htmlediting.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

    return 0;
}

static HTMLElement* embeddedSublist(Node* listItem)
{
    // Check the DOM so that we'll find collapsed sublists without renderers.
    for (Node* n = listItem->firstChild(); n; n = n->nextSibling()) {
        if (isListElement(n))
            return static_cast<HTMLElement*>(n);
    }
    
    return 0;
}

static Node* appendedSublist(Node* listItem)
{
    // Check the DOM so that we'll find collapsed sublists without renderers.
    for (Node* n = listItem->nextSibling(); n; n = n->nextSibling()) {
        if (isListElement(n))
            return static_cast<HTMLElement*>(n);
        if (n->renderer() && n->renderer()->isListItem())
            return 0;
    }
    
    return 0;
}

Node* enclosingEmptyListItem(const VisiblePosition& visiblePos)
{
    // Check that position is on a line by itself inside a list item
    Node* listChildNode = enclosingListChild(visiblePos.deepEquivalent().node());
    if (!listChildNode || !isStartOfParagraph(visiblePos) || !isEndOfParagraph(visiblePos))
        return 0;
        
    VisiblePosition firstInListChild(Position(listChildNode, 0));
    VisiblePosition lastInListChild(Position(listChildNode, maxDeepOffset(listChildNode)));
    
    if (firstInListChild != visiblePos || lastInListChild != visiblePos)
        return 0;
    
    if (embeddedSublist(listChildNode) || appendedSublist(listChildNode))
        return 0;
        
    return listChildNode;
}

HTMLElement* outermostEnclosingList(Node* node)
{
    HTMLElement* list = enclosingList(node);
    if (!list)
        return 0;
    while (HTMLElement* nextList = enclosingList(list))
        list = nextList;
    return list;
}

Node* highestAncestor(Node* node)
{
    ASSERT(node);
    Node* parent = node;
    while ((node = node->parentNode()))
        parent = node;
    return parent;
}

// FIXME: do not require renderer, so that this can be used within fragments, or rename to isRenderedTable()
bool isTableElement(Node* n)
{
    if (!n || !n->isElementNode())
        return false;

    RenderObject* renderer = n->renderer();
    return (renderer && (renderer->style()->display() == TABLE || renderer->style()->display() == INLINE_TABLE));
}

bool isTableCell(const Node* node)
{
    RenderObject* r = node->renderer();
    if (!r)
        return node->hasTagName(tdTag) || node->hasTagName(thTag);
    
    return r->isTableCell();
}

PassRefPtr<HTMLElement> createDefaultParagraphElement(Document* document)
{
    return new HTMLDivElement(divTag, document);
}

PassRefPtr<HTMLElement> createBreakElement(Document* document)
{
    return new HTMLBRElement(brTag, document);
}

PassRefPtr<HTMLElement> createOrderedListElement(Document* document)
{
    return new HTMLOListElement(olTag, document);
}

PassRefPtr<HTMLElement> createUnorderedListElement(Document* document)
{
    return new HTMLUListElement(ulTag, document);
}

PassRefPtr<HTMLElement> createListItemElement(Document* document)
{
    return new HTMLLIElement(liTag, document);
}

PassRefPtr<HTMLElement> createHTMLElement(Document* document, const QualifiedName& name)
{
    return HTMLElementFactory::createHTMLElement(name, document, 0, false);
}

PassRefPtr<HTMLElement> createHTMLElement(Document* document, const AtomicString& tagName)
{
    return createHTMLElement(document, QualifiedName(nullAtom, tagName, xhtmlNamespaceURI));
}

bool isTabSpanNode(const Node *node)
{
    return node && node->hasTagName(spanTag) && node->isElementNode() && static_cast<const Element *>(node)->getAttribute(classAttr) == AppleTabSpanClass;
}

bool isTabSpanTextNode(const Node *node)
{
    return node && node->isTextNode() && node->parentNode() && isTabSpanNode(node->parentNode());
}

Node *tabSpanNode(const Node *node)
{
    return isTabSpanTextNode(node) ? node->parentNode() : 0;
}

Position positionBeforeTabSpan(const Position& pos)
{
    Node *node = pos.node();
    if (isTabSpanTextNode(node))
        node = tabSpanNode(node);
    else if (!isTabSpanNode(node))
        return pos;
    
    return positionBeforeNode(node);
}

PassRefPtr<Element> createTabSpanElement(Document* document, PassRefPtr<Node> tabTextNode)
{
    // Make the span to hold the tab.
    RefPtr<Element> spanElement = document->createElement(spanTag, false);
    spanElement->setAttribute(classAttr, AppleTabSpanClass);
    spanElement->setAttribute(styleAttr, "white-space:pre");

    // Add tab text to that span.
    if (!tabTextNode)
        tabTextNode = document->createEditingTextNode("\t");

    ExceptionCode ec = 0;
    spanElement->appendChild(tabTextNode, ec);
    ASSERT(ec == 0);

    return spanElement.release();
}

PassRefPtr<Element> createTabSpanElement(Document* document, const String& tabText)
{
    return createTabSpanElement(document, document->createTextNode(tabText));
}

PassRefPtr<Element> createTabSpanElement(Document* document)
{
    return createTabSpanElement(document, PassRefPtr<Node>());
}

bool isNodeRendered(const Node *node)
{
    if (!node)
        return false;

    RenderObject *renderer = node->renderer();
    if (!renderer)
        return false;

    return renderer->style()->visibility() == VISIBLE;
}

Node *nearestMailBlockquote(const Node *node)
{
    for (Node *n = const_cast<Node *>(node); n; n = n->parentNode()) {
        if (isMailBlockquote(n))
            return n;
    }
    return 0;
}

unsigned numEnclosingMailBlockquotes(const Position& p)
{
    unsigned num = 0;
    for (Node* n = p.node(); n; n = n->parentNode())
        if (isMailBlockquote(n))
            num++;
    
    return num;
}

bool isMailBlockquote(const Node *node)
{
    if (!node || !node->isElementNode() && !node->hasTagName(blockquoteTag))
        return false;
        
    return static_cast<const Element *>(node)->getAttribute("type") == "cite";
}

int caretMinOffset(const Node* n)
{
    RenderObject* r = n->renderer();
    ASSERT(!n->isCharacterDataNode() || !r || r->isText()); // FIXME: This was a runtime check that seemingly couldn't fail; changed it to an assertion for now.
    return r ? r->caretMinOffset() : 0;
}

// If a node can contain candidates for VisiblePositions, return the offset of the last candidate, otherwise 
// return the number of children for container nodes and the length for unrendered text nodes.
int caretMaxOffset(const Node* n)
{
    // For rendered text nodes, return the last position that a caret could occupy.
    if (n->isTextNode() && n->renderer())
        return n->renderer()->caretMaxOffset();
    // For containers return the number of children.  For others do the same as above.
    return maxDeepOffset(n);
}

bool lineBreakExistsAtPosition(const VisiblePosition& visiblePosition)
{
    if (visiblePosition.isNull())
        return false;
        
    Position downstream(visiblePosition.deepEquivalent().downstream());
    return downstream.node()->hasTagName(brTag) ||
           downstream.node()->isTextNode() && downstream.node()->renderer()->style()->preserveNewline() && visiblePosition.characterAfter() == '\n';
}

// Modifies selections that have an end point at the edge of a table
// that contains the other endpoint so that they don't confuse
// code that iterates over selected paragraphs.
VisibleSelection selectionForParagraphIteration(const VisibleSelection& original)
{
    VisibleSelection newSelection(original);
    VisiblePosition startOfSelection(newSelection.visibleStart());
    VisiblePosition endOfSelection(newSelection.visibleEnd());
    
    // If the end of the selection to modify is just after a table, and
    // if the start of the selection is inside that table, then the last paragraph
    // that we'll want modify is the last one inside the table, not the table itself
    // (a table is itself a paragraph).
    if (Node* table = isFirstPositionAfterTable(endOfSelection))
        if (startOfSelection.deepEquivalent().node()->isDescendantOf(table))
            newSelection = VisibleSelection(startOfSelection, endOfSelection.previous(true));
    
    // If the start of the selection to modify is just before a table,
    // and if the end of the selection is inside that table, then the first paragraph
    // we'll want to modify is the first one inside the table, not the paragraph
    // containing the table itself.
    if (Node* table = isLastPositionBeforeTable(startOfSelection))
        if (endOfSelection.deepEquivalent().node()->isDescendantOf(table))
            newSelection = VisibleSelection(startOfSelection.next(true), endOfSelection);
    
    return newSelection;
}


int indexForVisiblePosition(VisiblePosition& visiblePosition)
{
    if (visiblePosition.isNull())
        return 0;
    Position p(visiblePosition.deepEquivalent());
    RefPtr<Range> range = Range::create(p.node()->document(), Position(p.node()->document(), 0), rangeCompliantEquivalent(p));
    return TextIterator::rangeLength(range.get(), true);
}

PassRefPtr<Range> avoidIntersectionWithNode(const Range* range, Node* node)
{
    if (!range)
        return 0;

    Document* document = range->ownerDocument();

    Node* startContainer = range->startContainer();
    int startOffset = range->startOffset();
    Node* endContainer = range->endContainer();
    int endOffset = range->endOffset();

    if (!startContainer)
        return 0;

    ASSERT(endContainer);

    if (startContainer == node || startContainer->isDescendantOf(node)) {
        ASSERT(node->parentNode());
        startContainer = node->parentNode();
        startOffset = node->nodeIndex();
    }
    if (endContainer == node || endContainer->isDescendantOf(node)) {
        ASSERT(node->parentNode());
        endContainer = node->parentNode();
        endOffset = node->nodeIndex();
    }

    return Range::create(document, startContainer, startOffset, endContainer, endOffset);
}

VisibleSelection avoidIntersectionWithNode(const VisibleSelection& selection, Node* node)
{
    if (selection.isNone())
        return VisibleSelection(selection);
        
    VisibleSelection updatedSelection(selection);
    Node* base = selection.base().node();
    Node* extent = selection.extent().node();
    ASSERT(base);
    ASSERT(extent);
    
    if (base == node || base->isDescendantOf(node)) {
        ASSERT(node->parentNode());
        updatedSelection.setBase(Position(node->parentNode(), node->nodeIndex()));
    }
    
    if (extent == node || extent->isDescendantOf(node)) {
        ASSERT(node->parentNode());
        updatedSelection.setExtent(Position(node->parentNode(), node->nodeIndex()));
    }
        
    return updatedSelection;
}

} // namespace WebCore