Source/WebCore/rendering/RenderObjectChildList.cpp

   1 /*
   2  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
   3  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "config.h"
  28 #include "RenderObjectChildList.h"
  29
  30 #include "AXObjectCache.h"
  31 #include "ContentData.h"
  32 #include "RenderBlock.h"
  33 #include "RenderCounter.h"
  34 #include "RenderFlowThread.h"
  35 #include "RenderImage.h"
  36 #include "RenderImageResourceStyleImage.h"
  37 #include "RenderInline.h"
  38 #include "RenderLayer.h"
  39 #include "RenderListItem.h"
  40 #include "RenderQuote.h"
  41 #include "RenderRegion.h"
  42 #include "RenderStyle.h"
  43 #include "RenderTextFragment.h"
  44 #include "RenderView.h"
  45
  46 namespace WebCore {
  47
  48 void RenderObjectChildList::destroyLeftoverChildren()
  49 {
  50     while (firstChild()) {
  51         if (firstChild()->isListMarker() || (firstChild()->style()->styleType() == FIRST_LETTER && !firstChild()->isText()))
  52             firstChild()->remove();  // List markers are owned by their enclosing list and so don't get destroyed by this container. Similarly, first letters are destroyed by their remaining text fragment.
  53         else if (firstChild()->isRunIn() && firstChild()->node()) {
  54             firstChild()->node()->setRenderer(0);
  55             firstChild()->node()->setNeedsStyleRecalc();
  56             firstChild()->destroy();
  57         } else {
  58             // Destroy any anonymous children remaining in the render tree, as well as implicit (shadow) DOM elements like those used in the engine-based text fields.
  59             if (firstChild()->node())
  60                 firstChild()->node()->setRenderer(0);
  61             firstChild()->destroy();
  62         }
  63     }
  64 }
  65
  66 static RenderFlowThread* renderFlowThreadContainer(RenderObject* object)
  67 {
  68     while (object && object->isAnonymousBlock() && !object->isRenderFlowThread())
  69         object = object->parent();
  70
  71     return object && object->isRenderFlowThread() ? toRenderFlowThread(object) : 0;
  72 }
  73
  74 RenderObject* RenderObjectChildList::removeChildNode(RenderObject* owner, RenderObject* oldChild, bool fullRemove)
  75 {
  76     ASSERT(oldChild->parent() == owner);
  77
  78     // So that we'll get the appropriate dirty bit set (either that a normal flow child got yanked or
  79     // that a positioned child got yanked).  We also repaint, so that the area exposed when the child
  80     // disappears gets repainted properly.
  81     if (!owner->documentBeingDestroyed() && fullRemove && oldChild->m_everHadLayout) {
  82         oldChild->setNeedsLayoutAndPrefWidthsRecalc();
  83         if (oldChild->isBody())
  84             owner->view()->repaint();
  85         else
  86             oldChild->repaint();
  87     }
  88
  89     // If we have a line box wrapper, delete it.
  90     if (oldChild->isBox())
  91         toRenderBox(oldChild)->deleteLineBoxWrapper();
  92
  93     if (!owner->documentBeingDestroyed() && fullRemove) {
  94         // if we remove visible child from an invisible parent, we don't know the layer visibility any more
  95         RenderLayer* layer = 0;
  96         if (owner->style()->visibility() != VISIBLE && oldChild->style()->visibility() == VISIBLE && !oldChild->hasLayer()) {
  97             if ((layer = owner->enclosingLayer()))
  98                 layer->dirtyVisibleContentStatus();
  99         }
 100
 101          // Keep our layer hierarchy updated.
 102         if (oldChild->firstChild() || oldChild->hasLayer()) {
 103             if (!layer)
 104                 layer = owner->enclosingLayer();
 105             oldChild->removeLayers(layer);
 106         }
 107
 108         if (oldChild->isListItem())
 109             toRenderListItem(oldChild)->updateListMarkerNumbers();
 110
 111         if (oldChild->isPositioned() && owner->childrenInline())
 112             owner->dirtyLinesFromChangedChild(oldChild);
 113
 114         if (oldChild->isRenderRegion())
 115             toRenderRegion(oldChild)->detachRegion();
 116
 117         if (oldChild->inRenderFlowThread() && oldChild->isBox())
 118             oldChild->enclosingRenderFlowThread()->removeRenderBoxRegionInfo(toRenderBox(oldChild));
 119
 120         if (RenderFlowThread* containerFlowThread = renderFlowThreadContainer(owner))
 121             containerFlowThread->removeFlowChild(oldChild);
 122
 123 #if ENABLE(SVG)
 124         // Update cached boundaries in SVG renderers, if a child is removed.
 125         owner->setNeedsBoundariesUpdate();
 126 #endif
 127     }
 128
 129     // If oldChild is the start or end of the selection, then clear the selection to
 130     // avoid problems of invalid pointers.
 131     // FIXME: The FrameSelection should be responsible for this when it
 132     // is notified of DOM mutations.
 133     if (!owner->documentBeingDestroyed() && oldChild->isSelectionBorder())
 134         owner->view()->clearSelection();
 135
 136     // remove the child
 137     if (oldChild->previousSibling())
 138         oldChild->previousSibling()->setNextSibling(oldChild->nextSibling());
 139     if (oldChild->nextSibling())
 140         oldChild->nextSibling()->setPreviousSibling(oldChild->previousSibling());
 141
 142     if (firstChild() == oldChild)
 143         setFirstChild(oldChild->nextSibling());
 144     if (lastChild() == oldChild)
 145         setLastChild(oldChild->previousSibling());
 146
 147     oldChild->setPreviousSibling(0);
 148     oldChild->setNextSibling(0);
 149     oldChild->setParent(0);
 150
 151     RenderCounter::rendererRemovedFromTree(oldChild);
 152     RenderQuote::rendererRemovedFromTree(oldChild);
 153
 154     if (AXObjectCache::accessibilityEnabled())
 155         owner->document()->axObjectCache()->childrenChanged(owner);
 156
 157     return oldChild;
 158 }
 159
 160 void RenderObjectChildList::appendChildNode(RenderObject* owner, RenderObject* newChild, bool fullAppend)
 161 {
 162     ASSERT(newChild->parent() == 0);
 163     ASSERT(!owner->isBlockFlow() || (!newChild->isTableSection() && !newChild->isTableRow() && !newChild->isTableCell()));
 164
 165     newChild->setParent(owner);
 166     RenderObject* lChild = lastChild();
 167
 168     if (lChild) {
 169         newChild->setPreviousSibling(lChild);
 170         lChild->setNextSibling(newChild);
 171     } else
 172         setFirstChild(newChild);
 173
 174     setLastChild(newChild);
 175
 176     if (fullAppend) {
 177         // Keep our layer hierarchy updated.  Optimize for the common case where we don't have any children
 178         // and don't have a layer attached to ourselves.
 179         RenderLayer* layer = 0;
 180         if (newChild->firstChild() || newChild->hasLayer()) {
 181             layer = owner->enclosingLayer();
 182             newChild->addLayers(layer);
 183         }
 184
 185         // if the new child is visible but this object was not, tell the layer it has some visible content
 186         // that needs to be drawn and layer visibility optimization can't be used
 187         if (owner->style()->visibility() != VISIBLE && newChild->style()->visibility() == VISIBLE && !newChild->hasLayer()) {
 188             if (!layer)
 189                 layer = owner->enclosingLayer();
 190             if (layer)
 191                 layer->setHasVisibleContent(true);
 192         }
 193
 194         if (newChild->isListItem())
 195             toRenderListItem(newChild)->updateListMarkerNumbers();
 196
 197         if (!newChild->isFloating() && owner->childrenInline())
 198             owner->dirtyLinesFromChangedChild(newChild);
 199
 200         if (newChild->isRenderRegion())
 201             toRenderRegion(newChild)->attachRegion();
 202
 203         if (RenderFlowThread* containerFlowThread = renderFlowThreadContainer(owner))
 204             containerFlowThread->addFlowChild(newChild);
 205     }
 206     RenderCounter::rendererSubtreeAttached(newChild);
 207     RenderQuote::rendererSubtreeAttached(newChild);
 208     newChild->setNeedsLayoutAndPrefWidthsRecalc(); // Goes up the containing block hierarchy.
 209     if (!owner->normalChildNeedsLayout())
 210         owner->setChildNeedsLayout(true); // We may supply the static position for an absolute positioned child.
 211
 212     if (AXObjectCache::accessibilityEnabled())
 213         owner->document()->axObjectCache()->childrenChanged(owner);
 214 }
 215
 216 void RenderObjectChildList::insertChildNode(RenderObject* owner, RenderObject* child, RenderObject* beforeChild, bool fullInsert)
 217 {
 218     if (!beforeChild) {
 219         appendChildNode(owner, child, fullInsert);
 220         return;
 221     }
 222
 223     ASSERT(!child->parent());
 224     while (beforeChild->parent() != owner && beforeChild->parent()->isAnonymousBlock())
 225         beforeChild = beforeChild->parent();
 226     ASSERT(beforeChild->parent() == owner);
 227
 228     ASSERT(!owner->isBlockFlow() || (!child->isTableSection() && !child->isTableRow() && !child->isTableCell()));
 229
 230     if (beforeChild == firstChild())
 231         setFirstChild(child);
 232
 233     RenderObject* prev = beforeChild->previousSibling();
 234     child->setNextSibling(beforeChild);
 235     beforeChild->setPreviousSibling(child);
 236     if (prev)
 237         prev->setNextSibling(child);
 238     child->setPreviousSibling(prev);
 239
 240     child->setParent(owner);
 241
 242     if (fullInsert) {
 243         // Keep our layer hierarchy updated.  Optimize for the common case where we don't have any children
 244         // and don't have a layer attached to ourselves.
 245         RenderLayer* layer = 0;
 246         if (child->firstChild() || child->hasLayer()) {
 247             layer = owner->enclosingLayer();
 248             child->addLayers(layer);
 249         }
 250
 251         // if the new child is visible but this object was not, tell the layer it has some visible content
 252         // that needs to be drawn and layer visibility optimization can't be used
 253         if (owner->style()->visibility() != VISIBLE && child->style()->visibility() == VISIBLE && !child->hasLayer()) {
 254             if (!layer)
 255                 layer = owner->enclosingLayer();
 256             if (layer)
 257                 layer->setHasVisibleContent(true);
 258         }
 259
 260         if (child->isListItem())
 261             toRenderListItem(child)->updateListMarkerNumbers();
 262
 263         if (!child->isFloating() && owner->childrenInline())
 264             owner->dirtyLinesFromChangedChild(child);
 265
 266         if (child->isRenderRegion())
 267             toRenderRegion(child)->attachRegion();
 268
 269         if (RenderFlowThread* containerFlowThread = renderFlowThreadContainer(owner))
 270             containerFlowThread->addFlowChild(child, beforeChild);
 271     }
 272
 273     RenderCounter::rendererSubtreeAttached(child);
 274     RenderQuote::rendererSubtreeAttached(child);
 275     child->setNeedsLayoutAndPrefWidthsRecalc();
 276     if (!owner->normalChildNeedsLayout())
 277         owner->setChildNeedsLayout(true); // We may supply the static position for an absolute positioned child.
 278
 279     if (AXObjectCache::accessibilityEnabled())
 280         owner->document()->axObjectCache()->childrenChanged(owner);
 281 }
 282
 283 static RenderObject* findBeforeAfterParent(RenderObject* object)
 284 {
 285     // Only table parts need to search for the :before or :after parent
 286     if (!(object->isTable() || object->isTableSection() || object->isTableRow()))
 287         return object;
 288
 289     // If there is a :first-letter style applied on the :before or :after content,
 290     // then we want the parent of the first-letter block
 291     RenderObject* beforeAfterParent = object;
 292     while (beforeAfterParent && !(beforeAfterParent->isText() || beforeAfterParent->isImage())
 293         && (beforeAfterParent->style()->styleType() != FIRST_LETTER))
 294         beforeAfterParent = beforeAfterParent->firstChild();
 295
 296     return beforeAfterParent ? beforeAfterParent->parent() : 0;
 297 }
 298
 299 RenderObject* RenderObjectChildList::beforePseudoElementRenderer(const RenderObject* owner) const
 300 {
 301     // An anonymous (generated) inline run-in that has PseudoId BEFORE must come from a grandparent.
 302     // Therefore we should skip these generated run-ins when checking our immediate children.
 303     // If we don't find our :before child immediately, then we should check if we own a
 304     // generated inline run-in in the next level of children.
 305     RenderObject* first = const_cast<RenderObject*>(owner);
 306     do {
 307         first = first->firstChild();
 308         // Skip list markers and generated run-ins.
 309         while (first && (first->isListMarker() || (first->isRenderInline() && first->isRunIn())))
 310             first = first->nextInPreOrderAfterChildren(owner);
 311     } while (first && first->isAnonymous() && first->style()->styleType() == NOPSEUDO);
 312
 313     if (!first)
 314         return 0;
 315
 316     if (first->isBeforeContent())
 317         return first;
 318
 319     // Check for a possible generated run-in, using run-in positioning rules.
 320     first = owner->firstChild();
 321     if (!first->isRenderBlock())
 322         return 0;
 323
 324     first = first->firstChild();
 325     // We still need to skip any list markers that could exist before the run-in.
 326     while (first && first->isListMarker())
 327         first = first->nextSibling();
 328     if (first && first->isBeforeContent() && first->isRenderInline() && first->isRunIn())
 329         return first;
 330
 331     return 0;
 332 }
 333
 334 RenderObject* RenderObjectChildList::afterPseudoElementRenderer(const RenderObject* owner) const
 335 {
 336     RenderObject* last = const_cast<RenderObject*>(owner);
 337     do {
 338         last = last->lastChild();
 339     } while (last && last->isAnonymous() && last->style()->styleType() == NOPSEUDO && !last->isListMarker());
 340     if (last && !last->isAfterContent())
 341         return 0;
 342     return last;
 343 }
 344
 345 void RenderObjectChildList::updateBeforeAfterContent(RenderObject* owner, PseudoId type, const RenderObject* styledObject)
 346 {
 347     // Double check that the document did in fact use generated content rules.  Otherwise we should not have been called.
 348     ASSERT(owner->document()->usesBeforeAfterRules());
 349
 350     // In CSS2, before/after pseudo-content cannot nest.  Check this first.
 351     if (owner->style()->styleType() == BEFORE || owner->style()->styleType() == AFTER)
 352         return;
 353
 354     if (!styledObject)
 355         styledObject = owner;
 356
 357     RenderStyle* pseudoElementStyle = styledObject->getCachedPseudoStyle(type);
 358     RenderObject* child;
 359     switch (type) {
 360     case BEFORE:
 361         child = beforePseudoElementRenderer(owner);
 362         break;
 363     case AFTER:
 364         child = afterPseudoElementRenderer(owner);
 365         break;
 366     default:
 367         ASSERT_NOT_REACHED();
 368         return;
 369     }
 370
 371     // Whether or not we currently have generated content attached.
 372     bool oldContentPresent = child;
 373
 374     // Whether or not we now want generated content.
 375     bool newContentWanted = pseudoElementStyle && pseudoElementStyle->display() != NONE;
 376
 377     // For <q><p/></q>, if this object is the inline continuation of the <q>, we only want to generate
 378     // :after content and not :before content.
 379     if (newContentWanted && type == BEFORE && owner->isElementContinuation())
 380         newContentWanted = false;
 381
 382     // Similarly, if we're the beginning of a <q>, and there's an inline continuation for our object,
 383     // then we don't generate the :after content.
 384     if (newContentWanted && type == AFTER && owner->virtualContinuation())
 385         newContentWanted = false;
 386
 387     // If we don't want generated content any longer, or if we have generated content, but it's no longer
 388     // identical to the new content data we want to build render objects for, then we nuke all
 389     // of the old generated content.
 390     if (oldContentPresent && (!newContentWanted || Node::diff(child->style(), pseudoElementStyle) == Node::Detach)) {
 391         // Nuke the child.
 392         if (child->style()->styleType() == type) {
 393             oldContentPresent = false;
 394             child->destroy();
 395             child = (type == BEFORE) ? owner->virtualChildren()->firstChild() : owner->virtualChildren()->lastChild();
 396         }
 397     }
 398
 399     // If we have no pseudo-element style or if the pseudo-element style's display type is NONE, then we
 400     // have no generated content and can now return.
 401     if (!newContentWanted)
 402         return;
 403
 404     if (owner->isRenderInline() && !pseudoElementStyle->isDisplayInlineType() && !pseudoElementStyle->isFloating() &&
 405         !(pseudoElementStyle->position() == AbsolutePosition || pseudoElementStyle->position() == FixedPosition))
 406         // According to the CSS2 spec (the end of section 12.1), the only allowed
 407         // display values for the pseudo style are NONE and INLINE for inline flows.
 408         // FIXME: CSS2.1 lifted this restriction, but block display types will crash.
 409         // For now we at least relax the restriction to allow all inline types like inline-block
 410         // and inline-table.
 411         pseudoElementStyle->setDisplay(INLINE);
 412
 413     if (oldContentPresent) {
 414         if (child && child->style()->styleType() == type) {
 415             // We have generated content present still.  We want to walk this content and update our
 416             // style information with the new pseudo-element style.
 417             child->setStyle(pseudoElementStyle);
 418
 419             RenderObject* beforeAfterParent = findBeforeAfterParent(child);
 420             if (!beforeAfterParent)
 421                 return;
 422
 423             // When beforeAfterParent is not equal to child (e.g. in tables),
 424             // we need to create new styles inheriting from pseudoElementStyle
 425             // on all the intermediate parents (leaving their display same).
 426             if (beforeAfterParent != child) {
 427                 RenderObject* curr = beforeAfterParent;
 428                 while (curr && curr != child) {
 429                     ASSERT(curr->isAnonymous());
 430                     RefPtr<RenderStyle> newStyle = RenderStyle::create();
 431                     newStyle->inheritFrom(pseudoElementStyle);
 432                     newStyle->setDisplay(curr->style()->display());
 433                     newStyle->setStyleType(curr->style()->styleType());
 434                     curr->setStyle(newStyle);
 435                     curr = curr->parent();
 436                 }
 437             }
 438
 439             // Note that if we ever support additional types of generated content (which should be way off
 440             // in the future), this code will need to be patched.
 441             for (RenderObject* genChild = beforeAfterParent->firstChild(); genChild; genChild = genChild->nextSibling()) {
 442                 if (genChild->isText())
 443                     // Generated text content is a child whose style also needs to be set to the pseudo-element style.
 444                     genChild->setStyle(pseudoElementStyle);
 445                 else if (genChild->isImage()) {
 446                     // Images get an empty style that inherits from the pseudo.
 447                     RefPtr<RenderStyle> style = RenderStyle::create();
 448                     style->inheritFrom(pseudoElementStyle);
 449                     genChild->setStyle(style.release());
 450                 } else {
 451                     // RenderListItem may insert a list marker here. We do not need to care about this case.
 452                     // Otherwise, genChild must be a first-letter container. updateFirstLetter() will take care of it.
 453                     ASSERT(genChild->isListMarker() || genChild->style()->styleType() == FIRST_LETTER);
 454                 }
 455             }
 456         }
 457         return; // We've updated the generated content. That's all we needed to do.
 458     }
 459
 460     RenderObject* insertBefore = (type == BEFORE) ? owner->virtualChildren()->firstChild() : 0;
 461     if (insertBefore && insertBefore->isAnonymousBlock() && insertBefore->childrenInline() && !insertBefore->isEmpty()) {
 462         // We are going to add the "before" element. We have to check whether the "insertBefore" element
 463         // is an anonymous block with inline children. If it is, then we should insert the "before" element
 464         // before the first inline child of the anonymous block, otherwise we will end up with the "before"
 465         // element in a different block. We do this only when the anonymous block has children, otherwise
 466         // we end up with the before element in a wrong block.
 467         insertBefore = insertBefore->firstChild();
 468     }
 469
 470     // Generated content consists of a single container that houses multiple children (specified
 471     // by the content property).  This generated content container gets the pseudo-element style set on it.
 472     RenderObject* generatedContentContainer = 0;
 473
 474     // Walk our list of generated content and create render objects for each.
 475     for (const ContentData* content = pseudoElementStyle->contentData(); content; content = content->next()) {
 476         RenderObject* renderer = 0;
 477         switch (content->type()) {
 478             case CONTENT_NONE:
 479                 break;
 480             case CONTENT_TEXT:
 481                 renderer = new (owner->renderArena()) RenderTextFragment(owner->document() /* anonymous object */, static_cast<const TextContentData*>(content)->text().impl());
 482                 renderer->setStyle(pseudoElementStyle);
 483                 break;
 484             case CONTENT_OBJECT: {
 485                 RenderImage* image = new (owner->renderArena()) RenderImage(owner->document()); // anonymous object
 486                 RefPtr<RenderStyle> style = RenderStyle::create();
 487                 style->inheritFrom(pseudoElementStyle);
 488                 image->setStyle(style.release());
 489                 if (const StyleImage* styleImage = static_cast<const ImageContentData*>(content)->image())
 490                     image->setImageResource(RenderImageResourceStyleImage::create(const_cast<StyleImage*>(styleImage)));
 491                 else
 492                     image->setImageResource(RenderImageResource::create());
 493                 renderer = image;
 494                 break;
 495             }
 496         case CONTENT_COUNTER:
 497             renderer = new (owner->renderArena()) RenderCounter(owner->document(), *static_cast<const CounterContentData*>(content)->counter());
 498             renderer->setStyle(pseudoElementStyle);
 499             break;
 500         case CONTENT_QUOTE:
 501             renderer = new (owner->renderArena()) RenderQuote(owner->document(), static_cast<const QuoteContentData*>(content)->quote());
 502             renderer->setStyle(pseudoElementStyle);
 503             break;
 504         }
 505
 506         if (renderer) {
 507             if (!generatedContentContainer) {
 508                 // Make a generated box that might be any display type now that we are able to drill down into children
 509                 // to find the original content properly.
 510                 generatedContentContainer = RenderObject::createObject(owner->document(), pseudoElementStyle);
 511                 ASSERT(styledObject->node()); // The styled object cannot be anonymous or else it could not have ':before' or ':after' pseudo elements.
 512                 generatedContentContainer->setNode(styledObject->node()); // This allows access to the generatingNode.
 513                 generatedContentContainer->setStyle(pseudoElementStyle);
 514                 if (!owner->isChildAllowed(generatedContentContainer, pseudoElementStyle)) {
 515                     // The generated content container is not allowed here -> abort.
 516                     generatedContentContainer->destroy();
 517                     renderer->destroy();
 518                     return;
 519                 }
 520                 owner->addChild(generatedContentContainer, insertBefore);
 521             }
 522             if (generatedContentContainer->isChildAllowed(renderer, pseudoElementStyle))
 523                 generatedContentContainer->addChild(renderer);
 524             else
 525                 renderer->destroy();
 526         }
 527     }
 528 }
 529
 530 } // namespace WebCore