bool VisiblePosition::isCandidate(const Position &pos)
{
if (pos.isNull())
return false;
RenderObject *renderer = pos.node()->renderer();
if (!renderer)
return false;
if (renderer->style()->visibility() != VISIBLE)
return false;
if (renderer->isReplaced())
// return true for replaced elements
return pos.offset() == 0 || pos.offset() == 1;
if (renderer->isBR()) {
if (pos.offset() == 0) {
InlineBox* box = static_cast<RenderText*>(renderer)->firstTextBox();
if (box) {
// return true for offset 0 into BR element on a line by itself
RootInlineBox* root = box->root();
if (root)
return root->firstLeafChild() == box && root->lastLeafChild() == box;
}
}
return false;
}
if (renderer->isText()) {
RenderText *textRenderer = static_cast<RenderText *>(renderer);
for (InlineTextBox *box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
if (pos.offset() >= box->m_start && pos.offset() <= box->m_start + box->m_len) {
// return true if in a text node
return true;
}
}
}
if (renderer->isBlockFlow() && (!renderer->firstChild() || !pos.node()->firstChild()) &&
(renderer->height() || pos.node()->id() == ID_BODY)) {
// return true for offset 0 into rendered blocks that are empty of rendered kids, but have a height
return pos.offset() == 0;
}
return false;
}
static VisiblePosition startPositionForLine(const VisiblePosition& c)
{
if (c.isNull())
return VisiblePosition();
RootInlineBox *rootBox = rootBoxForLine(c);
if (!rootBox) {
// There are VisiblePositions at offset 0 in blocks without
// RootInlineBoxes, like empty editable blocks and bordered blocks.
Position p = c.deepEquivalent();
if (p.node()->renderer() && p.node()->renderer()->isRenderBlock() && p.deprecatedEditingOffset() == 0)
return positionAvoidingFirstPositionInTable(c);
return VisiblePosition();
}
// Generated content (e.g. list markers and CSS :before and :after
// pseudoelements) have no corresponding DOM element, and so cannot be
// represented by a VisiblePosition. Use whatever follows instead.
InlineBox *startBox = rootBox->firstLeafChild();
Node *startNode;
while (1) {
if (!startBox)
return VisiblePosition();
RenderObject *startRenderer = startBox->renderer();
if (!startRenderer)
return VisiblePosition();
startNode = startRenderer->node();
if (startNode)
break;
startBox = startBox->nextLeafChild();
}
int startOffset = 0;
if (startBox->isInlineTextBox()) {
InlineTextBox *startTextBox = static_cast<InlineTextBox *>(startBox);
startOffset = startTextBox->start();
}
VisiblePosition visPos = VisiblePosition(startNode, startOffset, DOWNSTREAM);
return positionAvoidingFirstPositionInTable(visPos);
}