configurablepopupmenu.java

本系统是用 java 语言实现的一个 Email客户端

package net.suberic.util.gui;
import javax.swing.*;
import net.suberic.util.VariableBundle;
import java.util.Hashtable;
import java.util.StringTokenizer;
import java.util.MissingResourceException;
import javax.swing.Action;

/**
 * This is a JMenu which implements the ConfigurableUI interface, and
 * therefore may be dynamically created using a VariableBundle and key,
 * and updated using an array of Actions.
 */

public class ConfigurablePopupMenu extends JPopupMenu implements ConfigurableUI {
  
  // the latest commands list.  i'm storing this for now because i 
  // can't do a JButton.removeActionListeners().
  
  protected Hashtable commands = new Hashtable();
  
  public ConfigurablePopupMenu() {
    super();
  }
  
  /**
   * This creates a new ConfigurableMenu using the menuID as the
   * configuration key, and vars as the source for the values of all the
   * properties.
   *
   * If menuID doesn't exist in vars, then this returns an empty 
   * Menu.
   */
  
  public ConfigurablePopupMenu(String menuID, VariableBundle vars) {
    super();
    
    configureComponent(menuID, vars);
  }
  
  /**
   * This configures the Menu using the given menuID and 
   * VariableBundle.
   *
   * As defined in interface net.suberic.util.gui.ConfigurableUI.
   */
  
  public void configureComponent(String key, VariableBundle vars) {
    StringTokenizer iKeys = null;
    try {
      iKeys = new StringTokenizer(vars.getProperty(key), ":");
    } catch (MissingResourceException mre) {
      try {
	System.err.println(vars.getProperty("error.NoSuchResource") + " " + mre.getKey());
      } catch (MissingResourceException mretwo) {
	System.err.println("Unable to load resource " + mre.getKey());
      }

      return;
      
    }
    String currentToken;
    
    try {
      setLabel(vars.getProperty(key + ".Label"));
    } catch (MissingResourceException mre) {
    }
    
    while (iKeys.hasMoreTokens()) {
      currentToken=iKeys.nextToken();
      if (currentToken.equals("-")) {
	this.addSeparator();
      } else {
	JMenuItem mi = createMenuItem(key, currentToken, vars);
	this.add(mi);
      }
    }
  }
  /**
   * And this actually creates the menu items themselves.
   */
  protected JMenuItem createMenuItem(String menuID, String menuItemID, VariableBundle vars) {
    // TODO:  should also make these undo-able.
    
    if (vars.getProperty(menuID + "." + menuItemID + ".class", "") == "") {

      if (vars.getProperty(menuID + "." + menuItemID, "") != "") {
	return new ConfigurableMenu(menuID + "." + menuItemID, vars);
      } 
      
      JMenuItem mi;
      try {
	mi = new JMenuItem(vars.getProperty(menuID + "." + menuItemID + ".Label"));
      } catch (MissingResourceException mre) {
	mi = new JMenuItem(menuItemID);
      }
      
      java.net.URL url = null;
      
      try {
	url = this.getClass().getResource(vars.getProperty(menuID + "." + menuItemID + ".Image"));
      } catch (MissingResourceException mre) {
      }
      
      if (url != null) {
	mi.setHorizontalTextPosition(JButton.RIGHT);
	mi.setIcon(new ImageIcon(url));
      }
      
      String cmd = vars.getProperty(menuID + "." + menuItemID + ".Action", menuItemID);
      
      mi.setActionCommand(cmd);	
      
      return mi;
    } else {
      // this means that we have a submenu.
      ConfigurableMenu m;
      
      if (vars.getProperty(menuID + "." + menuItemID + ".class", "").equals("")) {
	m = new ConfigurableMenu(menuID + "." + menuItemID, vars);
	
      } else {
	// this means we're using a custom Menu.
	
	try {
	  Class menuClass = Class.forName(vars.getProperty(menuID + "." + menuItemID + ".class", "net.suberic.util.gui.ConfigurableMenu"));
	  m = (ConfigurableMenu) menuClass.newInstance();
	  m.configureComponent(menuID + "." + menuItemID, vars);
	} catch (Exception e) {
	  // if we get any errors, just create a plain 
	  // ConfigurableMenu.
	  System.err.println("Unable to create menu with class " + vars.getProperty(menuID + "." + menuItemID + ".class", "net.suberic.util.gui.ConfigurableMenu") + ":  " + e.getMessage());
	  e.printStackTrace();
	  m = new ConfigurableMenu(menuID + "." + menuItemID, vars);
	}
      }
      
      return m;
      
    }
  }

  /**
   * As defined in net.suberic.util.gui.ConfigurableUI
   */
  public void setActive(javax.swing.Action[] newActions) {
    Hashtable tmpHash = new Hashtable();
    if (newActions != null && newActions.length > 0) {
      for (int i = 0; i < newActions.length; i++) {
	String cmdName = (String)newActions[i].getValue(Action.NAME);
	tmpHash.put(cmdName, newActions[i]);
      }
    }
    setActive(tmpHash);	
  }
  
  /**
   * As defined in net.suberic.util.gui.ConfigurableUI
   */
  public void setActive(Hashtable newCommands) {
    clearListeners();
    commands = newCommands;
    setActiveMenuItems();
  }
  
  protected void setActiveMenuItems() {
    for (int j = 0; j < getSubElements().length; j++) {
      if (getComponent(j) instanceof ConfigurableMenu) {
	((ConfigurableMenu)getComponent(j)).setActive(commands);
      } else {
	JMenuItem mi = (JMenuItem)getComponent(j);
	Action a = getAction(mi.getActionCommand());
	if (a != null) {
	  //mi.removeActionListener(a);
	  mi.addActionListener(a);
	  mi.setEnabled(true);
	} else {
	  mi.setEnabled(false);
	}
      }
    }
  }	    
  
  /**
   * This clears all of the current listeners on the Menu.
   */
    
  private void clearListeners() {
    for (int j = 0; j < getSubElements().length; j++) {
      if (getComponent(j) instanceof ConfigurableMenu) {
	// we don't have to clear the listeners here because
	// it will be done in setActive().
	;
      } else {
	JMenuItem mi = (JMenuItem)getComponent(j);
	Action a = getAction(mi.getActionCommand());
	if (a != null) {
	  mi.removeActionListener(a);
	}
      }
    }
  }
  
  /**
   * This gets an action from the supported commands.  If there is no
   * supported action, it returns null
   */
  
  public Action getAction(String command) {
    return (Action)commands.get(command);
  }
  

}