Event Example 1
/* 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 * nuclear facility. */ 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; } } } }