Java/J2ME/Alert
Содержание
An example MIDlet with simple Alert UI component containing an Image.
<source lang="java">
import javax.microedition.midlet.*; import javax.microedition.lcdui.*; /**
* An example MIDlet with simple "Alert" UI component containing an Image. */
public class AlertImage extends MIDlet {
private Display display; // The display for this MIDlet
private Alert myAlert = null;
public AlertImage() {
}
/**
* Call showAlert
*/
public void startApp() {
display = Display.getDisplay(this);
TextBox t = new TextBox("Hello MIDlet", "Hello J2MECamp!", 256, 0);
display.setCurrent(t);
System.out.println( "Gonna create Alert.." );
createAlert();
}
/**
* Puts up an Alert with an Image
*/
private void createAlert()
{
myAlert = new Alert("MIDlet Alert");
String[] alertString = { " Alert String" };
myAlert.setTimeout(Alert.FOREVER);
// Add an image to Alert
if (display.numColors() > 2)
{
String icon = (display.isColor()) ?"/JavaPowered-8.png" : "/JavaPowered-2.png";
try
{
Image image = Image.createImage( icon );
if (image != null)
{
myAlert.setImage(image);
System.out.println( "Image created and added to alert.. " );
}
else
{
System.out.println( "No Image created... " );
}
// Add string to Alert
for ( int i = 0; i < alertString.length; i++ ) {
myAlert.setString( alertString[i] );
}
if ( myAlert != null ) {
display.setCurrent( myAlert );
}
}
catch( Exception e )
{
System.out.println( "Exception in CreateImage() " );
}
}
}
/**
* Pause is a no-op since there are no background activities or
* record stores that need to be closed.
*/
public void pauseApp() {
}
/**
* Destroy must cleanup everything not handled by the garbage collector.
* In this case there is nothing to cleanup.
*/
public void destroyApp(boolean unconditional) {
}
}
</source>
High-Level Display Screens : Alert
<source lang="java">
//jad file (please verify the jar size) /* MIDlet-Name: DisplayAlert MIDlet-Version: 1.0 MIDlet-Vendor: MyCompany MIDlet-Jar-URL: DisplayAlert.jar MIDlet-1: DisplayAlert, , DisplayAlert MicroEdition-Configuration: CLDC-1.0 MicroEdition-Profile: MIDP-1.0 MIDlet-JAR-SIZE: 100
- /
import javax.microedition.lcdui.Alert; import javax.microedition.lcdui.AlertType; import javax.microedition.lcdui.rumand; import javax.microedition.lcdui.rumandListener; import javax.microedition.lcdui.Display; import javax.microedition.lcdui.Displayable; import javax.microedition.lcdui.Form; import javax.microedition.midlet.MIDlet; import javax.microedition.midlet.MIDletStateChangeException; public class DisplayAlert extends MIDlet implements CommandListener {
private Display display;
private Alert alert;
private Form form = new Form("Throw Exception");
private Command exit = new Command("Exit", Command.SCREEN, 1);
private boolean exitFlag = false;
public DisplayAlert() {
display = Display.getDisplay(this);
form.addCommand(exit);
form.setCommandListener(this);
}
public void startApp() {
display.setCurrent(form);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) throws MIDletStateChangeException {
if (unconditional == false) {
throw new MIDletStateChangeException();
}
}
public void commandAction(Command command, Displayable displayable) {
if (command == exit) {
try {
if (exitFlag == false) {
alert = new Alert("Busy", "Please try again.", null, AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert, form);
destroyApp(false);
} else {
destroyApp(true);
notifyDestroyed();
}
} catch (Exception exception) {
exitFlag = true;
}
}
}
}
</source>
Modal Alert
<source lang="java">
/*--------------------------------------------------
- ModalAlert.java
- Example from the book: Core J2ME Technology
- Copyright John W. Muchow http://www.CoreJ2ME.ru
- You may use/modify for any non-commercial purpose
- -------------------------------------------------*/
import javax.microedition.midlet.*; import javax.microedition.lcdui.*; public class ModalAlert extends MIDlet implements CommandListener {
private Display display; // Reference to Display object
private Form fmMain; // Main form
private Alert alTest; // Alert to show text and image
private Command cmExit; // Command to exit the MIDlet
public ModalAlert()
{
display = Display.getDisplay(this);
cmExit = new Command("Exit", Command.SCREEN, 1);
fmMain = new Form("Welcome");
fmMain.append("Text string inside the Form");
fmMain.addCommand(cmExit);
fmMain.setCommandListener(this);
}
public void startApp()
{
showAlert();
}
public void pauseApp()
{
}
public void destroyApp(boolean unconditional)
{
}
public void showAlert()
{
try
{
// Create an image
Image im = Image.createImage("/coffee.png");
// Create Alert, add text and image, associate a sound
alTest = new Alert("New Alert", "Time for more Java",
im, AlertType.INFO);
// Set Alert to type Modal
alTest.setTimeout(Alert.FOREVER);
}
catch(Exception e)
{
System.out.println("Unable to read png image.");
}
// Display the Alert. Once dismissed, display the form
display.setCurrent(alTest, fmMain);
}
public void commandAction(Command c, Displayable s)
{
if (c == cmExit)
{
destroyApp(true);
notifyDestroyed();
}
}
}
</source>
Multi Alert
<source lang="java">
/* 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.midlet.*; import javax.microedition.lcdui.*; import java.util.*;
public class MultiAlert extends MIDlet {
Display display;
Command exitCommand = new Command( "Exit", Command.EXIT,
1 );
Timer timer1 = new Timer();
Timer timer2 = new Timer();
Timer timer3 = new Timer();
MainForm form = new MainForm();
AlertRouter router;
public MultiAlert() {
display = Display.getDisplay( this );
router = new AlertRouter( display );
timer1.schedule( new AlertTrigger( "Alert 1",
"This is alert #1" ), 5000, 10000 );
timer2.schedule( new AlertTrigger( "Alert 2",
"This is alert #2" ), 5000, 7000 );
timer3.schedule( new AlertTrigger( "Alert 3",
"This is alert #3" ), 5000, 9000 );
}
protected void destroyApp( boolean unconditional ) {
timer1.cancel();
timer2.cancel();
timer3.cancel();
}
protected void startApp() {
display.setCurrent( form );
}
protected void pauseApp() {
}
public void exit(){
destroyApp( true );
notifyDestroyed();
}
class AlertTrigger extends TimerTask {
public AlertTrigger( String title, String message )
{
this.title = title;
this.message = message;
}
public void run(){
Alert alert = new Alert( title, message, null, null );
alert.setTimeout( Alert.FOREVER );
router.showAlert( alert );
}
private String title;
private String message;
}
class MainForm extends Form implements CommandListener {
public MainForm(){
super( "MultiAlert Demo" );
addCommand( exitCommand );
setCommandListener( this );
}
public void commandAction( Command c, Displayable d ){
exit();
}
}
}
</source>
Two Alerts
<source lang="java">
import javax.microedition.lcdui.Alert; import javax.microedition.lcdui.AlertType; import javax.microedition.lcdui.rumand; import javax.microedition.lcdui.rumandListener; import javax.microedition.lcdui.Display; import javax.microedition.lcdui.Displayable; import javax.microedition.lcdui.TextBox; import javax.microedition.lcdui.TextField; import javax.microedition.midlet.MIDlet; public class TwoAlerts extends MIDlet implements CommandListener {
private Display mDisplay;
private TextBox mTextBox;
private Alert mTimedAlert;
private Alert mModalAlert;
private Command aboutCommand, goCommand, exitCommand;
public TwoAlerts() {
aboutCommand = new Command("About", Command.SCREEN, 1);
goCommand = new Command("Go", Command.SCREEN, 1);
exitCommand = new Command("Exit", Command.EXIT, 2);
mTextBox = new TextBox("TwoAlerts", "", 32, TextField.ANY);
mTextBox.addCommand(aboutCommand);
mTextBox.addCommand(goCommand);
mTextBox.addCommand(exitCommand);
mTextBox.setCommandListener(this);
mTimedAlert = new Alert("Network error", "A network error occurred. Please try again.", null,
AlertType.INFO);
mModalAlert = new Alert("About TwoAlerts",
"TwoAlerts is a simple MIDlet that demonstrates the use of Alerts.", null, AlertType.INFO);
mModalAlert.setTimeout(Alert.FOREVER);
}
public void startApp() {
mDisplay = Display.getDisplay(this);
mDisplay.setCurrent(mTextBox);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
}
public void commandAction(Command c, Displayable s) {
if (c == aboutCommand)
mDisplay.setCurrent(mModalAlert);
else if (c == goCommand)
mDisplay.setCurrent(mTimedAlert, mTextBox);
else if (c == exitCommand)
notifyDestroyed();
}
}
</source>
