package com.dwave.util;   
/*
 *  VPopupMenu
 *
 *   Copyright (C) 2000  Cris Sinnott
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

import javax.swing.*;
import java.awt.*;

/**
This component extends JPopupMenu and adds a method to display the menu inside the screen,
even if the mouse pointer is near the edge of the screen.
<br>
Class created by Cris Sinnott
<br>
Source at : http://www.egroups.com/list/advanced-java/md1875700976.html
*/
public class VPopupMenu extends  JPopupMenu implements java.io.Serializable {
/**Displays the popUpMenu at a specified position*/
  public void show(Component invoker, int x, int y){
    Point p = getPopupMenuOrigin(invoker, x, y);
    super.show(invoker, p.x, p.y);
  }
/**Figures out the sizes needed to calculate the menu position*/
  protected Point getPopupMenuOrigin(Component invoker, int x, int y){
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Dimension pmSize = this.getSize();
    // For the first time the menu is popped up
    // the size has not yet been initialised
    if(pmSize.width==0){
      pmSize=this.getPreferredSize();
    }
    Point absp = new Point(x,y);
    SwingUtilities.convertPointToScreen(absp, invoker);
    int aleft = absp.x+pmSize.width;
    int abottom = absp.y+pmSize.height;
    if(aleft > screenSize.width)
      x -= aleft - screenSize.width;
    if(abottom > screenSize.height)
      y -= abottom - screenSize.height;
    return new Point(x,y);
  }
}