compositeeditcommand.cpp

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    ASSERT(anchorNode->isLink());
    
    setEndingSelection(VisibleSelection::selectionFromContentsOfNode(anchorNode));
    applyStyledElement(static_cast<Element*>(anchorNode));
    // Clones of anchorNode have been pushed down, now remove it.
    if (anchorNode->inDocument())
        removeNodePreservingChildren(anchorNode);
}

// We must push partially selected anchors down before creating or removing
// links from a selection to create fully selected chunks that can be removed.
// ApplyStyleCommand doesn't do this for us because styles can be nested.
// Anchors cannot be nested.
void CompositeEditCommand::pushPartiallySelectedAnchorElementsDown()
{
    VisibleSelection originalSelection = endingSelection();
    VisiblePosition visibleStart(originalSelection.start());
    VisiblePosition visibleEnd(originalSelection.end());
    
    Node* startAnchor = enclosingAnchorElement(originalSelection.start());
    VisiblePosition startOfStartAnchor(Position(startAnchor, 0));
    if (startAnchor && startOfStartAnchor != visibleStart)
        pushAnchorElementDown(startAnchor);

    Node* endAnchor = enclosingAnchorElement(originalSelection.end());
    VisiblePosition endOfEndAnchor(Position(endAnchor, 0));
    if (endAnchor && endOfEndAnchor != visibleEnd)
        pushAnchorElementDown(endAnchor);

    ASSERT(originalSelection.start().node()->inDocument() && originalSelection.end().node()->inDocument());
    setEndingSelection(originalSelection);
}

// This moves a paragraph preserving its style.
void CompositeEditCommand::moveParagraph(const VisiblePosition& startOfParagraphToMove, const VisiblePosition& endOfParagraphToMove, const VisiblePosition& destination, bool preserveSelection, bool preserveStyle)
{
    ASSERT(isStartOfParagraph(startOfParagraphToMove));
    ASSERT(isEndOfParagraph(endOfParagraphToMove));
    moveParagraphs(startOfParagraphToMove, endOfParagraphToMove, destination, preserveSelection, preserveStyle);
}

void CompositeEditCommand::moveParagraphs(const VisiblePosition& startOfParagraphToMove, const VisiblePosition& endOfParagraphToMove, const VisiblePosition& destination, bool preserveSelection, bool preserveStyle)
{
    if (startOfParagraphToMove == destination)
        return;
    
    int startIndex = -1;
    int endIndex = -1;
    int destinationIndex = -1;
    if (preserveSelection && !endingSelection().isNone()) {
        VisiblePosition visibleStart = endingSelection().visibleStart();
        VisiblePosition visibleEnd = endingSelection().visibleEnd();
        
        bool startAfterParagraph = Range::compareBoundaryPoints(visibleStart.deepEquivalent(), endOfParagraphToMove.deepEquivalent()) > 0;
        bool endBeforeParagraph = Range::compareBoundaryPoints(visibleEnd.deepEquivalent(), startOfParagraphToMove.deepEquivalent()) < 0;
        
        if (!startAfterParagraph && !endBeforeParagraph) {
            bool startInParagraph = Range::compareBoundaryPoints(visibleStart.deepEquivalent(), startOfParagraphToMove.deepEquivalent()) >= 0;
            bool endInParagraph = Range::compareBoundaryPoints(visibleEnd.deepEquivalent(), endOfParagraphToMove.deepEquivalent()) <= 0;
            
            startIndex = 0;
            if (startInParagraph) {
                RefPtr<Range> startRange = Range::create(document(), rangeCompliantEquivalent(startOfParagraphToMove.deepEquivalent()), rangeCompliantEquivalent(visibleStart.deepEquivalent()));
                startIndex = TextIterator::rangeLength(startRange.get(), true);
            }

            endIndex = 0;
            if (endInParagraph) {
                RefPtr<Range> endRange = Range::create(document(), rangeCompliantEquivalent(startOfParagraphToMove.deepEquivalent()), rangeCompliantEquivalent(visibleEnd.deepEquivalent()));
                endIndex = TextIterator::rangeLength(endRange.get(), true);
            }
        }
    }
    
    VisiblePosition beforeParagraph = startOfParagraphToMove.previous();
    VisiblePosition afterParagraph(endOfParagraphToMove.next());

    // We upstream() the end and downstream() the start so that we don't include collapsed whitespace in the move.
    // When we paste a fragment, spaces after the end and before the start are treated as though they were rendered.    
    Position start = startOfParagraphToMove.deepEquivalent().downstream();
    Position end = endOfParagraphToMove.deepEquivalent().upstream();
    
    // start and end can't be used directly to create a Range; they are "editing positions"
    Position startRangeCompliant = rangeCompliantEquivalent(start);
    Position endRangeCompliant = rangeCompliantEquivalent(end);
    RefPtr<Range> range = Range::create(document(), startRangeCompliant.node(), startRangeCompliant.offset(), endRangeCompliant.node(), endRangeCompliant.offset());

    // FIXME: This is an inefficient way to preserve style on nodes in the paragraph to move.  It 
    // shouldn't matter though, since moved paragraphs will usually be quite small.
    RefPtr<DocumentFragment> fragment = startOfParagraphToMove != endOfParagraphToMove ? createFragmentFromMarkup(document(), createMarkup(range.get(), 0, DoNotAnnotateForInterchange, true), "") : 0;
    
    // A non-empty paragraph's style is moved when we copy and move it.  We don't move 
    // anything if we're given an empty paragraph, but an empty paragraph can have style
    // too, <div><b><br></b></div> for example.  Save it so that we can preserve it later.
    RefPtr<CSSMutableStyleDeclaration> styleInEmptyParagraph;
    if (startOfParagraphToMove == endOfParagraphToMove && preserveStyle) {
        styleInEmptyParagraph = styleAtPosition(startOfParagraphToMove.deepEquivalent());
        // The moved paragraph should assume the block style of the destination.
        styleInEmptyParagraph->removeBlockProperties();
    }
    
    // FIXME (5098931): We should add a new insert action "WebViewInsertActionMoved" and call shouldInsertFragment here.
    
    setEndingSelection(VisibleSelection(start, end, DOWNSTREAM));
    deleteSelection(false, false, false, false);

    ASSERT(destination.deepEquivalent().node()->inDocument());
    
    // There are bugs in deletion when it removes a fully selected table/list.  
    // It expands and removes the entire table/list, but will let content
    // before and after the table/list collapse onto one line.
    
    // Deleting a paragraph will leave a placeholder.  Remove it (and prune
    // empty or unrendered parents).
    VisiblePosition caretAfterDelete = endingSelection().visibleStart();
    if (isStartOfParagraph(caretAfterDelete) && isEndOfParagraph(caretAfterDelete)) {
        // Note: We want the rightmost candidate.
        Position position = caretAfterDelete.deepEquivalent().downstream();
        Node* node = position.node();
        // Normally deletion will leave a br as a placeholder.
        if (node->hasTagName(brTag))
            removeNodeAndPruneAncestors(node);
        // If the selection to move was empty and in an empty block that 
        // doesn't require a placeholder to prop itself open (like a bordered 
        // div or an li), remove it during the move (the list removal code 
        // expects this behavior).
        else if (isBlock(node))
            removeNodeAndPruneAncestors(node);
        else if (lineBreakExistsAtPosition(caretAfterDelete)) {
            // There is a preserved '\n' at caretAfterDelete.
            Text* textNode = static_cast<Text*>(node);
            if (textNode->length() == 1)
                removeNodeAndPruneAncestors(node);
            else 
                deleteTextFromNode(textNode, position.offset(), 1);
        }
    }

    // Add a br if pruning an empty block level element caused a collapse.  For example:
    // foo^
    // <div>bar</div>
    // baz
    // Imagine moving 'bar' to ^.  'bar' will be deleted and its div pruned.  That would
    // cause 'baz' to collapse onto the line with 'foobar' unless we insert a br.
    // Must recononicalize these two VisiblePositions after the pruning above.
    beforeParagraph = VisiblePosition(beforeParagraph.deepEquivalent());
    afterParagraph = VisiblePosition(afterParagraph.deepEquivalent());
    if (beforeParagraph.isNotNull() && (!isEndOfParagraph(beforeParagraph) || beforeParagraph == afterParagraph)) {
        // FIXME: Trim text between beforeParagraph and afterParagraph if they aren't equal.
        insertNodeAt(createBreakElement(document()), beforeParagraph.deepEquivalent());
        // Need an updateLayout here in case inserting the br has split a text node.
        updateLayout();
    }
        
    RefPtr<Range> startToDestinationRange(Range::create(document(), Position(document(), 0), rangeCompliantEquivalent(destination.deepEquivalent())));
    destinationIndex = TextIterator::rangeLength(startToDestinationRange.get(), true);
    
    setEndingSelection(destination);
    applyCommandToComposite(ReplaceSelectionCommand::create(document(), fragment, true, false, !preserveStyle, false, true));
    // Restore styles from an empty paragraph to the new empty paragraph.
    if (styleInEmptyParagraph)
        applyStyle(styleInEmptyParagraph.get());
    
    if (preserveSelection && startIndex != -1) {
        // Fragment creation (using createMarkup) incorrectly uses regular
        // spaces instead of nbsps for some spaces that were rendered (11475), which
        // causes spaces to be collapsed during the move operation.  This results
        // in a call to rangeFromLocationAndLength with a location past the end
        // of the document (which will return null).
        RefPtr<Range> start = TextIterator::rangeFromLocationAndLength(document()->documentElement(), destinationIndex + startIndex, 0, true);
        RefPtr<Range> end = TextIterator::rangeFromLocationAndLength(document()->documentElement(), destinationIndex + endIndex, 0, true);
        if (start && end)
            setEndingSelection(VisibleSelection(start->startPosition(), end->startPosition(), DOWNSTREAM));
    }
}

// FIXME: Send an appropriate shouldDeleteRange call.
bool CompositeEditCommand::breakOutOfEmptyListItem()
{
    Node* emptyListItem = enclosingEmptyListItem(endingSelection().visibleStart());
    if (!emptyListItem)
        return false;
        
    RefPtr<CSSMutableStyleDeclaration> style = styleAtPosition(endingSelection().start());

    Node* listNode = emptyListItem->parentNode();
    
    if (!listNode->isContentEditable())
        return false;
    
    RefPtr<Element> newBlock = isListElement(listNode->parentNode()) ? createListItemElement(document()) : createDefaultParagraphElement(document());
    
    if (emptyListItem->renderer()->nextSibling()) {
        if (emptyListItem->renderer()->previousSibling())
            splitElement(static_cast<Element*>(listNode), emptyListItem);
        insertNodeBefore(newBlock, listNode);
        removeNode(emptyListItem);
    } else {
        insertNodeAfter(newBlock, listNode);
        removeNode(emptyListItem->renderer()->previousSibling() ? emptyListItem : listNode);
    }
    
    appendBlockPlaceholder(newBlock);
    setEndingSelection(VisibleSelection(Position(newBlock.get(), 0), DOWNSTREAM));
    
    computedStyle(endingSelection().start().node())->diff(style.get());
    if (style->length() > 0)
        applyStyle(style.get());
    
    return true;
}

// If the caret is in an empty quoted paragraph, and either there is nothing before that
// paragraph, or what is before is unquoted, and the user presses delete, unquote that paragraph.
bool CompositeEditCommand::breakOutOfEmptyMailBlockquotedParagraph()
{
    if (!endingSelection().isCaret())
        return false;
        
    VisiblePosition caret(endingSelection().visibleStart());
    Node* highestBlockquote = highestEnclosingNodeOfType(caret.deepEquivalent(), &isMailBlockquote);
    if (!highestBlockquote)
        return false;
        
    if (!isStartOfParagraph(caret) || !isEndOfParagraph(caret))
        return false;
    
    VisiblePosition previous(caret.previous(true));
    // Only move forward if there's nothing before the caret, or if there's unquoted content before it.
    if (enclosingNodeOfType(previous.deepEquivalent(), &isMailBlockquote))
        return false;
    
    RefPtr<Node> br = createBreakElement(document());
    // We want to replace this quoted paragraph with an unquoted one, so insert a br
    // to hold the caret before the highest blockquote.
    insertNodeBefore(br, highestBlockquote);
    VisiblePosition atBR(Position(br.get(), 0));
    // If the br we inserted collapsed, for example foo<br><blockquote>...</blockquote>, insert 
    // a second one.
    if (!isStartOfParagraph(atBR))
        insertNodeBefore(createBreakElement(document()), br);
    setEndingSelection(VisibleSelection(atBR));
    
    // If this is an empty paragraph there must be a line break here.
    if (!lineBreakExistsAtPosition(caret))
        return false;
    
    Position caretPos(caret.deepEquivalent());
    // A line break is either a br or a preserved newline.
    ASSERT(caretPos.node()->hasTagName(brTag) || caretPos.node()->isTextNode() && caretPos.node()->renderer()->style()->preserveNewline());
    
    if (caretPos.node()->hasTagName(brTag)) {
        Position beforeBR(positionBeforeNode(caretPos.node()));
        removeNode(caretPos.node());
        prune(beforeBR.node());
    } else {
        ASSERT(caretPos.offset() == 0);
        Text* textNode = static_cast<Text*>(caretPos.node());
        Node* parentNode = textNode->parentNode();
        // The preserved newline must be the first thing in the node, since otherwise the previous
        // paragraph would be quoted, and we verified that it wasn't above.
        deleteTextFromNode(textNode, 0, 1);
        prune(parentNode);
    }
    
    return true;
}

// Operations use this function to avoid inserting content into an anchor when at the start or the end of 
// that anchor, as in NSTextView.
// FIXME: This is only an approximation of NSTextViews insertion behavior, which varies depending on how
// the caret was made. 
Position CompositeEditCommand::positionAvoidingSpecialElementBoundary(const Position& original)
{
    if (original.isNull())
        return original;
        
    VisiblePosition visiblePos(original);
    Node* enclosingAnchor = enclosingAnchorElement(original);
    Position result = original;
    // Don't avoid block level anchors, because that would insert content into the wrong paragraph.
    if (enclosingAnchor && !isBlock(enclosingAnchor)) {
        VisiblePosition firstInAnchor(Position(enclosingAnchor, 0));
        VisiblePosition lastInAnchor(Position(enclosingAnchor, maxDeepOffset(enclosingAnchor)));
        // If visually just after the anchor, insert *inside* the anchor unless it's the last 
        // VisiblePosition in the document, to match NSTextView.
        if (visiblePos == lastInAnchor) {
            // Make sure anchors are pushed down before avoiding them so that we don't
            // also avoid structural elements like lists and blocks (5142012).
            if (original.node() != enclosingAnchor && original.node()->parentNode() != enclosingAnchor) {
                pushAnchorElementDown(enclosingAnchor);
                enclosingAnchor = enclosingAnchorElement(original);
                if (!enclosingAnchor)
                    return original;
            }
            // Don't insert outside an anchor if doing so would skip over a line break.  It would
            // probably be safe to move the line break so that we could still avoid the anchor here.
            Position downstream(visiblePos.deepEquivalent().downstream());
            if (lineBreakExistsAtPosition(visiblePos) && downstream.node()->isDescendantOf(enclosingAnchor))
                return original;
            
            result = positionAfterNode(enclosingAnchor);
        }
        // If visually just before an anchor, insert *outside* the anchor unless it's the first
        // VisiblePosition in a paragraph, to match NSTextView.
        if (visiblePos == firstInAnchor) {
            // Make sure anchors are pushed down before avoiding them so that we don't
            // also avoid structural elements like lists and blocks (5142012).
            if (original.node() != enclosingAnchor && original.node()->parentNode() != enclosingAnchor) {
                pushAnchorElementDown(enclosingAnchor);
                enclosingAnchor = enclosingAnchorElement(original);
            }
            result = positionBeforeNode(enclosingAnchor);
        }
    }
        
    if (result.isNull() || !editableRootForPosition(result))
        result = original;
    
    return result;
}

// Splits the tree parent by parent until we reach the specified ancestor. We use VisiblePositions
// to determine if the split is necessary. Returns the last split node.
PassRefPtr<Node> CompositeEditCommand::splitTreeToNode(Node* start, Node* end, bool splitAncestor)
{
    RefPtr<Node> node;
    for (node = start; node && node->parent() != end; node = node->parent()) {
        VisiblePosition positionInParent(Position(node->parent(), 0), DOWNSTREAM);
        VisiblePosition positionInNode(Position(node, 0), DOWNSTREAM);
        if (positionInParent != positionInNode)
            applyCommandToComposite(SplitElementCommand::create(static_cast<Element*>(node->parent()), node));
    }
    if (splitAncestor)
        return splitTreeToNode(end, end->parent());
    return node.release();
}

PassRefPtr<Element> createBlockPlaceholderElement(Document* document)
{
    RefPtr<Element> breakNode = document->createElement(brTag, false);
    return breakNode.release();
}

} // namespace WebCore