replaceselectioncommand.cpp

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        if (!isNodeRendered(node) && !isTableStructureNode(node))
            unrendered.append(node);

    size_t n = unrendered.size();
    for (size_t i = 0; i < n; ++i)
        removeNode(unrendered[i]);
}

void ReplacementFragment::removeInterchangeNodes(Node* container)
{
    // Interchange newlines at the "start" of the incoming fragment must be
    // either the first node in the fragment or the first leaf in the fragment.
    Node* node = container->firstChild();
    while (node) {
        if (isInterchangeNewlineNode(node)) {
            m_hasInterchangeNewlineAtStart = true;
            removeNode(node);
            break;
        }
        node = node->firstChild();
    }
    if (!container->hasChildNodes())
        return;
    // Interchange newlines at the "end" of the incoming fragment must be
    // either the last node in the fragment or the last leaf in the fragment.
    node = container->lastChild();
    while (node) {
        if (isInterchangeNewlineNode(node)) {
            m_hasInterchangeNewlineAtEnd = true;
            removeNode(node);
            break;
        }
        node = node->lastChild();
    }
    
    node = container->firstChild();
    while (node) {
        Node *next = node->traverseNextNode();
        if (isInterchangeConvertedSpaceSpan(node)) {
            RefPtr<Node> n = 0;
            while ((n = node->firstChild())) {
                removeNode(n);
                insertNodeBefore(n, node);
            }
            removeNode(node);
            if (n)
                next = n->traverseNextNode();
        }
        node = next;
    }
}

ReplaceSelectionCommand::ReplaceSelectionCommand(Document* document, PassRefPtr<DocumentFragment> fragment,
        bool selectReplacement, bool smartReplace, bool matchStyle, bool preventNesting, bool movingParagraph,
        EditAction editAction) 
    : CompositeEditCommand(document),
      m_selectReplacement(selectReplacement), 
      m_smartReplace(smartReplace),
      m_matchStyle(matchStyle),
      m_documentFragment(fragment),
      m_preventNesting(preventNesting),
      m_movingParagraph(movingParagraph),
      m_editAction(editAction),
      m_shouldMergeEnd(false)
{
}

static bool hasMatchingQuoteLevel(VisiblePosition endOfExistingContent, VisiblePosition endOfInsertedContent)
{
    Position existing = endOfExistingContent.deepEquivalent();
    Position inserted = endOfInsertedContent.deepEquivalent();
    bool isInsideMailBlockquote = nearestMailBlockquote(inserted.node());
    return isInsideMailBlockquote && (numEnclosingMailBlockquotes(existing) == numEnclosingMailBlockquotes(inserted));
}

bool ReplaceSelectionCommand::shouldMergeStart(bool selectionStartWasStartOfParagraph, bool fragmentHasInterchangeNewlineAtStart)
{
    VisiblePosition startOfInsertedContent(positionAtStartOfInsertedContent());
    VisiblePosition prev = startOfInsertedContent.previous(true);
    if (prev.isNull())
        return false;
    
    if (!m_movingParagraph && hasMatchingQuoteLevel(prev, positionAtEndOfInsertedContent()))
        return true;

    return !selectionStartWasStartOfParagraph && 
           !fragmentHasInterchangeNewlineAtStart &&
           isStartOfParagraph(startOfInsertedContent) && 
           !startOfInsertedContent.deepEquivalent().node()->hasTagName(brTag) &&
           shouldMerge(startOfInsertedContent, prev);
}

bool ReplaceSelectionCommand::shouldMergeEnd(bool selectionEndWasEndOfParagraph)
{
    VisiblePosition endOfInsertedContent(positionAtEndOfInsertedContent());
    VisiblePosition next = endOfInsertedContent.next(true);
    if (next.isNull())
        return false;

    return !selectionEndWasEndOfParagraph &&
           isEndOfParagraph(endOfInsertedContent) && 
           !endOfInsertedContent.deepEquivalent().node()->hasTagName(brTag) &&
           shouldMerge(endOfInsertedContent, next);
}

static bool isMailPasteAsQuotationNode(const Node* node)
{
    return node && node->hasTagName(blockquoteTag) && node->isElementNode() && static_cast<const Element*>(node)->getAttribute(classAttr) == ApplePasteAsQuotation;
}

// Wrap CompositeEditCommand::removeNodePreservingChildren() so we can update the nodes we track
void ReplaceSelectionCommand::removeNodePreservingChildren(Node* node)
{
    if (m_firstNodeInserted == node)
        m_firstNodeInserted = node->traverseNextNode();
    if (m_lastLeafInserted == node)
        m_lastLeafInserted = node->lastChild() ? node->lastChild() : node->traverseNextSibling();
    CompositeEditCommand::removeNodePreservingChildren(node);
}

// Wrap CompositeEditCommand::removeNodeAndPruneAncestors() so we can update the nodes we track
void ReplaceSelectionCommand::removeNodeAndPruneAncestors(Node* node)
{
    // prepare in case m_firstNodeInserted and/or m_lastLeafInserted get removed
    // FIXME: shouldn't m_lastLeafInserted be adjusted using traversePreviousNode()?
    Node* afterFirst = m_firstNodeInserted ? m_firstNodeInserted->traverseNextSibling() : 0;
    Node* afterLast = m_lastLeafInserted ? m_lastLeafInserted->traverseNextSibling() : 0;
    
    CompositeEditCommand::removeNodeAndPruneAncestors(node);
    
    // adjust m_firstNodeInserted and m_lastLeafInserted since either or both may have been removed
    if (m_lastLeafInserted && !m_lastLeafInserted->inDocument())
        m_lastLeafInserted = afterLast;
    if (m_firstNodeInserted && !m_firstNodeInserted->inDocument())
        m_firstNodeInserted = m_lastLeafInserted && m_lastLeafInserted->inDocument() ? afterFirst : 0;
}

static bool isHeaderElement(Node* a)
{
    if (!a)
        return false;
        
    return a->hasTagName(h1Tag) ||
           a->hasTagName(h2Tag) ||
           a->hasTagName(h3Tag) ||
           a->hasTagName(h4Tag) ||
           a->hasTagName(h5Tag);
}

static bool haveSameTagName(Node* a, Node* b)
{
    return a && b && a->isElementNode() && b->isElementNode() && static_cast<Element*>(a)->tagName() == static_cast<Element*>(b)->tagName();
}

bool ReplaceSelectionCommand::shouldMerge(const VisiblePosition& source, const VisiblePosition& destination)
{
    if (source.isNull() || destination.isNull())
        return false;
        
    Node* sourceNode = source.deepEquivalent().node();
    Node* destinationNode = destination.deepEquivalent().node();
    Node* sourceBlock = enclosingBlock(sourceNode);
    Node* destinationBlock = enclosingBlock(destinationNode);
    return !enclosingNodeOfType(source.deepEquivalent(), &isMailPasteAsQuotationNode) &&
           sourceBlock && (!sourceBlock->hasTagName(blockquoteTag) || isMailBlockquote(sourceBlock))  &&
           enclosingListChild(sourceBlock) == enclosingListChild(destinationNode) &&
           enclosingTableCell(source.deepEquivalent()) == enclosingTableCell(destination.deepEquivalent()) &&
           (!isHeaderElement(sourceBlock) || haveSameTagName(sourceBlock, destinationBlock)) &&
           // Don't merge to or from a position before or after a block because it would
           // be a no-op and cause infinite recursion.
           !isBlock(sourceNode) && !isBlock(destinationNode);
}

// Style rules that match just inserted elements could change their appearance, like
// a div inserted into a document with div { display:inline; }.
void ReplaceSelectionCommand::negateStyleRulesThatAffectAppearance()
{
    for (RefPtr<Node> node = m_firstNodeInserted.get(); node; node = node->traverseNextNode()) {
        // FIXME: <rdar://problem/5371536> Style rules that match pasted content can change it's appearance
        if (isStyleSpan(node.get())) {
            HTMLElement* e = static_cast<HTMLElement*>(node.get());
            // There are other styles that style rules can give to style spans,
            // but these are the two important ones because they'll prevent
            // inserted content from appearing in the right paragraph.
            // FIXME: Hyatt is concerned that selectively using display:inline will give inconsistent
            // results. We already know one issue because td elements ignore their display property
            // in quirks mode (which Mail.app is always in). We should look for an alternative.
            if (isBlock(e))
                e->getInlineStyleDecl()->setProperty(CSSPropertyDisplay, CSSValueInline);
            if (e->renderer() && e->renderer()->style()->floating() != FNONE)
                e->getInlineStyleDecl()->setProperty(CSSPropertyFloat, CSSValueNone);
        }
        if (node == m_lastLeafInserted)
            break;
    }
}

void ReplaceSelectionCommand::removeUnrenderedTextNodesAtEnds()
{
    document()->updateLayoutIgnorePendingStylesheets();
    if (!m_lastLeafInserted->renderer() && 
        m_lastLeafInserted->isTextNode() && 
        !enclosingNodeWithTag(Position(m_lastLeafInserted.get(), 0), selectTag) && 
        !enclosingNodeWithTag(Position(m_lastLeafInserted.get(), 0), scriptTag)) {
        if (m_firstNodeInserted == m_lastLeafInserted) {
            removeNode(m_lastLeafInserted.get());
            m_lastLeafInserted = 0;
            m_firstNodeInserted = 0;
            return;
        }
        RefPtr<Node> previous = m_lastLeafInserted->traversePreviousNode();
        removeNode(m_lastLeafInserted.get());
        m_lastLeafInserted = previous;
    }
    
    // We don't have to make sure that m_firstNodeInserted isn't inside a select or script element, because
    // it is a top level node in the fragment and the user can't insert into those elements.
    if (!m_firstNodeInserted->renderer() && 
        m_firstNodeInserted->isTextNode()) {
        if (m_firstNodeInserted == m_lastLeafInserted) {
            removeNode(m_firstNodeInserted.get());
            m_firstNodeInserted = 0;
            m_lastLeafInserted = 0;
            return;
        }
        RefPtr<Node> next = m_firstNodeInserted->traverseNextSibling();
        removeNode(m_firstNodeInserted.get());
        m_firstNodeInserted = next;
    }
}

void ReplaceSelectionCommand::handlePasteAsQuotationNode()
{
    Node* node = m_firstNodeInserted.get();
    if (isMailPasteAsQuotationNode(node))
        removeNodeAttribute(static_cast<Element*>(node), classAttr);
}

VisiblePosition ReplaceSelectionCommand::positionAtEndOfInsertedContent()
{
    Node* lastNode = m_lastLeafInserted.get();
    Node* enclosingSelect = enclosingNodeWithTag(Position(lastNode, 0), selectTag);
    if (enclosingSelect)
        lastNode = enclosingSelect;
    return VisiblePosition(Position(lastNode, maxDeepOffset(lastNode)));
}

VisiblePosition ReplaceSelectionCommand::positionAtStartOfInsertedContent()
{
    // Return the inserted content's first VisiblePosition.
    return VisiblePosition(nextCandidate(positionBeforeNode(m_firstNodeInserted.get())));
}

// Remove style spans before insertion if they are unnecessary.  It's faster because we'll 
// avoid doing a layout.
static bool handleStyleSpansBeforeInsertion(ReplacementFragment& fragment, const Position& insertionPos)
{
    Node* topNode = fragment.firstChild();
    
    // Handling this case is more complicated (see handleStyleSpans) and doesn't receive the optimization.
    if (isMailPasteAsQuotationNode(topNode))
        return false;
    
    // Either there are no style spans in the fragment or a WebKit client has added content to the fragment
    // before inserting it.  Look for and handle style spans after insertion.
    if (!isStyleSpan(topNode))
        return false;
    
    Node* sourceDocumentStyleSpan = topNode;
    RefPtr<Node> copiedRangeStyleSpan = sourceDocumentStyleSpan->firstChild();