void quantize(Grid<Y> & dst, Grid<Y> & src)
{
assert(dst.h < src.h);
assert(dst.w < src.w);
Position tile(src.h / dst.h, src.w / dst.w); // assume dst divides src
for (PositionIterator it = dst.positions(); it.more(); ++it) {
Position & p = it.position;
std::map<Y, size_t> counts;
for (PositionIterator to(tile.i, tile.j); to.more(); ++to) {
Position & tilep = to.position;
++counts[src.cell(
p.i * tile.i + tilep.i,
p.j * tile.j + tilep.j)];
}
size_t r = 0;
const Y * q = NULL;
for (typename std::map<Y, size_t>::const_iterator m = counts.begin();
m != counts.end(); ++m) {
if (m->second > r) {
r = m->second;
q = & m->first;
}
}
dst.cell(it) = *q;
}
}
Position previousCandidate(const Position& position)
{
PositionIterator p = position;
while (!p.atStart()) {
p.decrement();
if (p.isCandidate())
return p;
}
return Position();
}
Position nextCandidate(const Position& position)
{
PositionIterator p = position;
while (!p.atEnd()) {
p.increment();
if (p.isCandidate())
return p;
}
return Position();
}
// upstream() and downstream() want to return positions that are either in a
// text node or at just before a non-text node. This method checks for that.
static bool isStreamer(const PositionIterator& pos)
{
if (!pos.node())
return true;
if (isAtomicNode(pos.node()))
return true;
return pos.atStartOfNode();
}
static bool forwardIterator(PositionIterator& iterator, int distance)
{
int remaining = distance;
while (!iterator.atEnd()) {
if (iterator.node()->isCharacterDataNode()) {
int length = lastOffsetForEditing(iterator.node());
int last = length - iterator.offsetInLeafNode();
if (remaining < last) {
iterator.setOffsetInLeafNode(iterator.offsetInLeafNode() + remaining);
return true;
}
remaining -= last;
iterator.setOffsetInLeafNode(iterator.offsetInLeafNode() + last);
}
iterator.increment();
}
return false;
}
// P.downstream() returns the end of the range of positions that map to the same VisiblePosition as P.
Position Position::downstream() const
{
Node* startNode = node();
if (!startNode)
return Position();
// iterate forward from there, looking for a qualified position
Node* block = enclosingBlock(startNode);
PositionIterator lastVisible = *this;
PositionIterator currentPos = lastVisible;
Node* originalRoot = node()->rootEditableElement();
for (; !currentPos.atEnd(); currentPos.increment()) {
Node* currentNode = currentPos.node();
if (currentNode->rootEditableElement() != originalRoot)
break;
// stop before going above the body, up into the head
// return the last visible streamer position
if (currentNode->hasTagName(bodyTag) && currentPos.atEndOfNode())
break;
// Do not enter a new enclosing block flow or table element, and don't leave the original one.
if (block != enclosingBlock(currentNode))
return lastVisible;
// skip position in unrendered or invisible node
RenderObject* renderer = currentNode->renderer();
if (!renderer || renderer->style()->visibility() != VISIBLE)
continue;
// track last visible streamer position
if (isStreamer(currentPos))
lastVisible = currentPos;
// Return position before brs, tables, and nodes which have content that can be ignored.
if (editingIgnoresContent(currentNode) || renderer->isBR() || isTableElement(currentNode)) {
if (currentPos.offsetInLeafNode() <= renderer->caretMinOffset())
return Position(currentNode, renderer->caretMinOffset());
continue;
}
// return current position if it is in rendered text
if (renderer->isText() && static_cast<RenderText*>(renderer)->firstTextBox()) {
if (currentNode != startNode) {
ASSERT(currentPos.atStartOfNode());
return Position(currentNode, renderer->caretMinOffset());
}
unsigned textOffset = currentPos.offsetInLeafNode();
RenderText* textRenderer = static_cast<RenderText*>(renderer);
for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
if (textOffset >= box->start() && textOffset <= box->end())
return currentPos;
if (box != textRenderer->lastTextBox() &&
!box->nextOnLine() &&
textOffset == box->start() + box->len()) {
return currentPos;
}
}
}
}
return lastVisible;
}
// p.upstream() returns the start of the range of positions that map to the same VisiblePosition as P.
Position Position::upstream() const
{
Node* startNode = node();
if (!startNode)
return Position();
// iterate backward from there, looking for a qualified position
Node* block = enclosingBlock(startNode);
PositionIterator lastVisible = *this;
PositionIterator currentPos = lastVisible;
Node* originalRoot = node()->rootEditableElement();
for (; !currentPos.atStart(); currentPos.decrement()) {
Node* currentNode = currentPos.node();
if (currentNode->rootEditableElement() != originalRoot)
break;
// Don't enter a new enclosing block flow or table element. There is code below that
// terminates early if we're about to leave an enclosing block flow or table element.
if (block != enclosingBlock(currentNode))
return lastVisible;
// skip position in unrendered or invisible node
RenderObject* renderer = currentNode->renderer();
if (!renderer || renderer->style()->visibility() != VISIBLE)
continue;
// track last visible streamer position
if (isStreamer(currentPos))
lastVisible = currentPos;
// Don't leave a block flow or table element. We could rely on code above to terminate and
// return lastVisible on the next iteration, but we terminate early.
if (currentNode == enclosingBlock(currentNode) && currentPos.atStartOfNode())
return lastVisible;
// Return position after brs, tables, and nodes which have content that can be ignored.
if (editingIgnoresContent(currentNode) || renderer->isBR() || isTableElement(currentNode)) {
if (currentPos.atEndOfNode())
return Position(currentNode, maxDeepOffset(currentNode));
continue;
}
// return current position if it is in rendered text
if (renderer->isText() && static_cast<RenderText*>(renderer)->firstTextBox()) {
if (currentNode != startNode) {
// This assertion fires in layout tests in the case-transform.html test because
// of a mix-up between offsets in the text in the DOM tree with text in the
// render tree which can have a different length due to case transformation.
// Until we resolve that, disable this so we can run the layout tests!
//ASSERT(currentOffset >= renderer->caretMaxOffset());
return Position(currentNode, renderer->caretMaxOffset());
}
unsigned textOffset = currentPos.offsetInLeafNode();
RenderText* textRenderer = static_cast<RenderText*>(renderer);
for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
if (textOffset > box->start() && textOffset <= box->start() + box->len())
return currentPos;
if (box != textRenderer->lastTextBox() &&
!box->nextOnLine() &&
textOffset == box->start() + box->len() + 1)
return currentPos;
}
}
}
return lastVisible;
}
