C++ Accessible::GetFrame方法代码示例

bool
XULColorPickerAccessible::AreItemsOperable() const
{
  Accessible* menuPopup = mChildren.SafeElementAt(0, nullptr);
  if (menuPopup) {
    nsMenuPopupFrame* menuPopupFrame = do_QueryFrame(menuPopup->GetFrame());
    return menuPopupFrame && menuPopupFrame->IsOpen();
  }
  return false;
}

bool
XULButtonAccessible::AreItemsOperable() const
{
  if (IsMenuButton()) {
    Accessible* menuPopup = mChildren.SafeElementAt(0, nullptr);
    if (menuPopup) {
      nsMenuPopupFrame* menuPopupFrame = do_QueryFrame(menuPopup->GetFrame());
      return menuPopupFrame->IsOpen();
    }
  }
  return false; // no items
}

nsIntPoint
nsAccUtils::GetScreenCoordsForParent(Accessible* aAccessible)
{
  Accessible* parent = aAccessible->Parent();
  if (!parent)
    return nsIntPoint(0, 0);

  nsIFrame *parentFrame = parent->GetFrame();
  if (!parentFrame)
    return nsIntPoint(0, 0);

  nsRect rect = parentFrame->GetScreenRectInAppUnits();
  return nsPoint(rect.X(), rect.Y()).
    ToNearestPixels(parentFrame->PresContext()->AppUnitsPerDevPixel());
}

nsIntPoint
nsAccUtils::GetScreenCoordsForParent(nsAccessNode *aAccessNode)
{
  DocAccessible* document = aAccessNode->Document();
  Accessible* parent = document->GetContainerAccessible(aAccessNode->GetNode());
  if (!parent)
    return nsIntPoint(0, 0);

  nsIFrame *parentFrame = parent->GetFrame();
  if (!parentFrame)
    return nsIntPoint(0, 0);

  nsIntRect parentRect = parentFrame->GetScreenRectExternal();
  return nsIntPoint(parentRect.x, parentRect.y);
}

nsIntPoint
nsAccUtils::GetScreenCoordsForParent(nsAccessNode *aAccessNode)
{
  DocAccessible* document = aAccessNode->Document();
  Accessible* parent = document->GetContainerAccessible(aAccessNode->GetNode());
  if (!parent)
    return nsIntPoint(0, 0);

  nsIFrame *parentFrame = parent->GetFrame();
  if (!parentFrame)
    return nsIntPoint(0, 0);

  nsRect rect = parentFrame->GetScreenRectInAppUnits();
  return nsPoint(rect.x, rect.y).
    ToNearestPixels(parentFrame->PresContext()->AppUnitsPerDevPixel());
}

//.........这里部分代码省略.........
                RETURN_LAYOUT_ANSWER(false,
                                     "has abbr -- legitimate table structures");
              }
            }
          }
        }
      }
    }
  }

  if (HasDescendant(NS_LITERAL_STRING("table"))) {
    RETURN_LAYOUT_ANSWER(true, "Has a nested table within it");
  }

  // If only 1 column or only 1 row, it's for layout
  uint32_t colCount = ColCount();
  if (colCount <=1) {
    RETURN_LAYOUT_ANSWER(true, "Has only 1 column");
  }
  uint32_t 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(mContent->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).
  uint32_t childCount = ChildCount();
  nscolor rowColor = 0;
  nscolor prevRowColor;
  for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
    Accessible* child = GetChildAt(childIdx);
    if (child->Role() == roles::ROW) {
      prevRowColor = rowColor;
      nsIFrame* rowFrame = child->GetFrame();
      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 = Document()->GetFrame();
  nsSize documentSize = documentFrame->GetSize();
  if (documentSize.width > 0) {
    nsSize tableSize = 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");
  }

  if (HasDescendant(NS_LITERAL_STRING("embed")) ||
      HasDescendant(NS_LITERAL_STRING("object")) ||
      HasDescendant(NS_LITERAL_STRING("iframe"))) {
    RETURN_LAYOUT_ANSWER(true, "Has no borders, and has iframe, object, or iframe, typical of advertisements");
  }

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

//.........这里部分代码省略.........
  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"
  );
}