package ca.spaz.gui;
   
   import java.awt.Toolkit;
   import java.awt.event.*;
   import java.io.*;
   import java.lang.reflect.Method;
   import java.util.*;
   
   import javax.swing.*;
  import javax.xml.parsers.*;
  
  import org.w3c.dom.*;
  
  
  /***
   * A JMenuBar that can be created from an XML description.
   * Reflection is used to automatically dispatch the menu selections
   * without need of registering listeners for each item.
   *
   *
   * @author Aaron Davidson 
   * @date   September 2002
   */
   
  /* EXAMPLE:
  			<menubar>
  				<menu title="File">
  					<item title="Quit" key="q" action="doQuit"/>
  				</menu>
  				<menu title="Plot">
  					<item title="GC Density" key="g" action="doGCDensity"/>
  					<item title="AT Density" key="a" action="doATDensity"/>
  				</menu>
  			</menubar>
  */
  
  public class SpazMenuBar extends JMenuBar implements ActionListener {
  	private Hashtable actions;
  	private Object listener;
  	
     public SpazMenuBar(InputStream file, Object listener) {
        super();
        this.listener = listener;
        this.actions = new Hashtable();
        loadXML(file);
     }
     
     public SpazMenuBar(String file, Object listener) {
        super();
        this.listener = listener;
        this.actions = new Hashtable();
        
        InputStream xmlFile = getClass().getResourceAsStream(file);
        loadXML(xmlFile);
     }
  	
  
  	public void loadXML(InputStream file) {
        try {
           DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
           dbf.setNamespaceAware(true);
           DocumentBuilder db = dbf.newDocumentBuilder();
  //         File f = new File(fname);
           Document d = db.parse(file);    
           loadXML(d);
        } catch (Exception e) {
          e.printStackTrace();
        }
     }    
     
  	public void loadXML(Document d) {
        try {
     	   Element e = d.getDocumentElement();
     	   NodeList nl = e.getElementsByTagName("menu");
     	   for (int n=0; n<nl.getLength(); n++) {
  	         Element elm = (Element)(nl.item(n));  
  				loadXMLMenu(elm);
  	      }
        } catch (Exception e) {
          e.printStackTrace();
        }
     }
     
     public void loadXMLMenu(Element elm) {
        String title = elm.getAttribute("title");
        String key = elm.getAttribute("key");
  		JMenu menu = new JMenu(title);
  		this.add(menu);
  	   NodeList nl = elm.getElementsByTagName("item");
  		for (int n=0; n<nl.getLength(); n++) {
  			Element e = (Element)(nl.item(n));  
  			loadXMLMenuItem(e, menu);
  		}
  		if (key != null && key.length() > 0) {
  			menu.setMnemonic(key.charAt(0));
  		}
     }
  
     public void loadXMLMenuItem(Element elm, JMenu jm) {
       String separator = elm.getAttribute("separator");
       if (separator != null) {
          if (separator.equals("true")) {
             jm.addSeparator();
             return;
          }
       }
 
       String title = elm.getAttribute("title");
       String tooltip = elm.getAttribute("tooltip");
       String action = elm.getAttribute("action");
       String key = elm.getAttribute("key");
       String acc = elm.getAttribute("acc");
       String checkbox = elm.getAttribute("checkbox");
       JMenuItem item = new JMenuItem(title);
       if (checkbox != null) {
          if (checkbox.equals("true")) {
             item = new JCheckBoxMenuItem(title);
          }
       }
       jm.add(item);
       item.addActionListener(this);
       actions.put(item, action);
       if (key != null && key.length() > 0) {
          item.setMnemonic(key.charAt(0));
       }
       if (acc != null && acc.length() > 0) {
          try {
             Class c = KeyEvent.class;
             item.setAccelerator(  
                KeyStroke.getKeyStroke(c.getDeclaredField(acc).getInt(c),
                 Toolkit.getDefaultToolkit().getMenuShortcutKeyMask()));            
          } catch (Exception e) {
             e.printStackTrace();
          }
       }
       if (tooltip != null) {
          item.setToolTipText(tooltip);
       }
    }  
    
    public void setEnabled(String action, boolean on) {
    	JMenuItem item = (JMenuItem)getItem(action);
    	if (item != null) {
 			item.setEnabled(on);   
 		}
    }
    
    public JMenuItem getItem(String action) {
    	Enumeration e = actions.keys();
    	while (e.hasMoreElements()) {
    		JMenuItem item = (JMenuItem)e.nextElement();
    		String s = (String)actions.get(item);
    		if (s.equals(action)) {
    			return item;
    		}
    	}
    	return null;
    }
    
    
    public boolean isSelected(String name) {
 		JCheckBoxMenuItem item = (JCheckBoxMenuItem)getItem(name);		
 		return item.isSelected();
    }
    
    public void actionPerformed(ActionEvent e) {
    	String methodName = (String)actions.get(e.getSource());
    	if (methodName != null) {
    		try {
 	   		Class[] params = null;
    			Method m = listener.getClass().getMethod(methodName, params);
 	   		Object[] params2 = null;
    			m.invoke(listener, params2);
    		} catch (NoSuchMethodException me) { 
    			JOptionPane.showMessageDialog(null, "No Menu Handler for  '"+methodName+"'");
 /*   		} catch (SecurityException se) {
    		} catch (IllegalAccessException ae) {
    		} catch (InvocationTargetException  ie) {*/
    		} catch (Exception ex) {
 				ex.printStackTrace();
    		}
    	}
    }
    
 
 }