PopupMenuDemo.java

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package jpl.util;

import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;


/*
 * Adapted from a Swing Connection demo
 * see pcm's jpl_demo:jpl_popup_demo/0
 */
public class PopupMenuDemo extends JFrame 
                           implements ActionListener {
        private static final long       serialVersionUID        = 1L;
        // JTextArea output;
    public JPopupMenu popup;
        JMenuItem source;
        int mi;

    public PopupMenuDemo() {

     // Add regular components to the window, using the default BorderLayout.
     // output = new JTextArea(5, 30);
     // output.setEditable(false);
     // getContentPane().add(new JScrollPane(output), BorderLayout.CENTER);
    }

/*      JPopupMenu
         +-     JMenuItem
         +-     JMenuItem
         +-     JMenu -----     JPopupMenu
         |                               +-     JMenuItem
         |                               +-     JMenuItem
         +-     JMenuItem
         +-     JMenuItem
 */
    public boolean search(JPopupMenu p) {
                Object[] mes = p.getSubElements();              // array of JMenuItem or JMenu (see diagram)
                int i;

                for ( i=0 ; i<mes.length ; i++ ) {
                        if ( mes[i] == source ) {                       // it's the clicked JMenuItem
                                return true;
                        }
                        else
                        if ( mes[i] instanceof JMenu ) {        // it's a submenu
                                if ( search((JPopupMenu)(((JMenu)mes[i]).getSubElements())[0]) ) {
                                        return true;                            // clicked JMenuItem was within this submenu tree
                                }
                        }
                        else {                                                          // it's a non-matching leaf element
                                mi++;                                                   // next JMenuItemm will be the mi-th
                        }
                }
                return false;
        }

        public void actionPerformed(ActionEvent e) {
        source = (JMenuItem)(e.getSource());
     // output.append("action event source: " + source.getText()
     //          + " (an instance of " + getClassName(source) + ")\n");
                mi = 1;
                if ( search(popup) ) {
         //             output.append("clicked " + mi + "\n");
                        if ( (new jpl.Query("jpl_popup_demo_callback", new jpl.Term[] {new jpl.Integer(mi)})).hasSolution() ) {
                 //             output.append("succeeded\n");
                        }
                        else {
                 //             output.append("failed\n");
                        }
                }
         //     output.append("jpl_popup_demo_callback(" + mi + ")\n");
    }

 // protected String getClassName(Object o) {                   // Returns just the class name -- no package info.
 //     String classString = o.getClass().getName();
 //     int dotIndex = classString.lastIndexOf(".");
 //     return classString.substring(dotIndex+1);
 // }

        public JPopupMenu buildPopupMenu(Object[] mis) {
                int i;
                JPopupMenu m = new JPopupMenu((String)mis[0]);
                JMenuItem mi;

                for ( i=1 ; i<mis.length ; i++ ) {
                        if ( mis[i] instanceof String ) {
                                mi = new JMenuItem((String)mis[i]);
                                mi.addActionListener(this);
                                m.add(mi);
                        }
                        else
                        if ( mis[i] instanceof Object[] ) {
                                m.add(buildSubMenu((Object[])mis[i]));
                        }
                        else {
                                return null;                                                    // bad menuitems array
                        }
                }
                return m;
        }

        public JMenu buildSubMenu(Object[] mis) {
                int i;
                JMenu m = new JMenu((String)mis[0]);
                JMenuItem mi;

                for ( i=1 ; i<mis.length ; i++ ) {
                        if ( mis[i] instanceof String ) {
                                mi = new JMenuItem((String)mis[i]);
                                mi.addActionListener(this);
                                m.add(mi);
                        }
                        else
                        if ( mis[i] instanceof Object[] ) {
                                m.add(buildSubMenu((Object[])mis[i]));
                        }
                        else {
                                return null;                                                    // bad menuitems array
                        }
                }
                return m;
        }

        public void showPopup(Object[] mis, int x, int y) {
                Point p = getLocationOnScreen();                // on-screen location of origin of this Frame

                popup = buildPopupMenu(mis);                    // discarding any previous one...
                setVisible(true);                                               // ensure this Frame thingy is visible (else we get an error)
                popup.show(this,x-p.x,y-p.y);                   // must show over some Component (e.g. this)
        }

}

---

jpl
Author(s): Lorenz Moesenlechner
autogenerated on Fri Jan 11 09:40:29 2013