/*
* @(#)Selector.java 1.46 02/09/11 @(#)
*
* Copyright (c) 1999-2002 Sun Microsystems, Inc. All rights reserved.
* PROPRIETARY/CONFIDENTIAL
* Use is subject to license terms.
*/
package com.sun.midp.midlet;
import javax.microedition.midlet.MIDlet;
import javax.microedition.lcdui.*;
import com.sun.midp.lcdui.Resource;
/**
* Selector provides a simple user interface to select MIDlets to run.
* It extracts the list of MIDlets from the attributes in the
* descriptor file and presents them to the user using the MIDlet-<n> name
* and icon if any. When the user selects a MIDlet an instance
* of the class indicated by MIDlet-<n> classname is created.
*/
public class Selector extends MIDlet implements CommandListener, Runnable {
/**
* The List of all the MIDlets.
*/
private List mlist;
/**
* The Display.
*/
private Display display;
/**
* Number of midlets in minfo.
*/
private int mcount;
/**
* should this MIDlet exit after launching another MIDlet
*/
private boolean exitAfterLaunch = true;
/**
* MIDlet information, class, name, icon; one per MIDlet.
*/
private MIDletInfo[] minfo;
/**
* the Command object to exit back to the MIDlet Suite Manager
*/
private Command backCmd = new Command(Resource.getString("Back"),
Command.BACK, 2);
/**
* the Command object for "Launch".
*/
private Command launchCmd = new Command(Resource.getString("Launch"),
Command.ITEM, 1);
/**
* Index of the selected MIDlet, starts at -1 for non-selected.
*/
private int selectedMidlet = -1;
/**
* Create and initialize a new Selector MIDlet.
* The Display is retreived and the list of MIDlets read
* from the descriptor file.
*/
public Selector() {
this(true);
}
/**
* Create and initialize a new Selector MIDlet.
* The Display is retreived and the list of MIDlets read
* from the descriptor file.
*
* @param exitFlag set this to true if the selector should exit after
* launching a MIDlet.
*/
protected Selector(boolean exitFlag) {
exitAfterLaunch = exitFlag;
display = Display.getDisplay(this); // TBD: is this value value here?
mcount = 0;
minfo = new MIDletInfo[20];
readMIDletInfo();
}
/**
* Start puts up a List of the MIDlets found in the descriptor file.
*/
public void startApp() {
setupList();
mlist.addCommand(launchCmd);
if (exitAfterLaunch) {
mlist.addCommand(backCmd);
}
mlist.setCommandListener(this); // Listen for the selection
display.setCurrent(mlist);
}
/**
* Pause; there are no resources that need to be released.
*/
public void pauseApp() {
}
/**
* Destroy cleans up.
* The only resource used is in the objects that will be
* reclaimed by the garbage collector.
* @param unconditional is ignored; the Selector always
* destroys itself when requested.
*/
public void destroyApp(boolean unconditional) {
}
/**
* Respond to a command issued on any Screen.
* The commands on list is Select and About.
* Select triggers the creation of the MIDlet of the same name.
* About puts up the copyright notice.
*
* @param c command activiated by the user
* @param s the Displayable the command was on.
*/
public void commandAction(Command c, Displayable s) {
if ((s == mlist && c == List.SELECT_COMMAND) || (c == launchCmd)) {
synchronized (this) {
if (selectedMidlet != -1) {
// the previous selected MIDlet is being launched
return;
}
selectedMidlet = mlist.getSelectedIndex();
}
new Thread(this).start();
} else if (c == backCmd) {
destroyApp(false);
notifyDestroyed();
return;
}
}
/**
* Launch a the select MIDlet.
*/
public void run() {
Scheduler scheduler = Scheduler.getScheduler();
String classname = minfo[selectedMidlet].classname;
try {
scheduler.register(MIDletState.createMIDlet(classname));
if (exitAfterLaunch) {
// exit
destroyApp(false);
notifyDestroyed();
return;
}
// Give the new MIDlet the screen by setting current to null
display.setCurrent(null);
// let another MIDlet be selected after MIDlet ends
selectedMidlet = -1;
return;
} catch (Exception ex) {
StringBuffer sb = new StringBuffer()
.append(minfo[selectedMidlet].name)
.append(", ")
.append(classname)
.append("\n")
.append(Resource.getString("Exception"))
.append(": ")
.append(ex.toString());
Alert a = new Alert(Resource.getString("Cannot start: "),
sb.toString(), null, null);
System.out.println("Unable to create MIDlet " + classname);
ex.printStackTrace();
display.setCurrent(a, mlist);
// let another MIDlet be selected after the alert
selectedMidlet = -1;
return;
}
}
/**
* Read the set of MIDlet names, icons and classes
* Fill in the list.
*/
private void setupList() {
if (mlist == null) {
mlist = new List(Resource.getString("Select one to launch:"),
Choice.IMPLICIT);
// Add each midlet
for (int i = 0; i < mcount; i++) {
Image icon = null;
if (minfo[i].icon != null) {
try {
icon = Image.createImage(minfo[i].icon);
} catch (java.io.IOException noImage) {
// TBD: use a default ICON of the app has none.
}
}
mlist.append(" " + minfo[i].name, icon);
}
}
}
/**
* Read in and create a MIDletInfor for each MIDlet-<n>
*/
private void readMIDletInfo() {
for (int n = 1; n < 100; n++) {
String nth = "MIDlet-"+ n;
String attr = getAppProperty(nth);
if (attr == null || attr.length() == 0)
break;
addMIDlet(new MIDletInfo(attr));
}
}
/**
* Add a MIDlet to the list.
* @param info MIDlet information to add to MIDlet
*/
private void addMIDlet(MIDletInfo info) {
if (mcount >= minfo.length) {
MIDletInfo[] n = new MIDletInfo[mcount+4];
System.arraycopy(minfo, 0, n, 0, mcount);
minfo = n;
}
minfo[mcount++] = info;
}
}
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