Exemplo n.º 1
0
nsresult
AccessibleWrap::HandleAccEvent(AccEvent* aEvent)
{
  nsresult rv = Accessible::HandleAccEvent(aEvent);
  NS_ENSURE_SUCCESS(rv, rv);

    Accessible* accessible = aEvent->GetAccessible();
    NS_ENSURE_TRUE(accessible, NS_ERROR_FAILURE);

    // The accessible can become defunct if we have an xpcom event listener
    // which decides it would be fun to change the DOM and flush layout.
    if (accessible->IsDefunct())
        return NS_OK;

    uint32_t type = aEvent->GetEventType();

    AtkObject* atkObj = AccessibleWrap::GetAtkObject(accessible);

  // We don't create ATK objects for plain text leaves, just return NS_OK in
  // such case.
    if (!atkObj) {
        NS_ASSERTION(type == nsIAccessibleEvent::EVENT_SHOW ||
                     type == nsIAccessibleEvent::EVENT_HIDE,
                     "Event other than SHOW and HIDE fired for plain text leaves");
        return NS_OK;
    }

    AccessibleWrap* accWrap = GetAccessibleWrap(atkObj);
    if (!accWrap) {
        return NS_OK; // Node is shut down
    }

    switch (type) {
    case nsIAccessibleEvent::EVENT_STATE_CHANGE:
      {
        AccStateChangeEvent* event = downcast_accEvent(aEvent);
        MAI_ATK_OBJECT(atkObj)->FireStateChangeEvent(event->GetState(),
                                                     event->IsStateEnabled());
        break;
      }

    case nsIAccessibleEvent::EVENT_TEXT_REMOVED:
    case nsIAccessibleEvent::EVENT_TEXT_INSERTED:
        return FireAtkTextChangedEvent(aEvent, atkObj);

    case nsIAccessibleEvent::EVENT_FOCUS:
      {
        a11y::RootAccessible* rootAccWrap = accWrap->RootAccessible();
        if (rootAccWrap && rootAccWrap->mActivated) {
            atk_focus_tracker_notify(atkObj);
            // Fire state change event for focus
            atk_object_notify_state_change(atkObj, ATK_STATE_FOCUSED, true);
            return NS_OK;
        }
      } break;

    case nsIAccessibleEvent::EVENT_NAME_CHANGE:
      {
        nsAutoString newName;
        accessible->Name(newName);

        MaybeFireNameChange(atkObj, newName);

        break;
      }

  case nsIAccessibleEvent::EVENT_VALUE_CHANGE:
    if (accessible->HasNumericValue()) {
      // Make sure this is a numeric value. Don't fire for string value changes
      // (e.g. text editing) ATK values are always numeric.
      g_object_notify((GObject*)atkObj, "accessible-value");
    }
    break;

    case nsIAccessibleEvent::EVENT_SELECTION:
    case nsIAccessibleEvent::EVENT_SELECTION_ADD:
    case nsIAccessibleEvent::EVENT_SELECTION_REMOVE:
    {
      // XXX: dupe events may be fired
      AccSelChangeEvent* selChangeEvent = downcast_accEvent(aEvent);
      g_signal_emit_by_name(AccessibleWrap::GetAtkObject(selChangeEvent->Widget()),
                            "selection_changed");
      break;
    }

    case nsIAccessibleEvent::EVENT_SELECTION_WITHIN:
    {
      g_signal_emit_by_name(atkObj, "selection_changed");
      break;
    }

    case nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED:
        g_signal_emit_by_name(atkObj, "text_selection_changed");
        break;

    case nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED:
      {
        AccCaretMoveEvent* caretMoveEvent = downcast_accEvent(aEvent);
        NS_ASSERTION(caretMoveEvent, "Event needs event data");
        if (!caretMoveEvent)
            break;

        int32_t caretOffset = caretMoveEvent->GetCaretOffset();
        g_signal_emit_by_name(atkObj, "text_caret_moved", caretOffset);
      } break;

    case nsIAccessibleEvent::EVENT_TEXT_ATTRIBUTE_CHANGED:
        g_signal_emit_by_name(atkObj, "text-attributes-changed");
        break;

    case nsIAccessibleEvent::EVENT_TABLE_MODEL_CHANGED:
        g_signal_emit_by_name(atkObj, "model_changed");
        break;

    case nsIAccessibleEvent::EVENT_TABLE_ROW_INSERT:
      {
        AccTableChangeEvent* tableEvent = downcast_accEvent(aEvent);
        NS_ENSURE_TRUE(tableEvent, NS_ERROR_FAILURE);

        int32_t rowIndex = tableEvent->GetIndex();
        int32_t numRows = tableEvent->GetCount();

        g_signal_emit_by_name(atkObj, "row_inserted", rowIndex, numRows);
     } break;

   case nsIAccessibleEvent::EVENT_TABLE_ROW_DELETE:
     {
        AccTableChangeEvent* tableEvent = downcast_accEvent(aEvent);
        NS_ENSURE_TRUE(tableEvent, NS_ERROR_FAILURE);

        int32_t rowIndex = tableEvent->GetIndex();
        int32_t numRows = tableEvent->GetCount();

        g_signal_emit_by_name(atkObj, "row_deleted", rowIndex, numRows);
      } break;

    case nsIAccessibleEvent::EVENT_TABLE_ROW_REORDER:
      {
        g_signal_emit_by_name(atkObj, "row_reordered");
        break;
      }

    case nsIAccessibleEvent::EVENT_TABLE_COLUMN_INSERT:
      {
        AccTableChangeEvent* tableEvent = downcast_accEvent(aEvent);
        NS_ENSURE_TRUE(tableEvent, NS_ERROR_FAILURE);

        int32_t colIndex = tableEvent->GetIndex();
        int32_t numCols = tableEvent->GetCount();
        g_signal_emit_by_name(atkObj, "column_inserted", colIndex, numCols);
      } break;

    case nsIAccessibleEvent::EVENT_TABLE_COLUMN_DELETE:
      {
        AccTableChangeEvent* tableEvent = downcast_accEvent(aEvent);
        NS_ENSURE_TRUE(tableEvent, NS_ERROR_FAILURE);

        int32_t colIndex = tableEvent->GetIndex();
        int32_t numCols = tableEvent->GetCount();
        g_signal_emit_by_name(atkObj, "column_deleted", colIndex, numCols);
      } break;

    case nsIAccessibleEvent::EVENT_TABLE_COLUMN_REORDER:
        g_signal_emit_by_name(atkObj, "column_reordered");
        break;

    case nsIAccessibleEvent::EVENT_SECTION_CHANGED:
        g_signal_emit_by_name(atkObj, "visible_data_changed");
        break;

    case nsIAccessibleEvent::EVENT_SHOW:
        return FireAtkShowHideEvent(aEvent, atkObj, true);

    case nsIAccessibleEvent::EVENT_HIDE:
        // XXX - Handle native dialog accessibles.
        if (!accessible->IsRoot() && accessible->HasARIARole() &&
            accessible->ARIARole() == roles::DIALOG) {
          guint id = g_signal_lookup("deactivate", MAI_TYPE_ATK_OBJECT);
          g_signal_emit(atkObj, id, 0);
        }
        return FireAtkShowHideEvent(aEvent, atkObj, false);

        /*
         * Because dealing with menu is very different between nsIAccessible
         * and ATK, and the menu activity is important, specially transfer the
         * following two event.
         * Need more verification by AT test.
         */
    case nsIAccessibleEvent::EVENT_MENU_START:
    case nsIAccessibleEvent::EVENT_MENU_END:
        break;

    case nsIAccessibleEvent::EVENT_WINDOW_ACTIVATE:
      {
        accessible->AsRoot()->mActivated = true;
        guint id = g_signal_lookup("activate", MAI_TYPE_ATK_OBJECT);
        g_signal_emit(atkObj, id, 0);

        // Always fire a current focus event after activation.
        FocusMgr()->ForceFocusEvent();
      } break;

    case nsIAccessibleEvent::EVENT_WINDOW_DEACTIVATE:
      {
        accessible->AsRoot()->mActivated = false;
        guint id = g_signal_lookup("deactivate", MAI_TYPE_ATK_OBJECT);
        g_signal_emit(atkObj, id, 0);
      } break;

    case nsIAccessibleEvent::EVENT_WINDOW_MAXIMIZE:
      {
        guint id = g_signal_lookup("maximize", MAI_TYPE_ATK_OBJECT);
        g_signal_emit(atkObj, id, 0);
      } break;

    case nsIAccessibleEvent::EVENT_WINDOW_MINIMIZE:
      {
        guint id = g_signal_lookup("minimize", MAI_TYPE_ATK_OBJECT);
        g_signal_emit(atkObj, id, 0);
      } break;

    case nsIAccessibleEvent::EVENT_WINDOW_RESTORE:
      {
        guint id = g_signal_lookup("restore", MAI_TYPE_ATK_OBJECT);
        g_signal_emit(atkObj, id, 0);
      } break;

    case nsIAccessibleEvent::EVENT_DOCUMENT_LOAD_COMPLETE:
        g_signal_emit_by_name (atkObj, "load_complete");
        // XXX - Handle native dialog accessibles.
        if (!accessible->IsRoot() && accessible->HasARIARole() &&
            accessible->ARIARole() == roles::DIALOG) {
          guint id = g_signal_lookup("activate", MAI_TYPE_ATK_OBJECT);
          g_signal_emit(atkObj, id, 0);
        }
      break;

    case nsIAccessibleEvent::EVENT_DOCUMENT_RELOAD:
        g_signal_emit_by_name (atkObj, "reload");
      break;

    case nsIAccessibleEvent::EVENT_DOCUMENT_LOAD_STOPPED:
        g_signal_emit_by_name (atkObj, "load_stopped");
      break;

    case nsIAccessibleEvent::EVENT_MENUPOPUP_START:
        atk_focus_tracker_notify(atkObj); // fire extra focus event
        atk_object_notify_state_change(atkObj, ATK_STATE_VISIBLE, true);
        atk_object_notify_state_change(atkObj, ATK_STATE_SHOWING, true);
        break;

    case nsIAccessibleEvent::EVENT_MENUPOPUP_END:
        atk_object_notify_state_change(atkObj, ATK_STATE_VISIBLE, false);
        atk_object_notify_state_change(atkObj, ATK_STATE_SHOWING, false);
        break;
    }

    return NS_OK;
}
Exemplo n.º 2
0
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 &&
                  cell->FirstChild()->IsAbbreviation()) {
                RETURN_LAYOUT_ANSWER(false,
                                     "has abbr -- legitimate table structures");
              }
            }
          }
        }
      }
    }
  }

  // Check for nested tables.
  nsCOMPtr<nsIHTMLCollection> nestedTables =
    el->GetElementsByTagName(NS_LITERAL_STRING("table"));
  if (nestedTables->Length() > 0) {
    RETURN_LAYOUT_ANSWER(true, "Has a nested table within it");
  }

  // If only 1 column or only 1 row, it's for layout.
  auto colCount = ColCount();
  if (colCount <= 1) {
    RETURN_LAYOUT_ANSWER(true, "Has only 1 column");
  }
  auto rowCount = RowCount();
  if (rowCount <=1) {
    RETURN_LAYOUT_ANSWER(true, "Has only 1 row");
  }

  // Check for many columns.
  if (colCount >= 5) {
    RETURN_LAYOUT_ANSWER(false, ">=5 columns");
  }

  // Now we know there are 2-4 columns and 2 or more rows. Check to see if
  // there are visible borders on the cells.
  // XXX currently, we just check the first cell -- do we really need to do more?
  nsTableWrapperFrame* tableFrame = do_QueryFrame(el->GetPrimaryFrame());
  if (!tableFrame) {
    RETURN_LAYOUT_ANSWER(false, "table with no frame!");
  }

  nsIFrame* cellFrame = tableFrame->GetCellFrameAt(0, 0);
  if (!cellFrame) {
    RETURN_LAYOUT_ANSWER(false, "table's first cell has no frame!");
  }

  nsMargin border;
  cellFrame->GetXULBorder(border);
  if (border.top && border.bottom && border.left && border.right) {
    RETURN_LAYOUT_ANSWER(false, "Has nonzero border-width on table cell");
  }

  // Rules for non-bordered tables with 2-4 columns and 2+ rows from here on
  // forward.

  // Check for styled background color across rows (alternating background
  // color is a common feature for data tables).
  auto childCount = thisacc->ChildCount();
  nscolor rowColor = 0;
  nscolor prevRowColor;
  for (auto childIdx = 0U; childIdx < childCount; childIdx++) {
    Accessible* child = thisacc->GetChildAt(childIdx);
    if (child->IsHTMLTableRow()) {
      prevRowColor = rowColor;
      nsIFrame* rowFrame = child->GetFrame();
      MOZ_ASSERT(rowFrame, "Table hierarchy got screwed up");
      if (!rowFrame) {
        RETURN_LAYOUT_ANSWER(false, "Unexpected table hierarchy");
      }

      rowColor = rowFrame->StyleBackground()->BackgroundColor(rowFrame);

      if (childIdx > 0 && prevRowColor != rowColor) {
        RETURN_LAYOUT_ANSWER(
          false, "2 styles of row background color, non-bordered"
        );
      }
    }
  }

  // Check for many rows.
  const uint32_t kMaxLayoutRows = 20;
  if (rowCount > kMaxLayoutRows) { // A ton of rows, this is probably for data
    RETURN_LAYOUT_ANSWER(false, ">= kMaxLayoutRows (20) and non-bordered");
  }

  // Check for very wide table.
  nsIFrame* documentFrame = thisacc->Document()->GetFrame();
  nsSize documentSize = documentFrame->GetSize();
  if (documentSize.width > 0) {
    nsSize tableSize = thisacc->GetFrame()->GetSize();
    int32_t percentageOfDocWidth = (100 * tableSize.width) / documentSize.width;
    if (percentageOfDocWidth > 95) {
      // 3-4 columns, no borders, not a lot of rows, and 95% of the doc's width
      // Probably for layout
      RETURN_LAYOUT_ANSWER(
        true, "<= 4 columns, table width is 95% of document width"
      );
    }
  }

  // Two column rules.
  if (rowCount * colCount <= 10) {
    RETURN_LAYOUT_ANSWER(true, "2-4 columns, 10 cells or less, non-bordered");
  }

  static const nsLiteralString tags[] = {
    NS_LITERAL_STRING("embed"),
    NS_LITERAL_STRING("object"),
    NS_LITERAL_STRING("iframe")
  };
  for (auto& tag : tags) {
    nsCOMPtr<nsIHTMLCollection> descendants = el->GetElementsByTagName(tag);
    if (descendants->Length() > 0) {
      RETURN_LAYOUT_ANSWER(
        true, "Has no borders, and has iframe, object or embed, typical of advertisements"
      );
    }
  }

  RETURN_LAYOUT_ANSWER(
    false, "No layout factor strong enough, so will guess data"
  );
}