C++ Accessible::IsText方法代码示例

bool
nsAccUtils::IsTextInterfaceSupportCorrect(Accessible* aAccessible)
{
  // Don't test for accessible docs, it makes us create accessibles too
  // early and fire mutation events before we need to
  if (aAccessible->IsDoc())
    return true;

  bool foundText = false;
  uint32_t childCount = aAccessible->ChildCount();
  for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
    Accessible* child = aAccessible->GetChildAt(childIdx);
    if (child->IsText()) {
      foundText = true;
      break;
    }
  }

  return !foundText || aAccessible->IsHyperText();
}

void
TextAttrsMgr::GetAttributes(nsIPersistentProperties* aAttributes,
                            uint32_t* aStartOffset,
                            uint32_t* aEndOffset)
{
  // 1. Hyper text accessible must be specified always.
  // 2. Offset accessible and result hyper text offsets must be specified in
  // the case of text attributes.
  // 3. Offset accessible and result hyper text offsets must not be specified
  // but include default text attributes flag and attributes list must be
  // specified in the case of default text attributes.
  NS_PRECONDITION(mHyperTextAcc &&
                  ((mOffsetAcc && mOffsetAccIdx != -1 &&
                    aStartOffset && aEndOffset) ||
                  (!mOffsetAcc && mOffsetAccIdx == -1 &&
                    !aStartOffset && !aEndOffset &&
                   mIncludeDefAttrs && aAttributes)),
                  "Wrong usage of TextAttrsMgr!");

  // Embedded objects are combined into own range with empty attributes set.
  if (mOffsetAcc && !mOffsetAcc->IsText()) {
    for (int32_t childIdx = mOffsetAccIdx - 1; childIdx >= 0; childIdx--) {
      Accessible* currAcc = mHyperTextAcc->GetChildAt(childIdx);
      if (currAcc->IsText())
        break;

      (*aStartOffset)--;
    }

    uint32_t childCount = mHyperTextAcc->ChildCount();
    for (uint32_t childIdx = mOffsetAccIdx + 1; childIdx < childCount;
         childIdx++) {
      Accessible* currAcc = mHyperTextAcc->GetChildAt(childIdx);
      if (currAcc->IsText())
        break;

      (*aEndOffset)++;
    }

    return;
  }

  // Get the content and frame of the accessible. In the case of document
  // accessible it's role content and root frame.
  nsIContent* hyperTextElm = mHyperTextAcc->GetContent();
  if (!hyperTextElm)
    return; // XXX: we don't support text attrs on document with no body

  nsIFrame* rootFrame = mHyperTextAcc->GetFrame();
  MOZ_ASSERT(rootFrame, "No frame for accessible!");
  if (!rootFrame)
    return;

  nsIContent *offsetNode = nullptr, *offsetElm = nullptr;
  nsIFrame *frame = nullptr;
  if (mOffsetAcc) {
    offsetNode = mOffsetAcc->GetContent();
    offsetElm = nsCoreUtils::GetDOMElementFor(offsetNode);
    MOZ_ASSERT(offsetElm, "No element for offset accessible!");
    if (!offsetElm)
      return;

    frame = offsetElm->GetPrimaryFrame();
  }

  // "language" text attribute
  LangTextAttr langTextAttr(mHyperTextAcc, hyperTextElm, offsetNode);

  // "aria-invalid" text attribute
  InvalidTextAttr invalidTextAttr(hyperTextElm, offsetNode);

  // "background-color" text attribute
  BGColorTextAttr bgColorTextAttr(rootFrame, frame);

  // "color" text attribute
  ColorTextAttr colorTextAttr(rootFrame, frame);

  // "font-family" text attribute
  FontFamilyTextAttr fontFamilyTextAttr(rootFrame, frame);

  // "font-size" text attribute
  FontSizeTextAttr fontSizeTextAttr(rootFrame, frame);

  // "font-style" text attribute
  FontStyleTextAttr fontStyleTextAttr(rootFrame, frame);

  // "font-weight" text attribute
  FontWeightTextAttr fontWeightTextAttr(rootFrame, frame);

  // "auto-generated" text attribute
  AutoGeneratedTextAttr autoGenTextAttr(mHyperTextAcc, mOffsetAcc);

  // "text-underline(line-through)-style(color)" text attributes
  TextDecorTextAttr textDecorTextAttr(rootFrame, frame);

  // "text-position" text attribute
  TextPosTextAttr textPosTextAttr(rootFrame, frame);

  TextAttr* attrArray[] =
  {
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        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 && !childAtOffset->IsText()) {
        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 && !childAtOffset->IsText() &&
        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,
                        (aArgc > 0) ? aIsFromUserInput : true);
    return NS_OK;
  }
}