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      1 /*
      2  * Copyright (C) 2005, 2006, 2008, 2009 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "ApplyStyleCommand.h"
     28 
     29 #include "CSSComputedStyleDeclaration.h"
     30 #include "CSSMutableStyleDeclaration.h"
     31 #include "CSSParser.h"
     32 #include "CSSProperty.h"
     33 #include "CSSPropertyNames.h"
     34 #include "CSSStyleSelector.h"
     35 #include "CSSValueKeywords.h"
     36 #include "CSSValueList.h"
     37 #include "Document.h"
     38 #include "EditingStyle.h"
     39 #include "Editor.h"
     40 #include "Frame.h"
     41 #include "HTMLFontElement.h"
     42 #include "HTMLInterchange.h"
     43 #include "HTMLNames.h"
     44 #include "NodeList.h"
     45 #include "Range.h"
     46 #include "RenderObject.h"
     47 #include "Text.h"
     48 #include "TextIterator.h"
     49 #include "htmlediting.h"
     50 #include "visible_units.h"
     51 #include <wtf/StdLibExtras.h>
     52 
     53 namespace WebCore {
     54 
     55 using namespace HTMLNames;
     56 
     57 static String& styleSpanClassString()
     58 {
     59     DEFINE_STATIC_LOCAL(String, styleSpanClassString, ((AppleStyleSpanClass)));
     60     return styleSpanClassString;
     61 }
     62 
     63 bool isStyleSpan(const Node *node)
     64 {
     65     if (!node || !node->isHTMLElement())
     66         return false;
     67 
     68     const HTMLElement* elem = static_cast<const HTMLElement*>(node);
     69     return elem->hasLocalName(spanAttr) && elem->getAttribute(classAttr) == styleSpanClassString();
     70 }
     71 
     72 static bool isUnstyledStyleSpan(const Node* node)
     73 {
     74     if (!node || !node->isHTMLElement() || !node->hasTagName(spanTag))
     75         return false;
     76 
     77     const HTMLElement* elem = static_cast<const HTMLElement*>(node);
     78     CSSMutableStyleDeclaration* inlineStyleDecl = elem->inlineStyleDecl();
     79     return (!inlineStyleDecl || inlineStyleDecl->isEmpty()) && elem->getAttribute(classAttr) == styleSpanClassString();
     80 }
     81 
     82 static bool isSpanWithoutAttributesOrUnstyleStyleSpan(const Node* node)
     83 {
     84     if (!node || !node->isHTMLElement() || !node->hasTagName(spanTag))
     85         return false;
     86 
     87     const HTMLElement* elem = static_cast<const HTMLElement*>(node);
     88     NamedNodeMap* attributes = elem->attributes(true); // readonly
     89     if (attributes->isEmpty())
     90         return true;
     91 
     92     return isUnstyledStyleSpan(node);
     93 }
     94 
     95 static bool isEmptyFontTag(const Node *node)
     96 {
     97     if (!node || !node->hasTagName(fontTag))
     98         return false;
     99 
    100     const Element *elem = static_cast<const Element *>(node);
    101     NamedNodeMap *map = elem->attributes(true); // true for read-only
    102     if (!map)
    103         return true;
    104     return map->isEmpty() || (map->length() == 1 && elem->getAttribute(classAttr) == styleSpanClassString());
    105 }
    106 
    107 static PassRefPtr<Element> createFontElement(Document* document)
    108 {
    109     RefPtr<Element> fontNode = createHTMLElement(document, fontTag);
    110     fontNode->setAttribute(classAttr, styleSpanClassString());
    111     return fontNode.release();
    112 }
    113 
    114 PassRefPtr<HTMLElement> createStyleSpanElement(Document* document)
    115 {
    116     RefPtr<HTMLElement> styleElement = createHTMLElement(document, spanTag);
    117     styleElement->setAttribute(classAttr, styleSpanClassString());
    118     return styleElement.release();
    119 }
    120 
    121 ApplyStyleCommand::ApplyStyleCommand(Document* document, const EditingStyle* style, EditAction editingAction, EPropertyLevel propertyLevel)
    122     : CompositeEditCommand(document)
    123     , m_style(style->copy())
    124     , m_editingAction(editingAction)
    125     , m_propertyLevel(propertyLevel)
    126     , m_start(endingSelection().start().downstream())
    127     , m_end(endingSelection().end().upstream())
    128     , m_useEndingSelection(true)
    129     , m_styledInlineElement(0)
    130     , m_removeOnly(false)
    131     , m_isInlineElementToRemoveFunction(0)
    132 {
    133 }
    134 
    135 ApplyStyleCommand::ApplyStyleCommand(Document* document, const EditingStyle* style, const Position& start, const Position& end, EditAction editingAction, EPropertyLevel propertyLevel)
    136     : CompositeEditCommand(document)
    137     , m_style(style->copy())
    138     , m_editingAction(editingAction)
    139     , m_propertyLevel(propertyLevel)
    140     , m_start(start)
    141     , m_end(end)
    142     , m_useEndingSelection(false)
    143     , m_styledInlineElement(0)
    144     , m_removeOnly(false)
    145     , m_isInlineElementToRemoveFunction(0)
    146 {
    147 }
    148 
    149 ApplyStyleCommand::ApplyStyleCommand(PassRefPtr<Element> element, bool removeOnly, EditAction editingAction)
    150     : CompositeEditCommand(element->document())
    151     , m_style(EditingStyle::create())
    152     , m_editingAction(editingAction)
    153     , m_propertyLevel(PropertyDefault)
    154     , m_start(endingSelection().start().downstream())
    155     , m_end(endingSelection().end().upstream())
    156     , m_useEndingSelection(true)
    157     , m_styledInlineElement(element)
    158     , m_removeOnly(removeOnly)
    159     , m_isInlineElementToRemoveFunction(0)
    160 {
    161 }
    162 
    163 ApplyStyleCommand::ApplyStyleCommand(Document* document, const EditingStyle* style, IsInlineElementToRemoveFunction isInlineElementToRemoveFunction, EditAction editingAction)
    164     : CompositeEditCommand(document)
    165     , m_style(style->copy())
    166     , m_editingAction(editingAction)
    167     , m_propertyLevel(PropertyDefault)
    168     , m_start(endingSelection().start().downstream())
    169     , m_end(endingSelection().end().upstream())
    170     , m_useEndingSelection(true)
    171     , m_styledInlineElement(0)
    172     , m_removeOnly(true)
    173     , m_isInlineElementToRemoveFunction(isInlineElementToRemoveFunction)
    174 {
    175 }
    176 
    177 void ApplyStyleCommand::updateStartEnd(const Position& newStart, const Position& newEnd)
    178 {
    179     ASSERT(comparePositions(newEnd, newStart) >= 0);
    180 
    181     if (!m_useEndingSelection && (newStart != m_start || newEnd != m_end))
    182         m_useEndingSelection = true;
    183 
    184     setEndingSelection(VisibleSelection(newStart, newEnd, VP_DEFAULT_AFFINITY));
    185     m_start = newStart;
    186     m_end = newEnd;
    187 }
    188 
    189 Position ApplyStyleCommand::startPosition()
    190 {
    191     if (m_useEndingSelection)
    192         return endingSelection().start();
    193 
    194     return m_start;
    195 }
    196 
    197 Position ApplyStyleCommand::endPosition()
    198 {
    199     if (m_useEndingSelection)
    200         return endingSelection().end();
    201 
    202     return m_end;
    203 }
    204 
    205 void ApplyStyleCommand::doApply()
    206 {
    207     switch (m_propertyLevel) {
    208     case PropertyDefault: {
    209         // Apply the block-centric properties of the style.
    210         RefPtr<EditingStyle> blockStyle = m_style->extractAndRemoveBlockProperties();
    211         if (!blockStyle->isEmpty())
    212             applyBlockStyle(blockStyle.get());
    213         // Apply any remaining styles to the inline elements.
    214         if (!m_style->isEmpty() || m_styledInlineElement || m_isInlineElementToRemoveFunction) {
    215             applyRelativeFontStyleChange(m_style.get());
    216             applyInlineStyle(m_style.get());
    217         }
    218         break;
    219     }
    220     case ForceBlockProperties:
    221         // Force all properties to be applied as block styles.
    222         applyBlockStyle(m_style.get());
    223         break;
    224     }
    225 }
    226 
    227 EditAction ApplyStyleCommand::editingAction() const
    228 {
    229     return m_editingAction;
    230 }
    231 
    232 void ApplyStyleCommand::applyBlockStyle(EditingStyle *style)
    233 {
    234     // update document layout once before removing styles
    235     // so that we avoid the expense of updating before each and every call
    236     // to check a computed style
    237     updateLayout();
    238 
    239     // get positions we want to use for applying style
    240     Position start = startPosition();
    241     Position end = endPosition();
    242     if (comparePositions(end, start) < 0) {
    243         Position swap = start;
    244         start = end;
    245         end = swap;
    246     }
    247 
    248     VisiblePosition visibleStart(start);
    249     VisiblePosition visibleEnd(end);
    250 
    251     if (visibleStart.isNull() || visibleStart.isOrphan() || visibleEnd.isNull() || visibleEnd.isOrphan())
    252         return;
    253 
    254     // Save and restore the selection endpoints using their indices in the document, since
    255     // addBlockStyleIfNeeded may moveParagraphs, which can remove these endpoints.
    256     // Calculate start and end indices from the start of the tree that they're in.
    257     Node* scope = highestAncestor(visibleStart.deepEquivalent().deprecatedNode());
    258     RefPtr<Range> startRange = Range::create(document(), firstPositionInNode(scope), visibleStart.deepEquivalent().parentAnchoredEquivalent());
    259     RefPtr<Range> endRange = Range::create(document(), firstPositionInNode(scope), visibleEnd.deepEquivalent().parentAnchoredEquivalent());
    260     int startIndex = TextIterator::rangeLength(startRange.get(), true);
    261     int endIndex = TextIterator::rangeLength(endRange.get(), true);
    262 
    263     VisiblePosition paragraphStart(startOfParagraph(visibleStart));
    264     VisiblePosition nextParagraphStart(endOfParagraph(paragraphStart).next());
    265     VisiblePosition beyondEnd(endOfParagraph(visibleEnd).next());
    266     while (paragraphStart.isNotNull() && paragraphStart != beyondEnd) {
    267         StyleChange styleChange(style, paragraphStart.deepEquivalent());
    268         if (styleChange.cssStyle().length() || m_removeOnly) {
    269             RefPtr<Node> block = enclosingBlock(paragraphStart.deepEquivalent().deprecatedNode());
    270             if (!m_removeOnly) {
    271                 RefPtr<Node> newBlock = moveParagraphContentsToNewBlockIfNecessary(paragraphStart.deepEquivalent());
    272                 if (newBlock)
    273                     block = newBlock;
    274             }
    275             ASSERT(block->isHTMLElement());
    276             if (block->isHTMLElement()) {
    277                 removeCSSStyle(style, toHTMLElement(block.get()));
    278                 if (!m_removeOnly)
    279                     addBlockStyle(styleChange, toHTMLElement(block.get()));
    280             }
    281 
    282             if (nextParagraphStart.isOrphan())
    283                 nextParagraphStart = endOfParagraph(paragraphStart).next();
    284         }
    285 
    286         paragraphStart = nextParagraphStart;
    287         nextParagraphStart = endOfParagraph(paragraphStart).next();
    288     }
    289 
    290     startRange = TextIterator::rangeFromLocationAndLength(static_cast<Element*>(scope), startIndex, 0, true);
    291     endRange = TextIterator::rangeFromLocationAndLength(static_cast<Element*>(scope), endIndex, 0, true);
    292     if (startRange && endRange)
    293         updateStartEnd(startRange->startPosition(), endRange->startPosition());
    294 }
    295 
    296 void ApplyStyleCommand::applyRelativeFontStyleChange(EditingStyle* style)
    297 {
    298     static const float MinimumFontSize = 0.1f;
    299 
    300     if (!style || !style->hasFontSizeDelta())
    301         return;
    302 
    303     Position start = startPosition();
    304     Position end = endPosition();
    305     if (comparePositions(end, start) < 0) {
    306         Position swap = start;
    307         start = end;
    308         end = swap;
    309     }
    310 
    311     // Join up any adjacent text nodes.
    312     if (start.deprecatedNode()->isTextNode()) {
    313         joinChildTextNodes(start.deprecatedNode()->parentNode(), start, end);
    314         start = startPosition();
    315         end = endPosition();
    316     }
    317     if (end.deprecatedNode()->isTextNode() && start.deprecatedNode()->parentNode() != end.deprecatedNode()->parentNode()) {
    318         joinChildTextNodes(end.deprecatedNode()->parentNode(), start, end);
    319         start = startPosition();
    320         end = endPosition();
    321     }
    322 
    323     // Split the start text nodes if needed to apply style.
    324     if (isValidCaretPositionInTextNode(start)) {
    325         splitTextAtStart(start, end);
    326         start = startPosition();
    327         end = endPosition();
    328     }
    329 
    330     if (isValidCaretPositionInTextNode(end)) {
    331         splitTextAtEnd(start, end);
    332         start = startPosition();
    333         end = endPosition();
    334     }
    335 
    336     // Calculate loop end point.
    337     // If the end node is before the start node (can only happen if the end node is
    338     // an ancestor of the start node), we gather nodes up to the next sibling of the end node
    339     Node *beyondEnd;
    340     if (start.deprecatedNode()->isDescendantOf(end.deprecatedNode()))
    341         beyondEnd = end.deprecatedNode()->traverseNextSibling();
    342     else
    343         beyondEnd = end.deprecatedNode()->traverseNextNode();
    344 
    345     start = start.upstream(); // Move upstream to ensure we do not add redundant spans.
    346     Node* startNode = start.deprecatedNode();
    347     if (startNode->isTextNode() && start.deprecatedEditingOffset() >= caretMaxOffset(startNode)) // Move out of text node if range does not include its characters.
    348         startNode = startNode->traverseNextNode();
    349 
    350     // Store away font size before making any changes to the document.
    351     // This ensures that changes to one node won't effect another.
    352     HashMap<Node*, float> startingFontSizes;
    353     for (Node *node = startNode; node != beyondEnd; node = node->traverseNextNode())
    354         startingFontSizes.set(node, computedFontSize(node));
    355 
    356     // These spans were added by us. If empty after font size changes, they can be removed.
    357     Vector<RefPtr<HTMLElement> > unstyledSpans;
    358 
    359     Node* lastStyledNode = 0;
    360     for (Node* node = startNode; node != beyondEnd; node = node->traverseNextNode()) {
    361         RefPtr<HTMLElement> element;
    362         if (node->isHTMLElement()) {
    363             // Only work on fully selected nodes.
    364             if (!nodeFullySelected(node, start, end))
    365                 continue;
    366             element = toHTMLElement(node);
    367         } else if (node->isTextNode() && node->renderer() && node->parentNode() != lastStyledNode) {
    368             // Last styled node was not parent node of this text node, but we wish to style this
    369             // text node. To make this possible, add a style span to surround this text node.
    370             RefPtr<HTMLElement> span = createStyleSpanElement(document());
    371             surroundNodeRangeWithElement(node, node, span.get());
    372             element = span.release();
    373         }  else {
    374             // Only handle HTML elements and text nodes.
    375             continue;
    376         }
    377         lastStyledNode = node;
    378 
    379         CSSMutableStyleDeclaration* inlineStyleDecl = element->getInlineStyleDecl();
    380         float currentFontSize = computedFontSize(node);
    381         float desiredFontSize = max(MinimumFontSize, startingFontSizes.get(node) + style->fontSizeDelta());
    382         RefPtr<CSSValue> value = inlineStyleDecl->getPropertyCSSValue(CSSPropertyFontSize);
    383         if (value) {
    384             inlineStyleDecl->removeProperty(CSSPropertyFontSize, true);
    385             currentFontSize = computedFontSize(node);
    386         }
    387         if (currentFontSize != desiredFontSize) {
    388             inlineStyleDecl->setProperty(CSSPropertyFontSize, String::number(desiredFontSize) + "px", false, false);
    389             setNodeAttribute(element.get(), styleAttr, inlineStyleDecl->cssText());
    390         }
    391         if (inlineStyleDecl->isEmpty()) {
    392             removeNodeAttribute(element.get(), styleAttr);
    393             // FIXME: should this be isSpanWithoutAttributesOrUnstyleStyleSpan?  Need a test.
    394             if (isUnstyledStyleSpan(element.get()))
    395                 unstyledSpans.append(element.release());
    396         }
    397     }
    398 
    399     size_t size = unstyledSpans.size();
    400     for (size_t i = 0; i < size; ++i)
    401         removeNodePreservingChildren(unstyledSpans[i].get());
    402 }
    403 
    404 static Node* dummySpanAncestorForNode(const Node* node)
    405 {
    406     while (node && !isStyleSpan(node))
    407         node = node->parentNode();
    408 
    409     return node ? node->parentNode() : 0;
    410 }
    411 
    412 void ApplyStyleCommand::cleanupUnstyledAppleStyleSpans(Node* dummySpanAncestor)
    413 {
    414     if (!dummySpanAncestor)
    415         return;
    416 
    417     // Dummy spans are created when text node is split, so that style information
    418     // can be propagated, which can result in more splitting. If a dummy span gets
    419     // cloned/split, the new node is always a sibling of it. Therefore, we scan
    420     // all the children of the dummy's parent
    421     Node* next;
    422     for (Node* node = dummySpanAncestor->firstChild(); node; node = next) {
    423         next = node->nextSibling();
    424         if (isUnstyledStyleSpan(node))
    425             removeNodePreservingChildren(node);
    426         node = next;
    427     }
    428 }
    429 
    430 HTMLElement* ApplyStyleCommand::splitAncestorsWithUnicodeBidi(Node* node, bool before, WritingDirection allowedDirection)
    431 {
    432     // We are allowed to leave the highest ancestor with unicode-bidi unsplit if it is unicode-bidi: embed and direction: allowedDirection.
    433     // In that case, we return the unsplit ancestor. Otherwise, we return 0.
    434     Node* block = enclosingBlock(node);
    435     if (!block)
    436         return 0;
    437 
    438     Node* highestAncestorWithUnicodeBidi = 0;
    439     Node* nextHighestAncestorWithUnicodeBidi = 0;
    440     int highestAncestorUnicodeBidi = 0;
    441     for (Node* n = node->parentNode(); n != block; n = n->parentNode()) {
    442         int unicodeBidi = getIdentifierValue(computedStyle(n).get(), CSSPropertyUnicodeBidi);
    443         if (unicodeBidi && unicodeBidi != CSSValueNormal) {
    444             highestAncestorUnicodeBidi = unicodeBidi;
    445             nextHighestAncestorWithUnicodeBidi = highestAncestorWithUnicodeBidi;
    446             highestAncestorWithUnicodeBidi = n;
    447         }
    448     }
    449 
    450     if (!highestAncestorWithUnicodeBidi)
    451         return 0;
    452 
    453     HTMLElement* unsplitAncestor = 0;
    454 
    455     WritingDirection highestAncestorDirection;
    456     if (allowedDirection != NaturalWritingDirection
    457         && highestAncestorUnicodeBidi != CSSValueBidiOverride
    458         && highestAncestorWithUnicodeBidi->isHTMLElement()
    459         && EditingStyle::create(highestAncestorWithUnicodeBidi, EditingStyle::AllProperties)->textDirection(highestAncestorDirection)
    460         && highestAncestorDirection == allowedDirection) {
    461         if (!nextHighestAncestorWithUnicodeBidi)
    462             return toHTMLElement(highestAncestorWithUnicodeBidi);
    463 
    464         unsplitAncestor = toHTMLElement(highestAncestorWithUnicodeBidi);
    465         highestAncestorWithUnicodeBidi = nextHighestAncestorWithUnicodeBidi;
    466     }
    467 
    468     // Split every ancestor through highest ancestor with embedding.
    469     Node* n = node;
    470     while (true) {
    471         Element* parent = static_cast<Element*>(n->parentNode());
    472         if (before ? n->previousSibling() : n->nextSibling())
    473             splitElement(parent, before ? n : n->nextSibling());
    474         if (parent == highestAncestorWithUnicodeBidi)
    475             break;
    476         n = n->parentNode();
    477     }
    478     return unsplitAncestor;
    479 }
    480 
    481 void ApplyStyleCommand::removeEmbeddingUpToEnclosingBlock(Node* node, Node* unsplitAncestor)
    482 {
    483     Node* block = enclosingBlock(node);
    484     if (!block)
    485         return;
    486 
    487     Node* parent = 0;
    488     for (Node* n = node->parentNode(); n != block && n != unsplitAncestor; n = parent) {
    489         parent = n->parentNode();
    490         if (!n->isStyledElement())
    491             continue;
    492 
    493         StyledElement* element = static_cast<StyledElement*>(n);
    494         int unicodeBidi = getIdentifierValue(computedStyle(element).get(), CSSPropertyUnicodeBidi);
    495         if (!unicodeBidi || unicodeBidi == CSSValueNormal)
    496             continue;
    497 
    498         // FIXME: This code should really consider the mapped attribute 'dir', the inline style declaration,
    499         // and all matching style rules in order to determine how to best set the unicode-bidi property to 'normal'.
    500         // For now, it assumes that if the 'dir' attribute is present, then removing it will suffice, and
    501         // otherwise it sets the property in the inline style declaration.
    502         if (element->hasAttribute(dirAttr)) {
    503             // FIXME: If this is a BDO element, we should probably just remove it if it has no
    504             // other attributes, like we (should) do with B and I elements.
    505             removeNodeAttribute(element, dirAttr);
    506         } else {
    507             RefPtr<CSSMutableStyleDeclaration> inlineStyle = element->getInlineStyleDecl()->copy();
    508             inlineStyle->setProperty(CSSPropertyUnicodeBidi, CSSValueNormal);
    509             inlineStyle->removeProperty(CSSPropertyDirection);
    510             setNodeAttribute(element, styleAttr, inlineStyle->cssText());
    511             // FIXME: should this be isSpanWithoutAttributesOrUnstyleStyleSpan?  Need a test.
    512             if (isUnstyledStyleSpan(element))
    513                 removeNodePreservingChildren(element);
    514         }
    515     }
    516 }
    517 
    518 static Node* highestEmbeddingAncestor(Node* startNode, Node* enclosingNode)
    519 {
    520     for (Node* n = startNode; n && n != enclosingNode; n = n->parentNode()) {
    521         if (n->isHTMLElement() && getIdentifierValue(computedStyle(n).get(), CSSPropertyUnicodeBidi) == CSSValueEmbed)
    522             return n;
    523     }
    524 
    525     return 0;
    526 }
    527 
    528 void ApplyStyleCommand::applyInlineStyle(EditingStyle* style)
    529 {
    530     Node* startDummySpanAncestor = 0;
    531     Node* endDummySpanAncestor = 0;
    532 
    533     style->collapseTextDecorationProperties();
    534 
    535     // update document layout once before removing styles
    536     // so that we avoid the expense of updating before each and every call
    537     // to check a computed style
    538     updateLayout();
    539 
    540     // adjust to the positions we want to use for applying style
    541     Position start = startPosition();
    542     Position end = endPosition();
    543     if (comparePositions(end, start) < 0) {
    544         Position swap = start;
    545         start = end;
    546         end = swap;
    547     }
    548 
    549     // split the start node and containing element if the selection starts inside of it
    550     bool splitStart = isValidCaretPositionInTextNode(start);
    551     if (splitStart) {
    552         if (shouldSplitTextElement(start.deprecatedNode()->parentElement(), style))
    553             splitTextElementAtStart(start, end);
    554         else
    555             splitTextAtStart(start, end);
    556         start = startPosition();
    557         end = endPosition();
    558         startDummySpanAncestor = dummySpanAncestorForNode(start.deprecatedNode());
    559     }
    560 
    561     // split the end node and containing element if the selection ends inside of it
    562     bool splitEnd = isValidCaretPositionInTextNode(end);
    563     if (splitEnd) {
    564         if (shouldSplitTextElement(end.deprecatedNode()->parentElement(), style))
    565             splitTextElementAtEnd(start, end);
    566         else
    567             splitTextAtEnd(start, end);
    568         start = startPosition();
    569         end = endPosition();
    570         endDummySpanAncestor = dummySpanAncestorForNode(end.deprecatedNode());
    571     }
    572 
    573     // Remove style from the selection.
    574     // Use the upstream position of the start for removing style.
    575     // This will ensure we remove all traces of the relevant styles from the selection
    576     // and prevent us from adding redundant ones, as described in:
    577     // <rdar://problem/3724344> Bolding and unbolding creates extraneous tags
    578     Position removeStart = start.upstream();
    579     WritingDirection textDirection = NaturalWritingDirection;
    580     bool hasTextDirection = style->textDirection(textDirection);
    581     RefPtr<EditingStyle> styleWithoutEmbedding;
    582     RefPtr<EditingStyle> embeddingStyle;
    583     if (hasTextDirection) {
    584         // Leave alone an ancestor that provides the desired single level embedding, if there is one.
    585         HTMLElement* startUnsplitAncestor = splitAncestorsWithUnicodeBidi(start.deprecatedNode(), true, textDirection);
    586         HTMLElement* endUnsplitAncestor = splitAncestorsWithUnicodeBidi(end.deprecatedNode(), false, textDirection);
    587         removeEmbeddingUpToEnclosingBlock(start.deprecatedNode(), startUnsplitAncestor);
    588         removeEmbeddingUpToEnclosingBlock(end.deprecatedNode(), endUnsplitAncestor);
    589 
    590         // Avoid removing the dir attribute and the unicode-bidi and direction properties from the unsplit ancestors.
    591         Position embeddingRemoveStart = removeStart;
    592         if (startUnsplitAncestor && nodeFullySelected(startUnsplitAncestor, removeStart, end))
    593             embeddingRemoveStart = positionInParentAfterNode(startUnsplitAncestor);
    594 
    595         Position embeddingRemoveEnd = end;
    596         if (endUnsplitAncestor && nodeFullySelected(endUnsplitAncestor, removeStart, end))
    597             embeddingRemoveEnd = positionInParentBeforeNode(endUnsplitAncestor).downstream();
    598 
    599         if (embeddingRemoveEnd != removeStart || embeddingRemoveEnd != end) {
    600             styleWithoutEmbedding = style->copy();
    601             embeddingStyle = styleWithoutEmbedding->extractAndRemoveTextDirection();
    602 
    603             if (comparePositions(embeddingRemoveStart, embeddingRemoveEnd) <= 0)
    604                 removeInlineStyle(embeddingStyle.get(), embeddingRemoveStart, embeddingRemoveEnd);
    605         }
    606     }
    607 
    608     removeInlineStyle(styleWithoutEmbedding ? styleWithoutEmbedding.get() : style, removeStart, end);
    609     start = startPosition();
    610     end = endPosition();
    611     if (start.isNull() || start.isOrphan() || end.isNull() || end.isOrphan())
    612         return;
    613 
    614     if (splitStart && mergeStartWithPreviousIfIdentical(start, end)) {
    615         start = startPosition();
    616         end = endPosition();
    617     }
    618 
    619     if (splitEnd) {
    620         mergeEndWithNextIfIdentical(start, end);
    621         start = startPosition();
    622         end = endPosition();
    623     }
    624 
    625     // update document layout once before running the rest of the function
    626     // so that we avoid the expense of updating before each and every call
    627     // to check a computed style
    628     updateLayout();
    629 
    630     RefPtr<EditingStyle> styleToApply = style;
    631     if (hasTextDirection) {
    632         // Avoid applying the unicode-bidi and direction properties beneath ancestors that already have them.
    633         Node* embeddingStartNode = highestEmbeddingAncestor(start.deprecatedNode(), enclosingBlock(start.deprecatedNode()));
    634         Node* embeddingEndNode = highestEmbeddingAncestor(end.deprecatedNode(), enclosingBlock(end.deprecatedNode()));
    635 
    636         if (embeddingStartNode || embeddingEndNode) {
    637             Position embeddingApplyStart = embeddingStartNode ? positionInParentAfterNode(embeddingStartNode) : start;
    638             Position embeddingApplyEnd = embeddingEndNode ? positionInParentBeforeNode(embeddingEndNode) : end;
    639             ASSERT(embeddingApplyStart.isNotNull() && embeddingApplyEnd.isNotNull());
    640 
    641             if (!embeddingStyle) {
    642                 styleWithoutEmbedding = style->copy();
    643                 embeddingStyle = styleWithoutEmbedding->extractAndRemoveTextDirection();
    644             }
    645             fixRangeAndApplyInlineStyle(embeddingStyle.get(), embeddingApplyStart, embeddingApplyEnd);
    646 
    647             styleToApply = styleWithoutEmbedding;
    648         }
    649     }
    650 
    651     fixRangeAndApplyInlineStyle(styleToApply.get(), start, end);
    652 
    653     // Remove dummy style spans created by splitting text elements.
    654     cleanupUnstyledAppleStyleSpans(startDummySpanAncestor);
    655     if (endDummySpanAncestor != startDummySpanAncestor)
    656         cleanupUnstyledAppleStyleSpans(endDummySpanAncestor);
    657 }
    658 
    659 void ApplyStyleCommand::fixRangeAndApplyInlineStyle(EditingStyle* style, const Position& start, const Position& end)
    660 {
    661     Node* startNode = start.deprecatedNode();
    662 
    663     if (start.deprecatedEditingOffset() >= caretMaxOffset(start.deprecatedNode())) {
    664         startNode = startNode->traverseNextNode();
    665         if (!startNode || comparePositions(end, firstPositionInOrBeforeNode(startNode)) < 0)
    666             return;
    667     }
    668 
    669     Node* pastEndNode = end.deprecatedNode();
    670     if (end.deprecatedEditingOffset() >= caretMaxOffset(end.deprecatedNode()))
    671         pastEndNode = end.deprecatedNode()->traverseNextSibling();
    672 
    673     // FIXME: Callers should perform this operation on a Range that includes the br
    674     // if they want style applied to the empty line.
    675     if (start == end && start.deprecatedNode()->hasTagName(brTag))
    676         pastEndNode = start.deprecatedNode()->traverseNextNode();
    677 
    678     // Start from the highest fully selected ancestor so that we can modify the fully selected node.
    679     // e.g. When applying font-size: large on <font color="blue">hello</font>, we need to include the font element in our run
    680     // to generate <font color="blue" size="4">hello</font> instead of <font color="blue"><font size="4">hello</font></font>
    681     RefPtr<Range> range = Range::create(startNode->document(), start, end);
    682     Element* editableRoot = startNode->rootEditableElement();
    683     if (startNode != editableRoot) {
    684         while (editableRoot && startNode->parentNode() != editableRoot && isNodeVisiblyContainedWithin(startNode->parentNode(), range.get()))
    685             startNode = startNode->parentNode();
    686     }
    687 
    688     applyInlineStyleToNodeRange(style, startNode, pastEndNode);
    689 }
    690 
    691 static bool containsNonEditableRegion(Node* node)
    692 {
    693     if (!node->rendererIsEditable())
    694         return true;
    695 
    696     Node* sibling = node->traverseNextSibling();
    697     for (Node* descendent = node->firstChild(); descendent && descendent != sibling; descendent = descendent->traverseNextNode()) {
    698         if (!descendent->rendererIsEditable())
    699             return true;
    700     }
    701 
    702     return false;
    703 }
    704 
    705 void ApplyStyleCommand::applyInlineStyleToNodeRange(EditingStyle* style, Node* node, Node* pastEndNode)
    706 {
    707     if (m_removeOnly)
    708         return;
    709 
    710     for (RefPtr<Node> next; node && node != pastEndNode; node = next.get()) {
    711         next = node->traverseNextNode();
    712 
    713         if (!node->renderer() || !node->rendererIsEditable())
    714             continue;
    715 
    716         if (!node->rendererIsRichlyEditable() && node->isHTMLElement()) {
    717             // This is a plaintext-only region. Only proceed if it's fully selected.
    718             // pastEndNode is the node after the last fully selected node, so if it's inside node then
    719             // node isn't fully selected.
    720             if (pastEndNode && pastEndNode->isDescendantOf(node))
    721                 break;
    722             // Add to this element's inline style and skip over its contents.
    723             HTMLElement* element = toHTMLElement(node);
    724             RefPtr<CSSMutableStyleDeclaration> inlineStyle = element->getInlineStyleDecl()->copy();
    725             inlineStyle->merge(style->style());
    726             setNodeAttribute(element, styleAttr, inlineStyle->cssText());
    727             next = node->traverseNextSibling();
    728             continue;
    729         }
    730 
    731         if (isBlock(node))
    732             continue;
    733 
    734         if (node->childNodeCount()) {
    735             if (node->contains(pastEndNode) || containsNonEditableRegion(node) || !node->parentNode()->rendererIsEditable())
    736                 continue;
    737             if (editingIgnoresContent(node)) {
    738                 next = node->traverseNextSibling();
    739                 continue;
    740             }
    741         }
    742 
    743         RefPtr<Node> runStart = node;
    744         RefPtr<Node> runEnd = node;
    745         Node* sibling = node->nextSibling();
    746         while (sibling && sibling != pastEndNode && !sibling->contains(pastEndNode)
    747                && (!isBlock(sibling) || sibling->hasTagName(brTag))
    748                && !containsNonEditableRegion(sibling)) {
    749             runEnd = sibling;
    750             sibling = runEnd->nextSibling();
    751         }
    752         next = runEnd->traverseNextSibling();
    753 
    754         if (!removeStyleFromRunBeforeApplyingStyle(style, runStart, runEnd))
    755             continue;
    756         addInlineStyleIfNeeded(style, runStart.get(), runEnd.get(), AddStyledElement);
    757     }
    758 }
    759 
    760 bool ApplyStyleCommand::isStyledInlineElementToRemove(Element* element) const
    761 {
    762     return (m_styledInlineElement && element->hasTagName(m_styledInlineElement->tagQName()))
    763         || (m_isInlineElementToRemoveFunction && m_isInlineElementToRemoveFunction(element));
    764 }
    765 
    766 bool ApplyStyleCommand::removeStyleFromRunBeforeApplyingStyle(EditingStyle* style, RefPtr<Node>& runStart, RefPtr<Node>& runEnd)
    767 {
    768     ASSERT(runStart && runEnd && runStart->parentNode() == runEnd->parentNode());
    769     RefPtr<Node> pastEndNode = runEnd->traverseNextSibling();
    770     bool needToApplyStyle = false;
    771     for (Node* node = runStart.get(); node && node != pastEndNode.get(); node = node->traverseNextNode()) {
    772         if (node->childNodeCount())
    773             continue;
    774         // We don't consider m_isInlineElementToRemoveFunction here because we never apply style when m_isInlineElementToRemoveFunction is specified
    775         if (!style->styleIsPresentInComputedStyleOfNode(node)
    776             || (m_styledInlineElement && !enclosingNodeWithTag(positionBeforeNode(node), m_styledInlineElement->tagQName()))) {
    777             needToApplyStyle = true;
    778             break;
    779         }
    780     }
    781     if (!needToApplyStyle)
    782         return false;
    783 
    784     RefPtr<Node> next = runStart;
    785     for (RefPtr<Node> node = next; node && node->inDocument() && node != pastEndNode; node = next) {
    786         next = node->traverseNextNode();
    787         if (!node->isHTMLElement())
    788             continue;
    789 
    790         RefPtr<Node> previousSibling = node->previousSibling();
    791         RefPtr<Node> nextSibling = node->nextSibling();
    792         RefPtr<ContainerNode> parent = node->parentNode();
    793         removeInlineStyleFromElement(style, toHTMLElement(node.get()), RemoveAlways);
    794         if (!node->inDocument()) {
    795             // FIXME: We might need to update the start and the end of current selection here but need a test.
    796             if (runStart == node)
    797                 runStart = previousSibling ? previousSibling->nextSibling() : parent->firstChild();
    798             if (runEnd == node)
    799                 runEnd = nextSibling ? nextSibling->previousSibling() : parent->lastChild();
    800         }
    801     }
    802 
    803     return true;
    804 }
    805 
    806 bool ApplyStyleCommand::removeInlineStyleFromElement(EditingStyle* style, PassRefPtr<HTMLElement> element, InlineStyleRemovalMode mode, EditingStyle* extractedStyle)
    807 {
    808     ASSERT(element);
    809 
    810     if (!element->parentNode() || !element->parentNode()->rendererIsEditable())
    811         return false;
    812 
    813     if (isStyledInlineElementToRemove(element.get())) {
    814         if (mode == RemoveNone)
    815             return true;
    816         ASSERT(extractedStyle);
    817         extractedStyle->mergeInlineStyleOfElement(element.get());
    818         removeNodePreservingChildren(element);
    819         return true;
    820     }
    821 
    822     bool removed = false;
    823     if (removeImplicitlyStyledElement(style, element.get(), mode, extractedStyle))
    824         removed = true;
    825 
    826     if (!element->inDocument())
    827         return removed;
    828 
    829     // If the node was converted to a span, the span may still contain relevant
    830     // styles which must be removed (e.g. <b style='font-weight: bold'>)
    831     if (removeCSSStyle(style, element.get(), mode, extractedStyle))
    832         removed = true;
    833 
    834     return removed;
    835 }
    836 
    837 void ApplyStyleCommand::replaceWithSpanOrRemoveIfWithoutAttributes(HTMLElement*& elem)
    838 {
    839     bool removeNode = false;
    840 
    841     // Similar to isSpanWithoutAttributesOrUnstyleStyleSpan, but does not look for Apple-style-span.
    842     NamedNodeMap* attributes = elem->attributes(true); // readonly
    843     if (!attributes || attributes->isEmpty())
    844         removeNode = true;
    845     else if (attributes->length() == 1 && elem->hasAttribute(styleAttr)) {
    846         // Remove the element even if it has just style='' (this might be redundantly checked later too)
    847         CSSMutableStyleDeclaration* inlineStyleDecl = elem->inlineStyleDecl();
    848         if (!inlineStyleDecl || inlineStyleDecl->isEmpty())
    849             removeNode = true;
    850     }
    851 
    852     if (removeNode)
    853         removeNodePreservingChildren(elem);
    854     else {
    855         HTMLElement* newSpanElement = replaceElementWithSpanPreservingChildrenAndAttributes(elem);
    856         ASSERT(newSpanElement && newSpanElement->inDocument());
    857         elem = newSpanElement;
    858     }
    859 }
    860 
    861 bool ApplyStyleCommand::removeImplicitlyStyledElement(EditingStyle* style, HTMLElement* element, InlineStyleRemovalMode mode, EditingStyle* extractedStyle)
    862 {
    863     ASSERT(style);
    864     if (mode == RemoveNone) {
    865         ASSERT(!extractedStyle);
    866         return style->conflictsWithImplicitStyleOfElement(element) || style->conflictsWithImplicitStyleOfAttributes(element);
    867     }
    868 
    869     ASSERT(mode == RemoveIfNeeded || mode == RemoveAlways);
    870     if (style->conflictsWithImplicitStyleOfElement(element, extractedStyle, mode == RemoveAlways ? EditingStyle::ExtractMatchingStyle : EditingStyle::DoNotExtractMatchingStyle)) {
    871         replaceWithSpanOrRemoveIfWithoutAttributes(element);
    872         return true;
    873     }
    874 
    875     // unicode-bidi and direction are pushed down separately so don't push down with other styles
    876     Vector<QualifiedName> attributes;
    877     if (!style->extractConflictingImplicitStyleOfAttributes(element, extractedStyle ? EditingStyle::PreserveWritingDirection : EditingStyle::DoNotPreserveWritingDirection,
    878         extractedStyle, attributes, mode == RemoveAlways ? EditingStyle::ExtractMatchingStyle : EditingStyle::DoNotExtractMatchingStyle))
    879         return false;
    880 
    881     for (size_t i = 0; i < attributes.size(); i++)
    882         removeNodeAttribute(element, attributes[i]);
    883 
    884     if (isEmptyFontTag(element) || isSpanWithoutAttributesOrUnstyleStyleSpan(element))
    885         removeNodePreservingChildren(element);
    886 
    887     return true;
    888 }
    889 
    890 bool ApplyStyleCommand::removeCSSStyle(EditingStyle* style, HTMLElement* element, InlineStyleRemovalMode mode, EditingStyle* extractedStyle)
    891 {
    892     ASSERT(style);
    893     ASSERT(element);
    894 
    895     if (mode == RemoveNone)
    896         return style->conflictsWithInlineStyleOfElement(element);
    897 
    898     Vector<CSSPropertyID> properties;
    899     if (!style->conflictsWithInlineStyleOfElement(element, extractedStyle, properties))
    900         return false;
    901 
    902     CSSMutableStyleDeclaration* inlineStyle = element->inlineStyleDecl();
    903     ASSERT(inlineStyle);
    904     // FIXME: We should use a mass-removal function here but we don't have an undoable one yet.
    905     for (size_t i = 0; i < properties.size(); i++)
    906         removeCSSProperty(element, properties[i]);
    907 
    908     // No need to serialize <foo style=""> if we just removed the last css property
    909     if (inlineStyle->isEmpty())
    910         removeNodeAttribute(element, styleAttr);
    911 
    912     if (isSpanWithoutAttributesOrUnstyleStyleSpan(element))
    913         removeNodePreservingChildren(element);
    914 
    915     return true;
    916 }
    917 
    918 HTMLElement* ApplyStyleCommand::highestAncestorWithConflictingInlineStyle(EditingStyle* style, Node* node)
    919 {
    920     if (!node)
    921         return 0;
    922 
    923     HTMLElement* result = 0;
    924     Node* unsplittableElement = unsplittableElementForPosition(firstPositionInOrBeforeNode(node));
    925 
    926     for (Node *n = node; n; n = n->parentNode()) {
    927         if (n->isHTMLElement() && shouldRemoveInlineStyleFromElement(style, toHTMLElement(n)))
    928             result = toHTMLElement(n);
    929         // Should stop at the editable root (cannot cross editing boundary) and
    930         // also stop at the unsplittable element to be consistent with other UAs
    931         if (n == unsplittableElement)
    932             break;
    933     }
    934 
    935     return result;
    936 }
    937 
    938 void ApplyStyleCommand::applyInlineStyleToPushDown(Node* node, EditingStyle* style)
    939 {
    940     ASSERT(node);
    941 
    942     if (!style || style->isEmpty() || !node->renderer())
    943         return;
    944 
    945     RefPtr<EditingStyle> newInlineStyle = style;
    946     if (node->isHTMLElement() && static_cast<HTMLElement*>(node)->inlineStyleDecl()) {
    947         newInlineStyle = style->copy();
    948         newInlineStyle->mergeInlineStyleOfElement(static_cast<HTMLElement*>(node));
    949     }
    950 
    951     // Since addInlineStyleIfNeeded can't add styles to block-flow render objects, add style attribute instead.
    952     // FIXME: applyInlineStyleToRange should be used here instead.
    953     if ((node->renderer()->isBlockFlow() || node->childNodeCount()) && node->isHTMLElement()) {
    954         setNodeAttribute(toHTMLElement(node), styleAttr, newInlineStyle->style()->cssText());
    955         return;
    956     }
    957 
    958     if (node->renderer()->isText() && static_cast<RenderText*>(node->renderer())->isAllCollapsibleWhitespace())
    959         return;
    960 
    961     // We can't wrap node with the styled element here because new styled element will never be removed if we did.
    962     // If we modified the child pointer in pushDownInlineStyleAroundNode to point to new style element
    963     // then we fall into an infinite loop where we keep removing and adding styled element wrapping node.
    964     addInlineStyleIfNeeded(newInlineStyle.get(), node, node, DoNotAddStyledElement);
    965 }
    966 
    967 void ApplyStyleCommand::pushDownInlineStyleAroundNode(EditingStyle* style, Node* targetNode)
    968 {
    969     HTMLElement* highestAncestor = highestAncestorWithConflictingInlineStyle(style, targetNode);
    970     if (!highestAncestor)
    971         return;
    972 
    973     // The outer loop is traversing the tree vertically from highestAncestor to targetNode
    974     Node* current = highestAncestor;
    975     // Along the way, styled elements that contain targetNode are removed and accumulated into elementsToPushDown.
    976     // Each child of the removed element, exclusing ancestors of targetNode, is then wrapped by clones of elements in elementsToPushDown.
    977     Vector<RefPtr<Element> > elementsToPushDown;
    978     while (current != targetNode) {
    979         ASSERT(current);
    980         ASSERT(current->contains(targetNode));
    981         Node* child = current->firstChild();
    982         Node* lastChild = current->lastChild();
    983         RefPtr<StyledElement> styledElement;
    984         if (current->isStyledElement() && isStyledInlineElementToRemove(static_cast<Element*>(current))) {
    985             styledElement = static_cast<StyledElement*>(current);
    986             elementsToPushDown.append(styledElement);
    987         }
    988 
    989         RefPtr<EditingStyle> styleToPushDown = EditingStyle::create();
    990         if (current->isHTMLElement())
    991             removeInlineStyleFromElement(style, toHTMLElement(current), RemoveIfNeeded, styleToPushDown.get());
    992 
    993         // The inner loop will go through children on each level
    994         // FIXME: we should aggregate inline child elements together so that we don't wrap each child separately.
    995         while (child) {
    996             Node* nextChild = child->nextSibling();
    997 
    998             if (!child->contains(targetNode) && elementsToPushDown.size()) {
    999                 for (size_t i = 0; i < elementsToPushDown.size(); i++) {
   1000                     RefPtr<Element> wrapper = elementsToPushDown[i]->cloneElementWithoutChildren();
   1001                     ExceptionCode ec = 0;
   1002                     wrapper->removeAttribute(styleAttr, ec);
   1003                     ASSERT(!ec);
   1004                     surroundNodeRangeWithElement(child, child, wrapper);
   1005                 }
   1006             }
   1007 
   1008             // Apply text decoration to all nodes containing targetNode and their siblings but NOT to targetNode
   1009             // But if we've removed styledElement then go ahead and always apply the style.
   1010             if (child != targetNode || styledElement)
   1011                 applyInlineStyleToPushDown(child, styleToPushDown.get());
   1012 
   1013             // We found the next node for the outer loop (contains targetNode)
   1014             // When reached targetNode, stop the outer loop upon the completion of the current inner loop
   1015             if (child == targetNode || child->contains(targetNode))
   1016                 current = child;
   1017 
   1018             if (child == lastChild || child->contains(lastChild))
   1019                 break;
   1020             child = nextChild;
   1021         }
   1022     }
   1023 }
   1024 
   1025 void ApplyStyleCommand::removeInlineStyle(EditingStyle* style, const Position &start, const Position &end)
   1026 {
   1027     ASSERT(start.isNotNull());
   1028     ASSERT(end.isNotNull());
   1029     ASSERT(start.anchorNode()->inDocument());
   1030     ASSERT(end.anchorNode()->inDocument());
   1031     ASSERT(comparePositions(start, end) <= 0);
   1032 
   1033     Position pushDownStart = start.downstream();
   1034     // If the pushDownStart is at the end of a text node, then this node is not fully selected.
   1035     // Move it to the next deep quivalent position to avoid removing the style from this node.
   1036     // e.g. if pushDownStart was at Position("hello", 5) in <b>hello<div>world</div></b>, we want Position("world", 0) instead.
   1037     Node* pushDownStartContainer = pushDownStart.containerNode();
   1038     if (pushDownStartContainer && pushDownStartContainer->isTextNode()
   1039         && pushDownStart.computeOffsetInContainerNode() == pushDownStartContainer->maxCharacterOffset())
   1040         pushDownStart = nextVisuallyDistinctCandidate(pushDownStart);
   1041     Position pushDownEnd = end.upstream();
   1042 
   1043     pushDownInlineStyleAroundNode(style, pushDownStart.deprecatedNode());
   1044     pushDownInlineStyleAroundNode(style, pushDownEnd.deprecatedNode());
   1045 
   1046     // The s and e variables store the positions used to set the ending selection after style removal
   1047     // takes place. This will help callers to recognize when either the start node or the end node
   1048     // are removed from the document during the work of this function.
   1049     // If pushDownInlineStyleAroundNode has pruned start.deprecatedNode() or end.deprecatedNode(),
   1050     // use pushDownStart or pushDownEnd instead, which pushDownInlineStyleAroundNode won't prune.
   1051     Position s = start.isNull() || start.isOrphan() ? pushDownStart : start;
   1052     Position e = end.isNull() || end.isOrphan() ? pushDownEnd : end;
   1053 
   1054     Node* node = start.deprecatedNode();
   1055     while (node) {
   1056         RefPtr<Node> next = node->traverseNextNode();
   1057         if (node->isHTMLElement() && nodeFullySelected(node, start, end)) {
   1058             RefPtr<HTMLElement> elem = toHTMLElement(node);
   1059             RefPtr<Node> prev = elem->traversePreviousNodePostOrder();
   1060             RefPtr<Node> next = elem->traverseNextNode();
   1061             RefPtr<EditingStyle> styleToPushDown;
   1062             PassRefPtr<Node> childNode = 0;
   1063             if (isStyledInlineElementToRemove(elem.get())) {
   1064                 styleToPushDown = EditingStyle::create();
   1065                 childNode = elem->firstChild();
   1066             }
   1067 
   1068             removeInlineStyleFromElement(style, elem.get(), RemoveIfNeeded, styleToPushDown.get());
   1069             if (!elem->inDocument()) {
   1070                 if (s.deprecatedNode() == elem) {
   1071                     // Since elem must have been fully selected, and it is at the start
   1072                     // of the selection, it is clear we can set the new s offset to 0.
   1073                     ASSERT(s.anchorType() == Position::PositionIsBeforeAnchor || s.offsetInContainerNode() <= 0);
   1074                     s = firstPositionInOrBeforeNode(next.get());
   1075                 }
   1076                 if (e.deprecatedNode() == elem) {
   1077                     // Since elem must have been fully selected, and it is at the end
   1078                     // of the selection, it is clear we can set the new e offset to
   1079                     // the max range offset of prev.
   1080                     ASSERT(s.anchorType() == Position::PositionIsAfterAnchor
   1081                            || s.offsetInContainerNode() >= lastOffsetInNode(s.containerNode()));
   1082                     e = lastPositionInOrAfterNode(prev.get());
   1083                 }
   1084             }
   1085 
   1086             if (styleToPushDown) {
   1087                 for (; childNode; childNode = childNode->nextSibling())
   1088                     applyInlineStyleToPushDown(childNode.get(), styleToPushDown.get());
   1089             }
   1090         }
   1091         if (node == end.deprecatedNode())
   1092             break;
   1093         node = next.get();
   1094     }
   1095 
   1096     updateStartEnd(s, e);
   1097 }
   1098 
   1099 bool ApplyStyleCommand::nodeFullySelected(Node *node, const Position &start, const Position &end) const
   1100 {
   1101     ASSERT(node);
   1102     ASSERT(node->isElementNode());
   1103 
   1104     return comparePositions(firstPositionInOrBeforeNode(node), start) >= 0
   1105         && comparePositions(lastPositionInOrAfterNode(node).upstream(), end) <= 0;
   1106 }
   1107 
   1108 bool ApplyStyleCommand::nodeFullyUnselected(Node *node, const Position &start, const Position &end) const
   1109 {
   1110     ASSERT(node);
   1111     ASSERT(node->isElementNode());
   1112 
   1113     bool isFullyBeforeStart = comparePositions(lastPositionInOrAfterNode(node).upstream(), start) < 0;
   1114     bool isFullyAfterEnd = comparePositions(firstPositionInOrBeforeNode(node), end) > 0;
   1115 
   1116     return isFullyBeforeStart || isFullyAfterEnd;
   1117 }
   1118 
   1119 void ApplyStyleCommand::splitTextAtStart(const Position& start, const Position& end)
   1120 {
   1121     ASSERT(start.anchorType() == Position::PositionIsOffsetInAnchor);
   1122 
   1123     Position newEnd;
   1124     if (end.anchorType() == Position::PositionIsOffsetInAnchor && start.containerNode() == end.containerNode())
   1125         newEnd = Position(end.containerNode(), end.offsetInContainerNode() - start.offsetInContainerNode(), Position::PositionIsOffsetInAnchor);
   1126     else
   1127         newEnd = end;
   1128 
   1129     Text* text = static_cast<Text*>(start.deprecatedNode());
   1130     splitTextNode(text, start.offsetInContainerNode());
   1131     updateStartEnd(firstPositionInNode(start.deprecatedNode()), newEnd);
   1132 }
   1133 
   1134 void ApplyStyleCommand::splitTextAtEnd(const Position& start, const Position& end)
   1135 {
   1136     ASSERT(end.anchorType() == Position::PositionIsOffsetInAnchor);
   1137 
   1138     bool shouldUpdateStart = start.anchorType() == Position::PositionIsOffsetInAnchor && start.containerNode() == end.containerNode();
   1139     Text* text = static_cast<Text *>(end.deprecatedNode());
   1140     splitTextNode(text, end.offsetInContainerNode());
   1141 
   1142     Node* prevNode = text->previousSibling();
   1143     ASSERT(prevNode);
   1144     Position newStart = shouldUpdateStart ? Position(prevNode, start.offsetInContainerNode(), Position::PositionIsOffsetInAnchor) : start;
   1145     updateStartEnd(newStart, lastPositionInNode(prevNode));
   1146 }
   1147 
   1148 void ApplyStyleCommand::splitTextElementAtStart(const Position& start, const Position& end)
   1149 {
   1150     ASSERT(start.anchorType() == Position::PositionIsOffsetInAnchor);
   1151 
   1152     Position newEnd;
   1153     if (end.anchorType() == Position::PositionIsOffsetInAnchor && start.containerNode() == end.containerNode())
   1154         newEnd = Position(end.containerNode(), end.offsetInContainerNode() - start.offsetInContainerNode(), Position::PositionIsOffsetInAnchor);
   1155     else
   1156         newEnd = end;
   1157 
   1158     Text* text = static_cast<Text*>(start.deprecatedNode());
   1159     splitTextNodeContainingElement(text, start.deprecatedEditingOffset());
   1160     updateStartEnd(Position(start.deprecatedNode()->parentNode(), start.deprecatedNode()->nodeIndex(), Position::PositionIsOffsetInAnchor), newEnd);
   1161 }
   1162 
   1163 void ApplyStyleCommand::splitTextElementAtEnd(const Position& start, const Position& end)
   1164 {
   1165     ASSERT(end.anchorType() == Position::PositionIsOffsetInAnchor);
   1166 
   1167     bool shouldUpdateStart = start.anchorType() == Position::PositionIsOffsetInAnchor && start.containerNode() == end.containerNode();
   1168     Text* text = static_cast<Text*>(end.deprecatedNode());
   1169     splitTextNodeContainingElement(text, end.deprecatedEditingOffset());
   1170 
   1171     Node* prevNode = text->parentNode()->previousSibling()->lastChild();
   1172     ASSERT(prevNode);
   1173     Position newStart = shouldUpdateStart ? Position(prevNode, start.offsetInContainerNode(), Position::PositionIsOffsetInAnchor) : start;
   1174     updateStartEnd(newStart, Position(prevNode->parentNode(), prevNode->nodeIndex() + 1, Position::PositionIsOffsetInAnchor));
   1175 }
   1176 
   1177 bool ApplyStyleCommand::shouldSplitTextElement(Element* element, EditingStyle* style)
   1178 {
   1179     if (!element || !element->isHTMLElement())
   1180         return false;
   1181 
   1182     return shouldRemoveInlineStyleFromElement(style, toHTMLElement(element));
   1183 }
   1184 
   1185 bool ApplyStyleCommand::isValidCaretPositionInTextNode(const Position& position)
   1186 {
   1187     Node* node = position.containerNode();
   1188     if (position.anchorType() != Position::PositionIsOffsetInAnchor || !node->isTextNode())
   1189         return false;
   1190     int offsetInText = position.offsetInContainerNode();
   1191     return offsetInText > caretMinOffset(node) && offsetInText < caretMaxOffset(node);
   1192 }
   1193 
   1194 static bool areIdenticalElements(Node *first, Node *second)
   1195 {
   1196     // check that tag name and all attribute names and values are identical
   1197 
   1198     if (!first->isElementNode())
   1199         return false;
   1200 
   1201     if (!second->isElementNode())
   1202         return false;
   1203 
   1204     Element *firstElement = static_cast<Element *>(first);
   1205     Element *secondElement = static_cast<Element *>(second);
   1206 
   1207     if (!firstElement->tagQName().matches(secondElement->tagQName()))
   1208         return false;
   1209 
   1210     NamedNodeMap *firstMap = firstElement->attributes();
   1211     NamedNodeMap *secondMap = secondElement->attributes();
   1212 
   1213     unsigned firstLength = firstMap->length();
   1214 
   1215     if (firstLength != secondMap->length())
   1216         return false;
   1217 
   1218     for (unsigned i = 0; i < firstLength; i++) {
   1219         Attribute *attribute = firstMap->attributeItem(i);
   1220         Attribute *secondAttribute = secondMap->getAttributeItem(attribute->name());
   1221 
   1222         if (!secondAttribute || attribute->value() != secondAttribute->value())
   1223             return false;
   1224     }
   1225 
   1226     return true;
   1227 }
   1228 
   1229 bool ApplyStyleCommand::mergeStartWithPreviousIfIdentical(const Position& start, const Position& end)
   1230 {
   1231     Node* startNode = start.containerNode();
   1232     int startOffset = start.computeOffsetInContainerNode();
   1233     if (startOffset)
   1234         return false;
   1235 
   1236     if (isAtomicNode(startNode)) {
   1237         // note: prior siblings could be unrendered elements. it's silly to miss the
   1238         // merge opportunity just for that.
   1239         if (startNode->previousSibling())
   1240             return false;
   1241 
   1242         startNode = startNode->parentNode();
   1243         startOffset = 0;
   1244     }
   1245 
   1246     if (!startNode->isElementNode())
   1247         return false;
   1248 
   1249     Node* previousSibling = startNode->previousSibling();
   1250 
   1251     if (previousSibling && areIdenticalElements(startNode, previousSibling)) {
   1252         Element* previousElement = static_cast<Element*>(previousSibling);
   1253         Element* element = static_cast<Element*>(startNode);
   1254         Node* startChild = element->firstChild();
   1255         ASSERT(startChild);
   1256         mergeIdenticalElements(previousElement, element);
   1257 
   1258         int startOffsetAdjustment = startChild->nodeIndex();
   1259         int endOffsetAdjustment = startNode == end.deprecatedNode() ? startOffsetAdjustment : 0;
   1260         updateStartEnd(Position(startNode, startOffsetAdjustment, Position::PositionIsOffsetInAnchor),
   1261                        Position(end.deprecatedNode(), end.deprecatedEditingOffset() + endOffsetAdjustment, Position::PositionIsOffsetInAnchor));
   1262         return true;
   1263     }
   1264 
   1265     return false;
   1266 }
   1267 
   1268 bool ApplyStyleCommand::mergeEndWithNextIfIdentical(const Position& start, const Position& end)
   1269 {
   1270     Node* endNode = end.containerNode();
   1271     int endOffset = end.computeOffsetInContainerNode();
   1272 
   1273     if (isAtomicNode(endNode)) {
   1274         if (endOffset < lastOffsetInNode(endNode))
   1275             return false;
   1276 
   1277         unsigned parentLastOffset = end.deprecatedNode()->parentNode()->childNodes()->length() - 1;
   1278         if (end.deprecatedNode()->nextSibling())
   1279             return false;
   1280 
   1281         endNode = end.deprecatedNode()->parentNode();
   1282         endOffset = parentLastOffset;
   1283     }
   1284 
   1285     if (!endNode->isElementNode() || endNode->hasTagName(brTag))
   1286         return false;
   1287 
   1288     Node* nextSibling = endNode->nextSibling();
   1289     if (nextSibling && areIdenticalElements(endNode, nextSibling)) {
   1290         Element* nextElement = static_cast<Element *>(nextSibling);
   1291         Element* element = static_cast<Element *>(endNode);
   1292         Node* nextChild = nextElement->firstChild();
   1293 
   1294         mergeIdenticalElements(element, nextElement);
   1295 
   1296         bool shouldUpdateStart = start.containerNode() == endNode;
   1297         int endOffset = nextChild ? nextChild->nodeIndex() : nextElement->childNodes()->length();
   1298         updateStartEnd(shouldUpdateStart ? Position(nextElement, start.offsetInContainerNode(), Position::PositionIsOffsetInAnchor) : start,
   1299                        Position(nextElement, endOffset, Position::PositionIsOffsetInAnchor));
   1300         return true;
   1301     }
   1302 
   1303     return false;
   1304 }
   1305 
   1306 void ApplyStyleCommand::surroundNodeRangeWithElement(PassRefPtr<Node> passedStartNode, PassRefPtr<Node> endNode, PassRefPtr<Element> elementToInsert)
   1307 {
   1308     ASSERT(passedStartNode);
   1309     ASSERT(endNode);
   1310     ASSERT(elementToInsert);
   1311     RefPtr<Node> startNode = passedStartNode;
   1312     RefPtr<Element> element = elementToInsert;
   1313 
   1314     insertNodeBefore(element, startNode);
   1315 
   1316     RefPtr<Node> node = startNode;
   1317     while (node) {
   1318         RefPtr<Node> next = node->nextSibling();
   1319         if (node->isContentEditable()) {
   1320             removeNode(node);
   1321             appendNode(node, element);
   1322         }
   1323         if (node == endNode)
   1324             break;
   1325         node = next;
   1326     }
   1327 
   1328     RefPtr<Node> nextSibling = element->nextSibling();
   1329     RefPtr<Node> previousSibling = element->previousSibling();
   1330     if (nextSibling && nextSibling->isElementNode() && nextSibling->rendererIsEditable()
   1331         && areIdenticalElements(element.get(), static_cast<Element*>(nextSibling.get())))
   1332         mergeIdenticalElements(element.get(), static_cast<Element*>(nextSibling.get()));
   1333 
   1334     if (previousSibling && previousSibling->isElementNode() && previousSibling->rendererIsEditable()) {
   1335         Node* mergedElement = previousSibling->nextSibling();
   1336         if (mergedElement->isElementNode() && mergedElement->rendererIsEditable()
   1337             && areIdenticalElements(static_cast<Element*>(previousSibling.get()), static_cast<Element*>(mergedElement)))
   1338             mergeIdenticalElements(static_cast<Element*>(previousSibling.get()), static_cast<Element*>(mergedElement));
   1339     }
   1340 
   1341     // FIXME: We should probably call updateStartEnd if the start or end was in the node
   1342     // range so that the endingSelection() is canonicalized.  See the comments at the end of
   1343     // VisibleSelection::validate().
   1344 }
   1345 
   1346 void ApplyStyleCommand::addBlockStyle(const StyleChange& styleChange, HTMLElement* block)
   1347 {
   1348     // Do not check for legacy styles here. Those styles, like <B> and <I>, only apply for
   1349     // inline content.
   1350     if (!block)
   1351         return;
   1352 
   1353     String cssText = styleChange.cssStyle();
   1354     CSSMutableStyleDeclaration* decl = block->inlineStyleDecl();
   1355     if (decl)
   1356         cssText += decl->cssText();
   1357     setNodeAttribute(block, styleAttr, cssText);
   1358 }
   1359 
   1360 void ApplyStyleCommand::addInlineStyleIfNeeded(EditingStyle* style, PassRefPtr<Node> passedStart, PassRefPtr<Node> passedEnd, EAddStyledElement addStyledElement)
   1361 {
   1362     if (!passedStart || !passedEnd || !passedStart->inDocument() || !passedEnd->inDocument())
   1363         return;
   1364     RefPtr<Node> startNode = passedStart;
   1365     RefPtr<Node> endNode = passedEnd;
   1366 
   1367     // It's okay to obtain the style at the startNode because we've removed all relevant styles from the current run.
   1368     RefPtr<HTMLElement> dummyElement;
   1369     Position positionForStyleComparison;
   1370     if (!startNode->isElementNode()) {
   1371         dummyElement = createStyleSpanElement(document());
   1372         insertNodeAt(dummyElement, positionBeforeNode(startNode.get()));
   1373         positionForStyleComparison = positionBeforeNode(dummyElement.get());
   1374     } else
   1375         positionForStyleComparison = firstPositionInOrBeforeNode(startNode.get());
   1376 
   1377     StyleChange styleChange(style, positionForStyleComparison);
   1378 
   1379     if (dummyElement)
   1380         removeNode(dummyElement);
   1381 
   1382     // Find appropriate font and span elements top-down.
   1383     HTMLElement* fontContainer = 0;
   1384     HTMLElement* styleContainer = 0;
   1385     for (Node* container = startNode.get(); container && startNode == endNode; container = container->firstChild()) {
   1386         if (container->isHTMLElement() && container->hasTagName(fontTag))
   1387             fontContainer = toHTMLElement(container);
   1388         bool styleContainerIsNotSpan = !styleContainer || !styleContainer->hasTagName(spanTag);
   1389         if (container->isHTMLElement() && (container->hasTagName(spanTag) || (styleContainerIsNotSpan && container->childNodeCount())))
   1390             styleContainer = toHTMLElement(container);
   1391         if (!container->firstChild())
   1392             break;
   1393         startNode = container->firstChild();
   1394         endNode = container->lastChild();
   1395     }
   1396 
   1397     // Font tags need to go outside of CSS so that CSS font sizes override leagcy font sizes.
   1398     if (styleChange.applyFontColor() || styleChange.applyFontFace() || styleChange.applyFontSize()) {
   1399         if (fontContainer) {
   1400             if (styleChange.applyFontColor())
   1401                 setNodeAttribute(fontContainer, colorAttr, styleChange.fontColor());
   1402             if (styleChange.applyFontFace())
   1403                 setNodeAttribute(fontContainer, faceAttr, styleChange.fontFace());
   1404             if (styleChange.applyFontSize())
   1405                 setNodeAttribute(fontContainer, sizeAttr, styleChange.fontSize());
   1406         } else {
   1407             RefPtr<Element> fontElement = createFontElement(document());
   1408             if (styleChange.applyFontColor())
   1409                 fontElement->setAttribute(colorAttr, styleChange.fontColor());
   1410             if (styleChange.applyFontFace())
   1411                 fontElement->setAttribute(faceAttr, styleChange.fontFace());
   1412             if (styleChange.applyFontSize())
   1413                 fontElement->setAttribute(sizeAttr, styleChange.fontSize());
   1414             surroundNodeRangeWithElement(startNode, endNode, fontElement.get());
   1415         }
   1416     }
   1417 
   1418     if (styleChange.cssStyle().length()) {
   1419         if (styleContainer) {
   1420             CSSMutableStyleDeclaration* existingStyle = toHTMLElement(styleContainer)->inlineStyleDecl();
   1421             if (existingStyle)
   1422                 setNodeAttribute(styleContainer, styleAttr, existingStyle->cssText() + styleChange.cssStyle());
   1423             else
   1424                 setNodeAttribute(styleContainer, styleAttr, styleChange.cssStyle());
   1425         } else {
   1426             RefPtr<Element> styleElement = createStyleSpanElement(document());
   1427             styleElement->setAttribute(styleAttr, styleChange.cssStyle());
   1428             surroundNodeRangeWithElement(startNode, endNode, styleElement.release());
   1429         }
   1430     }
   1431 
   1432     if (styleChange.applyBold())
   1433         surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), bTag));
   1434 
   1435     if (styleChange.applyItalic())
   1436         surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), iTag));
   1437 
   1438     if (styleChange.applyUnderline())
   1439         surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), uTag));
   1440 
   1441     if (styleChange.applyLineThrough())
   1442         surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), strikeTag));
   1443 
   1444     if (styleChange.applySubscript())
   1445         surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), subTag));
   1446     else if (styleChange.applySuperscript())
   1447         surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), supTag));
   1448 
   1449     if (m_styledInlineElement && addStyledElement == AddStyledElement)
   1450         surroundNodeRangeWithElement(startNode, endNode, m_styledInlineElement->cloneElementWithoutChildren());
   1451 }
   1452 
   1453 float ApplyStyleCommand::computedFontSize(Node* node)
   1454 {
   1455     if (!node)
   1456         return 0;
   1457 
   1458     RefPtr<CSSComputedStyleDeclaration> style = computedStyle(node);
   1459     if (!style)
   1460         return 0;
   1461 
   1462     RefPtr<CSSPrimitiveValue> value = static_pointer_cast<CSSPrimitiveValue>(style->getPropertyCSSValue(CSSPropertyFontSize));
   1463     if (!value)
   1464         return 0;
   1465 
   1466     return value->getFloatValue(CSSPrimitiveValue::CSS_PX);
   1467 }
   1468 
   1469 void ApplyStyleCommand::joinChildTextNodes(Node* node, const Position& start, const Position& end)
   1470 {
   1471     if (!node)
   1472         return;
   1473 
   1474     Position newStart = start;
   1475     Position newEnd = end;
   1476 
   1477     Node* child = node->firstChild();
   1478     while (child) {
   1479         Node* next = child->nextSibling();
   1480         if (child->isTextNode() && next && next->isTextNode()) {
   1481             Text* childText = static_cast<Text *>(child);
   1482             Text* nextText = static_cast<Text *>(next);
   1483             if (start.anchorType() == Position::PositionIsOffsetInAnchor && next == start.containerNode())
   1484                 newStart = Position(childText, childText->length() + start.offsetInContainerNode(), Position::PositionIsOffsetInAnchor);
   1485             if (end.anchorType() == Position::PositionIsOffsetInAnchor && next == end.containerNode())
   1486                 newEnd = Position(childText, childText->length() + end.offsetInContainerNode(), Position::PositionIsOffsetInAnchor);
   1487             String textToMove = nextText->data();
   1488             insertTextIntoNode(childText, childText->length(), textToMove);
   1489             removeNode(next);
   1490             // don't move child node pointer. it may want to merge with more text nodes.
   1491         }
   1492         else {
   1493             child = child->nextSibling();
   1494         }
   1495     }
   1496 
   1497     updateStartEnd(newStart, newEnd);
   1498 }
   1499 
   1500 }
   1501