static Position previousIfPositionIsAfterLineBreak(const Position& position, HTMLElement* innerEditor)
{
if (position.isNull())
return Position();
// Move back if position is just after line break.
if (isHTMLBRElement(*position.anchorNode())) {
if (position.isAfterAnchor())
return Position(position.anchorNode(), PositionAnchorType::BeforeAnchor);
if (position.isBeforeAnchor())
return previousIfPositionIsAfterLineBreak(endOfPrevious(*position.anchorNode(), innerEditor), innerEditor);
// We don't place caret into BR element, since well-formed BR element
// doesn't have child nodes.
ASSERT_NOT_REACHED();
return position;
}
if (!position.anchorNode()->isTextNode())
return position;
Text* textNode = toText(position.anchorNode());
unsigned offset = position.offsetInContainerNode();
if (textNode->length() == 0 || offset == 0)
return previousIfPositionIsAfterLineBreak(endOfPrevious(*position.anchorNode(), innerEditor), innerEditor);
if (offset <= textNode->length() && textNode->data()[offset - 1] == '\n')
return Position(textNode, offset - 1);
return position;
}
static Position previousIfPositionIsAfterLineBreak(const Position& position, HTMLElement* innerEditor)
{
if (position.isNull())
return Position();
// Move back if position is just after line break.
if (isHTMLBRElement(*position.anchorNode())) {
switch (position.anchorType()) {
case Position::PositionIsAfterAnchor:
return Position(position.anchorNode(), Position::PositionIsBeforeAnchor);
case Position::PositionIsBeforeAnchor:
return previousIfPositionIsAfterLineBreak(endOfPrevious(*position.anchorNode(), innerEditor), innerEditor);
default:
ASSERT_NOT_REACHED();
}
} else if (position.anchorNode()->isTextNode()) {
Text* textNode = toText(position.anchorNode());
unsigned offset = position.offsetInContainerNode();
if (textNode->length() == 0 || offset == 0) {
return previousIfPositionIsAfterLineBreak(endOfPrevious(*position.anchorNode(), innerEditor), innerEditor);
}
if (offset <= textNode->length() && textNode->data()[offset - 1] == '\n') {
return Position(textNode, offset - 1);
}
}
return position;
}
Position HTMLTextFormControlElement::startOfSentence(const Position& position)
{
HTMLTextFormControlElement* textFormControl = enclosingTextFormControl(position);
ASSERT(textFormControl);
HTMLElement* innerEditor = textFormControl->innerEditorElement();
if (!innerEditor->childNodes()->length())
return startOfInnerText(textFormControl);
const Position innerPosition = position.anchorNode() == innerEditor ? innerNodePosition(position) : position;
const Position pivotPosition = previousIfPositionIsAfterLineBreak(innerPosition, innerEditor);
if (pivotPosition.isNull())
return startOfInnerText(textFormControl);
for (Node* node = pivotPosition.anchorNode(); node; node = NodeTraversal::previous(*node, innerEditor)) {
bool isPivotNode = (node == pivotPosition.anchorNode());
if (isHTMLBRElement(node) && (!isPivotNode || pivotPosition.isAfterAnchor()))
return Position(node, PositionAnchorType::AfterAnchor);
if (node->isTextNode()) {
Text* textNode = toText(node);
size_t lastLineBreak = textNode->data().substring(0, isPivotNode ? pivotPosition.offsetInContainerNode() : textNode->length()).reverseFind('\n');
if (lastLineBreak != kNotFound)
return Position(textNode, lastLineBreak + 1);
}
}
return startOfInnerText(textFormControl);
}