C++ Accessible::HasChildren方法代码示例

NS_IMETHODIMP
nsAccessiblePivot::MoveLast(nsIAccessibleTraversalRule* aRule,
                            bool* aResult)
{
  NS_ENSURE_ARG(aResult);
  NS_ENSURE_ARG(aRule);

  Accessible* root = GetActiveRoot();
  NS_ENSURE_TRUE(root && !root->IsDefunct(), NS_ERROR_NOT_IN_TREE);

  *aResult = false;
  nsresult rv = NS_OK;
  Accessible* lastAccessible = root;
  Accessible* accessible = nullptr;

  // First go to the last accessible in pre-order
  while (lastAccessible->HasChildren())
    lastAccessible = lastAccessible->LastChild();

  // Search backwards from last accessible and find the last occurrence in the doc
  accessible = SearchBackward(lastAccessible, aRule, true, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  if (accessible)
    *aResult = MovePivotInternal(accessible, nsAccessiblePivot::REASON_LAST);

  return NS_OK;
}

bool
HTMLTableAccessible::IsProbablyLayoutTable()
{
  // Implement a heuristic to determine if table is most likely used for layout
  // XXX do we want to look for rowspan or colspan, especialy that span all but a couple cells
  // at the beginning or end of a row/col, and especially when they occur at the edge of a table?
  // XXX expose this info via object attributes to AT-SPI

  // XXX For now debugging descriptions are always on via SHOW_LAYOUT_HEURISTIC
  // This will allow release trunk builds to be used by testers to refine the algorithm
  // Change to |#define SHOW_LAYOUT_HEURISTIC DEBUG| before final release
#ifdef SHOW_LAYOUT_HEURISTIC
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) \
  { \
    mLayoutHeuristic = isLayout ? \
      NS_LITERAL_STRING("layout table: " heuristic) : \
      NS_LITERAL_STRING("data table: " heuristic); \
    return isLayout; \
  }
#else
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) { return isLayout; }
#endif

  DocAccessible* docAccessible = Document();
  if (docAccessible) {
    uint64_t docState = docAccessible->State();
    if (docState & states::EDITABLE) {  // Need to see all elements while document is being edited
      RETURN_LAYOUT_ANSWER(false, "In editable document");
    }
  }

  // Check to see if an ARIA role overrides the role from native markup,
  // but for which we still expose table semantics (treegrid, for example).
  if (Role() != roles::TABLE)
    RETURN_LAYOUT_ANSWER(false, "Has role attribute");

  if (mContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::role)) {
    // Role attribute is present, but overridden roles have already been dealt with.
    // Only landmarks and other roles that don't override the role from native
    // markup are left to deal with here.
    RETURN_LAYOUT_ANSWER(false, "Has role attribute, weak role, and role is table");
  }

  NS_ASSERTION(mContent->IsHTMLElement(nsGkAtoms::table),
    "table should not be built by CSS display:table style");

  // Check if datatable attribute has "0" value.
  if (mContent->AsElement()->AttrValueIs(kNameSpaceID_None, nsGkAtoms::datatable,
                            NS_LITERAL_STRING("0"), eCaseMatters)) {
    RETURN_LAYOUT_ANSWER(true, "Has datatable = 0 attribute, it's for layout");
  }

  // Check for legitimate data table attributes.
  nsAutoString summary;
  if (mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::summary, summary) &&
      !summary.IsEmpty())
    RETURN_LAYOUT_ANSWER(false, "Has summary -- legitimate table structures");

  // Check for legitimate data table elements.
  Accessible* caption = FirstChild();
  if (caption && caption->Role() == roles::CAPTION && caption->HasChildren())
    RETURN_LAYOUT_ANSWER(false, "Not empty caption -- legitimate table structures");

  for (nsIContent* childElm = mContent->GetFirstChild(); childElm;
       childElm = childElm->GetNextSibling()) {
    if (!childElm->IsHTMLElement())
      continue;

    if (childElm->IsAnyOfHTMLElements(nsGkAtoms::col,
                                      nsGkAtoms::colgroup,
                                      nsGkAtoms::tfoot,
                                      nsGkAtoms::thead)) {
      RETURN_LAYOUT_ANSWER(false,
                           "Has col, colgroup, tfoot or thead -- legitimate table structures");
    }

    if (childElm->IsHTMLElement(nsGkAtoms::tbody)) {
      for (nsIContent* rowElm = childElm->GetFirstChild(); rowElm;
           rowElm = rowElm->GetNextSibling()) {
        if (rowElm->IsHTMLElement(nsGkAtoms::tr)) {
          for (nsIContent* cellElm = rowElm->GetFirstChild(); cellElm;
               cellElm = cellElm->GetNextSibling()) {
            if (cellElm->IsHTMLElement()) {

              if (cellElm->NodeInfo()->Equals(nsGkAtoms::th)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has th -- legitimate table structures");
              }

              if (cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::headers) ||
                  cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::scope) ||
                  cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::abbr)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has headers, scope, or abbr attribute -- legitimate table structures");
              }

              Accessible* cell = mDoc->GetAccessible(cellElm);
              if (cell && cell->ChildCount() == 1 &&
                  cell->FirstChild()->IsAbbreviation()) {
                RETURN_LAYOUT_ANSWER(false,
//.........这里部分代码省略.........

bool
TableAccessible::IsProbablyLayoutTable()
{
  // Implement a heuristic to determine if table is most likely used for layout.

  // XXX do we want to look for rowspan or colspan, especialy that span all but
  // a couple cells  at the beginning or end of a row/col, and especially when
  // they occur at the edge of a table?

  // XXX For now debugging descriptions are always on via SHOW_LAYOUT_HEURISTIC
  // This will allow release trunk builds to be used by testers to refine
  // the algorithm. Integrate it into Logging.
  // Change to |#define SHOW_LAYOUT_HEURISTIC DEBUG| before final release
#ifdef SHOW_LAYOUT_HEURISTIC
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) \
  { \
    mLayoutHeuristic = isLayout ? \
      NS_LITERAL_STRING("layout table: " heuristic) : \
      NS_LITERAL_STRING("data table: " heuristic); \
    return isLayout; \
  }
#else
#define RETURN_LAYOUT_ANSWER(isLayout, heuristic) { return isLayout; }
#endif

  Accessible* thisacc = AsAccessible();

  // Need to see all elements while document is being edited.
  if (thisacc->Document()->State() & states::EDITABLE) {
    RETURN_LAYOUT_ANSWER(false, "In editable document");
  }

  // Check to see if an ARIA role overrides the role from native markup,
  // but for which we still expose table semantics (treegrid, for example).
  if (thisacc->HasARIARole()) {
    RETURN_LAYOUT_ANSWER(false, "Has role attribute");
  }

  dom::Element* el = thisacc->Elm();
  if (el->IsMathMLElement(nsGkAtoms::mtable_)) {
    RETURN_LAYOUT_ANSWER(false, "MathML matrix");
  }

  MOZ_ASSERT(el->IsHTMLElement(nsGkAtoms::table),
             "Table should not be built by CSS display:table style");

  // Check if datatable attribute has "0" value.
  if (el->AttrValueIs(kNameSpaceID_None, nsGkAtoms::datatable,
                      NS_LITERAL_STRING("0"), eCaseMatters)) {
    RETURN_LAYOUT_ANSWER(true, "Has datatable = 0 attribute, it's for layout");
  }

  // Check for legitimate data table attributes.
  nsAutoString summary;
  if (el->GetAttr(kNameSpaceID_None, nsGkAtoms::summary, summary) &&
      !summary.IsEmpty()) {
    RETURN_LAYOUT_ANSWER(false, "Has summary -- legitimate table structures");
  }

  // Check for legitimate data table elements.
  Accessible* caption = thisacc->FirstChild();
  if (caption && caption->IsHTMLCaption() && caption->HasChildren()) {
    RETURN_LAYOUT_ANSWER(false, "Not empty caption -- legitimate table structures");
  }

  for (nsIContent* childElm = el->GetFirstChild(); childElm;
       childElm = childElm->GetNextSibling()) {
    if (!childElm->IsHTMLElement())
      continue;

    if (childElm->IsAnyOfHTMLElements(nsGkAtoms::col,
                                      nsGkAtoms::colgroup,
                                      nsGkAtoms::tfoot,
                                      nsGkAtoms::thead)) {
      RETURN_LAYOUT_ANSWER(false,
                           "Has col, colgroup, tfoot or thead -- legitimate table structures");
    }

    if (childElm->IsHTMLElement(nsGkAtoms::tbody)) {
      for (nsIContent* rowElm = childElm->GetFirstChild(); rowElm;
           rowElm = rowElm->GetNextSibling()) {
        if (rowElm->IsHTMLElement(nsGkAtoms::tr)) {
          for (nsIContent* cellElm = rowElm->GetFirstChild(); cellElm;
               cellElm = cellElm->GetNextSibling()) {
            if (cellElm->IsHTMLElement()) {

              if (cellElm->NodeInfo()->Equals(nsGkAtoms::th)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has th -- legitimate table structures");
              }

              if (cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::headers) ||
                  cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::scope) ||
                  cellElm->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::abbr)) {
                RETURN_LAYOUT_ANSWER(false,
                                     "Has headers, scope, or abbr attribute -- legitimate table structures");
              }

              Accessible* cell = thisacc->Document()->GetAccessible(cellElm);
              if (cell && cell->ChildCount() == 1 &&
//.........这里部分代码省略.........