.
   1461     if (style()->userSelect() == SELECT_NONE
   1462         || (frame()->view()->paintBehavior() & PaintBehaviorSelectionOnly))
   1463         return color;
   1464 
   1465     if (RefPtr<RenderStyle> pseudoStyle = getUncachedPseudoStyle(SELECTION)) {
   1466         color = pseudoStyle->visitedDependentColor(colorProperty);
   1467         if (!color.isValid())
   1468             color = pseudoStyle->visitedDependentColor(CSSPropertyColor);
   1469     } else
   1470         color = frame()->selection()->isFocusedAndActive() ?
   1471                 theme()->activeSelectionForegroundColor() :
   1472                 theme()->inactiveSelectionForegroundColor();
   1473 
   1474     return color;
   1475 }
   1476 
   1477 Color RenderObject::selectionForegroundColor() const
   1478 {
   1479     return selectionColor(CSSPropertyWebkitTextFillColor);
   1480 }
   1481 
   1482 Color RenderObject::selectionEmphasisMarkColor() const
   1483 {
   1484     return selectionColor(CSSPropertyWebkitTextEmphasisColor);
   1485 }
   1486 
   1487 #if ENABLE(DRAG_SUPPORT)
   1488 Node* RenderObject::draggableNode(bool dhtmlOK, bool uaOK, int x, int y, bool& dhtmlWillDrag) const
   1489 {
   1490     if (!dhtmlOK && !uaOK)
   1491         return 0;
   1492 
   1493     for (const RenderObject* curr = this; curr; curr = curr->parent()) {
   1494         Node* elt = curr->node();
   1495         if (elt && elt->nodeType() == Node::TEXT_NODE) {
   1496             // Since there's no way for the author to address the -webkit-user-drag style for a text node,
   1497             // we use our own judgement.
   1498             if (uaOK && view()->frameView()->frame()->eventHandler()->shouldDragAutoNode(curr->node(), IntPoint(x, y))) {
   1499                 dhtmlWillDrag = false;
   1500                 return curr->node();
   1501             }
   1502             if (elt->canStartSelection())
   1503                 // In this case we have a click in the unselected portion of text.  If this text is
   1504                 // selectable, we want to start the selection process instead of looking for a parent
   1505                 // to try to drag.
   1506                 return 0;
   1507         } else {
   1508             EUserDrag dragMode = curr->style()->userDrag();
   1509             if (dhtmlOK && dragMode == DRAG_ELEMENT) {
   1510                 dhtmlWillDrag = true;
   1511                 return curr->node();
   1512             }
   1513             if (uaOK && dragMode == DRAG_AUTO
   1514                     && view()->frameView()->frame()->eventHandler()->shouldDragAutoNode(curr->node(), IntPoint(x, y))) {
   1515                 dhtmlWillDrag = false;
   1516                 return curr->node();
   1517             }
   1518         }
   1519     }
   1520     return 0;
   1521 }
   1522 #endif // ENABLE(DRAG_SUPPORT)
   1523 
   1524 void RenderObject::selectionStartEnd(int& spos, int& epos) const
   1525 {
   1526     view()->selectionStartEnd(spos, epos);
   1527 }
   1528 
   1529 void RenderObject::handleDynamicFloatPositionChange()
   1530 {
   1531     // We have gone from not affecting the inline status of the parent flow to suddenly
   1532     // having an impact.  See if there is a mismatch between the parent flow's
   1533     // childrenInline() state and our state.
   1534     setInline(style()->isDisplayInlineType());
   1535     if (isInline() != parent()->childrenInline()) {
   1536         if (!isInline())
   1537             toRenderBoxModelObject(parent())->childBecameNonInline(this);
   1538         else {
   1539             // An anonymous block must be made to wrap this inline.
   1540             RenderBlock* block = toRenderBlock(parent())->createAnonymousBlock();
   1541             RenderObjectChildList* childlist = parent()->virtualChildren();
   1542             childlist->insertChildNode(parent(), block, this);
   1543             block->children()->appendChildNode(block, childlist->removeChildNode(parent(), this));
   1544         }
   1545     }
   1546 }
   1547 
   1548 void RenderObject::setAnimatableStyle(PassRefPtr<RenderStyle> style)
   1549 {
   1550     if (!isText() && style)
   1551         setStyle(animation()->updateAnimations(this, style.get()));
   1552     else
   1553         setStyle(style);
   1554 }
   1555 
   1556 StyleDifference RenderObject::adjustStyleDifference(StyleDifference diff, unsigned contextSensitiveProperties) const
   1557 {
   1558 #if USE(ACCELERATED_COMPOSITING)
   1559     // If transform changed, and we are not composited, need to do a layout.
   1560     if (contextSensitiveProperties & ContextSensitivePropertyTransform) {
   1561         // Text nodes share style with their parents but transforms don't apply to them,
   1562         // hence the !isText() check.
   1563         // FIXME: when transforms are taken into account for overflow, we will need to do a layout.
   1564         if (!isText() && (!hasLayer() || !toRenderBoxModelObject(this)->layer()->isComposited())) {
   1565             if (!hasLayer())
   1566                 diff = StyleDifferenceLayout; // FIXME: Do this for now since SimplifiedLayout cannot handle updating floating objects lists.
   1567             else if (diff < StyleDifferenceSimplifiedLayout)
   1568                 diff = StyleDifferenceSimplifiedLayout;
   1569         } else if (diff < StyleDifferenceRecompositeLayer)
   1570             diff = StyleDifferenceRecompositeLayer;
   1571     }
   1572 
   1573     // If opacity changed, and we are not composited, need to repaint (also
   1574     // ignoring text nodes)
   1575     if (contextSensitiveProperties & ContextSensitivePropertyOpacity) {
   1576         if (!isText() && (!hasLayer() || !toRenderBoxModelObject(this)->layer()->isComposited()))
   1577             diff = StyleDifferenceRepaintLayer;
   1578         else if (diff < StyleDifferenceRecompositeLayer)
   1579             diff = StyleDifferenceRecompositeLayer;
   1580     }
   1581 
   1582     // The answer to requiresLayer() for plugins and iframes can change outside of the style system,
   1583     // since it depends on whether we decide to composite these elements. When the layer status of
   1584     // one of these elements changes, we need to force a layout.
   1585     if (diff == StyleDifferenceEqual && style() && isBoxModelObject()) {
   1586         if (hasLayer() != toRenderBoxModelObject(this)->requiresLayer())
   1587             diff = StyleDifferenceLayout;
   1588     }
   1589 #else
   1590     UNUSED_PARAM(contextSensitiveProperties);
   1591 #endif
   1592 
   1593     // If we have no layer(), just treat a RepaintLayer hint as a normal Repaint.
   1594     if (diff == StyleDifferenceRepaintLayer && !hasLayer())
   1595         diff = StyleDifferenceRepaint;
   1596 
   1597     return diff;
   1598 }
   1599 
   1600 void RenderObject::setStyle(PassRefPtr<RenderStyle> style)
   1601 {
   1602     if (m_style == style) {
   1603 #if USE(ACCELERATED_COMPOSITING)
   1604         // We need to run through adjustStyleDifference() for iframes and plugins, so
   1605         // style sharing is disabled for them. That should ensure that we never hit this code path.
   1606         ASSERT(!isRenderIFrame() && !isEmbeddedObject() &&!isApplet());
   1607 #endif
   1608         return;
   1609     }
   1610 
   1611     StyleDifference diff = StyleDifferenceEqual;
   1612     unsigned contextSensitiveProperties = ContextSensitivePropertyNone;
   1613     if (m_style)
   1614         diff = m_style->diff(style.get(), contextSensitiveProperties);
   1615 
   1616     diff = adjustStyleDifference(diff, contextSensitiveProperties);
   1617 
   1618     styleWillChange(diff, style.get());
   1619 
   1620     RefPtr<RenderStyle> oldStyle = m_style.release();
   1621     m_style = style;
   1622 
   1623     updateFillImages(oldStyle ? oldStyle->backgroundLayers() : 0, m_style ? m_style->backgroundLayers() : 0);
   1624     updateFillImages(oldStyle ? oldStyle->maskLayers() : 0, m_style ? m_style->maskLayers() : 0);
   1625 
   1626     updateImage(oldStyle ? oldStyle->borderImage().image() : 0, m_style ? m_style->borderImage().image() : 0);
   1627     updateImage(oldStyle ? oldStyle->maskBoxImage().image() : 0, m_style ? m_style->maskBoxImage().image() : 0);
   1628 
   1629     // We need to ensure that view->maximalOutlineSize() is valid for any repaints that happen
   1630     // during styleDidChange (it's used by clippedOverflowRectForRepaint()).
   1631     if (m_style->outlineWidth() > 0 && m_style->outlineSize() > maximalOutlineSize(PaintPhaseOutline))
   1632         toRenderView(document()->renderer())->setMaximalOutlineSize(m_style->outlineSize());
   1633 
   1634     styleDidChange(diff, oldStyle.get());
   1635 
   1636     if (!m_parent || isText())
   1637         return;
   1638 
   1639     // Now that the layer (if any) has been updated, we need to adjust the diff again,
   1640     // check whether we should layout now, and decide if we need to repaint.
   1641     StyleDifference updatedDiff = adjustStyleDifference(diff, contextSensitiveProperties);
   1642 
   1643     if (diff <= StyleDifferenceLayoutPositionedMovementOnly) {
   1644         if (updatedDiff == StyleDifferenceLayout)
   1645             setNeedsLayoutAndPrefWidthsRecalc();
   1646         else if (updatedDiff == StyleDifferenceLayoutPositionedMovementOnly)
   1647             setNeedsPositionedMovementLayout();
   1648         else if (updatedDiff == StyleDifferenceSimplifiedLayout)
   1649             setNeedsSimplifiedNormalFlowLayout();
   1650     }
   1651 
   1652     if (updatedDiff == StyleDifferenceRepaintLayer || updatedDiff == StyleDifferenceRepaint) {
   1653         // Do a repaint with the new style now, e.g., for example if we go from
   1654         // not having an outline to having an outline.
   1655         repaint();
   1656     }
   1657 }
   1658 
   1659 void RenderObject::setStyleInternal(PassRefPtr<RenderStyle> style)
   1660 {
   1661     m_style = style;
   1662 }
   1663 
   1664 void RenderObject::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
   1665 {
   1666     if (m_style) {
   1667         // If our z-index changes value or our visibility changes,
   1668         // we need to dirty our stacking context's z-order list.
   1669         if (newStyle) {
   1670             bool visibilityChanged = m_style->visibility() != newStyle->visibility()
   1671                 || m_style->zIndex() != newStyle->zIndex()
   1672                 || m_style->hasAutoZIndex() != newStyle->hasAutoZIndex();
   1673 #if ENABLE(DASHBOARD_SUPPORT)
   1674             if (visibilityChanged)
   1675                 document()->setDashboardRegionsDirty(true);
   1676 #endif
   1677             if (visibilityChanged && AXObjectCache::accessibilityEnabled())
   1678                 document()->axObjectCache()->childrenChanged(this);
   1679 
   1680             // Keep layer hierarchy visibility bits up to date if visibility changes.
   1681             if (m_style->visibility() != newStyle->visibility()) {
   1682                 if (RenderLayer* l = enclosingLayer()) {
   1683                     if (newStyle->visibility() == VISIBLE)
   1684                         l->setHasVisibleContent(true);
   1685                     else if (l->hasVisibleContent() && (this == l->renderer() || l->renderer()->style()->visibility() != VISIBLE)) {
   1686                         l->dirtyVisibleContentStatus();
   1687                         if (diff > StyleDifferenceRepaintLayer)
   1688                             repaint();
   1689                     }
   1690                 }
   1691             }
   1692         }
   1693 
   1694         if (m_parent && (diff == StyleDifferenceRepaint || newStyle->outlineSize() < m_style->outlineSize()))
   1695             repaint();
   1696         if (isFloating() && (m_style->floating() != newStyle->floating()))
   1697             // For changes in float styles, we need to conceivably remove ourselves
   1698             // from the floating objects list.
   1699             toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
   1700         else if (isPositioned() && (m_style->position() != newStyle->position()))
   1701             // For changes in positioning styles, we need to conceivably remove ourselves
   1702             // from the positioned objects list.
   1703             toRenderBox(this)->removeFloatingOrPositionedChildFromBlockLists();
   1704 
   1705         s_affectsParentBlock = isFloatingOrPositioned() &&
   1706             (!newStyle->isFloating() && newStyle->position() != AbsolutePosition && newStyle->position() != FixedPosition)
   1707             && parent() && (parent()->isBlockFlow() || parent()->isRenderInline());
   1708 
   1709         // reset style flags
   1710         if (diff == StyleDifferenceLayout || diff == StyleDifferenceLayoutPositionedMovementOnly) {
   1711             m_floating = false;
   1712             m_positioned = false;
   1713             m_relPositioned = false;
   1714         }
   1715         m_horizontalWritingMode = true;
   1716         m_paintBackground = false;
   1717         m_hasOverflowClip = false;
   1718         m_hasTransform = false;
   1719         m_hasReflection = false;
   1720     } else
   1721         s_affectsParentBlock = false;
   1722 
   1723     if (view()->frameView()) {
   1724         bool shouldBlitOnFixedBackgroundImage = false;
   1725 #if ENABLE(FAST_MOBILE_SCROLLING)
   1726         // On low-powered/mobile devices, preventing blitting on a scroll can cause noticeable delays
   1727         // when scrolling a page with a fixed background image. As an optimization, assuming there are
   1728         // no fixed positoned elements on the page, we can acclerate scrolling (via blitting) if we
   1729         // ignore the CSS property "background-attachment: fixed".
   1730         shouldBlitOnFixedBackgroundImage = true;
   1731 #endif
   1732 
   1733         bool newStyleSlowScroll = newStyle && !shouldBlitOnFixedBackgroundImage && newStyle->hasFixedBackgroundImage();
   1734         bool oldStyleSlowScroll = m_style && !shouldBlitOnFixedBackgroundImage && m_style->hasFixedBackgroundImage();
   1735         if (oldStyleSlowScroll != newStyleSlowScroll) {
   1736             if (oldStyleSlowScroll)
   1737                 view()->frameView()->removeSlowRepaintObject();
   1738             if (newStyleSlowScroll)
   1739                 view()->frameView()->addSlowRepaintObject();
   1740         }
   1741     }
   1742 }
   1743 
   1744 static bool areNonIdenticalCursorListsEqual(const RenderStyle* a, const RenderStyle* b)
   1745 {
   1746     ASSERT(a->cursors() != b->cursors());
   1747     return a->cursors() && b->cursors() && *a->cursors() == *b->cursors();
   1748 }
   1749 
   1750 static inline bool areCursorsEqual(const RenderStyle* a, const RenderStyle* b)
   1751 {
   1752     return a->cursor() == b->cursor() && (a->cursors() == b->cursors() || areNonIdenticalCursorListsEqual(a, b));
   1753 }
   1754 
   1755 void RenderObject::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
   1756 {
   1757     if (s_affectsParentBlock)
   1758         handleDynamicFloatPositionChange();
   1759 
   1760     if (!m_parent)
   1761         return;
   1762 
   1763     if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {
   1764         RenderCounter::rendererStyleChanged(this, oldStyle, m_style.get());
   1765 
   1766         // If the object already needs layout, then setNeedsLayout won't do
   1767         // any work. But if the containing block has changed, then we may need
   1768         // to mark the new containing blocks for layout. The change that can
   1769         // directly affect the containing block of this object is a change to
   1770         // the position style.
   1771         if (m_needsLayout && oldStyle->position() != m_style->position())
   1772             markContainingBlocksForLayout();
   1773 
   1774         if (diff == StyleDifferenceLayout)
   1775             setNeedsLayoutAndPrefWidthsRecalc();
   1776         else
   1777             setNeedsSimplifiedNormalFlowLayout();
   1778     } else if (diff == StyleDifferenceLayoutPositionedMovementOnly)
   1779         setNeedsPositionedMovementLayout();
   1780 
   1781     // Don't check for repaint here; we need to wait until the layer has been
   1782     // updated by subclasses before we know if we have to repaint (in setStyle()).
   1783 
   1784     if (oldStyle && !areCursorsEqual(oldStyle, style())) {
   1785         if (Frame* frame = this->frame())
   1786             frame->eventHandler()->dispatchFakeMouseMoveEventSoon();
   1787     }
   1788 }
   1789 
   1790 void RenderObject::propagateStyleToAnonymousChildren()
   1791 {
   1792     for (RenderObject* child = firstChild(); child; child = child->nextSibling()) {
   1793         if (child->isAnonymous() && !child->isBeforeOrAfterContent()) {
   1794             RefPtr<RenderStyle> newStyle = RenderStyle::createAnonymousStyle(style());
   1795             if (style()->specifiesColumns()) {
   1796                 if (child->style()->specifiesColumns())
   1797                     newStyle->inheritColumnPropertiesFrom(style());
   1798                 if (child->style()->columnSpan())
   1799                     newStyle->setColumnSpan(true);
   1800             }
   1801             newStyle->setDisplay(child->style()->display());
   1802             child->setStyle(newStyle.release());
   1803         }
   1804     }
   1805 }
   1806 
   1807 void RenderObject::updateFillImages(const FillLayer* oldLayers, const FillLayer* newLayers)
   1808 {
   1809     // Optimize the common case
   1810     if (oldLayers && !oldLayers->next() && newLayers && !newLayers->next() && (oldLayers->image() == newLayers->image()))
   1811         return;
   1812 
   1813     // Go through the new layers and addClients first, to avoid removing all clients of an image.
   1814     for (const FillLayer* currNew = newLayers; currNew; currNew = currNew->next()) {
   1815         if (currNew->image())
   1816             currNew->image()->addClient(this);
   1817     }
   1818 
   1819     for (const FillLayer* currOld = oldLayers; currOld; currOld = currOld->next()) {
   1820         if (currOld->image())
   1821             currOld->image()->removeClient(this);
   1822     }
   1823 }
   1824 
   1825 void RenderObject::updateImage(StyleImage* oldImage, StyleImage* newImage)
   1826 {
   1827     if (oldImage != newImage) {
   1828         if (oldImage)
   1829             oldImage->removeClient(this);
   1830         if (newImage)
   1831             newImage->addClient(this);
   1832     }
   1833 }
   1834 
   1835 IntRect RenderObject::viewRect() const
   1836 {
   1837     return view()->viewRect();
   1838 }
   1839 
   1840 FloatPoint RenderObject::localToAbsolute(const FloatPoint& localPoint, bool fixed, bool useTransforms) const
   1841 {
   1842     TransformState transformState(TransformState::ApplyTransformDirection, localPoint);
   1843     mapLocalToContainer(0, fixed, useTransforms, transformState);
   1844     transformState.flatten();
   1845 
   1846     return transformState.lastPlanarPoint();
   1847 }
   1848 
   1849 FloatPoint RenderObject::absoluteToLocal(const FloatPoint& containerPoint, bool fixed, bool useTransforms) const
   1850 {
   1851     TransformState transformState(TransformState::UnapplyInverseTransformDirection, containerPoint);
   1852     mapAbsoluteToLocalPoint(fixed, useTransforms, transformState);
   1853     transformState.flatten();
   1854 
   1855     return transformState.lastPlanarPoint();
   1856 }
   1857 
   1858 void RenderObject::mapLocalToContainer(RenderBoxModelObject* repaintContainer, bool fixed, bool useTransforms, TransformState& transformState) const
   1859 {
   1860     if (repaintContainer == this)
   1861         return;
   1862 
   1863     RenderObject* o = parent();
   1864     if (!o)
   1865         return;
   1866 
   1867     IntPoint centerPoint = roundedIntPoint(transformState.mappedPoint());
   1868     if (o->isBox() && o->style()->isFlippedBlocksWritingMode())
   1869         transformState.move(toRenderBox(o)->flipForWritingModeIncludingColumns(roundedIntPoint(transformState.mappedPoint())) - centerPoint);
   1870 
   1871     IntSize columnOffset;
   1872     o->adjustForColumns(columnOffset, roundedIntPoint(transformState.mappedPoint()));
   1873     if (!columnOffset.isZero())
   1874         transformState.move(columnOffset);
   1875 
   1876     if (o->hasOverflowClip())
   1877         transformState.move(-toRenderBox(o)->layer()->scrolledContentOffset());
   1878 
   1879     o->mapLocalToContainer(repaintContainer, fixed, useTransforms, transformState);
   1880 }
   1881 
   1882 void RenderObject::mapAbsoluteToLocalPoint(bool fixed, bool useTransforms, TransformState& transformState) const
   1883 {
   1884     RenderObject* o = parent();
   1885     if (o) {
   1886         o->mapAbsoluteToLocalPoint(fixed, useTransforms, transformState);
   1887         if (o->hasOverflowClip())
   1888             transformState.move(toRenderBox(o)->layer()->scrolledContentOffset());
   1889     }
   1890 }
   1891 
   1892 bool RenderObject::shouldUseTransformFromContainer(const RenderObject* containerObject) const
   1893 {
   1894 #if ENABLE(3D_RENDERING)
   1895     // hasTransform() indicates whether the object has transform, transform-style or perspective. We just care about transform,
   1896     // so check the layer's transform directly.
   1897     return (hasLayer() && toRenderBoxModelObject(this)->layer()->transform()) || (containerObject && containerObject->style()->hasPerspective());
   1898 #else
   1899     UNUSED_PARAM(containerObject);
   1900     return hasTransform();
   1901 #endif
   1902 }
   1903 
   1904 void RenderObject::getTransformFromContainer(const RenderObject* containerObject, const IntSize& offsetInContainer, TransformationMatrix& transform) const
   1905 {
   1906     transform.makeIdentity();
   1907     transform.translate(offsetInContainer.width(), offsetInContainer.height());
   1908     RenderLayer* layer;
   1909     if (hasLayer() && (layer = toRenderBoxModelObject(this)->layer()) && layer->transform())
   1910         transform.multiply(layer->currentTransform());
   1911 
   1912 #if ENABLE(3D_RENDERING)
   1913     if (containerObject && containerObject->hasLayer() && containerObject->style()->hasPerspective()) {
   1914         // Perpsective on the container affects us, so we have to factor it in here.
   1915         ASSERT(containerObject->hasLayer());
   1916         FloatPoint perspectiveOrigin = toRenderBoxModelObject(containerObject)->layer()->perspectiveOrigin();
   1917 
   1918         TransformationMatrix perspectiveMatrix;
   1919         perspectiveMatrix.applyPerspective(containerObject->style()->perspective());
   1920 
   1921         transform.translateRight3d(-perspectiveOrigin.x(), -perspectiveOrigin.y(), 0);
   1922         transform = perspectiveMatrix * transform;
   1923         transform.translateRight3d(perspectiveOrigin.x(), perspectiveOrigin.y(), 0);
   1924     }
   1925 #else
   1926     UNUSED_PARAM(containerObject);
   1927 #endif
   1928 }
   1929 
   1930 FloatQuad RenderObject::localToContainerQuad(const FloatQuad& localQuad, RenderBoxModelObject* repaintContainer, bool fixed) const
   1931 {
   1932     // Track the point at the center of the quad's bounding box. As mapLocalToContainer() calls offsetFromContainer(),
   1933     // it will use that point as the reference point to decide which column's transform to apply in multiple-column blocks.
   1934     TransformState transformState(TransformState::ApplyTransformDirection, localQuad.boundingBox().center(), &localQuad);
   1935     mapLocalToContainer(repaintContainer, fixed, true, transformState);
   1936     transformState.flatten();
   1937 
   1938     return transformState.lastPlanarQuad();
   1939 }
   1940 
   1941 IntSize RenderObject::offsetFromContainer(RenderObject* o, const IntPoint& point) const
   1942 {
   1943     ASSERT(o == container());
   1944 
   1945     IntSize offset;
   1946 
   1947     o->adjustForColumns(offset, point);
   1948 
   1949     if (o->hasOverflowClip())
   1950         offset -= toRenderBox(o)->layer()->scrolledContentOffset();
   1951 
   1952     return offset;
   1953 }
   1954 
   1955 IntSize RenderObject::offsetFromAncestorContainer(RenderObject* container) const
   1956 {
   1957     IntSize offset;
   1958     IntPoint referencePoint;
   1959     const RenderObject* currContainer = this;
   1960     do {
   1961         RenderObject* nextContainer = currContainer->container();
   1962         ASSERT(nextContainer);  // This means we reached the top without finding container.
   1963         if (!nextContainer)
   1964             break;
   1965         ASSERT(!currContainer->hasTransform());
   1966         IntSize currentOffset = currContainer->offsetFromContainer(nextContainer, referencePoint);
   1967         offset += currentOffset;
   1968         referencePoint.move(currentOffset);
   1969         currContainer = nextContainer;
   1970     } while (currContainer != container);
   1971 
   1972     return offset;
   1973 }
   1974 
   1975 IntRect RenderObject::localCaretRect(InlineBox*, int, int* extraWidthToEndOfLine)
   1976 {
   1977     if (extraWidthToEndOfLine)
   1978         *extraWidthToEndOfLine = 0;
   1979 
   1980     return IntRect();
   1981 }
   1982 
   1983 RenderView* RenderObject::view() const
   1984 {
   1985     return toRenderView(document()->renderer());
   1986 }
   1987 
   1988 bool RenderObject::isRooted(RenderView** view)
   1989 {
   1990     RenderObject* o = this;
   1991     while (o->parent())
   1992         o = o->parent();
   1993 
   1994     if (!o->isRenderView())
   1995         return false;
   1996 
   1997     if (view)
   1998         *view = toRenderView(o);
   1999 
   2000     return true;
   2001 }
   2002 
   2003 bool RenderObject::hasOutlineAnnotation() const
   2004 {
   2005     return node() && node()->isLink() && document()->printing();
   2006 }
   2007 
   2008 RenderObject* RenderObject::container(RenderBoxModelObject* repaintContainer, bool* repaintContainerSkipped) const
   2009 {
   2010     if (repaintContainerSkipped)
   2011         *repaintContainerSkipped = false;
   2012 
   2013     // This method is extremely similar to containingBlock(), but with a few notable
   2014     // exceptions.
   2015     // (1) It can be used on orphaned subtrees, i.e., it can be called safely even when
   2016     // the object is not part of the primary document subtree yet.
   2017     // (2) For normal flow elements, it just returns the parent.
   2018     // (3) For absolute positioned elements, it will return a relative positioned inline.
   2019     // containingBlock() simply skips relpositioned inlines and lets an enclosing block handle
   2020     // the layout of the positioned object.  This does mean that computePositionedLogicalWidth and
   2021     // computePositionedLogicalHeight have to use container().
   2022     RenderObject* o = parent();
   2023 
   2024     if (isText())
   2025         return o;
   2026 
   2027     EPosition pos = m_style->position();
   2028     if (pos == FixedPosition) {
   2029         // container() can be called on an object that is not in the
   2030         // tree yet.  We don't call view() since it will assert if it
   2031         // can't get back to the canvas.  Instead we just walk as high up
   2032         // as we can.  If we're in the tree, we'll get the root.  If we
   2033         // aren't we'll get the root of our little subtree (most likely
   2034         // we'll just return 0).
   2035         // FIXME: The definition of view() has changed to not crawl up the render tree.  It might
   2036         // be safe now to use it.
   2037         while (o && o->parent() && !(o->hasTransform() && o->isRenderBlock())) {
   2038             if (repaintContainerSkipped && o == repaintContainer)
   2039                 *repaintContainerSkipped = true;
   2040             o = o->parent();
   2041         }
   2042     } else if (pos == AbsolutePosition) {
   2043         // Same goes here.  We technically just want our containing block, but
   2044         // we may not have one if we're part of an uninstalled subtree.  We'll
   2045         // climb as high as we can though.
   2046         while (o && o->style()->position() == StaticPosition && !o->isRenderView() && !(o->hasTransform() && o->isRenderBlock())) {
   2047             if (repaintContainerSkipped && o == repaintContainer)
   2048                 *repaintContainerSkipped = true;
   2049 #if ENABLE(SVG)
   2050                 if (o->isSVGForeignObject()) // foreignObject is the containing block for contents inside it
   2051                     break;
   2052 #endif
   2053             o = o->parent();
   2054         }
   2055     }
   2056 
   2057     return o;
   2058 }
   2059 
   2060 bool RenderObject::isSelectionBorder() const
   2061 {
   2062     SelectionState st = selectionState();
   2063     return st == SelectionStart || st == SelectionEnd || st == SelectionBoth;
   2064 }
   2065 
   2066 void RenderObject::destroy()
   2067 {
   2068     // Destroy any leftover anonymous children.
   2069     RenderObjectChildList* children = virtualChildren();
   2070     if (children)
   2071         children->destroyLeftoverChildren();
   2072 
   2073     // If this renderer is being autoscrolled, stop the autoscroll timer
   2074 
   2075     // FIXME: RenderObject::destroy should not get called with a renderer whose document
   2076     // has a null frame, so we assert this. However, we don't want release builds to crash which is why we
   2077     // check that the frame is not null.
   2078     ASSERT(frame());
   2079     if (frame() && frame()->eventHandler()->autoscrollRenderer() == this)
   2080         frame()->eventHandler()->stopAutoscrollTimer(true);
   2081 
   2082     if (AXObjectCache::accessibilityEnabled()) {
   2083         document()->axObjectCache()->childrenChanged(this->parent());
   2084         document()->axObjectCache()->remove(this);
   2085     }
   2086     animation()->cancelAnimations(this);
   2087 
   2088     // By default no ref-counting. RenderWidget::destroy() doesn't call
   2089     // this function because it needs to do ref-counting. If anything
   2090     // in this function changes, be sure to fix RenderWidget::destroy() as well.
   2091 
   2092     remove();
   2093 
   2094     // If this renderer had a parent, remove should have destroyed any counters
   2095     // attached to this renderer and marked the affected other counters for
   2096     // reevaluation. This apparently redundant check is here for the case when
   2097     // this renderer had no parent at the time remove() was called.
   2098 
   2099     if (m_hasCounterNodeMap)
   2100         RenderCounter::destroyCounterNodes(this);
   2101 
   2102     // FIXME: Would like to do this in RenderBoxModelObject, but the timing is so complicated that this can't easily
   2103     // be moved into RenderBoxModelObject::destroy.
   2104     if (hasLayer()) {
   2105         setHasLayer(false);
   2106         toRenderBoxModelObject(this)->destroyLayer();
   2107     }
   2108     arenaDelete(renderArena(), this);
   2109 }
   2110 
   2111 void RenderObject::arenaDelete(RenderArena* arena, void* base)
   2112 {
   2113     if (m_style) {
   2114         for (const FillLayer* bgLayer = m_style->backgroundLayers(); bgLayer; bgLayer = bgLayer->next()) {
   2115             if (StyleImage* backgroundImage = bgLayer->image())
   2116                 backgroundImage->removeClient(this);
   2117         }
   2118 
   2119         for (const FillLayer* maskLayer = m_style->maskLayers(); maskLayer; maskLayer = maskLayer->next()) {
   2120             if (StyleImage* maskImage = maskLayer->image())
   2121                 maskImage->removeClient(this);
   2122         }
   2123 
   2124         if (StyleImage* borderImage = m_style->borderImage().image())
   2125             borderImage->removeClient(this);
   2126 
   2127         if (StyleImage* maskBoxImage = m_style->maskBoxImage().image())
   2128             maskBoxImage->removeClient(this);
   2129     }
   2130 
   2131 #ifndef NDEBUG
   2132     void* savedBase = baseOfRenderObjectBeingDeleted;
   2133     baseOfRenderObjectBeingDeleted = base;
   2134 #endif
   2135     delete this;
   2136 #ifndef NDEBUG
   2137     baseOfRenderObjectBeingDeleted = savedBase;
   2138 #endif
   2139 
   2140     // Recover the size left there for us by operator delete and free the memory.
   2141     arena->free(*(size_t*)base, base);
   2142 }
   2143 
   2144 VisiblePosition RenderObject::positionForCoordinates(int x, int y)
   2145 {
   2146     return positionForPoint(IntPoint(x, y));
   2147 }
   2148 
   2149 VisiblePosition RenderObject::positionForPoint(const IntPoint&)
   2150 {
   2151     return createVisiblePosition(caretMinOffset(), DOWNSTREAM);
   2152 }
   2153 
   2154 void RenderObject::updateDragState(bool dragOn)
   2155 {
   2156     bool valueChanged = (dragOn != m_isDragging);
   2157     m_isDragging = dragOn;
   2158     if (valueChanged && style()->affectedByDragRules() && node())
   2159         node()->setNeedsStyleRecalc();
   2160     for (RenderObject* curr = firstChild(); curr; curr = curr->nextSibling())
   2161         curr->updateDragState(dragOn);
   2162 }
   2163 
   2164 bool RenderObject::hitTest(const HitTestRequest& request, HitTestResult& result, const IntPoint& point, int tx, int ty, HitTestFilter hitTestFilter)
   2165 {
   2166     bool inside = false;
   2167     if (hitTestFilter != HitTestSelf) {
   2168         // First test the foreground layer (lines and inlines).
   2169         inside = nodeAtPoint(request, result, point.x(), point.y(), tx, ty, HitTestForeground);
   2170 
   2171         // Test floats next.
   2172         if (!inside)
   2173             inside = nodeAtPoint(request, result, point.x(), point.y(), tx, ty, HitTestFloat);
   2174 
   2175         // Finally test to see if the mouse is in the background (within a child block's background).
   2176         if (!inside)
   2177             inside = nodeAtPoint(request, result, point.x(), point.y(), tx, ty, HitTestChildBlockBackgrounds);
   2178     }
   2179 
   2180     // See if the mouse is inside us but not any of our descendants
   2181     if (hitTestFilter != HitTestDescendants && !inside)
   2182         inside = nodeAtPoint(request, result, point.x(), point.y(), tx, ty, HitTestBlockBackground);
   2183 
   2184     return inside;
   2185 }
   2186 
   2187 void RenderObject::updateHitTestResult(HitTestResult& result, const IntPoint& point)
   2188 {
   2189     if (result.innerNode())
   2190         return;
   2191 
   2192     Node* n = node();
   2193     if (n) {
   2194         result.setInnerNode(n);
   2195         if (!result.innerNonSharedNode())
   2196             result.setInnerNonSharedNode(n);
   2197         result.setLocalPoint(point);
   2198     }
   2199 }
   2200 
   2201 bool RenderObject::nodeAtPoint(const HitTestRequest&, HitTestResult&, int /*x*/, int /*y*/, int /*tx*/, int /*ty*/, HitTestAction)
   2202 {
   2203     return false;
   2204 }
   2205 
   2206 void RenderObject::scheduleRelayout()
   2207 {
   2208     if (isRenderView()) {
   2209         FrameView* view = toRenderView(this)->frameView();
   2210         if (view)
   2211             view->scheduleRelayout();
   2212     } else if (parent()) {
   2213         FrameView* v = view() ? view()->frameView() : 0;
   2214         if (v)
   2215             v->scheduleRelayoutOfSubtree(this);
   2216     }
   2217 }
   2218 
   2219 void RenderObject::layout()
   2220 {
   2221     ASSERT(needsLayout());
   2222     RenderObject* child = firstChild();
   2223     while (child) {
   2224         child->layoutIfNeeded();
   2225         ASSERT(!child->needsLayout());
   2226         child = child->nextSibling();
   2227     }
   2228     setNeedsLayout(false);
   2229 }
   2230 
   2231 PassRefPtr<RenderStyle> RenderObject::uncachedFirstLineStyle(RenderStyle* style) const
   2232 {
   2233     if (!document()->usesFirstLineRules())
   2234         return 0;
   2235 
   2236     ASSERT(!isText());
   2237 
   2238     RefPtr<RenderStyle> result;
   2239 
   2240     if (isBlockFlow()) {
   2241         if (RenderBlock* firstLineBlock = this->firstLineBlock())
   2242             result = firstLineBlock->getUncachedPseudoStyle(FIRST_LINE, style, firstLineBlock == this ? style : 0);
   2243     } else if (!isAnonymous() && isRenderInline()) {
   2244         RenderStyle* parentStyle = parent()->firstLineStyle();
   2245         if (parentStyle != parent()->style())
   2246             result = getUncachedPseudoStyle(FIRST_LINE_INHERITED, parentStyle, style);
   2247     }
   2248 
   2249     return result.release();
   2250 }
   2251 
   2252 RenderStyle* RenderObject::firstLineStyleSlowCase() const
   2253 {
   2254     ASSERT(document()->usesFirstLineRules());
   2255 
   2256     RenderStyle* style = m_style.get();
   2257     const RenderObject* renderer = isText() ? parent() : this;
   2258     if (renderer->isBlockFlow()) {
   2259         if (RenderBlock* firstLineBlock = renderer->firstLineBlock())
   2260             style = firstLineBlock->getCachedPseudoStyle(FIRST_LINE, style);
   2261     } else if (!renderer->isAnonymous() && renderer->isRenderInline()) {
   2262         RenderStyle* parentStyle = renderer->parent()->firstLineStyle();
   2263         if (parentStyle != renderer->parent()->style()) {
   2264             // A first-line style is in effect. Cache a first-line style for ourselves.
   2265             renderer->style()->setHasPseudoStyle(FIRST_LINE_INHERITED);
   2266             style = renderer->getCachedPseudoStyle(FIRST_LINE_INHERITED, parentStyle);
   2267         }
   2268     }
   2269 
   2270     return style;
   2271 }
   2272 
   2273 RenderStyle* RenderObject::getCachedPseudoStyle(PseudoId pseudo, RenderStyle* parentStyle) const
   2274 {
   2275     if (pseudo < FIRST_INTERNAL_PSEUDOID && !style()->hasPseudoStyle(pseudo))
   2276         return 0;
   2277 
   2278     RenderStyle* cachedStyle = style()->getCachedPseudoStyle(pseudo);
   2279     if (cachedStyle)
   2280         return cachedStyle;
   2281 
   2282     RefPtr<RenderStyle> result = getUncachedPseudoStyle(pseudo, parentStyle);
   2283     if (result)
   2284         return style()->addCachedPseudoStyle(result.release());
   2285     return 0;
   2286 }
   2287 
   2288 PassRefPtr<RenderStyle> RenderObject::getUncachedPseudoStyle(PseudoId pseudo, RenderStyle* parentStyle, RenderStyle* ownStyle) const
   2289 {
   2290     if (pseudo < FIRST_INTERNAL_PSEUDOID && !ownStyle && !style()->hasPseudoStyle(pseudo))
   2291         return 0;
   2292 
   2293     if (!parentStyle) {
   2294         ASSERT(!ownStyle);
   2295         parentStyle = style();
   2296     }
   2297 
   2298     Node* n = node();
   2299     while (n && !n->isElementNode())
   2300         n = n->parentNode();
   2301     if (!n)
   2302         return 0;
   2303 
   2304     RefPtr<RenderStyle> result;
   2305     if (pseudo == FIRST_LINE_INHERITED) {
   2306         result = document()->styleSelector()->styleForElement(static_cast<Element*>(n), parentStyle, false);
   2307         result->setStyleType(FIRST_LINE_INHERITED);
   2308     } else
   2309         result = document()->styleSelector()->pseudoStyleForElement(pseudo, static_cast<Element*>(n), parentStyle);
   2310     return result.release();
   2311 }
   2312 
   2313 static Color decorationColor(RenderObject* renderer)
   2314 {
   2315     Color result;
   2316     if (renderer->style()->textStrokeWidth() > 0) {
   2317         // Prefer stroke color if possible but not if it's fully transparent.
   2318         result = renderer->style()->visitedDependentColor(CSSPropertyWebkitTextStrokeColor);
   2319         if (result.alpha())
   2320             return result;
   2321     }
   2322 
   2323     result = renderer->style()->visitedDependentColor(CSSPropertyWebkitTextFillColor);
   2324     return result;
   2325 }
   2326 
   2327 void RenderObject::getTextDecorationColors(int decorations, Color& underline, Color& overline,
   2328                                            Color& linethrough, bool quirksMode)
   2329 {
   2330     RenderObject* curr = this;
   2331     do {
   2332         int currDecs = curr->style()->textDecoration();
   2333         if (currDecs) {
   2334             if (currDecs & UNDERLINE) {
   2335                 decorations &= ~UNDERLINE;
   2336                 underline = decorationColor(curr);
   2337             }
   2338             if (currDecs & OVERLINE) {
   2339                 decorations &= ~OVERLINE;
   2340                 overline = decorationColor(curr);
   2341             }
   2342             if (currDecs & LINE_THROUGH) {
   2343                 decorations &= ~LINE_THROUGH;
   2344                 linethrough = decorationColor(curr);
   2345             }
   2346         }
   2347         curr = curr->parent();
   2348         if (curr && curr->isAnonymousBlock() && toRenderBlock(curr)->continuation())
   2349             curr = toRenderBlock(curr)->continuation();
   2350     } while (curr && decorations && (!quirksMode || !curr->node() ||
   2351                                      (!curr->node()->hasTagName(aTag) && !curr->node()->hasTagName(fontTag))));
   2352 
   2353     // If we bailed out, use the element we bailed out at (typically a <font> or <a> element).
   2354     if (decorations && curr) {
   2355         if (decorations & UNDERLINE)
   2356             underline = decorationColor(curr);
   2357         if (decorations & OVERLINE)
   2358             overline = decorationColor(curr);
   2359         if (decorations & LINE_THROUGH)
   2360             linethrough = decorationColor(curr);
   2361     }
   2362 }
   2363 
   2364 #if ENABLE(DASHBOARD_SUPPORT)
   2365 void RenderObject::addDashboardRegions(Vector<DashboardRegionValue>& regions)
   2366 {
   2367     // Convert the style regions to absolute coordinates.
   2368     if (style()->visibility() != VISIBLE || !isBox())
   2369         return;
   2370 
   2371     RenderBox* box = toRenderBox(this);
   2372 
   2373     const Vector<StyleDashboardRegion>& styleRegions = style()->dashboardRegions();
   2374     unsigned i, count = styleRegions.size();
   2375     for (i = 0; i < count; i++) {
   2376         StyleDashboardRegion styleRegion = styleRegions[i];
   2377 
   2378         int w = box->width();
   2379         int h = box->height();
   2380 
   2381         DashboardRegionValue region;
   2382         region.label = styleRegion.label;
   2383         region.bounds = IntRect(styleRegion.offset.left().value(),
   2384                                 styleRegion.offset.top().value(),
   2385                                 w - styleRegion.offset.left().value() - styleRegion.offset.right().value(),
   2386                                 h - styleRegion.offset.top().value() - styleRegion.offset.bottom().value());
   2387         region.type = styleRegion.type;
   2388 
   2389         region.clip = region.bounds;
   2390         computeAbsoluteRepaintRect(region.clip);
   2391         if (region.clip.height() < 0) {
   2392             region.clip.setHeight(0);
   2393             region.clip.setWidth(0);
   2394         }
   2395 
   2396         FloatPoint absPos = localToAbsolute();
   2397         region.bounds.setX(absPos.x() + styleRegion.offset.left().value());
   2398         region.bounds.setY(absPos.y() + styleRegion.offset.top().value());
   2399 
   2400         if (frame()) {
   2401             float pageScaleFactor = frame()->page()->chrome()->scaleFactor();
   2402             if (pageScaleFactor != 1.0f) {
   2403                 region.bounds.scale(pageScaleFactor);
   2404                 region.clip.scale(pageScaleFactor);
   2405             }
   2406         }
   2407 
   2408         regions.append(region);
   2409     }
   2410 }
   2411 
   2412 void RenderObject::collectDashboardRegions(Vector<DashboardRegionValue>& regions)
   2413 {
   2414     // RenderTexts don't have their own style, they just use their parent's style,
   2415     // so we don't want to include them.
   2416     if (isText())
   2417         return;
   2418 
   2419     addDashboardRegions(regions);
   2420     for (RenderObject* curr = firstChild(); curr; curr = curr->nextSibling())
   2421         curr->collectDashboardRegions(regions);
   2422 }
   2423 #endif
   2424 
   2425 bool RenderObject::willRenderImage(CachedImage*)
   2426 {
   2427     // Without visibility we won't render (and therefore don't care about animation).
   2428     if (style()->visibility() != VISIBLE)
   2429         return false;
   2430 
   2431     // If we're not in a window (i.e., we're dormant from being put in the b/f cache or in a background tab)
   2432     // then we don't want to render either.
   2433     return !document()->inPageCache() && !document()->view()->isOffscreen();
   2434 }
   2435 
   2436 int RenderObject::maximalOutlineSize(PaintPhase p) const
   2437 {
   2438     if (p != PaintPhaseOutline && p != PaintPhaseSelfOutline && p != PaintPhaseChildOutlines)
   2439         return 0;
   2440     return toRenderView(document()->renderer())->maximalOutlineSize();
   2441 }
   2442 
   2443 int RenderObject::caretMinOffset() const
   2444 {
   2445     return 0;
   2446 }
   2447 
   2448 int RenderObject::caretMaxOffset() const
   2449 {
   2450     if (isReplaced())
   2451         return node() ? max(1U, node()->childNodeCount()) : 1;
   2452     if (isHR())
   2453         return 1;
   2454     return 0;
   2455 }
   2456 
   2457 unsigned RenderObject::caretMaxRenderedOffset() const
   2458 {
   2459     return 0;
   2460 }
   2461 
   2462 int RenderObject::previousOffset(int current) const
   2463 {
   2464     return current - 1;
   2465 }
   2466 
   2467 int RenderObject::previousOffsetForBackwardDeletion(int current) const
   2468 {
   2469     return current - 1;
   2470 }
   2471 
   2472 int RenderObject::nextOffset(int current) const
   2473 {
   2474     return current + 1;
   2475 }
   2476 
   2477 void RenderObject::adjustRectForOutlineAndShadow(IntRect& rect) const
   2478 {
   2479     int outlineSize = outlineStyleForRepaint()->outlineSize();
   2480     if (const ShadowData* boxShadow = style()->boxShadow()) {
   2481         boxShadow->adjustRectForShadow(rect, outlineSize);
   2482         return;
   2483     }
   2484 
   2485     rect.inflate(outlineSize);
   2486 }
   2487 
   2488 AnimationController* RenderObject::animation() const
   2489 {
   2490     return frame()->animation();
   2491 }
   2492 
   2493 void RenderObject::imageChanged(CachedImage* image, const IntRect* rect)
   2494 {
   2495     imageChanged(static_cast<WrappedImagePtr>(image), rect);
   2496 }
   2497 
   2498 RenderBoxModelObject* RenderObject::offsetParent() const
   2499 {
   2500     // If any of the following holds true return null and stop this algorithm:
   2501     // A is the root element.
   2502     // A is the HTML body element.
   2503     // The computed value of the position property for element A is fixed.
   2504     if (isRoot() || isBody() || (isPositioned() && style()->position() == FixedPosition))
   2505         return 0;
   2506 
   2507     // If A is an area HTML element which has a map HTML element somewhere in the ancestor
   2508     // chain return the nearest ancestor map HTML element and stop this algorithm.
   2509     // FIXME: Implement!
   2510 
   2511     // Return the nearest ancestor element of A for which at least one of the following is
   2512     // true and stop this algorithm if such an ancestor is found:
   2513     //     * The computed value of the position property is not static.
   2514     //     * It is the HTML body element.
   2515     //     * The computed value of the position property of A is static and the ancestor
   2516     //       is one of the following HTML elements: td, th, or table.
   2517     //     * Our own extension: if there is a difference in the effective zoom
   2518 
   2519     bool skipTables = isPositioned() || isRelPositioned();
   2520     float currZoom = style()->effectiveZoom();
   2521     RenderObject* curr = parent();
   2522     while (curr && (!curr->node() || (!curr->isPositioned() && !curr->isRelPositioned() && !curr->isBody()))) {
   2523         Node* element = curr->node();
   2524         if (!skipTables && element) {
   2525             bool isTableElement = element->hasTagName(tableTag) ||
   2526                                   element->hasTagName(tdTag) ||
   2527                                   element->hasTagName(thTag);
   2528 
   2529 #if ENABLE(WML)
   2530             if (!isTableElement && element->isWMLElement())
   2531                 isTableElement = element->hasTagName(WMLNames::tableTag) ||
   2532                                  element->hasTagName(WMLNames::tdTag);
   2533 #endif
   2534 
   2535             if (isTableElement)
   2536                 break;
   2537         }
   2538 
   2539         float newZoom = curr->style()->effectiveZoom();
   2540         if (currZoom != newZoom)
   2541             break;
   2542         currZoom = newZoom;
   2543         curr = curr->parent();
   2544     }
   2545     return curr && curr->isBoxModelObject() ? toRenderBoxModelObject(curr) : 0;
   2546 }
   2547 
   2548 VisiblePosition RenderObject::createVisiblePosition(int offset, EAffinity affinity)
   2549 {
   2550     // If this is a non-anonymous renderer in an editable area, then it's simple.
   2551     if (Node* node = this->node()) {
   2552         if (!node->rendererIsEditable()) {
   2553             // If it can be found, we prefer a visually equivalent position that is editable.
   2554             Position position(node, offset);
   2555             Position candidate = position.downstream(CanCrossEditingBoundary);
   2556             if (candidate.deprecatedNode()->rendererIsEditable())
   2557                 return VisiblePosition(candidate, affinity);
   2558             candidate = position.upstream(CanCrossEditingBoundary);
   2559             if (candidate.deprecatedNode()->rendererIsEditable())
   2560                 return VisiblePosition(candidate, affinity);
   2561         }
   2562         // FIXME: Eliminate legacy editing positions
   2563         return VisiblePosition(Position(node, offset), affinity);
   2564     }
   2565 
   2566     // We don't want to cross the boundary between editable and non-editable
   2567     // regions of the document, but that is either impossible or at least
   2568     // extremely unlikely in any normal case because we stop as soon as we
   2569     // find a single non-anonymous renderer.
   2570 
   2571     // Find a nearby non-anonymous renderer.
   2572     RenderObject* child = this;
   2573     while (RenderObject* parent = child->parent()) {
   2574         // Find non-anonymous content after.
   2575         RenderObject* renderer = child;
   2576         while ((renderer = renderer->nextInPreOrder(parent))) {
   2577             if (Node* node = renderer->node())
   2578                 return VisiblePosition(firstPositionInOrBeforeNode(node), DOWNSTREAM);
   2579         }
   2580 
   2581         // Find non-anonymous content before.
   2582         renderer = child;
   2583         while ((renderer = renderer->previousInPreOrder())) {
   2584             if (renderer == parent)
   2585                 break;
   2586             if (Node* node = renderer->node())
   2587                 return VisiblePosition(lastPositionInOrAfterNode(node), DOWNSTREAM);
   2588         }
   2589 
   2590         // Use the parent itself unless it too is anonymous.
   2591         if (Node* node = parent->node())
   2592             return VisiblePosition(firstPositionInOrBeforeNode(node), DOWNSTREAM);
   2593 
   2594         // Repeat at the next level up.
   2595         child = parent;
   2596     }
   2597 
   2598     // Everything was anonymous. Give up.
   2599     return VisiblePosition();
   2600 }
   2601 
   2602 VisiblePosition RenderObject::createVisiblePosition(const Position& position)
   2603 {
   2604     if (position.isNotNull())
   2605         return VisiblePosition(position);
   2606 
   2607     ASSERT(!node());
   2608     return createVisiblePosition(0, DOWNSTREAM);
   2609 }
   2610 
   2611 #if ENABLE(SVG)
   2612 RenderSVGResourceContainer* RenderObject::toRenderSVGResourceContainer()
   2613 {
   2614     ASSERT_NOT_REACHED();
   2615     return 0;
   2616 }
   2617 
   2618 void RenderObject::setNeedsBoundariesUpdate()
   2619 {
   2620     if (RenderObject* renderer = parent())
   2621         renderer->setNeedsBoundariesUpdate();
   2622 }
   2623 
   2624 FloatRect RenderObject::objectBoundingBox() const
   2625 {
   2626     ASSERT_NOT_REACHED();
   2627     return FloatRect();
   2628 }
   2629 
   2630 FloatRect RenderObject::strokeBoundingBox() const
   2631 {
   2632     ASSERT_NOT_REACHED();
   2633     return FloatRect();
   2634 }
   2635 
   2636 // Returns the smallest rectangle enclosing all of the painted content
   2637 // respecting clipping, masking, filters, opacity, stroke-width and markers
   2638 FloatRect RenderObject::repaintRectInLocalCoordinates() const
   2639 {
   2640     ASSERT_NOT_REACHED();
   2641     return FloatRect();
   2642 }
   2643 
   2644 AffineTransform RenderObject::localTransform() const
   2645 {
   2646     static const AffineTransform identity;
   2647     return identity;
   2648 }
   2649 
   2650 const AffineTransform& RenderObject::localToParentTransform() const
   2651 {
   2652     static const AffineTransform identity;
   2653     return identity;
   2654 }
   2655 
   2656 bool RenderObject::nodeAtFloatPoint(const HitTestRequest&, HitTestResult&, const FloatPoint&, HitTestAction)
   2657 {
   2658     ASSERT_NOT_REACHED();
   2659     return false;
   2660 }
   2661 
   2662 #endif // ENABLE(SVG)
   2663 
   2664 } // namespace WebCore
   2665 
   2666 #ifndef NDEBUG
   2667 
   2668 void showTree(const WebCore::RenderObject* ro)
   2669 {
   2670     if (ro)
   2671         ro->showTreeForThis();
   2672 }
   2673 
   2674 void showRenderTree(const WebCore::RenderObject* object1)
   2675 {
   2676     showRenderTree(object1, 0);
   2677 }
   2678 
   2679 void showRenderTree(const WebCore::RenderObject* object1, const WebCore::RenderObject* object2)
   2680 {
   2681     if (object1) {
   2682         const WebCore::RenderObject* root = object1;
   2683         while (root->parent())
   2684             root = root->parent();
   2685         root->showRenderTreeAndMark(object1, "*", object2, "-", 0);
   2686     }
   2687 }
   2688 
   2689 #endif
   2690