applystylecommand.cpp

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        Node *prevNode = text->previousSibling();
        ASSERT(prevNode);
        Node *startNode = start.node() == end.node() ? prevNode : start.node();
        ASSERT(startNode);
        updateStartEnd(Position(startNode, start.offset()), Position(prevNode, caretMaxOffset(prevNode)));
        return true;
    }
    return false;
}

bool ApplyStyleCommand::splitTextElementAtStartIfNeeded(const Position &start, const Position &end)
{
    if (start.node()->isTextNode() && start.offset() > caretMinOffset(start.node()) && start.offset() < caretMaxOffset(start.node())) {
        int endOffsetAdjustment = start.node() == end.node() ? start.offset() : 0;
        Text *text = static_cast<Text *>(start.node());
        splitTextNodeContainingElement(text, start.offset());

        updateStartEnd(Position(start.node()->parentNode(), start.node()->nodeIndex()), Position(end.node(), end.offset() - endOffsetAdjustment));
        return true;
    }
    return false;
}

bool ApplyStyleCommand::splitTextElementAtEndIfNeeded(const Position &start, const Position &end)
{
    if (end.node()->isTextNode() && end.offset() > caretMinOffset(end.node()) && end.offset() < caretMaxOffset(end.node())) {
        Text *text = static_cast<Text *>(end.node());
        splitTextNodeContainingElement(text, end.offset());

        Node *prevNode = text->parent()->previousSibling()->lastChild();
        ASSERT(prevNode);
        Node *startNode = start.node() == end.node() ? prevNode : start.node();
        ASSERT(startNode);
        updateStartEnd(Position(startNode, start.offset()), 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;

    NamedAttrMap *firstMap = firstElement->attributes();
    NamedAttrMap *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.offset();

    if (isAtomicNode(start.node())) {
        if (start.offset() != 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.offset() + endOffsetAdjustment)); 
        return true;
    }

    return false;
}

bool ApplyStyleCommand::mergeEndWithNextIfIdentical(const Position &start, const Position &end)
{
    Node *endNode = end.node();
    int endOffset = end.offset();

    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.offset()), 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;
    }
    // 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(RenderStyle* computedStyle, StyleChange styleChange)
{
    if (styleChange.applyFontColor()) {
        if (Color(styleChange.fontColor()) != computedStyle->color())
            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, 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() > 0) {
        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.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->cloneElement());
}

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.offset());
            if (next == end.node())
                newEnd = Position(childText, childText->length() + end.offset());
            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);
}

}