public void actionPerformed(ActionEvent e) {
      JDesktopPane dp = (JDesktopPane) e.getSource();
      String key = getName();

      if (CLOSE == key || MAXIMIZE == key || MINIMIZE == key || RESTORE == key) {
        setState(dp, key);
      } else if (ESCAPE == key) {
        if (sourceFrame == dp.getSelectedFrame() && focusOwner != null) {
          focusOwner.requestFocus();
        }
        moving = false;
        resizing = false;
        sourceFrame = null;
        focusOwner = null;
      } else if (MOVE == key || RESIZE == key) {
        sourceFrame = dp.getSelectedFrame();
        if (sourceFrame == null) {
          return;
        }
        moving = (key == MOVE) ? true : false;
        resizing = (key == RESIZE) ? true : false;

        focusOwner = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
        if (!SwingUtilities.isDescendingFrom(focusOwner, sourceFrame)) {
          focusOwner = null;
        }
        sourceFrame.requestFocus();
      } else if (LEFT == key
          || RIGHT == key
          || UP == key
          || DOWN == key
          || SHRINK_RIGHT == key
          || SHRINK_LEFT == key
          || SHRINK_UP == key
          || SHRINK_DOWN == key) {
        JInternalFrame c = dp.getSelectedFrame();
        if (sourceFrame == null
            || c != sourceFrame
            || KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner()
                != sourceFrame) {
          return;
        }
        Insets minOnScreenInsets = UIManager.getInsets("Desktop.minOnScreenInsets");
        Dimension size = c.getSize();
        Dimension minSize = c.getMinimumSize();
        int dpWidth = dp.getWidth();
        int dpHeight = dp.getHeight();
        int delta;
        Point loc = c.getLocation();
        if (LEFT == key) {
          if (moving) {
            c.setLocation(
                loc.x + size.width - MOVE_RESIZE_INCREMENT < minOnScreenInsets.right
                    ? -size.width + minOnScreenInsets.right
                    : loc.x - MOVE_RESIZE_INCREMENT,
                loc.y);
          } else if (resizing) {
            c.setLocation(loc.x - MOVE_RESIZE_INCREMENT, loc.y);
            c.setSize(size.width + MOVE_RESIZE_INCREMENT, size.height);
          }
        } else if (RIGHT == key) {
          if (moving) {
            c.setLocation(
                loc.x + MOVE_RESIZE_INCREMENT > dpWidth - minOnScreenInsets.left
                    ? dpWidth - minOnScreenInsets.left
                    : loc.x + MOVE_RESIZE_INCREMENT,
                loc.y);
          } else if (resizing) {
            c.setSize(size.width + MOVE_RESIZE_INCREMENT, size.height);
          }
        } else if (UP == key) {
          if (moving) {
            c.setLocation(
                loc.x,
                loc.y + size.height - MOVE_RESIZE_INCREMENT < minOnScreenInsets.bottom
                    ? -size.height + minOnScreenInsets.bottom
                    : loc.y - MOVE_RESIZE_INCREMENT);
          } else if (resizing) {
            c.setLocation(loc.x, loc.y - MOVE_RESIZE_INCREMENT);
            c.setSize(size.width, size.height + MOVE_RESIZE_INCREMENT);
          }
        } else if (DOWN == key) {
          if (moving) {
            c.setLocation(
                loc.x,
                loc.y + MOVE_RESIZE_INCREMENT > dpHeight - minOnScreenInsets.top
                    ? dpHeight - minOnScreenInsets.top
                    : loc.y + MOVE_RESIZE_INCREMENT);
          } else if (resizing) {
            c.setSize(size.width, size.height + MOVE_RESIZE_INCREMENT);
          }
        } else if (SHRINK_LEFT == key && resizing) {
          // Make sure we don't resize less than minimum size.
          if (minSize.width < (size.width - MOVE_RESIZE_INCREMENT)) {
            delta = MOVE_RESIZE_INCREMENT;
          } else {
            delta = size.width - minSize.width;
          }

          // Ensure that we keep the internal frame on the desktop.
          if (loc.x + size.width - delta < minOnScreenInsets.left) {
            delta = loc.x + size.width - minOnScreenInsets.left;
          }
          c.setSize(size.width - delta, size.height);
        } else if (SHRINK_RIGHT == key && resizing) {
          // Make sure we don't resize less than minimum size.
          if (minSize.width < (size.width - MOVE_RESIZE_INCREMENT)) {
            delta = MOVE_RESIZE_INCREMENT;
          } else {
            delta = size.width - minSize.width;
          }

          // Ensure that we keep the internal frame on the desktop.
          if (loc.x + delta > dpWidth - minOnScreenInsets.right) {
            delta = (dpWidth - minOnScreenInsets.right) - loc.x;
          }

          c.setLocation(loc.x + delta, loc.y);
          c.setSize(size.width - delta, size.height);
        } else if (SHRINK_UP == key && resizing) {
          // Make sure we don't resize less than minimum size.
          if (minSize.height < (size.height - MOVE_RESIZE_INCREMENT)) {
            delta = MOVE_RESIZE_INCREMENT;
          } else {
            delta = size.height - minSize.height;
          }

          // Ensure that we keep the internal frame on the desktop.
          if (loc.y + size.height - delta < minOnScreenInsets.bottom) {
            delta = loc.y + size.height - minOnScreenInsets.bottom;
          }

          c.setSize(size.width, size.height - delta);
        } else if (SHRINK_DOWN == key && resizing) {
          // Make sure we don't resize less than minimum size.
          if (minSize.height < (size.height - MOVE_RESIZE_INCREMENT)) {
            delta = MOVE_RESIZE_INCREMENT;
          } else {
            delta = size.height - minSize.height;
          }

          // Ensure that we keep the internal frame on the desktop.
          if (loc.y + delta > dpHeight - minOnScreenInsets.top) {
            delta = (dpHeight - minOnScreenInsets.top) - loc.y;
          }

          c.setLocation(loc.x, loc.y + delta);
          c.setSize(size.width, size.height - delta);
        }
      } else if (NEXT_FRAME == key || PREVIOUS_FRAME == key) {
        dp.selectFrame((key == NEXT_FRAME) ? true : false);
      } else if (NAVIGATE_NEXT == key || NAVIGATE_PREVIOUS == key) {
        boolean moveForward = true;
        if (NAVIGATE_PREVIOUS == key) {
          moveForward = false;
        }
        Container cycleRoot = dp.getFocusCycleRootAncestor();

        if (cycleRoot != null) {
          FocusTraversalPolicy policy = cycleRoot.getFocusTraversalPolicy();
          if (policy != null && policy instanceof SortingFocusTraversalPolicy) {
            SortingFocusTraversalPolicy sPolicy = (SortingFocusTraversalPolicy) policy;
            boolean idc = sPolicy.getImplicitDownCycleTraversal();
            try {
              sPolicy.setImplicitDownCycleTraversal(false);
              if (moveForward) {
                KeyboardFocusManager.getCurrentKeyboardFocusManager().focusNextComponent(dp);
              } else {
                KeyboardFocusManager.getCurrentKeyboardFocusManager().focusPreviousComponent(dp);
              }
            } finally {
              sPolicy.setImplicitDownCycleTraversal(idc);
            }
          }
        }
      }
    }