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
  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 "RenderStyle.h"
  40 #include "RenderTextFragment.h"
  41 #include "RenderView.h"
  42
  43 namespace WebCore {
  44
  45 void RenderObjectChildList::destroyLeftoverChildren()
  46 {
  47     while (firstChild()) {
  48         if (firstChild()->isListMarker() || (firstChild()->style()->styleType() == FIRST_LETTER && !firstChild()->isText()))
  49             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.
  50         else if (firstChild()->isRunIn() && firstChild()->node()) {
  51             firstChild()->node()->setRenderer(0);
  52             firstChild()->node()->setNeedsStyleRecalc();
  53             firstChild()->destroy();
  54         } else {
  55             // 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.
  56             if (firstChild()->node())
  57                 firstChild()->node()->setRenderer(0);
  58             firstChild()->destroy();
  59         }
  60     }
  61 }
  62
  63 RenderObject* RenderObjectChildList::removeChildNode(RenderObject* owner, RenderObject* oldChild, bool fullRemove)
  64 {
  65     ASSERT(oldChild->parent() == owner);
  66
  67     // So that we'll get the appropriate dirty bit set (either that a normal flow child got yanked or
  68     // that a positioned child got yanked).  We also repaint, so that the area exposed when the child
  69     // disappears gets repainted properly.
  70     if (!owner->documentBeingDestroyed() && fullRemove && oldChild->m_everHadLayout) {
  71         oldChild->setNeedsLayoutAndPrefWidthsRecalc();
  72         if (oldChild->isBody())
  73             owner->view()->repaint();
  74         else
  75             oldChild->repaint();
  76     }
  77
  78     // If we have a line box wrapper, delete it.
  79     if (oldChild->isBox())
  80         toRenderBox(oldChild)->deleteLineBoxWrapper();
  81
  82     if (!owner->documentBeingDestroyed() && fullRemove) {
  83         // if we remove visible child from an invisible parent, we don't know the layer visibility any more
  84         RenderLayer* layer = 0;
  85         if (owner->style()->visibility() != VISIBLE && oldChild->style()->visibility() == VISIBLE && !oldChild->hasLayer()) {
  86             layer = owner->enclosingLayer();
  87             layer->dirtyVisibleContentStatus();
  88         }
  89
  90          // Keep our layer hierarchy updated.
  91         if (oldChild->firstChild() || oldChild->hasLayer()) {
  92             if (!layer)
  93                 layer = owner->enclosingLayer();
  94             oldChild->removeLayers(layer);
  95         }
  96
  97         if (oldChild->isListItem())
  98             toRenderListItem(oldChild)->updateListMarkerNumbers();
  99
 100         if (oldChild->isPositioned() && owner->childrenInline())
 101             owner->dirtyLinesFromChangedChild(oldChild);
 102
 103 #if ENABLE(SVG)
 104         // Update cached boundaries in SVG renderers, if a child is removed.
 105         owner->setNeedsBoundariesUpdate();
 106 #endif
 107     }
 108
 109     // If oldChild is the start or end of the selection, then clear the selection to
 110     // avoid problems of invalid pointers.
 111     // FIXME: The SelectionController should be responsible for this when it
 112     // is notified of DOM mutations.
 113     if (!owner->documentBeingDestroyed() && oldChild->isSelectionBorder())
 114         owner->view()->clearSelection();
 115
 116     // remove the child
 117     if (oldChild->previousSibling())
 118         oldChild->previousSibling()->setNextSibling(oldChild->nextSibling());
 119     if (oldChild->nextSibling())
 120         oldChild->nextSibling()->setPreviousSibling(oldChild->previousSibling());
 121
 122     if (firstChild() == oldChild)
 123         setFirstChild(oldChild->nextSibling());
 124     if (lastChild() == oldChild)
 125         setLastChild(oldChild->previousSibling());
 126
 127     oldChild->setPreviousSibling(0);
 128     oldChild->setNextSibling(0);
 129     oldChild->setParent(0);
 130
 131     if (oldChild->m_hasCounterNodeMap)
 132         RenderCounter::destroyCounterNodes(oldChild);
 133
 134     if (AXObjectCache::accessibilityEnabled())
 135         owner->document()->axObjectCache()->childrenChanged(owner);
 136
 137     return oldChild;
 138 }
 139
 140 void RenderObjectChildList::appendChildNode(RenderObject* owner, RenderObject* newChild, bool fullAppend)
 141 {
 142     ASSERT(newChild->parent() == 0);
 143     ASSERT(!owner->isBlockFlow() || (!newChild->isTableSection() && !newChild->isTableRow() && !newChild->isTableCell()));
 144
 145     newChild->setParent(owner);
 146     RenderObject* lChild = lastChild();
 147
 148     if (lChild) {
 149         newChild->setPreviousSibling(lChild);
 150         lChild->setNextSibling(newChild);
 151     } else
 152         setFirstChild(newChild);
 153
 154     setLastChild(newChild);
 155
 156     if (fullAppend) {
 157         // Keep our layer hierarchy updated.  Optimize for the common case where we don't have any children
 158         // and don't have a layer attached to ourselves.
 159         RenderLayer* layer = 0;
 160         if (newChild->firstChild() || newChild->hasLayer()) {
 161             layer = owner->enclosingLayer();
 162             newChild->addLayers(layer, newChild);
 163         }
 164
 165         // if the new child is visible but this object was not, tell the layer it has some visible content
 166         // that needs to be drawn and layer visibility optimization can't be used
 167         if (owner->style()->visibility() != VISIBLE && newChild->style()->visibility() == VISIBLE && !newChild->hasLayer()) {
 168             if (!layer)
 169                 layer = owner->enclosingLayer();
 170             if (layer)
 171                 layer->setHasVisibleContent(true);
 172         }
 173
 174         if (newChild->isListItem())
 175             toRenderListItem(newChild)->updateListMarkerNumbers();
 176
 177         if (!newChild->isFloatingOrPositioned() && owner->childrenInline())
 178             owner->dirtyLinesFromChangedChild(newChild);
 179     }
 180
 181     RenderCounter::rendererSubtreeAttached(newChild);
 182     newChild->setNeedsLayoutAndPrefWidthsRecalc(); // Goes up the containing block hierarchy.
 183     if (!owner->normalChildNeedsLayout())
 184         owner->setChildNeedsLayout(true); // We may supply the static position for an absolute positioned child.
 185
 186     if (AXObjectCache::accessibilityEnabled())
 187         owner->document()->axObjectCache()->childrenChanged(owner);
 188 }
 189
 190 void RenderObjectChildList::insertChildNode(RenderObject* owner, RenderObject* child, RenderObject* beforeChild, bool fullInsert)
 191 {
 192     if (!beforeChild) {
 193         appendChildNode(owner, child, fullInsert);
 194         return;
 195     }
 196
 197     ASSERT(!child->parent());
 198     while (beforeChild->parent() != owner && beforeChild->parent()->isAnonymousBlock())
 199         beforeChild = beforeChild->parent();
 200     ASSERT(beforeChild->parent() == owner);
 201
 202     ASSERT(!owner->isBlockFlow() || (!child->isTableSection() && !child->isTableRow() && !child->isTableCell()));
 203
 204     if (beforeChild == firstChild())
 205         setFirstChild(child);
 206
 207     RenderObject* prev = beforeChild->previousSibling();
 208     child->setNextSibling(beforeChild);
 209     beforeChild->setPreviousSibling(child);
 210     if (prev)
 211         prev->setNextSibling(child);
 212     child->setPreviousSibling(prev);
 213
 214     child->setParent(owner);
 215
 216     if (fullInsert) {
 217         // Keep our layer hierarchy updated.  Optimize for the common case where we don't have any children
 218         // and don't have a layer attached to ourselves.
 219         RenderLayer* layer = 0;
 220         if (child->firstChild() || child->hasLayer()) {
 221             layer = owner->enclosingLayer();
 222             child->addLayers(layer, child);
 223         }
 224
 225         // if the new child is visible but this object was not, tell the layer it has some visible content
 226         // that needs to be drawn and layer visibility optimization can't be used
 227         if (owner->style()->visibility() != VISIBLE && child->style()->visibility() == VISIBLE && !child->hasLayer()) {
 228             if (!layer)
 229                 layer = owner->enclosingLayer();
 230             if (layer)
 231                 layer->setHasVisibleContent(true);
 232         }
 233
 234         if (child->isListItem())
 235             toRenderListItem(child)->updateListMarkerNumbers();
 236
 237         if (!child->isFloating() && owner->childrenInline())
 238             owner->dirtyLinesFromChangedChild(child);
 239     }
 240
 241     RenderCounter::rendererSubtreeAttached(child);
 242     child->setNeedsLayoutAndPrefWidthsRecalc();
 243     if (!owner->normalChildNeedsLayout())
 244         owner->setChildNeedsLayout(true); // We may supply the static position for an absolute positioned child.
 245
 246     if (AXObjectCache::accessibilityEnabled())
 247         owner->document()->axObjectCache()->childrenChanged(owner);
 248 }
 249
 250 static RenderObject* findBeforeAfterParent(RenderObject* object)
 251 {
 252     // Only table parts need to search for the :before or :after parent
 253     if (!(object->isTable() || object->isTableSection() || object->isTableRow()))
 254         return object;
 255
 256     RenderObject* beforeAfterParent = object;
 257     while (beforeAfterParent && !(beforeAfterParent->isText() || beforeAfterParent->isImage()))
 258         beforeAfterParent = beforeAfterParent->firstChild();
 259     return beforeAfterParent;
 260 }
 261
 262 static void invalidateCountersInContainer(RenderObject* container, const AtomicString& identifier)
 263 {
 264     if (!container)
 265         return;
 266     container = findBeforeAfterParent(container);
 267     if (!container)
 268         return;
 269     // Sometimes the counter is attached directly on the container.
 270     if (container->isCounter()) {
 271         toRenderCounter(container)->invalidate(identifier);
 272         return;
 273     }
 274     for (RenderObject* content = container->firstChild(); content; content = content->nextSibling()) {
 275         if (content->isCounter())
 276             toRenderCounter(content)->invalidate(identifier);
 277     }
 278 }
 279
 280 void RenderObjectChildList::invalidateCounters(const RenderObject* owner, const AtomicString& identifier)
 281 {
 282     ASSERT(!owner->documentBeingDestroyed());
 283     invalidateCountersInContainer(beforePseudoElementRenderer(owner), identifier);
 284     invalidateCountersInContainer(afterPseudoElementRenderer(owner), identifier);
 285 }
 286
 287 RenderObject* RenderObjectChildList::beforePseudoElementRenderer(const RenderObject* owner) const
 288 {
 289     // An anonymous (generated) inline run-in that has PseudoId BEFORE must come from a grandparent.
 290     // Therefore we should skip these generated run-ins when checking our immediate children.
 291     // If we don't find our :before child immediately, then we should check if we own a
 292     // generated inline run-in in the next level of children.
 293     RenderObject* first = const_cast<RenderObject*>(owner);
 294     do {
 295         // Skip list markers and generated run-ins
 296         first = first->firstChild();
 297         while (first && (first->isListMarker() || (first->isRenderInline() && first->isRunIn() && first->isAnonymous())))
 298             first = first->nextSibling();
 299     } while (first && first->isAnonymous() && first->style()->styleType() == NOPSEUDO);
 300
 301     if (!first)
 302         return 0;
 303
 304     if (first->style()->styleType() == BEFORE)
 305         return first;
 306
 307     // Check for a possible generated run-in, using run-in positioning rules.
 308     // Skip inlines and floating / positioned blocks, and place as the first child.
 309     first = owner->firstChild();
 310     if (!first->isRenderBlock())
 311         return 0;
 312     while (first && first->isFloatingOrPositioned())
 313         first = first->nextSibling();
 314     if (first) {
 315         first = first->firstChild();
 316         // We still need to skip any list markers that could exist before the run-in.
 317         while (first && first->isListMarker())
 318             first = first->nextSibling();
 319         if (first && first->style()->styleType() == BEFORE && first->isRenderInline() && first->isRunIn() && first->isAnonymous())
 320             return first;
 321     }
 322     return 0;
 323 }
 324
 325 RenderObject* RenderObjectChildList::afterPseudoElementRenderer(const RenderObject* owner) const
 326 {
 327     RenderObject* last = const_cast<RenderObject*>(owner);
 328     do {
 329         last = last->lastChild();
 330     } while (last && last->isAnonymous() && last->style()->styleType() == NOPSEUDO && !last->isListMarker());
 331     if (last && last->style()->styleType() != AFTER)
 332         return 0;
 333     return last;
 334 }
 335
 336 void RenderObjectChildList::updateBeforeAfterContent(RenderObject* owner, PseudoId type, const RenderObject* styledObject)
 337 {
 338     // Double check that the document did in fact use generated content rules.  Otherwise we should not have been called.
 339     ASSERT(owner->document()->usesBeforeAfterRules());
 340
 341     // In CSS2, before/after pseudo-content cannot nest.  Check this first.
 342     if (owner->style()->styleType() == BEFORE || owner->style()->styleType() == AFTER)
 343         return;
 344
 345     if (!styledObject)
 346         styledObject = owner;
 347
 348     RenderStyle* pseudoElementStyle = styledObject->getCachedPseudoStyle(type);
 349     RenderObject* child;
 350     switch (type) {
 351     case BEFORE:
 352         child = beforePseudoElementRenderer(owner);
 353         break;
 354     case AFTER:
 355         child = afterPseudoElementRenderer(owner);
 356         break;
 357     default:
 358         ASSERT_NOT_REACHED();
 359         return;
 360     }
 361
 362     // Whether or not we currently have generated content attached.
 363     bool oldContentPresent = child;
 364
 365     // Whether or not we now want generated content.
 366     bool newContentWanted = pseudoElementStyle && pseudoElementStyle->display() != NONE;
 367
 368     // For <q><p/></q>, if this object is the inline continuation of the <q>, we only want to generate
 369     // :after content and not :before content.
 370     if (newContentWanted && type == BEFORE && owner->isElementContinuation())
 371         newContentWanted = false;
 372
 373     // Similarly, if we're the beginning of a <q>, and there's an inline continuation for our object,
 374     // then we don't generate the :after content.
 375     if (newContentWanted && type == AFTER && owner->virtualContinuation())
 376         newContentWanted = false;
 377
 378     // If we don't want generated content any longer, or if we have generated content, but it's no longer
 379     // identical to the new content data we want to build render objects for, then we nuke all
 380     // of the old generated content.
 381     if (oldContentPresent && (!newContentWanted || Node::diff(child->style(), pseudoElementStyle) == Node::Detach)) {
 382         // Nuke the child.
 383         if (child->style()->styleType() == type) {
 384             oldContentPresent = false;
 385             child->destroy();
 386             child = (type == BEFORE) ? owner->virtualChildren()->firstChild() : owner->virtualChildren()->lastChild();
 387         }
 388     }
 389
 390     // If we have no pseudo-element style or if the pseudo-element style's display type is NONE, then we
 391     // have no generated content and can now return.
 392     if (!newContentWanted)
 393         return;
 394
 395     if (owner->isRenderInline() && !pseudoElementStyle->isDisplayInlineType() && pseudoElementStyle->floating() == FNONE &&
 396         !(pseudoElementStyle->position() == AbsolutePosition || pseudoElementStyle->position() == FixedPosition))
 397         // According to the CSS2 spec (the end of section 12.1), the only allowed
 398         // display values for the pseudo style are NONE and INLINE for inline flows.
 399         // FIXME: CSS2.1 lifted this restriction, but block display types will crash.
 400         // For now we at least relax the restriction to allow all inline types like inline-block
 401         // and inline-table.
 402         pseudoElementStyle->setDisplay(INLINE);
 403
 404     if (oldContentPresent) {
 405         if (child && child->style()->styleType() == type) {
 406             // We have generated content present still.  We want to walk this content and update our
 407             // style information with the new pseudo-element style.
 408             child->setStyle(pseudoElementStyle);
 409
 410             RenderObject* beforeAfterParent = findBeforeAfterParent(child);
 411             if (!beforeAfterParent)
 412                 return;
 413
 414             // Note that if we ever support additional types of generated content (which should be way off
 415             // in the future), this code will need to be patched.
 416             for (RenderObject* genChild = beforeAfterParent->firstChild(); genChild; genChild = genChild->nextSibling()) {
 417                 if (genChild->isText())
 418                     // Generated text content is a child whose style also needs to be set to the pseudo-element style.
 419                     genChild->setStyle(pseudoElementStyle);
 420                 else if (genChild->isImage()) {
 421                     // Images get an empty style that inherits from the pseudo.
 422                     RefPtr<RenderStyle> style = RenderStyle::create();
 423                     style->inheritFrom(pseudoElementStyle);
 424                     genChild->setStyle(style.release());
 425                 } else {
 426                     // RenderListItem may insert a list marker here. We do not need to care about this case.
 427                     // Otherwise, genChild must be a first-letter container. updateFirstLetter() will take care of it.
 428                     ASSERT(genChild->isListMarker() || genChild->style()->styleType() == FIRST_LETTER);
 429                 }
 430             }
 431         }
 432         return; // We've updated the generated content. That's all we needed to do.
 433     }
 434
 435     RenderObject* insertBefore = (type == BEFORE) ? owner->virtualChildren()->firstChild() : 0;
 436
 437     // Generated content consists of a single container that houses multiple children (specified
 438     // by the content property).  This generated content container gets the pseudo-element style set on it.
 439     RenderObject* generatedContentContainer = 0;
 440
 441     // Walk our list of generated content and create render objects for each.
 442     for (const ContentData* content = pseudoElementStyle->contentData(); content; content = content->next()) {
 443         RenderObject* renderer = 0;
 444         switch (content->type()) {
 445             case CONTENT_NONE:
 446                 break;
 447             case CONTENT_TEXT:
 448                 renderer = new (owner->renderArena()) RenderTextFragment(owner->document() /* anonymous object */, content->text());
 449                 renderer->setStyle(pseudoElementStyle);
 450                 break;
 451             case CONTENT_OBJECT: {
 452                 RenderImage* image = new (owner->renderArena()) RenderImage(owner->document()); // anonymous object
 453                 RefPtr<RenderStyle> style = RenderStyle::create();
 454                 style->inheritFrom(pseudoElementStyle);
 455                 image->setStyle(style.release());
 456                 if (StyleImage* styleImage = content->image())
 457                     image->setImageResource(RenderImageResourceStyleImage::create(styleImage));
 458                 else
 459                     image->setImageResource(RenderImageResource::create());
 460                 renderer = image;
 461                 break;
 462             }
 463             case CONTENT_COUNTER:
 464                 renderer = new (owner->renderArena()) RenderCounter(owner->document(), *content->counter());
 465                 renderer->setStyle(pseudoElementStyle);
 466                 break;
 467         }
 468
 469         if (renderer) {
 470             if (!generatedContentContainer) {
 471                 // Make a generated box that might be any display type now that we are able to drill down into children
 472                 // to find the original content properly.
 473                 generatedContentContainer = RenderObject::createObject(owner->document(), pseudoElementStyle);
 474                 ASSERT(styledObject->node()); // The styled object cannot be anonymous or else it could not have ':before' or ':after' pseudo elements.
 475                 generatedContentContainer->setNode(styledObject->node()); // This allows access to the generatingNode.
 476                 generatedContentContainer->setStyle(pseudoElementStyle);
 477                 owner->addChild(generatedContentContainer, insertBefore);
 478             }
 479             if (generatedContentContainer->isChildAllowed(renderer, pseudoElementStyle))
 480                 generatedContentContainer->addChild(renderer);
 481             else
 482                 renderer->destroy();
 483         }
 484     }
 485 }
 486
 487 } // namespace WebCore