eventex1.java

是个J2ME手机事件处理程序 手机的键盘事件处理程序

/* License
 * 
 * Copyright 1994-2004 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  
 *  * Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *  * Redistribution in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *  
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *  
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
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 */

import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class EventEx1 extends MIDlet implements CommandListener {
    // display manager
    Display display = null;
    
    // a menu with items
    List menu = null; // main menu

    // textbox
    TextBox input = null;

    // command
    static final Command backCommand = new Command("Back", Command.BACK, 0);
    static final Command mainMenuCommand = new Command("Main", Command.SCREEN, 1);
    static final Command exitCommand = new Command("Exit", Command.STOP, 2);
    String currentMenu = null;

    // constructor.
    public EventEx1() {
    }

    /**
     * Start the MIDlet by creating a list of items and associating the
     * exit command with it.
     */
    public void startApp() throws MIDletStateChangeException {
      display = Display.getDisplay(this);

      menu = new List("Menu Items", Choice.IMPLICIT);
      menu.append("Item1", null);
      menu.append("Item2", null);
      menu.append("Item3", null);
      menu.append("Item4", null);
      menu.addCommand(exitCommand);
      menu.setCommandListener(this);

      mainMenu();
    }

    public void pauseApp() {
      display = null;
      menu = null;
      input = null;
    }

    public void destroyApp(boolean unconditional) {
      notifyDestroyed();
    }

    // main menu
    void mainMenu() {
      display.setCurrent(menu);
      currentMenu = "Main"; 
    }

    /**
     * a generic method that will be called when selected any of
     * the items on the list.
     */
    public void prepare() {
       input = new TextBox("Enter some text: ", "", 5, TextField.ANY);
       input.addCommand(backCommand);
       input.setCommandListener(this);
       input.setString("");
       display.setCurrent(input);
    }

    /**
     * Test item1.
     */
    public void testItem1() {
      prepare();
      currentMenu = "item1";
    }
   
    /**
     * Test item2.
     */
    public void testItem2() {
       prepare();
       currentMenu = "item2"; 
    }

    /**
     * Test item3.
     */
    public void testItem3() {
       prepare();
       currentMenu = "item3"; 
    }

    /**
     * Test item4.
     */
    public void testItem4() {
       prepare();
       currentMenu = "item4"; 
    }


   /**
    * Handle events.
    */  
   public void commandAction(Command c, Displayable d) {
      String label = c.getLabel();
      if (label.equals("Exit")) {
         destroyApp(true);
      } else if (label.equals("Back")) {
          if(currentMenu.equals("item1") || currentMenu.equals("item2") ||
             currentMenu.equals("item3") || currentMenu.equals("item4"))  {
            // go back to menu
            mainMenu();
          } 

      } else {
         List down = (List)display.getCurrent();
         switch(down.getSelectedIndex()) {
           case 0: testItem1();break;
           case 1: testItem2();break;
           case 2: testItem3();break;
           case 3: testItem4();break;
         }
            
      }
  }
}