C++ VisiblePosition::getInlineBoxAndOffset方法代码示例

RenderedPosition::RenderedPosition(const VisiblePosition& position)
    : m_offset(0)
    , m_prevLeafChild(uncachedInlineBox())
    , m_nextLeafChild(uncachedInlineBox())
{
    if (position.isNull())
        return;
    position.getInlineBoxAndOffset(m_inlineBox, m_offset);
    if (m_inlineBox)
        m_renderer = &m_inlineBox->renderer();
    else
        m_renderer = rendererFromPosition(position.deepEquivalent());
}

VisiblePosition nextLinePosition(const VisiblePosition &visiblePosition, int x)
{
    Position p = visiblePosition.deepEquivalent();
    Node *node = p.node();
    Node* highestRoot = highestEditableRoot(p);
    if (!node)
        return VisiblePosition();
    
    node->document()->updateLayoutIgnorePendingStylesheets();

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

    RenderBlock *containingBlock = 0;
    RootInlineBox *root = 0;
    InlineBox* box;
    int ignoredCaretOffset;
    visiblePosition.getInlineBoxAndOffset(box, ignoredCaretOffset);
    if (box) {
        root = box->root()->nextRootBox();
        if (root)
            containingBlock = renderer->containingBlock();
    }

    if (!root) {
        // This containing editable block does not have a next line.
        // Need to move forward to next containing editable block in this root editable
        // block and find the first root line box in that block.
        Node* startBlock = enclosingNodeWithNonInlineRenderer(node);
        Node* n = nextLeafWithSameEditability(node, p.deprecatedEditingOffset());
        while (n && startBlock == enclosingNodeWithNonInlineRenderer(n))
            n = nextLeafWithSameEditability(n);
        while (n) {
            if (highestEditableRoot(Position(n, 0)) != highestRoot)
                break;
            Position pos(n, caretMinOffset(n));
            if (pos.isCandidate()) {
                ASSERT(n->renderer());
                pos.getInlineBoxAndOffset(DOWNSTREAM, box, ignoredCaretOffset);
                if (box) {
                    // next root line box found
                    root = box->root();
                    containingBlock = n->renderer()->containingBlock();
                    break;
                }

                return VisiblePosition(pos, DOWNSTREAM);
            }
            n = nextLeafWithSameEditability(n);
        }
    }
    
    if (root) {
        // FIXME: Can be wrong for multi-column layout and with transforms.
        FloatPoint absPos = containingBlock->localToAbsolute(FloatPoint());
        if (containingBlock->hasOverflowClip())
            absPos -= containingBlock->layer()->scrolledContentOffset();
        RenderObject* renderer = root->closestLeafChildForXPos(x - absPos.x(), isEditablePosition(p))->renderer();
        Node* node = renderer->node();
        if (node && editingIgnoresContent(node))
            return Position(node->parent(), node->nodeIndex());
        return renderer->positionForPoint(IntPoint(x - absPos.x(), root->lineTop()));
    }    

    // Could not find a next line. This means we must already be on the last line.
    // Move to the end of the content in this block, which effectively moves us
    // to the end of the line we're on.
    Element* rootElement = node->isContentEditable() ? node->rootEditableElement() : node->document()->documentElement();
    return VisiblePosition(rootElement, rootElement ? rootElement->childNodeCount() : 0, DOWNSTREAM);
}

VisiblePosition previousLinePosition(const VisiblePosition &visiblePosition, int x)
{
    Position p = visiblePosition.deepEquivalent();
    Node *node = p.node();
    Node* highestRoot = highestEditableRoot(p);
    if (!node)
        return VisiblePosition();
    
    node->document()->updateLayoutIgnorePendingStylesheets();
    
    RenderObject *renderer = node->renderer();
    if (!renderer)
        return VisiblePosition();

    RenderBlock *containingBlock = 0;
    RootInlineBox *root = 0;
    InlineBox* box;
    int ignoredCaretOffset;
    visiblePosition.getInlineBoxAndOffset(box, ignoredCaretOffset);
    if (box) {
        root = box->root()->prevRootBox();
        if (root)
            containingBlock = renderer->containingBlock();
    }

    if (!root) {
        // This containing editable block does not have a previous line.
        // Need to move back to previous containing editable block in this root editable
        // block and find the last root line box in that block.
        Node* startBlock = enclosingBlock(node);
        Node* n = previousLeafWithSameEditability(node);
        while (n && startBlock == enclosingBlock(n))
            n = previousLeafWithSameEditability(n);
        while (n) {
            if (highestEditableRoot(Position(n, 0)) != highestRoot)
                break;
            Position pos(n, caretMinOffset(n));
            if (pos.isCandidate()) {
                ASSERT(n->renderer());
                Position maxPos(n, caretMaxOffset(n));
                maxPos.getInlineBoxAndOffset(DOWNSTREAM, box, ignoredCaretOffset);
                if (box) {
                    // previous root line box found
                    root = box->root();
                    containingBlock = n->renderer()->containingBlock();
                    break;
                }

                return VisiblePosition(pos, DOWNSTREAM);
            }
            n = previousLeafWithSameEditability(n);
        }
    }
    
    if (root) {
        // FIXME: Can be wrong for multi-column layout.
        int absx, absy;
        containingBlock->absolutePositionForContent(absx, absy);
        if (containingBlock->hasOverflowClip())
            containingBlock->layer()->subtractScrollOffset(absx, absy);
        RenderObject *renderer = root->closestLeafChildForXPos(x - absx, isEditablePosition(p))->object();
        Node* node = renderer->element();
        if (editingIgnoresContent(node))
            return Position(node->parent(), node->nodeIndex());
        return renderer->positionForCoordinates(x - absx, root->topOverflow());
    }
    
    // Could not find a previous line. This means we must already be on the first line.
    // Move to the start of the content in this block, which effectively moves us
    // to the start of the line we're on.
    Node* rootElement = node->isContentEditable() ? node->rootEditableElement() : node->document()->documentElement();
    return VisiblePosition(rootElement, 0, DOWNSTREAM);
}