/**
     * Returns the corner that contains the point <code>x</code>, <code>y</code>, or -1 if the
     * position doesn't match a corner.
     */
    private int calculateCorner(Window w, int x, int y) {
      Insets insets = w.getInsets();
      int xPosition = calculatePosition(x - insets.left, w.getWidth() - insets.left - insets.right);
      int yPosition = calculatePosition(y - insets.top, w.getHeight() - insets.top - insets.bottom);

      if (xPosition == -1 || yPosition == -1) {
        return -1;
      }
      return yPosition * 5 + xPosition;
    }
    public void mousePressed(MouseEvent ev) {
      JRootPane rootPane = getRootPane();

      if (rootPane.getWindowDecorationStyle() == JRootPane.NONE) {
        return;
      }
      Point dragWindowOffset = ev.getPoint();
      Window w = (Window) ev.getSource();
      if (w != null) {
        w.toFront();
      }
      Point convertedDragWindowOffset =
          SwingUtilities.convertPoint(w, dragWindowOffset, getTitlePane());

      Frame f = null;
      Dialog d = null;

      if (w instanceof Frame) {
        f = (Frame) w;
      } else if (w instanceof Dialog) {
        d = (Dialog) w;
      }

      int frameState = (f != null) ? f.getExtendedState() : 0;

      if (getTitlePane() != null && getTitlePane().contains(convertedDragWindowOffset)) {
        if ((f != null && ((frameState & Frame.MAXIMIZED_BOTH) == 0) || (d != null))
            && dragWindowOffset.y >= BORDER_DRAG_THICKNESS
            && dragWindowOffset.x >= BORDER_DRAG_THICKNESS
            && dragWindowOffset.x < w.getWidth() - BORDER_DRAG_THICKNESS) {
          isMovingWindow = true;
          dragOffsetX = dragWindowOffset.x;
          dragOffsetY = dragWindowOffset.y;
        }
      } else if (f != null && f.isResizable() && ((frameState & Frame.MAXIMIZED_BOTH) == 0)
          || (d != null && d.isResizable())) {
        dragOffsetX = dragWindowOffset.x;
        dragOffsetY = dragWindowOffset.y;
        dragWidth = w.getWidth();
        dragHeight = w.getHeight();
        dragCursor = getCursor(calculateCorner(w, dragWindowOffset.x, dragWindowOffset.y));
      }
    }