range.cpp

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void Range::surroundContents(PassRefPtr<Node> passNewParent, ExceptionCode& ec)
{
    RefPtr<Node> newParent = passNewParent;

    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return;
    }

    if (!newParent) {
        ec = NOT_FOUND_ERR;
        return;
    }

    // INVALID_NODE_TYPE_ERR: Raised if node is an Attr, Entity, DocumentType, Notation,
    // Document, or DocumentFragment node.
    switch (newParent->nodeType()) {
        case Node::ATTRIBUTE_NODE:
        case Node::DOCUMENT_FRAGMENT_NODE:
        case Node::DOCUMENT_NODE:
        case Node::DOCUMENT_TYPE_NODE:
        case Node::ENTITY_NODE:
        case Node::NOTATION_NODE:
            ec = RangeException::INVALID_NODE_TYPE_ERR;
            return;
        case Node::CDATA_SECTION_NODE:
        case Node::COMMENT_NODE:
        case Node::ELEMENT_NODE:
        case Node::ENTITY_REFERENCE_NODE:
        case Node::PROCESSING_INSTRUCTION_NODE:
        case Node::TEXT_NODE:
        case Node::XPATH_NAMESPACE_NODE:
            break;
    }

    // NO_MODIFICATION_ALLOWED_ERR: Raised if an ancestor container of either boundary-point of
    // the Range is read-only.
    if (containedByReadOnly()) {
        ec = NO_MODIFICATION_ALLOWED_ERR;
        return;
    }

    // WRONG_DOCUMENT_ERR: Raised if newParent and the container of the start of the Range were
    // not created from the same document.
    if (newParent->document() != m_start.container()->document()) {
        ec = WRONG_DOCUMENT_ERR;
        return;
    }

    // Raise a HIERARCHY_REQUEST_ERR if m_start.container() doesn't accept children like newParent.
    Node* parentOfNewParent = m_start.container();

    // If m_start.container() is a character data node, it will be split and it will be its parent that will 
    // need to accept newParent (or in the case of a comment, it logically "would" be inserted into the parent,
    // although this will fail below for another reason).
    if (parentOfNewParent->isCharacterDataNode())
        parentOfNewParent = parentOfNewParent->parentNode();
    if (!parentOfNewParent->childTypeAllowed(newParent->nodeType())) {
        ec = HIERARCHY_REQUEST_ERR;
        return;
    }
    
    if (m_start.container() == newParent || m_start.container()->isDescendantOf(newParent.get())) {
        ec = HIERARCHY_REQUEST_ERR;
        return;
    }

    // FIXME: Do we need a check if the node would end up with a child node of a type not
    // allowed by the type of node?

    // BAD_BOUNDARYPOINTS_ERR: Raised if the Range partially selects a non-Text node.
    Node* startNonTextContainer = m_start.container();
    if (startNonTextContainer->nodeType() == Node::TEXT_NODE)
        startNonTextContainer = startNonTextContainer->parentNode();
    Node* endNonTextContainer = m_end.container();
    if (endNonTextContainer->nodeType() == Node::TEXT_NODE)
        endNonTextContainer = endNonTextContainer->parentNode();
    if (startNonTextContainer != endNonTextContainer) {
        ec = RangeException::BAD_BOUNDARYPOINTS_ERR;
        return;
    }

    ec = 0;
    while (Node* n = newParent->firstChild()) {
        newParent->removeChild(n, ec);
        if (ec)
            return;
    }
    RefPtr<DocumentFragment> fragment = extractContents(ec);
    if (ec)
        return;
    insertNode(newParent, ec);
    if (ec)
        return;
    newParent->appendChild(fragment.release(), ec);
    if (ec)
        return;
    selectNode(newParent.get(), ec);
}

void Range::setStartBefore(Node* refNode, ExceptionCode& ec)
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return;
    }

    if (!refNode) {
        ec = NOT_FOUND_ERR;
        return;
    }

    if (refNode->document() != m_ownerDocument) {
        ec = WRONG_DOCUMENT_ERR;
        return;
    }

    ec = 0;
    checkNodeBA(refNode, ec);
    if (ec)
        return;

    setStart(refNode->parentNode(), refNode->nodeIndex(), ec);
}

void Range::checkDeleteExtract(ExceptionCode& ec)
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return;
    }

    ec = 0;
    if (!commonAncestorContainer(ec) || ec)
        return;
        
    Node* pastLast = pastLastNode();
    for (Node* n = firstNode(); n != pastLast; n = n->traverseNextNode()) {
        if (n->isReadOnlyNode()) {
            ec = NO_MODIFICATION_ALLOWED_ERR;
            return;
        }
        if (n->nodeType() == Node::DOCUMENT_TYPE_NODE) {
            ec = HIERARCHY_REQUEST_ERR;
            return;
        }
    }

    if (containedByReadOnly()) {
        ec = NO_MODIFICATION_ALLOWED_ERR;
        return;
    }
}

bool Range::containedByReadOnly() const
{
    for (Node* n = m_start.container(); n; n = n->parentNode()) {
        if (n->isReadOnlyNode())
            return true;
    }
    for (Node* n = m_end.container(); n; n = n->parentNode()) {
        if (n->isReadOnlyNode())
            return true;
    }
    return false;
}

Node* Range::firstNode() const
{
    if (!m_start.container())
        return 0;
    if (m_start.container()->offsetInCharacters())
        return m_start.container();
    if (Node* child = m_start.container()->childNode(m_start.offset()))
        return child;
    if (!m_start.offset())
        return m_start.container();
    return m_start.container()->traverseNextSibling();
}

Position Range::editingStartPosition() const
{
    // This function is used by range style computations to avoid bugs like:
    // <rdar://problem/4017641> REGRESSION (Mail): you can only bold/unbold a selection starting from end of line once
    // It is important to skip certain irrelevant content at the start of the selection, so we do not wind up 
    // with a spurious "mixed" style.
    
    VisiblePosition visiblePosition(m_start.container(), m_start.offset(), VP_DEFAULT_AFFINITY);
    if (visiblePosition.isNull())
        return Position();

    ExceptionCode ec = 0;
    // if the selection is a caret, just return the position, since the style
    // behind us is relevant
    if (collapsed(ec))
        return visiblePosition.deepEquivalent();

    // if the selection starts just before a paragraph break, skip over it
    if (isEndOfParagraph(visiblePosition))
        return visiblePosition.next().deepEquivalent().downstream();

    // otherwise, make sure to be at the start of the first selected node,
    // instead of possibly at the end of the last node before the selection
    return visiblePosition.deepEquivalent().downstream();
}

Node* Range::shadowTreeRootNode() const
{
    return startContainer() ? startContainer()->shadowTreeRootNode() : 0;
}

Node* Range::pastLastNode() const
{
    if (!m_start.container() || !m_end.container())
        return 0;
    if (m_end.container()->offsetInCharacters())
        return m_end.container()->traverseNextSibling();
    if (Node* child = m_end.container()->childNode(m_end.offset()))
        return child;
    return m_end.container()->traverseNextSibling();
}

IntRect Range::boundingBox()
{
    IntRect result;
    Vector<IntRect> rects;
    addLineBoxRects(rects);
    const size_t n = rects.size();
    for (size_t i = 0; i < n; ++i)
        result.unite(rects[i]);
    return result;
}

void Range::addLineBoxRects(Vector<IntRect>& rects, bool useSelectionHeight)
{
    if (!m_start.container() || !m_end.container())
        return;

    RenderObject* start = m_start.container()->renderer();
    RenderObject* end = m_end.container()->renderer();
    if (!start || !end)
        return;

    RenderObject* stop = end->nextInPreOrderAfterChildren();
    for (RenderObject* r = start; r && r != stop; r = r->nextInPreOrder()) {
        // only ask leaf render objects for their line box rects
        if (!r->firstChild()) {
            int startOffset = r == start ? m_start.offset() : 0;
            int endOffset = r == end ? m_end.offset() : INT_MAX;
            r->absoluteRectsForRange(rects, startOffset, endOffset, useSelectionHeight);
        }
    }
}

#ifndef NDEBUG
#define FormatBufferSize 1024
void Range::formatForDebugger(char* buffer, unsigned length) const
{
    String result;
    String s;
    
    if (!m_start.container() || !m_end.container())
        result = "<empty>";
    else {
        char s[FormatBufferSize];
        result += "from offset ";
        result += String::number(m_start.offset());
        result += " of ";
        m_start.container()->formatForDebugger(s, FormatBufferSize);
        result += s;
        result += " to offset ";
        result += String::number(m_end.offset());
        result += " of ";
        m_end.container()->formatForDebugger(s, FormatBufferSize);
        result += s;
    }
          
    strncpy(buffer, result.utf8().data(), length - 1);
}
#undef FormatBufferSize
#endif

bool operator==(const Range& a, const Range& b)
{
    if (&a == &b)
        return true;
    // Not strictly legal C++, but in practice this can happen, and this check works
    // fine with GCC to detect such cases and return false rather than crashing.
    if (!&a || !&b)
        return false;
    return a.startPosition() == b.startPosition() && a.endPosition() == b.endPosition();
}

PassRefPtr<Range> rangeOfContents(Node* node)
{
    ASSERT(node);
    RefPtr<Range> range = Range::create(node->document());
    int exception = 0;
    range->selectNodeContents(node, exception);
    return range.release();
}

int Range::maxStartOffset() const
{
    if (!m_start.container())
        return 0;
    if (!m_start.container()->offsetInCharacters())
        return m_start.container()->childNodeCount();
    return m_start.container()->maxCharacterOffset();
}

int Range::maxEndOffset() const
{
    if (!m_end.container())
        return 0;
    if (!m_end.container()->offsetInCharacters())
        return m_end.container()->childNodeCount();
    return m_end.container()->maxCharacterOffset();
}

static inline void boundaryNodeChildrenChanged(RangeBoundaryPoint& boundary, ContainerNode* container)
{
    if (!boundary.childBefore())
        return;
    if (boundary.container() != container)
        return;
    boundary.invalidateOffset();
}

void Range::nodeChildrenChanged(ContainerNode* container)
{
    ASSERT(container);
    ASSERT(container->document() == m_ownerDocument);
    boundaryNodeChildrenChanged(m_start, container);
    boundaryNodeChildrenChanged(m_end, container);
}

static inline void boundaryNodeWillBeRemoved(RangeBoundaryPoint& boundary, Node* nodeToBeRemoved)
{
    if (boundary.childBefore() == nodeToBeRemoved) {
        boundary.childBeforeWillBeRemoved();
        return;
    }

    for (Node* n = boundary.container(); n; n = n->parentNode()) {
        if (n == nodeToBeRemoved) {
            boundary.setToChild(nodeToBeRemoved);
            return;
        }
    }
}

void Range::nodeWillBeRemoved(Node* node)
{
    ASSERT(node);
    ASSERT(node->document() == m_ownerDocument);
    ASSERT(node != m_ownerDocument);
    ASSERT(node->parentNode());
    boundaryNodeWillBeRemoved(m_start, node);
    boundaryNodeWillBeRemoved(m_end, node);
}

static inline void boundaryTextInserted(RangeBoundaryPoint& boundary, Node* text, unsigned offset, unsigned length)
{
    if (boundary.container() != text)
        return;
    unsigned boundaryOffset = boundary.offset();
    if (offset >= boundaryOffset)
        return;
    boundary.setOffset(boundaryOffset + length);
}

void Range::textInserted(Node* text, unsigned offset, unsigned length)
{
    ASSERT(text);
    ASSERT(text->document() == m_ownerDocument);
    boundaryTextInserted(m_start, text, offset, length);
    boundaryTextInserted(m_end, text, offset, length);
}

static inline void boundaryTextRemoved(RangeBoundaryPoint& boundary, Node* text, unsigned offset, unsigned length)
{
    if (boundary.container() != text)
        return;
    unsigned boundaryOffset = boundary.offset();
    if (offset >= boundaryOffset)
        return;
    if (offset + length >= boundaryOffset)
        boundary.setOffset(offset);
    else
        boundary.setOffset(boundaryOffset - length);
}

void Range::textRemoved(Node* text, unsigned offset, unsigned length)
{
    ASSERT(text);
    ASSERT(text->document() == m_ownerDocument);
    boundaryTextRemoved(m_start, text, offset, length);
    boundaryTextRemoved(m_end, text, offset, length);
}

static inline void boundaryTextNodesMerged(RangeBoundaryPoint& boundary, NodeWithIndex& oldNode, unsigned offset)
{
    if (boundary.container() == oldNode.node())
        boundary.set(oldNode.node()->previousSibling(), boundary.offset() + offset, 0);
    else if (boundary.container() == oldNode.node()->parentNode() && boundary.offset() == oldNode.index())
        boundary.set(oldNode.node()->previousSibling(), offset, 0);
}

void Range::textNodesMerged(NodeWithIndex& oldNode, unsigned offset)
{
    ASSERT(oldNode.node());
    ASSERT(oldNode.node()->document() == m_ownerDocument);
    ASSERT(oldNode.node()->parentNode());
    ASSERT(oldNode.node()->isTextNode());
    ASSERT(oldNode.node()->previousSibling());
    ASSERT(oldNode.node()->previousSibling()->isTextNode());
    boundaryTextNodesMerged(m_start, oldNode, offset);
    boundaryTextNodesMerged(m_end, oldNode, offset);
}

static inline void boundaryTextNodesSplit(RangeBoundaryPoint& boundary, Text* oldNode)
{
    if (boundary.container() != oldNode)
        return;
    unsigned boundaryOffset = boundary.offset();
    if (boundaryOffset <= oldNode->length())
        return;
    boundary.set(oldNode->nextSibling(), boundaryOffset - oldNode->length(), 0);
}

void Range::textNodeSplit(Text* oldNode)
{
    ASSERT(oldNode);
    ASSERT(oldNode->document() == m_ownerDocument);
    ASSERT(oldNode->parentNode());
    ASSERT(oldNode->isTextNode());
    ASSERT(oldNode->nextSibling());
    ASSERT(oldNode->nextSibling()->isTextNode());
    boundaryTextNodesSplit(m_start, oldNode);
    boundaryTextNodesSplit(m_end, oldNode);
}

}