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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  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  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 "RenderImage.h"
  35 #include "RenderImageResourceStyleImage.h"
  36 #include "RenderInline.h"
  37 #include "RenderLayer.h"
  38 #include "RenderListItem.h"
  39 #include "RenderQuote.h"
  40 #include "RenderStyle.h"
  41 #include "RenderTextFragment.h"
  42 #include "RenderView.h"
  43
  44 namespace WebCore {
  45
  46 void RenderObjectChildList::destroyLeftoverChildren()
  47 {
  48     while (firstChild()) {
  49         if (firstChild()->isListMarker() || (firstChild()->style()->styleType() == FIRST_LETTER && !firstChild()->isText()))
  50             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.
  51         else if (firstChild()->isRunIn() && firstChild()->node()) {
  52             firstChild()->node()->setRenderer(0);
  53             firstChild()->node()->setNeedsStyleRecalc();
  54             firstChild()->destroy();
  55         } else {
  56             // 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.
  57             if (firstChild()->node())
  58                 firstChild()->node()->setRenderer(0);
  59             firstChild()->destroy();
  60         }
  61     }
  62 }
  63
  64 RenderObject* RenderObjectChildList::removeChildNode(RenderObject* owner, RenderObject* oldChild, bool fullRemove)
  65 {
  66     ASSERT(oldChild->parent() == owner);
  67
  68     // So that we'll get the appropriate dirty bit set (either that a normal flow child got yanked or
  69     // that a positioned child got yanked).  We also repaint, so that the area exposed when the child
  70     // disappears gets repainted properly.
  71     if (!owner->documentBeingDestroyed() && fullRemove && oldChild->m_everHadLayout) {
  72         oldChild->setNeedsLayoutAndPrefWidthsRecalc();
  73         if (oldChild->isBody())
  74             owner->view()->repaint();
  75         else
  76             oldChild->repaint();
  77     }
  78
  79     // If we have a line box wrapper, delete it.
  80     if (oldChild->isBox())
  81         toRenderBox(oldChild)->deleteLineBoxWrapper();
  82
  83     if (!owner->documentBeingDestroyed() && fullRemove) {
  84         // if we remove visible child from an invisible parent, we don't know the layer visibility any more
  85         RenderLayer* layer = 0;
  86         if (owner->style()->visibility() != VISIBLE && oldChild->style()->visibility() == VISIBLE && !oldChild->hasLayer()) {
  87             layer = owner->enclosingLayer();
  88             layer->dirtyVisibleContentStatus();
  89         }
  90
  91          // Keep our layer hierarchy updated.
  92         if (oldChild->firstChild() || oldChild->hasLayer()) {
  93             if (!layer)
  94                 layer = owner->enclosingLayer();
  95             oldChild->removeLayers(layer);
  96         }
  97
  98         if (oldChild->isListItem())
  99             toRenderListItem(oldChild)->updateListMarkerNumbers();
 100
 101         if (oldChild->isPositioned() && owner->childrenInline())
 102             owner->dirtyLinesFromChangedChild(oldChild);
 103
 104 #if ENABLE(SVG)
 105         // Update cached boundaries in SVG renderers, if a child is removed.
 106         owner->setNeedsBoundariesUpdate();
 107 #endif
 108     }
 109
 110     // If oldChild is the start or end of the selection, then clear the selection to
 111     // avoid problems of invalid pointers.
 112     // FIXME: The SelectionController should be responsible for this when it
 113     // is notified of DOM mutations.
 114     if (!owner->documentBeingDestroyed() && oldChild->isSelectionBorder())
 115         owner->view()->clearSelection();
 116
 117     // remove the child
 118     if (oldChild->previousSibling())
 119         oldChild->previousSibling()->setNextSibling(oldChild->nextSibling());
 120     if (oldChild->nextSibling())
 121         oldChild->nextSibling()->setPreviousSibling(oldChild->previousSibling());
 122
 123     if (firstChild() == oldChild)
 124         setFirstChild(oldChild->nextSibling());
 125     if (lastChild() == oldChild)
 126         setLastChild(oldChild->previousSibling());
 127
 128     oldChild->setPreviousSibling(0);
 129     oldChild->setNextSibling(0);
 130     oldChild->setParent(0);
 131
 132     RenderCounter::rendererRemovedFromTree(oldChild);
 133     RenderQuote::rendererRemovedFromTree(oldChild);
 134
 135     if (AXObjectCache::accessibilityEnabled())
 136         owner->document()->axObjectCache()->childrenChanged(owner);
 137
 138     return oldChild;
 139 }
 140
 141 void RenderObjectChildList::appendChildNode(RenderObject* owner, RenderObject* newChild, bool fullAppend)
 142 {
 143     ASSERT(newChild->parent() == 0);
 144     ASSERT(!owner->isBlockFlow() || (!newChild->isTableSection() && !newChild->isTableRow() && !newChild->isTableCell()));
 145
 146     newChild->setParent(owner);
 147     RenderObject* lChild = lastChild();
 148
 149     if (lChild) {
 150         newChild->setPreviousSibling(lChild);
 151         lChild->setNextSibling(newChild);
 152     } else
 153         setFirstChild(newChild);
 154
 155     setLastChild(newChild);
 156
 157     if (fullAppend) {
 158         // Keep our layer hierarchy updated.  Optimize for the common case where we don't have any children
 159         // and don't have a layer attached to ourselves.
 160         RenderLayer* layer = 0;
 161         if (newChild->firstChild() || newChild->hasLayer()) {
 162             layer = owner->enclosingLayer();
 163             newChild->addLayers(layer, newChild);
 164         }
 165
 166         // if the new child is visible but this object was not, tell the layer it has some visible content
 167         // that needs to be drawn and layer visibility optimization can't be used
 168         if (owner->style()->visibility() != VISIBLE && newChild->style()->visibility() == VISIBLE && !newChild->hasLayer()) {
 169             if (!layer)
 170                 layer = owner->enclosingLayer();
 171             if (layer)
 172                 layer->setHasVisibleContent(true);
 173         }
 174
 175         if (newChild->isListItem())
 176             toRenderListItem(newChild)->updateListMarkerNumbers();
 177
 178         if (!newChild->isFloatingOrPositioned() && owner->childrenInline())
 179             owner->dirtyLinesFromChangedChild(newChild);
 180     }
 181     RenderCounter::rendererSubtreeAttached(newChild);
 182     RenderQuote::rendererSubtreeAttached(newChild);
 183     newChild->setNeedsLayoutAndPrefWidthsRecalc(); // Goes up the containing block hierarchy.
 184     if (!owner->normalChildNeedsLayout())
 185         owner->setChildNeedsLayout(true); // We may supply the static position for an absolute positioned child.
 186
 187     if (AXObjectCache::accessibilityEnabled())
 188         owner->document()->axObjectCache()->childrenChanged(owner);
 189 }
 190
 191 void RenderObjectChildList::insertChildNode(RenderObject* owner, RenderObject* child, RenderObject* beforeChild, bool fullInsert)
 192 {
 193     if (!beforeChild) {
 194         appendChildNode(owner, child, fullInsert);
 195         return;
 196     }
 197
 198     ASSERT(!child->parent());
 199     while (beforeChild->parent() != owner && beforeChild->parent()->isAnonymousBlock())
 200         beforeChild = beforeChild->parent();
 201     ASSERT(beforeChild->parent() == owner);
 202
 203     ASSERT(!owner->isBlockFlow() || (!child->isTableSection() && !child->isTableRow() && !child->isTableCell()));
 204
 205     if (beforeChild == firstChild())
 206         setFirstChild(child);
 207
 208     RenderObject* prev = beforeChild->previousSibling();
 209     child->setNextSibling(beforeChild);
 210     beforeChild->setPreviousSibling(child);
 211     if (prev)
 212         prev->setNextSibling(child);
 213     child->setPreviousSibling(prev);
 214
 215     child->setParent(owner);
 216
 217     if (fullInsert) {
 218         // Keep our layer hierarchy updated.  Optimize for the common case where we don't have any children
 219         // and don't have a layer attached to ourselves.
 220         RenderLayer* layer = 0;
 221         if (child->firstChild() || child->hasLayer()) {
 222             layer = owner->enclosingLayer();
 223             child->addLayers(layer, child);
 224         }
 225
 226         // if the new child is visible but this object was not, tell the layer it has some visible content
 227         // that needs to be drawn and layer visibility optimization can't be used
 228         if (owner->style()->visibility() != VISIBLE && child->style()->visibility() == VISIBLE && !child->hasLayer()) {
 229             if (!layer)
 230                 layer = owner->enclosingLayer();
 231             if (layer)
 232                 layer->setHasVisibleContent(true);
 233         }
 234
 235         if (child->isListItem())
 236             toRenderListItem(child)->updateListMarkerNumbers();
 237
 238         if (!child->isFloating() && owner->childrenInline())
 239             owner->dirtyLinesFromChangedChild(child);
 240     }
 241
 242     RenderCounter::rendererSubtreeAttached(child);
 243     RenderQuote::rendererSubtreeAttached(child);
 244     child->setNeedsLayoutAndPrefWidthsRecalc();
 245     if (!owner->normalChildNeedsLayout())
 246         owner->setChildNeedsLayout(true); // We may supply the static position for an absolute positioned child.
 247
 248     if (AXObjectCache::accessibilityEnabled())
 249         owner->document()->axObjectCache()->childrenChanged(owner);
 250 }
 251
 252 static RenderObject* findBeforeAfterParent(RenderObject* object)
 253 {
 254     // Only table parts need to search for the :before or :after parent
 255     if (!(object->isTable() || object->isTableSection() || object->isTableRow()))
 256         return object;
 257
 258     RenderObject* beforeAfterParent = object;
 259     while (beforeAfterParent && !(beforeAfterParent->isText() || beforeAfterParent->isImage()))
 260         beforeAfterParent = beforeAfterParent->firstChild();
 261     return beforeAfterParent;
 262 }
 263
 264 RenderObject* RenderObjectChildList::beforePseudoElementRenderer(const RenderObject* owner) const
 265 {
 266     // An anonymous (generated) inline run-in that has PseudoId BEFORE must come from a grandparent.
 267     // Therefore we should skip these generated run-ins when checking our immediate children.
 268     // If we don't find our :before child immediately, then we should check if we own a
 269     // generated inline run-in in the next level of children.
 270     RenderObject* first = const_cast<RenderObject*>(owner);
 271     do {
 272         // Skip list markers and generated run-ins
 273         first = first->firstChild();
 274         while (first && (first->isListMarker() || (first->isRenderInline() && first->isRunIn() && first->isAnonymous())))
 275             first = first->nextSibling();
 276     } while (first && first->isAnonymous() && first->style()->styleType() == NOPSEUDO);
 277
 278     if (!first)
 279         return 0;
 280
 281     if (first->style()->styleType() == BEFORE)
 282         return first;
 283
 284     // Check for a possible generated run-in, using run-in positioning rules.
 285     // Skip inlines and floating / positioned blocks, and place as the first child.
 286     first = owner->firstChild();
 287     if (!first->isRenderBlock())
 288         return 0;
 289     while (first && first->isFloatingOrPositioned())
 290         first = first->nextSibling();
 291     if (first) {
 292         first = first->firstChild();
 293         // We still need to skip any list markers that could exist before the run-in.
 294         while (first && first->isListMarker())
 295             first = first->nextSibling();
 296         if (first && first->style()->styleType() == BEFORE && first->isRenderInline() && first->isRunIn() && first->isAnonymous())
 297             return first;
 298     }
 299     return 0;
 300 }
 301
 302 RenderObject* RenderObjectChildList::afterPseudoElementRenderer(const RenderObject* owner) const
 303 {
 304     RenderObject* last = const_cast<RenderObject*>(owner);
 305     do {
 306         last = last->lastChild();
 307     } while (last && last->isAnonymous() && last->style()->styleType() == NOPSEUDO && !last->isListMarker());
 308     if (last && last->style()->styleType() != AFTER)
 309         return 0;
 310     return last;
 311 }
 312
 313 void RenderObjectChildList::updateBeforeAfterContent(RenderObject* owner, PseudoId type, const RenderObject* styledObject)
 314 {
 315     // Double check that the document did in fact use generated content rules.  Otherwise we should not have been called.
 316     ASSERT(owner->document()->usesBeforeAfterRules());
 317
 318     // In CSS2, before/after pseudo-content cannot nest.  Check this first.
 319     if (owner->style()->styleType() == BEFORE || owner->style()->styleType() == AFTER)
 320         return;
 321
 322     if (!styledObject)
 323         styledObject = owner;
 324
 325     RenderStyle* pseudoElementStyle = styledObject->getCachedPseudoStyle(type);
 326     RenderObject* child;
 327     switch (type) {
 328     case BEFORE:
 329         child = beforePseudoElementRenderer(owner);
 330         break;
 331     case AFTER:
 332         child = afterPseudoElementRenderer(owner);
 333         break;
 334     default:
 335         ASSERT_NOT_REACHED();
 336         return;
 337     }
 338
 339     // Whether or not we currently have generated content attached.
 340     bool oldContentPresent = child;
 341
 342     // Whether or not we now want generated content.
 343     bool newContentWanted = pseudoElementStyle && pseudoElementStyle->display() != NONE;
 344
 345     // For <q><p/></q>, if this object is the inline continuation of the <q>, we only want to generate
 346     // :after content and not :before content.
 347     if (newContentWanted && type == BEFORE && owner->isElementContinuation())
 348         newContentWanted = false;
 349
 350     // Similarly, if we're the beginning of a <q>, and there's an inline continuation for our object,
 351     // then we don't generate the :after content.
 352     if (newContentWanted && type == AFTER && owner->virtualContinuation())
 353         newContentWanted = false;
 354
 355     // If we don't want generated content any longer, or if we have generated content, but it's no longer
 356     // identical to the new content data we want to build render objects for, then we nuke all
 357     // of the old generated content.
 358     if (oldContentPresent && (!newContentWanted || Node::diff(child->style(), pseudoElementStyle) == Node::Detach)) {
 359         // Nuke the child.
 360         if (child->style()->styleType() == type) {
 361             oldContentPresent = false;
 362             child->destroy();
 363             child = (type == BEFORE) ? owner->virtualChildren()->firstChild() : owner->virtualChildren()->lastChild();
 364         }
 365     }
 366
 367     // If we have no pseudo-element style or if the pseudo-element style's display type is NONE, then we
 368     // have no generated content and can now return.
 369     if (!newContentWanted)
 370         return;
 371
 372     if (owner->isRenderInline() && !pseudoElementStyle->isDisplayInlineType() && pseudoElementStyle->floating() == FNONE &&
 373         !(pseudoElementStyle->position() == AbsolutePosition || pseudoElementStyle->position() == FixedPosition))
 374         // According to the CSS2 spec (the end of section 12.1), the only allowed
 375         // display values for the pseudo style are NONE and INLINE for inline flows.
 376         // FIXME: CSS2.1 lifted this restriction, but block display types will crash.
 377         // For now we at least relax the restriction to allow all inline types like inline-block
 378         // and inline-table.
 379         pseudoElementStyle->setDisplay(INLINE);
 380
 381     if (oldContentPresent) {
 382         if (child && child->style()->styleType() == type) {
 383             // We have generated content present still.  We want to walk this content and update our
 384             // style information with the new pseudo-element style.
 385             child->setStyle(pseudoElementStyle);
 386
 387             RenderObject* beforeAfterParent = findBeforeAfterParent(child);
 388             if (!beforeAfterParent)
 389                 return;
 390
 391             // Note that if we ever support additional types of generated content (which should be way off
 392             // in the future), this code will need to be patched.
 393             for (RenderObject* genChild = beforeAfterParent->firstChild(); genChild; genChild = genChild->nextSibling()) {
 394                 if (genChild->isText())
 395                     // Generated text content is a child whose style also needs to be set to the pseudo-element style.
 396                     genChild->setStyle(pseudoElementStyle);
 397                 else if (genChild->isImage()) {
 398                     // Images get an empty style that inherits from the pseudo.
 399                     RefPtr<RenderStyle> style = RenderStyle::create();
 400                     style->inheritFrom(pseudoElementStyle);
 401                     genChild->setStyle(style.release());
 402                 } else {
 403                     // RenderListItem may insert a list marker here. We do not need to care about this case.
 404                     // Otherwise, genChild must be a first-letter container. updateFirstLetter() will take care of it.
 405                     ASSERT(genChild->isListMarker() || genChild->style()->styleType() == FIRST_LETTER);
 406                 }
 407             }
 408         }
 409         return; // We've updated the generated content. That's all we needed to do.
 410     }
 411
 412     RenderObject* insertBefore = (type == BEFORE) ? owner->virtualChildren()->firstChild() : 0;
 413
 414     // Generated content consists of a single container that houses multiple children (specified
 415     // by the content property).  This generated content container gets the pseudo-element style set on it.
 416     RenderObject* generatedContentContainer = 0;
 417
 418     // Walk our list of generated content and create render objects for each.
 419     for (const ContentData* content = pseudoElementStyle->contentData(); content; content = content->next()) {
 420         RenderObject* renderer = 0;
 421         switch (content->type()) {
 422             case CONTENT_NONE:
 423                 break;
 424             case CONTENT_TEXT:
 425                 renderer = new (owner->renderArena()) RenderTextFragment(owner->document() /* anonymous object */, content->text());
 426                 renderer->setStyle(pseudoElementStyle);
 427                 break;
 428             case CONTENT_OBJECT: {
 429                 RenderImage* image = new (owner->renderArena()) RenderImage(owner->document()); // anonymous object
 430                 RefPtr<RenderStyle> style = RenderStyle::create();
 431                 style->inheritFrom(pseudoElementStyle);
 432                 image->setStyle(style.release());
 433                 if (StyleImage* styleImage = content->image())
 434                     image->setImageResource(RenderImageResourceStyleImage::create(styleImage));
 435                 else
 436                     image->setImageResource(RenderImageResource::create());
 437                 renderer = image;
 438                 break;
 439             }
 440         case CONTENT_COUNTER:
 441             renderer = new (owner->renderArena()) RenderCounter(owner->document(), *content->counter());
 442             renderer->setStyle(pseudoElementStyle);
 443             break;
 444         case CONTENT_QUOTE:
 445             renderer = new (owner->renderArena()) RenderQuote(owner->document(), content->quote());
 446             renderer->setStyle(pseudoElementStyle);
 447             break;
 448         }
 449
 450         if (renderer) {
 451             if (!generatedContentContainer) {
 452                 // Make a generated box that might be any display type now that we are able to drill down into children
 453                 // to find the original content properly.
 454                 generatedContentContainer = RenderObject::createObject(owner->document(), pseudoElementStyle);
 455                 ASSERT(styledObject->node()); // The styled object cannot be anonymous or else it could not have ':before' or ':after' pseudo elements.
 456                 generatedContentContainer->setNode(styledObject->node()); // This allows access to the generatingNode.
 457                 generatedContentContainer->setStyle(pseudoElementStyle);
 458                 if (!owner->isChildAllowed(generatedContentContainer, pseudoElementStyle)) {
 459                     // The generated content container is not allowed here -> abort.
 460                     generatedContentContainer->destroy();
 461                     renderer->destroy();
 462                     return;
 463                 }
 464                 owner->addChild(generatedContentContainer, insertBefore);
 465             }
 466             if (generatedContentContainer->isChildAllowed(renderer, pseudoElementStyle))
 467                 generatedContentContainer->addChild(renderer);
 468             else
 469                 renderer->destroy();
 470         }
 471     }
 472 }
 473
 474 } // namespace WebCore