WebCore/editing/ApplyStyleCommand.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/editing/ApplyStyleCommand.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,1892 @@
+/*
+ * Copyright (C) 2005, 2006, 2008, 2009 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "ApplyStyleCommand.h"
+
+#include "CSSComputedStyleDeclaration.h"
+#include "CSSMutableStyleDeclaration.h"
+#include "CSSParser.h"
+#include "CSSProperty.h"
+#include "CSSPropertyNames.h"
+#include "CSSValueKeywords.h"
+#include "Document.h"
+#include "Editor.h"
+#include "Frame.h"
+#include "HTMLElement.h"
+#include "HTMLInterchange.h"
+#include "HTMLNames.h"
+#include "NodeList.h"
+#include "Range.h"
+#include "RenderObject.h"
+#include "Text.h"
+#include "TextIterator.h"
+#include "htmlediting.h"
+#include "visible_units.h"
+#include <wtf/StdLibExtras.h>
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+class StyleChange {
+public:
+    explicit StyleChange(CSSStyleDeclaration*, const Position&);
+
+    String cssStyle() const { return m_cssStyle; }
+    bool applyBold() const { return m_applyBold; }
+    bool applyItalic() const { return m_applyItalic; }
+    bool applyUnderline() const { return m_applyUnderline; }
+    bool applyLineThrough() const { return m_applyLineThrough; }
+    bool applySubscript() const { return m_applySubscript; }
+    bool applySuperscript() const { return m_applySuperscript; }
+    bool applyFontColor() const { return m_applyFontColor.length() > 0; }
+    bool applyFontFace() const { return m_applyFontFace.length() > 0; }
+    bool applyFontSize() const { return m_applyFontSize.length() > 0; }
+
+    String fontColor() { return m_applyFontColor; }
+    String fontFace() { return m_applyFontFace; }
+    String fontSize() { return m_applyFontSize; }
+
+private:
+    void init(PassRefPtr<CSSStyleDeclaration>, const Position&);
+    void reconcileTextDecorationProperties(CSSMutableStyleDeclaration*);
+    void extractTextStyles(CSSMutableStyleDeclaration*);
+
+    String m_cssStyle;
+    bool m_applyBold;
+    bool m_applyItalic;
+    bool m_applyUnderline;
+    bool m_applyLineThrough;
+    bool m_applySubscript;
+    bool m_applySuperscript;
+    String m_applyFontColor;
+    String m_applyFontFace;
+    String m_applyFontSize;
+};
+
+
+StyleChange::StyleChange(CSSStyleDeclaration* style, const Position& position)
+    : m_applyBold(false)
+    , m_applyItalic(false)
+    , m_applyUnderline(false)
+    , m_applyLineThrough(false)
+    , m_applySubscript(false)
+    , m_applySuperscript(false)
+{
+    init(style, position);
+}
+
+void StyleChange::init(PassRefPtr<CSSStyleDeclaration> style, const Position& position)
+{
+    Document* document = position.node() ? position.node()->document() : 0;
+    if (!document || !document->frame())
+        return;
+
+    RefPtr<CSSComputedStyleDeclaration> computedStyle = position.computedStyle();
+    RefPtr<CSSMutableStyleDeclaration> mutableStyle = getPropertiesNotInComputedStyle(style.get(), computedStyle.get());
+
+    reconcileTextDecorationProperties(mutableStyle.get());
+    if (!document->frame()->editor()->shouldStyleWithCSS())
+        extractTextStyles(mutableStyle.get());
+
+    // Changing the whitespace style in a tab span would collapse the tab into a space.
+    if (isTabSpanTextNode(position.node()) || isTabSpanNode((position.node())))
+        mutableStyle->removeProperty(CSSPropertyWhiteSpace);
+
+    // If unicode-bidi is present in mutableStyle and direction is not, then add direction to mutableStyle.
+    // FIXME: Shouldn't this be done in getPropertiesNotInComputedStyle?
+    if (mutableStyle->getPropertyCSSValue(CSSPropertyUnicodeBidi) && !style->getPropertyCSSValue(CSSPropertyDirection))
+        mutableStyle->setProperty(CSSPropertyDirection, style->getPropertyValue(CSSPropertyDirection));
+
+    // Save the result for later
+    m_cssStyle = mutableStyle->cssText().stripWhiteSpace();
+}
+
+void StyleChange::reconcileTextDecorationProperties(CSSMutableStyleDeclaration* style)
+{    
+    RefPtr<CSSValue> textDecorationsInEffect = style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+    RefPtr<CSSValue> textDecoration = style->getPropertyCSSValue(CSSPropertyTextDecoration);
+    // We shouldn't have both text-decoration and -webkit-text-decorations-in-effect because that wouldn't make sense.
+    ASSERT(!textDecorationsInEffect || !textDecoration);
+    if (textDecorationsInEffect) {
+        style->setProperty(CSSPropertyTextDecoration, textDecorationsInEffect->cssText());
+        style->removeProperty(CSSPropertyWebkitTextDecorationsInEffect);
+        textDecoration = textDecorationsInEffect;
+    }
+
+    // If text-decoration is set to "none", remove the property because we don't want to add redundant "text-decoration: none".
+    if (textDecoration && !textDecoration->isValueList())
+        style->removeProperty(CSSPropertyTextDecoration);
+}
+
+static int getIdentifierValue(CSSMutableStyleDeclaration* style, int propertyID)
+{
+    if (!style)
+        return 0;
+
+    RefPtr<CSSValue> value = style->getPropertyCSSValue(propertyID);
+    if (!value || !value->isPrimitiveValue())
+        return 0;
+
+    return static_cast<CSSPrimitiveValue*>(value.get())->getIdent();
+}
+
+static void setTextDecorationProperty(CSSMutableStyleDeclaration* style, const CSSValueList* newTextDecoration, int propertyID)
+{
+    if (newTextDecoration->length())
+        style->setProperty(propertyID, newTextDecoration->cssText(), style->getPropertyPriority(propertyID));
+    else {
+        // text-decoration: none is redundant since it does not remove any text decorations.
+        ASSERT(!style->getPropertyPriority(propertyID));
+        style->removeProperty(propertyID);
+    }
+}
+
+void StyleChange::extractTextStyles(CSSMutableStyleDeclaration* style)
+{
+    ASSERT(style);
+
+    if (getIdentifierValue(style, CSSPropertyFontWeight) == CSSValueBold) {
+        style->removeProperty(CSSPropertyFontWeight);
+        m_applyBold = true;
+    }
+
+    int fontStyle = getIdentifierValue(style, CSSPropertyFontStyle);
+    if (fontStyle == CSSValueItalic || fontStyle == CSSValueOblique) {
+        style->removeProperty(CSSPropertyFontStyle);
+        m_applyItalic = true;
+    }
+
+    // Assuming reconcileTextDecorationProperties has been called, there should not be -webkit-text-decorations-in-effect
+    // Furthermore, text-decoration: none has been trimmed so that text-decoration property is always a CSSValueList.
+    if (RefPtr<CSSValue> textDecoration = style->getPropertyCSSValue(CSSPropertyTextDecoration)) {
+        ASSERT(textDecoration->isValueList());
+        DEFINE_STATIC_LOCAL(RefPtr<CSSPrimitiveValue>, underline, (CSSPrimitiveValue::createIdentifier(CSSValueUnderline)));
+        DEFINE_STATIC_LOCAL(RefPtr<CSSPrimitiveValue>, lineThrough, (CSSPrimitiveValue::createIdentifier(CSSValueLineThrough)));
+
+        RefPtr<CSSValueList> newTextDecoration = static_cast<CSSValueList*>(textDecoration.get())->copy();
+        if (newTextDecoration->removeAll(underline.get()))
+            m_applyUnderline = true;
+        if (newTextDecoration->removeAll(lineThrough.get()))
+            m_applyLineThrough = true;
+
+        // If trimTextDecorations, delete underline and line-through
+        setTextDecorationProperty(style, newTextDecoration.get(), CSSPropertyTextDecoration);
+    }
+
+    int verticalAlign = getIdentifierValue(style, CSSPropertyVerticalAlign);
+    switch (verticalAlign) {
+    case CSSValueSub:
+        style->removeProperty(CSSPropertyVerticalAlign);
+        m_applySubscript = true;
+        break;
+    case CSSValueSuper:
+        style->removeProperty(CSSPropertyVerticalAlign);
+        m_applySuperscript = true;
+        break;
+    }
+
+    if (RefPtr<CSSValue> colorValue = style->getPropertyCSSValue(CSSPropertyColor)) {
+        ASSERT(colorValue->isPrimitiveValue());
+        CSSPrimitiveValue* primitiveColor = static_cast<CSSPrimitiveValue*>(colorValue.get());
+        RGBA32 rgba = 0;
+        if (primitiveColor->primitiveType() != CSSPrimitiveValue::CSS_RGBCOLOR) {
+            CSSParser::parseColor(rgba, colorValue->cssText());
+            // Need to take care of named color such as green and black
+            // This code should be removed after https://bugs.webkit.org/show_bug.cgi?id=28282 is fixed.
+        } else
+            rgba = primitiveColor->getRGBA32Value();
+        m_applyFontColor = Color(rgba).name();
+        style->removeProperty(CSSPropertyColor);
+    }
+
+    m_applyFontFace = style->getPropertyValue(CSSPropertyFontFamily);
+    style->removeProperty(CSSPropertyFontFamily);
+
+    if (RefPtr<CSSValue> fontSize = style->getPropertyCSSValue(CSSPropertyFontSize)) {
+        if (!fontSize->isPrimitiveValue())
+            style->removeProperty(CSSPropertyFontSize); // Can't make sense of the number. Put no font size.
+        else {
+            CSSPrimitiveValue* value = static_cast<CSSPrimitiveValue*>(fontSize.get());
+
+            // Only accept absolute scale
+            if (value->primitiveType() >= CSSPrimitiveValue::CSS_PX && value->primitiveType() <= CSSPrimitiveValue::CSS_PC) {
+                float number = value->getFloatValue(CSSPrimitiveValue::CSS_PX);
+                if (number <= 9)
+                    m_applyFontSize = "1";
+                else if (number <= 10)
+                    m_applyFontSize = "2";
+                else if (number <= 13)
+                    m_applyFontSize = "3";
+                else if (number <= 16)
+                    m_applyFontSize = "4";
+                else if (number <= 18)
+                    m_applyFontSize = "5";
+                else if (number <= 24)
+                    m_applyFontSize = "6";
+                else
+                    m_applyFontSize = "7";
+            }
+            // Huge quirk in Microsoft Entourage is that they understand CSS font-size, but also write 
+            // out legacy 1-7 values in font tags (I guess for mailers that are not CSS-savvy at all, 
+            // like Eudora). Yes, they write out *both*. We need to write out both as well.
+        }
+    }
+}
+
+static String& styleSpanClassString()
+{
+    DEFINE_STATIC_LOCAL(String, styleSpanClassString, ((AppleStyleSpanClass)));
+    return styleSpanClassString;
+}
+
+bool isStyleSpan(const Node *node)
+{
+    if (!node || !node->isHTMLElement())
+        return false;
+
+    const HTMLElement* elem = static_cast<const HTMLElement*>(node);
+    return elem->hasLocalName(spanAttr) && elem->getAttribute(classAttr) == styleSpanClassString();
+}
+
+static bool isUnstyledStyleSpan(const Node* node)
+{
+    if (!node || !node->isHTMLElement() || !node->hasTagName(spanTag))
+        return false;
+
+    const HTMLElement* elem = static_cast<const HTMLElement*>(node);
+    CSSMutableStyleDeclaration* inlineStyleDecl = elem->inlineStyleDecl();
+    return (!inlineStyleDecl || inlineStyleDecl->isEmpty()) && elem->getAttribute(classAttr) == styleSpanClassString();
+}
+
+static bool isSpanWithoutAttributesOrUnstyleStyleSpan(const Node* node)
+{
+    if (!node || !node->isHTMLElement() || !node->hasTagName(spanTag))
+        return false;
+
+    const HTMLElement* elem = static_cast<const HTMLElement*>(node);
+    NamedNodeMap* attributes = elem->attributes(true); // readonly
+    if (attributes->isEmpty())
+        return true;
+
+    return isUnstyledStyleSpan(node);
+}
+
+static bool isEmptyFontTag(const Node *node)
+{
+    if (!node || !node->hasTagName(fontTag))
+        return false;
+
+    const Element *elem = static_cast<const Element *>(node);
+    NamedNodeMap *map = elem->attributes(true); // true for read-only
+    if (!map)
+        return true;
+    return map->isEmpty() || (map->length() == 1 && elem->getAttribute(classAttr) == styleSpanClassString());
+}
+
+static PassRefPtr<Element> createFontElement(Document* document)
+{
+    RefPtr<Element> fontNode = createHTMLElement(document, fontTag);
+    fontNode->setAttribute(classAttr, styleSpanClassString());
+    return fontNode.release();
+}
+
+PassRefPtr<HTMLElement> createStyleSpanElement(Document* document)
+{
+    RefPtr<HTMLElement> styleElement = createHTMLElement(document, spanTag);
+    styleElement->setAttribute(classAttr, styleSpanClassString());
+    return styleElement.release();
+}
+
+static void diffTextDecorations(CSSMutableStyleDeclaration* style, int propertID, CSSValue* refTextDecoration)
+{
+    RefPtr<CSSValue> textDecoration = style->getPropertyCSSValue(propertID);
+    if (!textDecoration || !textDecoration->isValueList() || !refTextDecoration || !refTextDecoration->isValueList())
+        return;
+
+    RefPtr<CSSValueList> newTextDecoration = static_cast<CSSValueList*>(textDecoration.get())->copy();
+    CSSValueList* valuesInRefTextDecoration = static_cast<CSSValueList*>(refTextDecoration);
+
+    for (size_t i = 0; i < valuesInRefTextDecoration->length(); i++)
+        newTextDecoration->removeAll(valuesInRefTextDecoration->item(i));
+
+    setTextDecorationProperty(style, newTextDecoration.get(), propertID);
+}
+
+static bool fontWeightIsBold(CSSStyleDeclaration* style)
+{
+    ASSERT(style);
+    RefPtr<CSSValue> fontWeight = style->getPropertyCSSValue(CSSPropertyFontWeight);
+
+    if (!fontWeight)
+        return false;
+    if (!fontWeight->isPrimitiveValue())
+        return false;
+
+    // Because b tag can only bold text, there are only two states in plain html: bold and not bold.
+    // Collapse all other values to either one of these two states for editing purposes.
+    switch (static_cast<CSSPrimitiveValue*>(fontWeight.get())->getIdent()) {
+        case CSSValue100:
+        case CSSValue200:
+        case CSSValue300:
+        case CSSValue400:
+        case CSSValue500:
+        case CSSValueNormal:
+            return false;
+        case CSSValueBold:
+        case CSSValue600:
+        case CSSValue700:
+        case CSSValue800:
+        case CSSValue900:
+            return true;
+    }
+
+    ASSERT_NOT_REACHED(); // For CSSValueBolder and CSSValueLighter
+    return false; // Make compiler happy
+}
+
+RefPtr<CSSMutableStyleDeclaration> getPropertiesNotInComputedStyle(CSSStyleDeclaration* style, CSSComputedStyleDeclaration* computedStyle)
+{
+    ASSERT(style);
+    ASSERT(computedStyle);
+    RefPtr<CSSMutableStyleDeclaration> result = style->copy();
+    computedStyle->diff(result.get());
+
+    RefPtr<CSSValue> computedTextDecorationsInEffect = computedStyle->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+    diffTextDecorations(result.get(), CSSPropertyTextDecoration, computedTextDecorationsInEffect.get());
+    diffTextDecorations(result.get(), CSSPropertyWebkitTextDecorationsInEffect, computedTextDecorationsInEffect.get());
+
+    if (fontWeightIsBold(result.get()) == fontWeightIsBold(computedStyle))
+        result->removeProperty(CSSPropertyFontWeight);
+
+    return result;
+}
+
+// Editing style properties must be preserved during editing operation.
+// e.g. when a user inserts a new paragraph, all properties listed here must be copied to the new paragraph.
+// FIXME: The current editingStyleProperties contains all inheritableProperties but we may not need to preserve all inheritable properties
+static const int editingStyleProperties[] = {
+    // CSS inheritable properties
+    CSSPropertyBorderCollapse,
+    CSSPropertyColor,
+    CSSPropertyFontFamily,
+    CSSPropertyFontSize,
+    CSSPropertyFontStyle,
+    CSSPropertyFontVariant,
+    CSSPropertyFontWeight,
+    CSSPropertyLetterSpacing,
+    CSSPropertyLineHeight,
+    CSSPropertyOrphans,
+    CSSPropertyTextAlign,
+    CSSPropertyTextIndent,
+    CSSPropertyTextTransform,
+    CSSPropertyWhiteSpace,
+    CSSPropertyWidows,
+    CSSPropertyWordSpacing,
+    CSSPropertyWebkitBorderHorizontalSpacing,
+    CSSPropertyWebkitBorderVerticalSpacing,
+    CSSPropertyWebkitTextDecorationsInEffect,
+    CSSPropertyWebkitTextFillColor,
+    CSSPropertyWebkitTextSizeAdjust,
+    CSSPropertyWebkitTextStrokeColor,
+    CSSPropertyWebkitTextStrokeWidth,
+};
+size_t numEditingStyleProperties = sizeof(editingStyleProperties)/sizeof(editingStyleProperties[0]);
+
+PassRefPtr<CSSMutableStyleDeclaration> ApplyStyleCommand::editingStyleAtPosition(Position pos, ShouldIncludeTypingStyle shouldIncludeTypingStyle)
+{
+    RefPtr<CSSComputedStyleDeclaration> computedStyleAtPosition = pos.computedStyle();
+    RefPtr<CSSMutableStyleDeclaration> style;
+    if (!computedStyleAtPosition)
+        style = CSSMutableStyleDeclaration::create();
+    else
+        style = computedStyleAtPosition->copyPropertiesInSet(editingStyleProperties, numEditingStyleProperties);
+
+    if (style && pos.node() && pos.node()->computedStyle()) {
+        RenderStyle* renderStyle = pos.node()->computedStyle();
+        // If a node's text fill color is invalid, then its children use 
+        // their font-color as their text fill color (they don't
+        // inherit it).  Likewise for stroke color.
+        ExceptionCode ec = 0;
+        if (!renderStyle->textFillColor().isValid())
+            style->removeProperty(CSSPropertyWebkitTextFillColor, ec);
+        if (!renderStyle->textStrokeColor().isValid())
+            style->removeProperty(CSSPropertyWebkitTextStrokeColor, ec);
+        ASSERT(ec == 0);
+        if (renderStyle->fontDescription().keywordSize())
+            style->setProperty(CSSPropertyFontSize, computedStyleAtPosition->getFontSizeCSSValuePreferringKeyword()->cssText());
+    }
+
+    if (shouldIncludeTypingStyle == IncludeTypingStyle) {
+        CSSMutableStyleDeclaration* typingStyle = pos.node()->document()->frame()->typingStyle();
+        if (typingStyle)
+            style->merge(typingStyle);
+    }
+
+    return style.release();
+}
+
+void prepareEditingStyleToApplyAt(CSSMutableStyleDeclaration* editingStyle, Position pos)
+{
+    // ReplaceSelectionCommand::handleStyleSpans() requires that this function only removes the editing style.
+    // If this function was modified in the future to delete all redundant properties, then add a boolean value to indicate
+    // which one of editingStyleAtPosition or computedStyle is called.
+    RefPtr<CSSMutableStyleDeclaration> style = ApplyStyleCommand::editingStyleAtPosition(pos);
+    style->diff(editingStyle);
+
+    // if alpha value is zero, we don't add the background color.
+    RefPtr<CSSValue> backgroundColor = editingStyle->getPropertyCSSValue(CSSPropertyBackgroundColor);
+    if (backgroundColor && backgroundColor->isPrimitiveValue()) {
+        CSSPrimitiveValue* primitiveValue = static_cast<CSSPrimitiveValue*>(backgroundColor.get());
+        Color color = Color(primitiveValue->getRGBA32Value());
+        ExceptionCode ec;
+        if (color.alpha() == 0)
+            editingStyle->removeProperty(CSSPropertyBackgroundColor, ec);
+    }
+}
+
+void removeStylesAddedByNode(CSSMutableStyleDeclaration* editingStyle, Node* node)
+{
+    ASSERT(node);
+    ASSERT(node->parentNode());
+    RefPtr<CSSMutableStyleDeclaration> parentStyle = ApplyStyleCommand::editingStyleAtPosition(Position(node->parentNode(), 0));
+    RefPtr<CSSMutableStyleDeclaration> style = ApplyStyleCommand::editingStyleAtPosition(Position(node, 0));
+    parentStyle->diff(style.get());
+    style->diff(editingStyle);
+}
+    
+ApplyStyleCommand::ApplyStyleCommand(Document* document, CSSStyleDeclaration* style, EditAction editingAction, EPropertyLevel propertyLevel)
+    : CompositeEditCommand(document)
+    , m_style(style->makeMutable())
+    , m_editingAction(editingAction)
+    , m_propertyLevel(propertyLevel)
+    , m_start(endingSelection().start().downstream())
+    , m_end(endingSelection().end().upstream())
+    , m_useEndingSelection(true)
+    , m_styledInlineElement(0)
+    , m_removeOnly(false)
+{
+}
+
+ApplyStyleCommand::ApplyStyleCommand(Document* document, CSSStyleDeclaration* style, const Position& start, const Position& end, EditAction editingAction, EPropertyLevel propertyLevel)
+    : CompositeEditCommand(document)
+    , m_style(style->makeMutable())
+    , m_editingAction(editingAction)
+    , m_propertyLevel(propertyLevel)
+    , m_start(start)
+    , m_end(end)
+    , m_useEndingSelection(false)
+    , m_styledInlineElement(0)
+    , m_removeOnly(false)
+{
+}
+
+ApplyStyleCommand::ApplyStyleCommand(PassRefPtr<Element> element, bool removeOnly, EditAction editingAction)
+    : CompositeEditCommand(element->document())
+    , m_style(CSSMutableStyleDeclaration::create())
+    , m_editingAction(editingAction)
+    , m_propertyLevel(PropertyDefault)
+    , m_start(endingSelection().start().downstream())
+    , m_end(endingSelection().end().upstream())
+    , m_useEndingSelection(true)
+    , m_styledInlineElement(element)
+    , m_removeOnly(removeOnly)
+{
+}
+
+void ApplyStyleCommand::updateStartEnd(const Position& newStart, const Position& newEnd)
+{
+    ASSERT(comparePositions(newEnd, newStart) >= 0);
+
+    if (!m_useEndingSelection && (newStart != m_start || newEnd != m_end))
+        m_useEndingSelection = true;
+
+    setEndingSelection(VisibleSelection(newStart, newEnd, VP_DEFAULT_AFFINITY));
+    m_start = newStart;
+    m_end = newEnd;
+}
+
+Position ApplyStyleCommand::startPosition()
+{
+    if (m_useEndingSelection)
+        return endingSelection().start();
+    
+    return m_start;
+}
+
+Position ApplyStyleCommand::endPosition()
+{
+    if (m_useEndingSelection)
+        return endingSelection().end();
+    
+    return m_end;
+}
+
+void ApplyStyleCommand::doApply()
+{
+    switch (m_propertyLevel) {
+        case PropertyDefault: {
+            // apply the block-centric properties of the style
+            RefPtr<CSSMutableStyleDeclaration> blockStyle = m_style->copyBlockProperties();
+            if (blockStyle->length())
+                applyBlockStyle(blockStyle.get());
+            // apply any remaining styles to the inline elements
+            // NOTE: hopefully, this string comparison is the same as checking for a non-null diff
+            if (blockStyle->length() < m_style->length() || m_styledInlineElement) {
+                RefPtr<CSSMutableStyleDeclaration> inlineStyle = m_style->copy();
+                applyRelativeFontStyleChange(inlineStyle.get());
+                blockStyle->diff(inlineStyle.get());
+                applyInlineStyle(inlineStyle.get());
+            }
+            break;
+        }
+        case ForceBlockProperties:
+            // Force all properties to be applied as block styles.
+            applyBlockStyle(m_style.get());
+            break;
+    }
+}
+
+EditAction ApplyStyleCommand::editingAction() const
+{
+    return m_editingAction;
+}
+
+void ApplyStyleCommand::applyBlockStyle(CSSMutableStyleDeclaration *style)
+{
+    // update document layout once before removing styles
+    // so that we avoid the expense of updating before each and every call
+    // to check a computed style
+    updateLayout();
+
+    // get positions we want to use for applying style
+    Position start = startPosition();
+    Position end = endPosition();
+    if (comparePositions(end, start) < 0) {
+        Position swap = start;
+        start = end;
+        end = swap;
+    }
+        
+    VisiblePosition visibleStart(start);
+    VisiblePosition visibleEnd(end);
+    // Save and restore the selection endpoints using their indices in the document, since
+    // addBlockStyleIfNeeded may moveParagraphs, which can remove these endpoints.
+    // Calculate start and end indices from the start of the tree that they're in.
+    Node* scope = highestAncestor(visibleStart.deepEquivalent().node());
+    Position rangeStart(scope, 0);
+    RefPtr<Range> startRange = Range::create(document(), rangeStart, rangeCompliantEquivalent(visibleStart.deepEquivalent()));
+    RefPtr<Range> endRange = Range::create(document(), rangeStart, rangeCompliantEquivalent(visibleEnd.deepEquivalent()));
+    int startIndex = TextIterator::rangeLength(startRange.get(), true);
+    int endIndex = TextIterator::rangeLength(endRange.get(), true);
+    
+    VisiblePosition paragraphStart(startOfParagraph(visibleStart));
+    VisiblePosition nextParagraphStart(endOfParagraph(paragraphStart).next());
+    VisiblePosition beyondEnd(endOfParagraph(visibleEnd).next());
+    while (paragraphStart.isNotNull() && paragraphStart != beyondEnd) {
+        StyleChange styleChange(style, paragraphStart.deepEquivalent());
+        if (styleChange.cssStyle().length() || m_removeOnly) {
+            RefPtr<Node> block = enclosingBlock(paragraphStart.deepEquivalent().node());
+            RefPtr<Node> newBlock = moveParagraphContentsToNewBlockIfNecessary(paragraphStart.deepEquivalent());
+            if (newBlock)
+                block = newBlock;
+            ASSERT(block->isHTMLElement());
+            if (block->isHTMLElement()) {
+                removeCSSStyle(style, static_cast<HTMLElement*>(block.get()));
+                if (!m_removeOnly)
+                    addBlockStyle(styleChange, static_cast<HTMLElement*>(block.get()));
+            }
+
+            if (nextParagraphStart.isOrphan())
+                nextParagraphStart = endOfParagraph(paragraphStart).next();
+        }
+
+        paragraphStart = nextParagraphStart;
+        nextParagraphStart = endOfParagraph(paragraphStart).next();
+    }
+    
+    startRange = TextIterator::rangeFromLocationAndLength(static_cast<Element*>(scope), startIndex, 0, true);
+    endRange = TextIterator::rangeFromLocationAndLength(static_cast<Element*>(scope), endIndex, 0, true);
+    if (startRange && endRange)
+        updateStartEnd(startRange->startPosition(), endRange->startPosition());
+}
+
+#define NoFontDelta (0.0f)
+#define MinimumFontSize (0.1f)
+
+void ApplyStyleCommand::applyRelativeFontStyleChange(CSSMutableStyleDeclaration *style)
+{
+    RefPtr<CSSValue> value = style->getPropertyCSSValue(CSSPropertyFontSize);
+    if (value) {
+        // Explicit font size overrides any delta.
+        style->removeProperty(CSSPropertyWebkitFontSizeDelta);
+        return;
+    }
+
+    // Get the adjustment amount out of the style.
+    value = style->getPropertyCSSValue(CSSPropertyWebkitFontSizeDelta);
+    if (!value)
+        return;
+    float adjustment = NoFontDelta;
+    if (value->cssValueType() == CSSValue::CSS_PRIMITIVE_VALUE) {
+        CSSPrimitiveValue *primitiveValue = static_cast<CSSPrimitiveValue *>(value.get());
+        if (primitiveValue->primitiveType() == CSSPrimitiveValue::CSS_PX) {
+            // Only PX handled now. If we handle more types in the future, perhaps
+            // a switch statement here would be more appropriate.
+            adjustment = primitiveValue->getFloatValue();
+        }
+    }
+    style->removeProperty(CSSPropertyWebkitFontSizeDelta);
+    if (adjustment == NoFontDelta)
+        return;
+    
+    Position start = startPosition();
+    Position end = endPosition();
+    if (comparePositions(end, start) < 0) {
+        Position swap = start;
+        start = end;
+        end = swap;
+    }
+    
+    // Join up any adjacent text nodes.
+    if (start.node()->isTextNode()) {
+        joinChildTextNodes(start.node()->parentNode(), start, end);
+        start = startPosition();
+        end = endPosition();
+    }
+    if (end.node()->isTextNode() && start.node()->parentNode() != end.node()->parentNode()) {
+        joinChildTextNodes(end.node()->parentNode(), start, end);
+        start = startPosition();
+        end = endPosition();
+    }
+
+    // Split the start text nodes if needed to apply style.
+    bool splitStart = splitTextAtStartIfNeeded(start, end); 
+    if (splitStart) {
+        start = startPosition();
+        end = endPosition();
+    }
+    bool splitEnd = splitTextAtEndIfNeeded(start, end);
+    if (splitEnd) {
+        start = startPosition();
+        end = endPosition();
+    }
+
+    // Calculate loop end point.
+    // If the end node is before the start node (can only happen if the end node is
+    // an ancestor of the start node), we gather nodes up to the next sibling of the end node
+    Node *beyondEnd;
+    if (start.node()->isDescendantOf(end.node()))
+        beyondEnd = end.node()->traverseNextSibling();
+    else
+        beyondEnd = end.node()->traverseNextNode();
+    
+    start = start.upstream(); // Move upstream to ensure we do not add redundant spans.
+    Node *startNode = start.node();
+    if (startNode->isTextNode() && start.deprecatedEditingOffset() >= caretMaxOffset(startNode)) // Move out of text node if range does not include its characters.
+        startNode = startNode->traverseNextNode();
+
+    // Store away font size before making any changes to the document.
+    // This ensures that changes to one node won't effect another.
+    HashMap<Node*, float> startingFontSizes;
+    for (Node *node = startNode; node != beyondEnd; node = node->traverseNextNode())
+        startingFontSizes.set(node, computedFontSize(node));
+
+    // These spans were added by us. If empty after font size changes, they can be removed.
+    Vector<RefPtr<HTMLElement> > unstyledSpans;
+    
+    Node* lastStyledNode = 0;
+    for (Node* node = startNode; node != beyondEnd; node = node->traverseNextNode()) {
+        RefPtr<HTMLElement> element;
+        if (node->isHTMLElement()) {
+            // Only work on fully selected nodes.
+            if (!nodeFullySelected(node, start, end))
+                continue;
+            element = static_cast<HTMLElement*>(node);
+        } else if (node->isTextNode() && node->renderer() && node->parentNode() != lastStyledNode) {
+            // Last styled node was not parent node of this text node, but we wish to style this
+            // text node. To make this possible, add a style span to surround this text node.
+            RefPtr<HTMLElement> span = createStyleSpanElement(document());
+            surroundNodeRangeWithElement(node, node, span.get());
+            element = span.release();
+        }  else {
+            // Only handle HTML elements and text nodes.
+            continue;
+        }
+        lastStyledNode = node;
+
+        CSSMutableStyleDeclaration* inlineStyleDecl = element->getInlineStyleDecl();
+        float currentFontSize = computedFontSize(node);
+        float desiredFontSize = max(MinimumFontSize, startingFontSizes.get(node) + adjustment);
+        RefPtr<CSSValue> value = inlineStyleDecl->getPropertyCSSValue(CSSPropertyFontSize);
+        if (value) {
+            inlineStyleDecl->removeProperty(CSSPropertyFontSize, true);
+            currentFontSize = computedFontSize(node);
+        }
+        if (currentFontSize != desiredFontSize) {
+            inlineStyleDecl->setProperty(CSSPropertyFontSize, String::number(desiredFontSize) + "px", false, false);
+            setNodeAttribute(element.get(), styleAttr, inlineStyleDecl->cssText());
+        }
+        if (inlineStyleDecl->isEmpty()) {
+            removeNodeAttribute(element.get(), styleAttr);
+            // FIXME: should this be isSpanWithoutAttributesOrUnstyleStyleSpan?  Need a test.
+            if (isUnstyledStyleSpan(element.get()))
+                unstyledSpans.append(element.release());
+        }
+    }
+
+    size_t size = unstyledSpans.size();
+    for (size_t i = 0; i < size; ++i)
+        removeNodePreservingChildren(unstyledSpans[i].get());
+}
+
+#undef NoFontDelta
+#undef MinimumFontSize
+
+static Node* dummySpanAncestorForNode(const Node* node)
+{
+    while (node && !isStyleSpan(node))
+        node = node->parent();
+    
+    return node ? node->parent() : 0;
+}
+
+void ApplyStyleCommand::cleanupUnstyledAppleStyleSpans(Node* dummySpanAncestor)
+{
+    if (!dummySpanAncestor)
+        return;
+
+    // Dummy spans are created when text node is split, so that style information
+    // can be propagated, which can result in more splitting. If a dummy span gets
+    // cloned/split, the new node is always a sibling of it. Therefore, we scan
+    // all the children of the dummy's parent
+    Node* next;
+    for (Node* node = dummySpanAncestor->firstChild(); node; node = next) {
+        next = node->nextSibling();
+        if (isUnstyledStyleSpan(node))
+            removeNodePreservingChildren(node);
+        node = next;
+    }
+}
+
+HTMLElement* ApplyStyleCommand::splitAncestorsWithUnicodeBidi(Node* node, bool before, RefPtr<CSSPrimitiveValue> allowedDirection)
+{
+    // We are allowed to leave the highest ancestor with unicode-bidi unsplit if it is unicode-bidi: embed and direction: allowedDirection.
+    // In that case, we return the unsplit ancestor. Otherwise, we return 0.
+    Node* block = enclosingBlock(node);
+    if (!block)
+        return 0;
+
+    Node* highestAncestorWithUnicodeBidi = 0;
+    Node* nextHighestAncestorWithUnicodeBidi = 0;
+    RefPtr<CSSPrimitiveValue> highestAncestorUnicodeBidi;
+    for (Node* n = node->parent(); n != block; n = n->parent()) {
+        RefPtr<CSSValue> unicodeBidi = computedStyle(n)->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+        if (unicodeBidi) {
+            ASSERT(unicodeBidi->isPrimitiveValue());
+            if (static_cast<CSSPrimitiveValue*>(unicodeBidi.get())->getIdent() != CSSValueNormal) {
+                highestAncestorUnicodeBidi = static_cast<CSSPrimitiveValue*>(unicodeBidi.get());
+                nextHighestAncestorWithUnicodeBidi = highestAncestorWithUnicodeBidi;
+                highestAncestorWithUnicodeBidi = n;
+            }
+        }
+    }
+
+    if (!highestAncestorWithUnicodeBidi)
+        return 0;
+
+    HTMLElement* unsplitAncestor = 0;
+
+    if (allowedDirection && highestAncestorUnicodeBidi->getIdent() != CSSValueBidiOverride) {
+        RefPtr<CSSValue> highestAncestorDirection = computedStyle(highestAncestorWithUnicodeBidi)->getPropertyCSSValue(CSSPropertyDirection);
+        ASSERT(highestAncestorDirection->isPrimitiveValue());
+        if (static_cast<CSSPrimitiveValue*>(highestAncestorDirection.get())->getIdent() == allowedDirection->getIdent() && highestAncestorWithUnicodeBidi->isHTMLElement()) {
+            if (!nextHighestAncestorWithUnicodeBidi)
+                return static_cast<HTMLElement*>(highestAncestorWithUnicodeBidi);
+
+            unsplitAncestor = static_cast<HTMLElement*>(highestAncestorWithUnicodeBidi);
+            highestAncestorWithUnicodeBidi = nextHighestAncestorWithUnicodeBidi;
+        }
+    }
+
+    // Split every ancestor through highest ancestor with embedding.
+    Node* n = node;
+    while (true) {
+        Element* parent = static_cast<Element*>(n->parent());
+        if (before ? n->previousSibling() : n->nextSibling())
+            splitElement(parent, before ? n : n->nextSibling());
+        if (parent == highestAncestorWithUnicodeBidi)
+            break;
+        n = n->parent();
+    }
+    return unsplitAncestor;
+}
+
+void ApplyStyleCommand::removeEmbeddingUpToEnclosingBlock(Node* node, Node* unsplitAncestor)
+{
+    Node* block = enclosingBlock(node);
+    if (!block)
+        return;
+
+    Node* n = node->parent();
+    while (n != block && n != unsplitAncestor) {
+        Node* parent = n->parent();
+        if (!n->isStyledElement()) {
+            n = parent;
+            continue;
+        }
+
+        StyledElement* element = static_cast<StyledElement*>(n);
+        RefPtr<CSSValue> unicodeBidi = computedStyle(element)->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+        if (unicodeBidi) {
+            ASSERT(unicodeBidi->isPrimitiveValue());
+            if (static_cast<CSSPrimitiveValue*>(unicodeBidi.get())->getIdent() != CSSValueNormal) {
+                // FIXME: This code should really consider the mapped attribute 'dir', the inline style declaration,
+                // and all matching style rules in order to determine how to best set the unicode-bidi property to 'normal'.
+                // For now, it assumes that if the 'dir' attribute is present, then removing it will suffice, and
+                // otherwise it sets the property in the inline style declaration.
+                if (element->hasAttribute(dirAttr)) {
+                    // FIXME: If this is a BDO element, we should probably just remove it if it has no
+                    // other attributes, like we (should) do with B and I elements.
+                    removeNodeAttribute(element, dirAttr);
+                } else {
+                    RefPtr<CSSMutableStyleDeclaration> inlineStyle = element->getInlineStyleDecl()->copy();
+                    inlineStyle->setProperty(CSSPropertyUnicodeBidi, CSSValueNormal);
+                    inlineStyle->removeProperty(CSSPropertyDirection);
+                    setNodeAttribute(element, styleAttr, inlineStyle->cssText());
+                    // FIXME: should this be isSpanWithoutAttributesOrUnstyleStyleSpan?  Need a test.
+                    if (isUnstyledStyleSpan(element))
+                        removeNodePreservingChildren(element);
+                }
+            }
+        }
+        n = parent;
+    }
+}
+
+void ApplyStyleCommand::applyInlineStyle(CSSMutableStyleDeclaration *style)
+{
+    Node* startDummySpanAncestor = 0;
+    Node* endDummySpanAncestor = 0;
+    
+    // update document layout once before removing styles
+    // so that we avoid the expense of updating before each and every call
+    // to check a computed style
+    updateLayout();
+
+    // adjust to the positions we want to use for applying style
+    Position start = startPosition();
+    Position end = endPosition();
+    if (comparePositions(end, start) < 0) {
+        Position swap = start;
+        start = end;
+        end = swap;
+    }
+
+    // split the start node and containing element if the selection starts inside of it
+    bool splitStart = splitTextElementAtStartIfNeeded(start, end); 
+    if (splitStart) {
+        start = startPosition();
+        end = endPosition();
+        startDummySpanAncestor = dummySpanAncestorForNode(start.node());
+    }
+
+    // split the end node and containing element if the selection ends inside of it
+    bool splitEnd = splitTextElementAtEndIfNeeded(start, end);
+    if (splitEnd) {
+        start = startPosition();
+        end = endPosition();
+        endDummySpanAncestor = dummySpanAncestorForNode(end.node());
+    }
+
+    RefPtr<CSSValue> unicodeBidi = style->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+    RefPtr<CSSValue> direction;
+    HTMLElement* startUnsplitAncestor = 0;
+    HTMLElement* endUnsplitAncestor = 0;
+    if (unicodeBidi) {
+        RefPtr<CSSPrimitiveValue> allowedDirection;
+        ASSERT(unicodeBidi->isPrimitiveValue());
+        if (static_cast<CSSPrimitiveValue*>(unicodeBidi.get())->getIdent() == CSSValueEmbed) {
+            // Leave alone an ancestor that provides the desired single level embedding, if there is one.
+            direction = style->getPropertyCSSValue(CSSPropertyDirection);
+            ASSERT(direction->isPrimitiveValue());
+            allowedDirection = static_cast<CSSPrimitiveValue*>(direction.get());
+        }
+        startUnsplitAncestor = splitAncestorsWithUnicodeBidi(start.node(), true, allowedDirection);
+        endUnsplitAncestor = splitAncestorsWithUnicodeBidi(end.node(), false, allowedDirection);
+        removeEmbeddingUpToEnclosingBlock(start.node(), startUnsplitAncestor);
+        removeEmbeddingUpToEnclosingBlock(end.node(), endUnsplitAncestor);
+    }
+
+    // Remove style from the selection.
+    // Use the upstream position of the start for removing style.
+    // This will ensure we remove all traces of the relevant styles from the selection
+    // and prevent us from adding redundant ones, as described in:
+    // <rdar://problem/3724344> Bolding and unbolding creates extraneous tags
+    Position removeStart = start.upstream();
+    Position embeddingRemoveStart = removeStart;
+    Position embeddingRemoveEnd = end;
+    if (unicodeBidi) {
+        // Avoid removing the dir attribute and the unicode-bidi and direction properties from the unsplit ancestors.
+        if (startUnsplitAncestor && nodeFullySelected(startUnsplitAncestor, removeStart, end))
+            embeddingRemoveStart = positionInParentAfterNode(startUnsplitAncestor);
+        if (endUnsplitAncestor && nodeFullySelected(endUnsplitAncestor, removeStart, end))
+            embeddingRemoveEnd = positionInParentBeforeNode(endUnsplitAncestor).downstream();
+    }
+
+    if (embeddingRemoveStart != removeStart || embeddingRemoveEnd != end) {
+        RefPtr<CSSMutableStyleDeclaration> embeddingStyle = CSSMutableStyleDeclaration::create();
+        embeddingStyle->setProperty(CSSPropertyUnicodeBidi, CSSValueEmbed);
+        embeddingStyle->setProperty(CSSPropertyDirection, static_cast<CSSPrimitiveValue*>(direction.get())->getIdent());
+        if (comparePositions(embeddingRemoveStart, embeddingRemoveEnd) <= 0)
+            removeInlineStyle(embeddingStyle, embeddingRemoveStart, embeddingRemoveEnd);
+
+        RefPtr<CSSMutableStyleDeclaration> styleWithoutEmbedding = style->copy();
+        styleWithoutEmbedding->removeProperty(CSSPropertyUnicodeBidi);
+        styleWithoutEmbedding->removeProperty(CSSPropertyDirection);
+        removeInlineStyle(styleWithoutEmbedding, removeStart, end);
+    } else
+        removeInlineStyle(style, removeStart, end);
+
+    start = startPosition();
+    end = endPosition();
+
+    if (splitStart) {
+        bool mergedStart = mergeStartWithPreviousIfIdentical(start, end);
+        if (mergedStart) {
+            start = startPosition();
+            end = endPosition();
+        }
+    }
+
+    if (splitEnd) {
+        mergeEndWithNextIfIdentical(start, end);
+        start = startPosition();
+        end = endPosition();
+    }
+
+    // update document layout once before running the rest of the function
+    // so that we avoid the expense of updating before each and every call
+    // to check a computed style
+    updateLayout();
+
+    Position embeddingApplyStart = start;
+    Position embeddingApplyEnd = end;
+    if (unicodeBidi) {
+        // Avoid applying the unicode-bidi and direction properties beneath ancestors that already have them.
+        Node* startEnclosingBlock = enclosingBlock(start.node());
+        for (Node* n = start.node(); n != startEnclosingBlock; n = n->parent()) {
+            if (n->isHTMLElement()) {
+                RefPtr<CSSValue> ancestorUnicodeBidi = computedStyle(n)->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+                if (ancestorUnicodeBidi) {
+                    ASSERT(ancestorUnicodeBidi->isPrimitiveValue());
+                    if (static_cast<CSSPrimitiveValue*>(ancestorUnicodeBidi.get())->getIdent() == CSSValueEmbed) {
+                        embeddingApplyStart = positionInParentAfterNode(n);
+                        break;
+                    }
+                }
+            }
+        }
+
+        Node* endEnclosingBlock = enclosingBlock(end.node());
+        for (Node* n = end.node(); n != endEnclosingBlock; n = n->parent()) {
+            if (n->isHTMLElement()) {
+                RefPtr<CSSValue> ancestorUnicodeBidi = computedStyle(n)->getPropertyCSSValue(CSSPropertyUnicodeBidi);
+                if (ancestorUnicodeBidi) {
+                    ASSERT(ancestorUnicodeBidi->isPrimitiveValue());
+                    if (static_cast<CSSPrimitiveValue*>(ancestorUnicodeBidi.get())->getIdent() == CSSValueEmbed) {
+                        embeddingApplyEnd = positionInParentBeforeNode(n);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    if (embeddingApplyStart != start || embeddingApplyEnd != end) {
+        if (embeddingApplyStart.isNotNull() && embeddingApplyEnd.isNotNull()) {
+            RefPtr<CSSMutableStyleDeclaration> embeddingStyle = CSSMutableStyleDeclaration::create();
+            embeddingStyle->setProperty(CSSPropertyUnicodeBidi, CSSValueEmbed);
+            embeddingStyle->setProperty(CSSPropertyDirection, static_cast<CSSPrimitiveValue*>(direction.get())->getIdent());
+            applyInlineStyleToRange(embeddingStyle.get(), embeddingApplyStart, embeddingApplyEnd);
+        }
+
+        RefPtr<CSSMutableStyleDeclaration> styleWithoutEmbedding = style->copy();
+        styleWithoutEmbedding->removeProperty(CSSPropertyUnicodeBidi);
+        styleWithoutEmbedding->removeProperty(CSSPropertyDirection);
+        applyInlineStyleToRange(styleWithoutEmbedding.get(), start, end);
+    } else
+        applyInlineStyleToRange(style, start, end);
+
+    // Remove dummy style spans created by splitting text elements.
+    cleanupUnstyledAppleStyleSpans(startDummySpanAncestor);
+    if (endDummySpanAncestor != startDummySpanAncestor)
+        cleanupUnstyledAppleStyleSpans(endDummySpanAncestor);
+}
+
+void ApplyStyleCommand::applyInlineStyleToRange(CSSMutableStyleDeclaration* style, const Position& start, const Position& rangeEnd)
+{
+    Node* node = start.node();
+    Position end = rangeEnd;
+
+    bool rangeIsEmpty = false;
+
+    if (start.deprecatedEditingOffset() >= caretMaxOffset(start.node())) {
+        node = node->traverseNextNode();
+        Position newStart = Position(node, 0);
+        if (!node || comparePositions(end, newStart) < 0)
+            rangeIsEmpty = true;
+    }
+
+    if (!rangeIsEmpty) {
+        // pastEndNode is the node after the last fully selected node.
+        Node* pastEndNode = end.node();
+        if (end.deprecatedEditingOffset() >= caretMaxOffset(end.node()))
+            pastEndNode = end.node()->traverseNextSibling();
+        // FIXME: Callers should perform this operation on a Range that includes the br
+        // if they want style applied to the empty line.
+        if (start == end && start.node()->hasTagName(brTag))
+            pastEndNode = start.node()->traverseNextNode();
+        // Add the style to selected inline runs.
+        for (Node* next; node && node != pastEndNode; node = next) {
+            
+            next = node->traverseNextNode();
+            
+            if (!node->renderer() || !node->isContentEditable())
+                continue;
+            
+            if (!node->isContentRichlyEditable() && node->isHTMLElement()) {
+                // This is a plaintext-only region. Only proceed if it's fully selected.
+                // pastEndNode is the node after the last fully selected node, so if it's inside node then
+                // node isn't fully selected.
+                if (pastEndNode && pastEndNode->isDescendantOf(node))
+                    break;
+                // Add to this element's inline style and skip over its contents.
+                HTMLElement* element = static_cast<HTMLElement*>(node);
+                RefPtr<CSSMutableStyleDeclaration> inlineStyle = element->getInlineStyleDecl()->copy();
+                inlineStyle->merge(style);
+                setNodeAttribute(element, styleAttr, inlineStyle->cssText());
+                next = node->traverseNextSibling();
+                continue;
+            }
+        
+            if (isBlock(node))
+                continue;
+                
+            if (node->childNodeCount()) {
+                if (editingIgnoresContent(node)) {
+                    next = node->traverseNextSibling();
+                    continue;
+                }
+                continue;
+            }
+            
+            Node* runStart = node;
+            // Find the end of the run.
+            Node* sibling = node->nextSibling();
+            while (sibling && sibling != pastEndNode && (!sibling->isElementNode() || sibling->hasTagName(brTag)) && !isBlock(sibling)) {
+                node = sibling;
+                sibling = node->nextSibling();
+            }
+            // Recompute next, since node has changed.
+            next = node->traverseNextNode();
+            // Apply the style to the run.
+            addInlineStyleIfNeeded(style, runStart, node);
+        }
+    }
+}
+
+bool ApplyStyleCommand::shouldRemoveTextDecorationTag(CSSStyleDeclaration* styleToApply, int textDecorationAddedByTag) const
+{
+    // Honor text-decorations-in-effect
+    RefPtr<CSSValue> textDecorationsToApply = styleToApply->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+    if (!textDecorationsToApply || !textDecorationsToApply->isValueList())
+        textDecorationsToApply = styleToApply->getPropertyCSSValue(CSSPropertyTextDecoration);
+
+    // When there is no text decorations to apply, remove any one of u, s, & strike
+    if (!textDecorationsToApply || !textDecorationsToApply->isValueList())
+        return true;
+
+    // Remove node if it implicitly adds style not present in styleToApply
+    CSSValueList* valueList = static_cast<CSSValueList*>(textDecorationsToApply.get());
+    RefPtr<CSSPrimitiveValue> value = CSSPrimitiveValue::createIdentifier(textDecorationAddedByTag);
+    return !valueList->hasValue(value.get());
+}
+
+// This function maps from styling tags to CSS styles.  Used for knowing which
+// styling tags should be removed when toggling styles.
+bool ApplyStyleCommand::implicitlyStyledElementShouldBeRemovedWhenApplyingStyle(HTMLElement* elem, CSSMutableStyleDeclaration* style)
+{
+    CSSMutableStyleDeclaration::const_iterator end = style->end();
+    for (CSSMutableStyleDeclaration::const_iterator it = style->begin(); it != end; ++it) {
+        const CSSProperty& property = *it;
+        // FIXME: This should probably be re-written to lookup the tagname in a
+        // hash and match against an expected property/value pair.
+        switch (property.id()) {
+        case CSSPropertyFontWeight:
+            // IE inserts "strong" tags for execCommand("bold"), so we remove them, even though they're not strictly presentational
+            if (elem->hasLocalName(bTag) || elem->hasLocalName(strongTag))
+                return !equalIgnoringCase(property.value()->cssText(), "bold") || !elem->hasChildNodes();
+            break;
+        case CSSPropertyVerticalAlign:
+            if (elem->hasLocalName(subTag))
+                return !equalIgnoringCase(property.value()->cssText(), "sub") || !elem->hasChildNodes();
+            if (elem->hasLocalName(supTag))
+                return !equalIgnoringCase(property.value()->cssText(), "sup") || !elem->hasChildNodes();
+            break;
+        case CSSPropertyFontStyle:
+            // IE inserts "em" tags for execCommand("italic"), so we remove them, even though they're not strictly presentational
+            if (elem->hasLocalName(iTag) || elem->hasLocalName(emTag))
+                return !equalIgnoringCase(property.value()->cssText(), "italic") || !elem->hasChildNodes();
+            break;
+        case CSSPropertyTextDecoration:
+        case CSSPropertyWebkitTextDecorationsInEffect:
+                if (elem->hasLocalName(uTag))
+                    return shouldRemoveTextDecorationTag(style, CSSValueUnderline) || !elem->hasChildNodes();
+                else if (elem->hasLocalName(sTag) || elem->hasTagName(strikeTag))
+                    return shouldRemoveTextDecorationTag(style,CSSValueLineThrough) || !elem->hasChildNodes();
+        }
+    }
+    return false;
+}
+
+void ApplyStyleCommand::replaceWithSpanOrRemoveIfWithoutAttributes(HTMLElement*& elem)
+{
+    bool removeNode = false;
+
+    // Similar to isSpanWithoutAttributesOrUnstyleStyleSpan, but does not look for Apple-style-span.
+    NamedNodeMap* attributes = elem->attributes(true); // readonly
+    if (!attributes || attributes->isEmpty())
+        removeNode = true;
+    else if (attributes->length() == 1 && elem->hasAttribute(styleAttr)) {
+        // Remove the element even if it has just style='' (this might be redundantly checked later too)
+        CSSMutableStyleDeclaration* inlineStyleDecl = elem->inlineStyleDecl();
+        if (!inlineStyleDecl || inlineStyleDecl->isEmpty())
+            removeNode = true;
+    }
+
+    if (removeNode)
+        removeNodePreservingChildren(elem);
+    else {
+        HTMLElement* newSpanElement = replaceNodeWithSpanPreservingChildrenAndAttributes(elem);
+        ASSERT(newSpanElement && newSpanElement->inDocument());
+        elem = newSpanElement;
+    }
+}
+
+void ApplyStyleCommand::removeHTMLFontStyle(CSSMutableStyleDeclaration *style, HTMLElement *elem)
+{
+    ASSERT(style);
+    ASSERT(elem);
+
+    if (!elem->hasLocalName(fontTag))
+        return;
+        
+    CSSMutableStyleDeclaration::const_iterator end = style->end();
+    for (CSSMutableStyleDeclaration::const_iterator it = style->begin(); it != end; ++it) {
+        switch ((*it).id()) {
+            case CSSPropertyColor:
+                removeNodeAttribute(elem, colorAttr);
+                break;
+            case CSSPropertyFontFamily:
+                removeNodeAttribute(elem, faceAttr);
+                break;
+            case CSSPropertyFontSize:
+                removeNodeAttribute(elem, sizeAttr);
+                break;
+        }
+    }
+
+    if (isEmptyFontTag(elem))
+        removeNodePreservingChildren(elem);
+}
+
+void ApplyStyleCommand::removeHTMLBidiEmbeddingStyle(CSSMutableStyleDeclaration *style, HTMLElement *elem)
+{
+    ASSERT(style);
+    ASSERT(elem);
+
+    if (!elem->hasAttribute(dirAttr))
+        return;
+
+    if (!style->getPropertyCSSValue(CSSPropertyUnicodeBidi) && !style->getPropertyCSSValue(CSSPropertyDirection))
+        return;
+
+    removeNodeAttribute(elem, dirAttr);
+
+    // FIXME: should this be isSpanWithoutAttributesOrUnstyleStyleSpan?  Need a test.
+    if (isUnstyledStyleSpan(elem))
+        removeNodePreservingChildren(elem);
+}
+
+void ApplyStyleCommand::removeCSSStyle(CSSMutableStyleDeclaration* style, HTMLElement* elem)
+{
+    ASSERT(style);
+    ASSERT(elem);
+
+    CSSMutableStyleDeclaration* decl = elem->inlineStyleDecl();
+    if (!decl)
+        return;
+
+    CSSMutableStyleDeclaration::const_iterator end = style->end();
+    for (CSSMutableStyleDeclaration::const_iterator it = style->begin(); it != end; ++it) {
+        CSSPropertyID propertyID = static_cast<CSSPropertyID>((*it).id());
+        RefPtr<CSSValue> value = decl->getPropertyCSSValue(propertyID);
+        if (value && (propertyID != CSSPropertyWhiteSpace || !isTabSpanNode(elem))) {
+            removeCSSProperty(decl, propertyID);
+            if (propertyID == CSSPropertyUnicodeBidi && !decl->getPropertyValue(CSSPropertyDirection).isEmpty())
+                removeCSSProperty(decl, CSSPropertyDirection);
+        }
+    }
+
+    // No need to serialize <foo style=""> if we just removed the last css property
+    if (decl->isEmpty())
+        removeNodeAttribute(elem, styleAttr);
+
+    if (isSpanWithoutAttributesOrUnstyleStyleSpan(elem))
+        removeNodePreservingChildren(elem);
+}
+
+static bool hasTextDecorationProperty(Node *node)
+{
+    if (!node->isElementNode())
+        return false;
+
+    RefPtr<CSSValue> value = computedStyle(node)->getPropertyCSSValue(CSSPropertyTextDecoration, DoNotUpdateLayout);
+    return value && !equalIgnoringCase(value->cssText(), "none");
+}
+
+static Node* highestAncestorWithTextDecoration(Node *node)
+{
+    ASSERT(node);
+    Node* result = 0;
+    Node* unsplittableElement = unsplittableElementForPosition(Position(node, 0));
+
+    for (Node *n = node; n; n = n->parentNode()) {
+        if (hasTextDecorationProperty(n))
+            result = n;
+        // Should stop at the editable root (cannot cross editing boundary) and
+        // also stop at the unsplittable element to be consistent with other UAs
+        if (n == unsplittableElement)
+            break;
+    }
+
+    return result;
+}
+
+PassRefPtr<CSSMutableStyleDeclaration> ApplyStyleCommand::extractTextDecorationStyle(Node* node)
+{
+    ASSERT(node);
+    ASSERT(node->isElementNode());
+    
+    // non-html elements not handled yet
+    if (!node->isHTMLElement())
+        return 0;
+
+    HTMLElement *element = static_cast<HTMLElement *>(node);
+    RefPtr<CSSMutableStyleDeclaration> style = element->inlineStyleDecl();
+    if (!style)
+        return 0;
+
+    int properties[1] = { CSSPropertyTextDecoration };
+    RefPtr<CSSMutableStyleDeclaration> textDecorationStyle = style->copyPropertiesInSet(properties, 1);
+
+    RefPtr<CSSValue> property = style->getPropertyCSSValue(CSSPropertyTextDecoration);
+    if (property && !equalIgnoringCase(property->cssText(), "none"))
+        removeCSSProperty(style.get(), CSSPropertyTextDecoration);
+
+    return textDecorationStyle.release();
+}
+
+PassRefPtr<CSSMutableStyleDeclaration> ApplyStyleCommand::extractAndNegateTextDecorationStyle(Node* node)
+{
+    ASSERT(node);
+    ASSERT(node->isElementNode());
+    
+    // non-html elements not handled yet
+    if (!node->isHTMLElement())
+        return 0;
+
+    RefPtr<CSSComputedStyleDeclaration> nodeStyle = computedStyle(node);
+    ASSERT(nodeStyle);
+
+    int properties[1] = { CSSPropertyTextDecoration };
+    RefPtr<CSSMutableStyleDeclaration> textDecorationStyle = nodeStyle->copyPropertiesInSet(properties, 1);
+
+    RefPtr<CSSValue> property = nodeStyle->getPropertyCSSValue(CSSPropertyTextDecoration);
+    if (property && !equalIgnoringCase(property->cssText(), "none")) {
+        RefPtr<CSSMutableStyleDeclaration> newStyle = textDecorationStyle->copy();
+        newStyle->setProperty(CSSPropertyTextDecoration, "none");
+        applyTextDecorationStyle(node, newStyle.get());
+    }
+
+    return textDecorationStyle.release();
+}
+
+void ApplyStyleCommand::applyTextDecorationStyle(Node *node, CSSMutableStyleDeclaration *style)
+{
+    ASSERT(node);
+
+    if (!style || style->cssText().isEmpty())
+        return;
+
+    StyleChange styleChange(style, Position(node, 0));
+    if (styleChange.cssStyle().length()) {
+        if (node->isTextNode()) {
+            RefPtr<HTMLElement> styleSpan = createStyleSpanElement(document());
+            surroundNodeRangeWithElement(node, node, styleSpan.get());
+            node = styleSpan.get();
+        }
+
+        if (!node->isElementNode())
+            return;
+
+        HTMLElement *element = static_cast<HTMLElement *>(node);
+        String cssText = styleChange.cssStyle();
+        CSSMutableStyleDeclaration *decl = element->inlineStyleDecl();
+        if (decl)
+            cssText += decl->cssText();
+        setNodeAttribute(element, styleAttr, cssText);
+    }
+
+    if (styleChange.applyUnderline())
+        surroundNodeRangeWithElement(node, node, createHTMLElement(document(), uTag));
+
+    if (styleChange.applyLineThrough())
+        surroundNodeRangeWithElement(node, node, createHTMLElement(document(), sTag));    
+}
+
+void ApplyStyleCommand::pushDownTextDecorationStyleAroundNode(Node* targetNode, bool forceNegate)
+{
+    ASSERT(targetNode);
+    Node* highestAncestor = highestAncestorWithTextDecoration(targetNode);
+    if (!highestAncestor)
+        return;
+
+    // The outer loop is traversing the tree vertically from highestAncestor to targetNode
+    Node* current = highestAncestor;
+    while (current != targetNode) {
+        ASSERT(current);
+        ASSERT(current->contains(targetNode));
+        RefPtr<CSSMutableStyleDeclaration> decoration = forceNegate ? extractAndNegateTextDecorationStyle(current) : extractTextDecorationStyle(current);
+
+        // The inner loop will go through children on each level
+        Node* child = current->firstChild();
+        while (child) {
+            Node* nextChild = child->nextSibling();
+
+            // Apply text decoration to all nodes containing targetNode and their siblings but NOT to targetNode
+            if (child != targetNode)
+                applyTextDecorationStyle(child, decoration.get());
+            
+            // We found the next node for the outer loop (contains targetNode)
+            // When reached targetNode, stop the outer loop upon the completion of the current inner loop
+            if (child == targetNode || child->contains(targetNode))
+                current = child;
+
+            child = nextChild;
+        }
+    }
+}
+
+void ApplyStyleCommand::pushDownTextDecorationStyleAtBoundaries(const Position &start, const Position &end)
+{
+    // We need to work in two passes. First we push down any inline
+    // styles that set text decoration. Then we look for any remaining
+    // styles (caused by stylesheets) and explicitly negate text
+    // decoration while pushing down.
+
+    pushDownTextDecorationStyleAroundNode(start.node(), false);
+    updateLayout();
+    pushDownTextDecorationStyleAroundNode(start.node(), true);
+
+    pushDownTextDecorationStyleAroundNode(end.node(), false);
+    updateLayout();
+    pushDownTextDecorationStyleAroundNode(end.node(), true);
+}
+
+// FIXME: Why does this exist?  Callers should either use lastOffsetForEditing or lastOffsetInNode
+static int maxRangeOffset(Node *n)
+{
+    if (n->offsetInCharacters())
+        return n->maxCharacterOffset();
+
+    if (n->isElementNode())
+        return n->childNodeCount();
+
+    return 1;
+}
+
+void ApplyStyleCommand::removeInlineStyle(PassRefPtr<CSSMutableStyleDeclaration> style, const Position &start, const Position &end)
+{
+    ASSERT(start.isNotNull());
+    ASSERT(end.isNotNull());
+    ASSERT(start.node()->inDocument());
+    ASSERT(end.node()->inDocument());
+    ASSERT(comparePositions(start, end) <= 0);
+    
+    RefPtr<CSSValue> textDecorationSpecialProperty = style->getPropertyCSSValue(CSSPropertyWebkitTextDecorationsInEffect);
+
+    if (textDecorationSpecialProperty) {
+        pushDownTextDecorationStyleAtBoundaries(start.downstream(), end.upstream());
+        style = style->copy();
+        style->setProperty(CSSPropertyTextDecoration, textDecorationSpecialProperty->cssText(), style->getPropertyPriority(CSSPropertyWebkitTextDecorationsInEffect));
+    }
+
+    // The s and e variables store the positions used to set the ending selection after style removal
+    // takes place. This will help callers to recognize when either the start node or the end node
+    // are removed from the document during the work of this function.
+    Position s = start;
+    Position e = end;
+
+    Node* node = start.node();
+    while (node) {
+        Node* next = node->traverseNextNode();
+        if (node->isHTMLElement() && nodeFullySelected(node, start, end)) {
+            HTMLElement* elem = static_cast<HTMLElement*>(node);
+            Node* prev = elem->traversePreviousNodePostOrder();
+            Node* next = elem->traverseNextNode();
+            if (m_styledInlineElement && elem->hasTagName(m_styledInlineElement->tagQName()))
+                removeNodePreservingChildren(elem);
+
+            if (implicitlyStyledElementShouldBeRemovedWhenApplyingStyle(elem, style.get()))
+                replaceWithSpanOrRemoveIfWithoutAttributes(elem);
+
+            // If the node was converted to a span, the span may still contain relevant
+            // styles which must be removed (e.g. <b style='font-weight: bold'>)
+            if (elem->inDocument()) {
+                removeHTMLFontStyle(style.get(), elem);
+                removeHTMLBidiEmbeddingStyle(style.get(), elem);
+                removeCSSStyle(style.get(), elem);
+            }
+            if (!elem->inDocument()) {
+                if (s.node() == elem) {
+                    // Since elem must have been fully selected, and it is at the start
+                    // of the selection, it is clear we can set the new s offset to 0.
+                    ASSERT(s.deprecatedEditingOffset() <= caretMinOffset(s.node()));
+                    s = Position(next, 0);
+                }
+                if (e.node() == elem) {
+                    // Since elem must have been fully selected, and it is at the end
+                    // of the selection, it is clear we can set the new e offset to
+                    // the max range offset of prev.
+                    ASSERT(e.deprecatedEditingOffset() >= maxRangeOffset(e.node()));
+                    e = Position(prev, maxRangeOffset(prev));
+                }
+            }
+        }
+        if (node == end.node())
+            break;
+        node = next;
+    }
+    
+    ASSERT(s.node()->inDocument());
+    ASSERT(e.node()->inDocument());
+    updateStartEnd(s, e);
+}
+
+bool ApplyStyleCommand::nodeFullySelected(Node *node, const Position &start, const Position &end) const
+{
+    ASSERT(node);
+    ASSERT(node->isElementNode());
+
+    Position pos = Position(node, node->childNodeCount()).upstream();
+    return comparePositions(Position(node, 0), start) >= 0 && comparePositions(pos, end) <= 0;
+}
+
+bool ApplyStyleCommand::nodeFullyUnselected(Node *node, const Position &start, const Position &end) const
+{
+    ASSERT(node);
+    ASSERT(node->isElementNode());
+
+    Position pos = Position(node, node->childNodeCount()).upstream();
+    bool isFullyBeforeStart = comparePositions(pos, start) < 0;
+    bool isFullyAfterEnd = comparePositions(Position(node, 0), end) > 0;
+
+    return isFullyBeforeStart || isFullyAfterEnd;
+}
+
+
+bool ApplyStyleCommand::splitTextAtStartIfNeeded(const Position &start, const Position &end)
+{
+    if (start.node()->isTextNode() && start.deprecatedEditingOffset() > caretMinOffset(start.node()) && start.deprecatedEditingOffset() < caretMaxOffset(start.node())) {
+        int endOffsetAdjustment = start.node() == end.node() ? start.deprecatedEditingOffset() : 0;
+        Text *text = static_cast<Text *>(start.node());
+        splitTextNode(text, start.deprecatedEditingOffset());
+        updateStartEnd(Position(start.node(), 0), Position(end.node(), end.deprecatedEditingOffset() - endOffsetAdjustment));
+        return true;
+    }
+    return false;
+}
+
+bool ApplyStyleCommand::splitTextAtEndIfNeeded(const Position &start, const Position &end)
+{
+    if (end.node()->isTextNode() && end.deprecatedEditingOffset() > caretMinOffset(end.node()) && end.deprecatedEditingOffset() < caretMaxOffset(end.node())) {
+        Text *text = static_cast<Text *>(end.node());
+        splitTextNode(text, end.deprecatedEditingOffset());
+        
+        Node *prevNode = text->previousSibling();
+        ASSERT(prevNode);
+        Node *startNode = start.node() == end.node() ? prevNode : start.node();
+        ASSERT(startNode);
+        updateStartEnd(Position(startNode, start.deprecatedEditingOffset()), Position(prevNode, caretMaxOffset(prevNode)));
+        return true;
+    }
+    return false;
+}
+
+bool ApplyStyleCommand::splitTextElementAtStartIfNeeded(const Position &start, const Position &end)
+{
+    if (start.node()->isTextNode() && start.deprecatedEditingOffset() > caretMinOffset(start.node()) && start.deprecatedEditingOffset() < caretMaxOffset(start.node())) {
+        int endOffsetAdjustment = start.node() == end.node() ? start.deprecatedEditingOffset() : 0;
+        Text *text = static_cast<Text *>(start.node());
+        splitTextNodeContainingElement(text, start.deprecatedEditingOffset());
+
+        updateStartEnd(Position(start.node()->parentNode(), start.node()->nodeIndex()), Position(end.node(), end.deprecatedEditingOffset() - endOffsetAdjustment));
+        return true;
+    }
+    return false;
+}
+
+bool ApplyStyleCommand::splitTextElementAtEndIfNeeded(const Position &start, const Position &end)
+{
+    if (end.node()->isTextNode() && end.deprecatedEditingOffset() > caretMinOffset(end.node()) && end.deprecatedEditingOffset() < caretMaxOffset(end.node())) {
+        Text *text = static_cast<Text *>(end.node());
+        splitTextNodeContainingElement(text, end.deprecatedEditingOffset());
+
+        Node *prevNode = text->parent()->previousSibling()->lastChild();
+        ASSERT(prevNode);
+        Node *startNode = start.node() == end.node() ? prevNode : start.node();
+        ASSERT(startNode);
+        updateStartEnd(Position(startNode, start.deprecatedEditingOffset()), Position(prevNode->parent(), prevNode->nodeIndex() + 1));
+        return true;
+    }
+    return false;
+}
+
+static bool areIdenticalElements(Node *first, Node *second)
+{
+    // check that tag name and all attribute names and values are identical
+
+    if (!first->isElementNode())
+        return false;
+    
+    if (!second->isElementNode())
+        return false;
+
+    Element *firstElement = static_cast<Element *>(first);
+    Element *secondElement = static_cast<Element *>(second);
+    
+    if (!firstElement->tagQName().matches(secondElement->tagQName()))
+        return false;
+
+    NamedNodeMap *firstMap = firstElement->attributes();
+    NamedNodeMap *secondMap = secondElement->attributes();
+
+    unsigned firstLength = firstMap->length();
+
+    if (firstLength != secondMap->length())
+        return false;
+
+    for (unsigned i = 0; i < firstLength; i++) {
+        Attribute *attribute = firstMap->attributeItem(i);
+        Attribute *secondAttribute = secondMap->getAttributeItem(attribute->name());
+
+        if (!secondAttribute || attribute->value() != secondAttribute->value())
+            return false;
+    }
+    
+    return true;
+}
+
+bool ApplyStyleCommand::mergeStartWithPreviousIfIdentical(const Position &start, const Position &end)
+{
+    Node *startNode = start.node();
+    int startOffset = start.deprecatedEditingOffset();
+
+    if (isAtomicNode(start.node())) {
+        if (start.deprecatedEditingOffset() != 0)
+            return false;
+
+        // note: prior siblings could be unrendered elements. it's silly to miss the
+        // merge opportunity just for that.
+        if (start.node()->previousSibling())
+            return false;
+
+        startNode = start.node()->parent();
+        startOffset = 0;
+    }
+
+    if (!startNode->isElementNode())
+        return false;
+
+    if (startOffset != 0)
+        return false;
+
+    Node *previousSibling = startNode->previousSibling();
+
+    if (previousSibling && areIdenticalElements(startNode, previousSibling)) {
+        Element *previousElement = static_cast<Element *>(previousSibling);
+        Element *element = static_cast<Element *>(startNode);
+        Node *startChild = element->firstChild();
+        ASSERT(startChild);
+        mergeIdenticalElements(previousElement, element);
+
+        int startOffsetAdjustment = startChild->nodeIndex();
+        int endOffsetAdjustment = startNode == end.node() ? startOffsetAdjustment : 0;
+        updateStartEnd(Position(startNode, startOffsetAdjustment), Position(end.node(), end.deprecatedEditingOffset() + endOffsetAdjustment)); 
+        return true;
+    }
+
+    return false;
+}
+
+bool ApplyStyleCommand::mergeEndWithNextIfIdentical(const Position &start, const Position &end)
+{
+    Node *endNode = end.node();
+    int endOffset = end.deprecatedEditingOffset();
+
+    if (isAtomicNode(endNode)) {
+        if (endOffset < caretMaxOffset(endNode))
+            return false;
+
+        unsigned parentLastOffset = end.node()->parent()->childNodes()->length() - 1;
+        if (end.node()->nextSibling())
+            return false;
+
+        endNode = end.node()->parent();
+        endOffset = parentLastOffset;
+    }
+
+    if (!endNode->isElementNode() || endNode->hasTagName(brTag))
+        return false;
+
+    Node *nextSibling = endNode->nextSibling();
+
+    if (nextSibling && areIdenticalElements(endNode, nextSibling)) {
+        Element *nextElement = static_cast<Element *>(nextSibling);
+        Element *element = static_cast<Element *>(endNode);
+        Node *nextChild = nextElement->firstChild();
+
+        mergeIdenticalElements(element, nextElement);
+
+        Node *startNode = start.node() == endNode ? nextElement : start.node();
+        ASSERT(startNode);
+
+        int endOffset = nextChild ? nextChild->nodeIndex() : nextElement->childNodes()->length();
+        updateStartEnd(Position(startNode, start.deprecatedEditingOffset()), Position(nextElement, endOffset));
+        return true;
+    }
+
+    return false;
+}
+
+void ApplyStyleCommand::surroundNodeRangeWithElement(Node* startNode, Node* endNode, PassRefPtr<Element> elementToInsert)
+{
+    ASSERT(startNode);
+    ASSERT(endNode);
+    ASSERT(elementToInsert);
+    RefPtr<Element> element = elementToInsert;
+
+    insertNodeBefore(element, startNode);
+    
+    Node* node = startNode;
+    while (1) {
+        Node* next = node->traverseNextNode();
+        if (node->childNodeCount() == 0 && node->renderer() && node->renderer()->isInline()) {
+            removeNode(node);
+            appendNode(node, element);
+        }
+        if (node == endNode)
+            break;
+        node = next;
+    }
+
+    Node* nextSibling = element->nextSibling();
+    Node* previousSibling = element->previousSibling();
+    if (nextSibling && nextSibling->isElementNode() && nextSibling->isContentEditable()
+        && areIdenticalElements(element.get(), static_cast<Element*>(nextSibling)))
+        mergeIdenticalElements(element, static_cast<Element*>(nextSibling));
+
+    if (previousSibling && previousSibling->isElementNode() && previousSibling->isContentEditable()) {
+        Node* mergedElement = previousSibling->nextSibling();
+        if (mergedElement->isElementNode() && mergedElement->isContentEditable()
+            && areIdenticalElements(static_cast<Element*>(previousSibling), static_cast<Element*>(mergedElement)))
+            mergeIdenticalElements(static_cast<Element*>(previousSibling), static_cast<Element*>(mergedElement));
+    }
+
+    // FIXME: We should probably call updateStartEnd if the start or end was in the node
+    // range so that the endingSelection() is canonicalized.  See the comments at the end of
+    // VisibleSelection::validate().
+}
+
+void ApplyStyleCommand::addBlockStyle(const StyleChange& styleChange, HTMLElement* block)
+{
+    // Do not check for legacy styles here. Those styles, like <B> and <I>, only apply for
+    // inline content.
+    if (!block)
+        return;
+        
+    String cssText = styleChange.cssStyle();
+    CSSMutableStyleDeclaration* decl = block->inlineStyleDecl();
+    if (decl)
+        cssText += decl->cssText();
+    setNodeAttribute(block, styleAttr, cssText);
+}
+
+static bool fontColorChangesComputedStyle(const Color& computedStyleColor, StyleChange styleChange)
+{
+    if (styleChange.applyFontColor()) {
+        if (Color(styleChange.fontColor()) != computedStyleColor)
+            return true;
+    }
+    return false;
+}
+
+static bool fontSizeChangesComputedStyle(RenderStyle* computedStyle, StyleChange styleChange)
+{
+    if (styleChange.applyFontSize()) {
+        if (styleChange.fontSize().toInt() != computedStyle->fontSize())
+            return true;
+    }
+    return false;
+}
+
+static bool fontFaceChangesComputedStyle(RenderStyle* computedStyle, StyleChange styleChange)
+{
+    if (styleChange.applyFontFace()) {
+        if (computedStyle->fontDescription().family().family().string() != styleChange.fontFace())
+            return true;
+    }
+    return false;
+}
+
+void ApplyStyleCommand::addInlineStyleIfNeeded(CSSMutableStyleDeclaration *style, Node *startNode, Node *endNode)
+{
+    if (m_removeOnly)
+        return;
+
+    StyleChange styleChange(style, Position(startNode, 0));
+
+    //
+    // Font tags need to go outside of CSS so that CSS font sizes override leagcy font sizes.
+    //
+    if (styleChange.applyFontColor() || styleChange.applyFontFace() || styleChange.applyFontSize()) {
+        RefPtr<Element> fontElement = createFontElement(document());
+        RenderStyle* computedStyle = startNode->computedStyle();
+
+        // We only want to insert a font element if it will end up changing the style of the
+        // text somehow. Otherwise it will be a garbage node that will create problems for us
+        // most notably when we apply a blockquote style for a message reply.
+        if (fontColorChangesComputedStyle(computedStyle->color(), styleChange)
+                || fontFaceChangesComputedStyle(computedStyle, styleChange)
+                || fontSizeChangesComputedStyle(computedStyle, styleChange)) {
+            if (styleChange.applyFontColor())
+                fontElement->setAttribute(colorAttr, styleChange.fontColor());
+            if (styleChange.applyFontFace())
+                fontElement->setAttribute(faceAttr, styleChange.fontFace());
+            if (styleChange.applyFontSize())
+                fontElement->setAttribute(sizeAttr, styleChange.fontSize());
+            surroundNodeRangeWithElement(startNode, endNode, fontElement.get());
+        }
+    }
+
+    if (styleChange.cssStyle().length()) {
+        RefPtr<Element> styleElement = createStyleSpanElement(document());
+        styleElement->setAttribute(styleAttr, styleChange.cssStyle());
+        surroundNodeRangeWithElement(startNode, endNode, styleElement.release());
+    }
+
+    if (styleChange.applyBold())
+        surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), bTag));
+
+    if (styleChange.applyItalic())
+        surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), iTag));
+
+    if (styleChange.applyUnderline())
+        surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), uTag));
+
+    if (styleChange.applyLineThrough())
+        surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), sTag));
+
+    if (styleChange.applySubscript())
+        surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), subTag));
+    else if (styleChange.applySuperscript())
+        surroundNodeRangeWithElement(startNode, endNode, createHTMLElement(document(), supTag));
+
+    if (m_styledInlineElement)
+        surroundNodeRangeWithElement(startNode, endNode, m_styledInlineElement->cloneElementWithoutChildren());
+}
+
+float ApplyStyleCommand::computedFontSize(const Node *node)
+{
+    if (!node)
+        return 0;
+    
+    Position pos(const_cast<Node *>(node), 0);
+    RefPtr<CSSComputedStyleDeclaration> computedStyle = pos.computedStyle();
+    if (!computedStyle)
+        return 0;
+
+    RefPtr<CSSPrimitiveValue> value = static_pointer_cast<CSSPrimitiveValue>(computedStyle->getPropertyCSSValue(CSSPropertyFontSize));
+    if (!value)
+        return 0;
+
+    return value->getFloatValue(CSSPrimitiveValue::CSS_PX);
+}
+
+void ApplyStyleCommand::joinChildTextNodes(Node *node, const Position &start, const Position &end)
+{
+    if (!node)
+        return;
+
+    Position newStart = start;
+    Position newEnd = end;
+    
+    Node *child = node->firstChild();
+    while (child) {
+        Node *next = child->nextSibling();
+        if (child->isTextNode() && next && next->isTextNode()) {
+            Text *childText = static_cast<Text *>(child);
+            Text *nextText = static_cast<Text *>(next);
+            if (next == start.node())
+                newStart = Position(childText, childText->length() + start.deprecatedEditingOffset());
+            if (next == end.node())
+                newEnd = Position(childText, childText->length() + end.deprecatedEditingOffset());
+            String textToMove = nextText->data();
+            insertTextIntoNode(childText, childText->length(), textToMove);
+            removeNode(next);
+            // don't move child node pointer. it may want to merge with more text nodes.
+        }
+        else {
+            child = child->nextSibling();
+        }
+    }
+
+    updateStartEnd(newStart, newEnd);
+}
+
+}