Accessible*
nsAccessiblePivot::AdjustStartPosition(Accessible* aAccessible,
RuleCache& aCache,
uint16_t* aFilterResult,
nsresult* aResult)
{
Accessible* matched = aAccessible;
*aResult = aCache.ApplyFilter(aAccessible, aFilterResult);
if (aAccessible != mRoot && aAccessible != mModalRoot) {
for (Accessible* temp = aAccessible->Parent();
temp && temp != mRoot && temp != mModalRoot; temp = temp->Parent()) {
uint16_t filtered = nsIAccessibleTraversalRule::FILTER_IGNORE;
*aResult = aCache.ApplyFilter(temp, &filtered);
NS_ENSURE_SUCCESS(*aResult, nullptr);
if (filtered & nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE) {
*aFilterResult = filtered;
matched = temp;
}
}
}
if (aAccessible == mPosition && mStartOffset != -1 && mEndOffset != -1) {
HyperTextAccessible* text = aAccessible->AsHyperText();
if (text) {
matched = text->GetChildAtOffset(mStartOffset);
}
}
return matched;
}
NS_IMETHODIMP
nsAccessiblePivot::MovePreviousByText(TextBoundaryType aBoundary, bool* aResult)
{
NS_ENSURE_ARG(aResult);
*aResult = false;
int32_t tempStart = mStartOffset, tempEnd = mEndOffset;
Accessible* tempPosition = mPosition;
Accessible* root = GetActiveRoot();
while (true) {
Accessible* curPosition = tempPosition;
HyperTextAccessible* text;
// Find the nearest text node using a reverse preorder traversal starting
// from the current node.
if (!(text = tempPosition->AsHyperText())) {
text = SearchForText(tempPosition, true);
if (!text)
return NS_OK;
if (text != curPosition)
tempStart = tempEnd = -1;
tempPosition = text;
}
// If the search led to the parent of the node we started on (e.g. when
// starting on a text leaf), start the text movement from the end of that
// node, otherwise we just default to 0.
if (tempStart == -1) {
if (tempPosition != curPosition)
tempStart = text == curPosition->Parent() ?
text->GetChildOffset(curPosition) : text->CharacterCount();
else
tempStart = 0;
}
// If there's no more text on the current node, try to find the previous
// text node; if there isn't one, bail out.
if (tempStart == 0) {
if (tempPosition == root)
return NS_OK;
// If we're currently sitting on a link, try move to either the previous
// sibling or the parent, whichever is closer to the current end
// offset. Otherwise, do a forward search for the next node to land on
// (we don't do this in the first case because we don't want to go to the
// subtree).
Accessible* sibling = tempPosition->PrevSibling();
if (tempPosition->IsLink()) {
if (sibling && sibling->IsLink()) {
HyperTextAccessible* siblingText = sibling->AsHyperText();
tempStart = tempEnd = siblingText ?
siblingText->CharacterCount() : -1;
tempPosition = sibling;
} else {
tempStart = tempPosition->StartOffset();
tempEnd = tempPosition->EndOffset();
tempPosition = tempPosition->Parent();
}
} else {
HyperTextAccessible* tempText = SearchForText(tempPosition, true);
if (!tempText)
return NS_OK;
tempPosition = tempText;
tempStart = tempEnd = tempText->CharacterCount();
}
continue;
}
AccessibleTextBoundary startBoundary, endBoundary;
switch (aBoundary) {
case CHAR_BOUNDARY:
startBoundary = nsIAccessibleText::BOUNDARY_CHAR;
endBoundary = nsIAccessibleText::BOUNDARY_CHAR;
break;
case WORD_BOUNDARY:
startBoundary = nsIAccessibleText::BOUNDARY_WORD_START;
endBoundary = nsIAccessibleText::BOUNDARY_WORD_END;
break;
default:
return NS_ERROR_INVALID_ARG;
}
nsAutoString unusedText;
int32_t newStart = 0, newEnd = 0, currentStart = tempStart, potentialEnd = 0;
text->TextBeforeOffset(tempStart, startBoundary, &newStart, &newEnd, unusedText);
if (newStart < tempStart)
tempStart = newEnd >= currentStart ? newStart : newEnd;
else // XXX: In certain odd cases newStart is equal to tempStart
text->TextBeforeOffset(tempStart - 1, startBoundary, &newStart,
&tempStart, unusedText);
text->TextAtOffset(tempStart, endBoundary, &newStart, &potentialEnd,
unusedText);
tempEnd = potentialEnd < tempEnd ? potentialEnd : currentStart;
// The offset range we've obtained might have embedded characters in it,
// limit the range to the start of the last occurrence of an embedded
// character.
Accessible* childAtOffset = nullptr;
for (int32_t i = tempEnd - 1; i >= tempStart; i--) {
childAtOffset = text->GetChildAtOffset(i);
if (childAtOffset && nsAccUtils::IsEmbeddedObject(childAtOffset)) {
tempStart = childAtOffset->EndOffset();
break;
}
}
// If there's an embedded character at the very end of the range, we
// instead want to traverse into it. So restart the movement with
// the child as the starting point.
if (childAtOffset && nsAccUtils::IsEmbeddedObject(childAtOffset) &&
tempEnd == static_cast<int32_t>(childAtOffset->EndOffset())) {
tempPosition = childAtOffset;
tempStart = tempEnd = childAtOffset->AsHyperText()->CharacterCount();
continue;
}
*aResult = true;
Accessible* startPosition = mPosition;
int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
mPosition = tempPosition;
mStartOffset = tempStart;
mEndOffset = tempEnd;
NotifyOfPivotChange(startPosition, oldStart, oldEnd,
nsIAccessiblePivot::REASON_TEXT);
return NS_OK;
}
}