C++ HyperTextAccessible::GetChildOffset方法代码示例

void
EventQueue::CreateTextChangeEventFor(AccMutationEvent* aEvent)
{
    Accessible* container = aEvent->mAccessible->Parent();
    if (!container)
        return;

    HyperTextAccessible* textAccessible = container->AsHyperText();
    if (!textAccessible)
        return;

    // Don't fire event for the first html:br in an editor.
    if (aEvent->mAccessible->Role() == roles::WHITESPACE) {
        nsCOMPtr<nsIEditor> editor = textAccessible->GetEditor();
        if (editor) {
            bool isEmpty = false;
            editor->GetDocumentIsEmpty(&isEmpty);
            if (isEmpty)
                return;
        }
    }

    int32_t offset = textAccessible->GetChildOffset(aEvent->mAccessible);

    nsAutoString text;
    aEvent->mAccessible->AppendTextTo(text);
    if (text.IsEmpty())
        return;

    aEvent->mTextChangeEvent =
        new AccTextChangeEvent(textAccessible, offset, text, aEvent->IsShow(),
                               aEvent->mIsFromUserInput ? eFromUserInput : eNoUserInput);
}

NS_IMETHODIMP
nsAccessiblePivot::MovePreviousByText(TextBoundaryType aBoundary, bool* aResult)
{
  NS_ENSURE_ARG(aResult);

  *aResult = false;

  int32_t oldStart = mStartOffset, oldEnd = mEndOffset;
  HyperTextAccessible* text = mPosition->AsHyperText();
  Accessible* oldPosition = mPosition;
  while (!text) {
    oldPosition = mPosition;
    mPosition = mPosition->Parent();
    text = mPosition->AsHyperText();
  }

  if (mStartOffset == -1)
    mStartOffset = text != oldPosition ? text->GetChildOffset(oldPosition) : 0;

  if (mStartOffset == 0)
    return NS_OK;

  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;
  text->GetTextBeforeOffset(mStartOffset, startBoundary, &newStart, &newEnd,
                            unusedText);
  if (newStart < mStartOffset)
    mStartOffset = newEnd == mStartOffset ? newStart : newEnd;
  else // XXX: In certain odd cases newStart is equal to mStartOffset
    text->GetTextBeforeOffset(mStartOffset - 1, startBoundary, &newStart,
                              &mStartOffset, unusedText);
  text->GetTextAtOffset(mStartOffset, endBoundary, &newStart, &mEndOffset,
                        unusedText);

  *aResult = true;

  NotifyOfPivotChange(mPosition, oldStart, oldEnd,
                      nsIAccessiblePivot::REASON_TEXT);
  return NS_OK;
}

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);
//.........这里部分代码省略.........