tickerdemo.java

j2me手机应用开发环境下的UI程序

/*
 *
 * Copyright © 2007 Sun Microsystems, Inc. All rights reserved.
 * Use is subject to license terms.
 */
package ticker;

import javax.microedition.lcdui.*;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.midlet.MIDlet;


/**
 * The Ticker Demo simply sets a rather long ticker to the screen.
 *
 * @version 2.0
 */
public class TickerDemo extends MIDlet implements CommandListener {
    /**
     * This is the text displayed in the ticker.
     */
    private static final String TICKER_TEXT =
        "This is a ticker see it " + "scroll along the way... On and on it goes without " +
        "stopping even for a second!";
    private boolean firstTime;
    private Form mainForm;
    private Command exitCommand = new Command("Exit", Command.EXIT, 1);
    private Display myDisplay;
    private Ticker t;

    public TickerDemo() {
        myDisplay = Display.getDisplay(this);
        firstTime = true;
        mainForm = new Form("Ticker");
        mainForm.setCommandListener(this);
    }

    protected void startApp() {
        if (firstTime) {
            t = new Ticker(TICKER_TEXT);
            mainForm.setTicker(t);
            firstTime = false;
        }

        mainForm.addCommand(exitCommand);
        myDisplay.setCurrent(mainForm);
    }

    protected void destroyApp(boolean unconditional) {
        myDisplay.setCurrent((Displayable)null);
        notifyDestroyed();
    }

    protected void pauseApp() {
    }

    public void commandAction(Command c, Displayable s) {
        if (c == exitCommand) {
            destroyApp(true);
        }
    }
}