/*
*
*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.midp.main;
import java.util.*;
/**
* This class controls which MIDlet's display is in the foreground.
* Running only in the AMS Isolate (0) the controller consulted by the MIDlet
* proxy list for any foreground when various state changes occur in a MIDlet.
* The display controller automatically selects the next foreground if
* needed.
* <p>
* From the user perspective when the last MIDlet the user launched is created,
* that MIDlet should automatically get the foreground (see the midletCreated
* and foregroundRequest methods).
* <p>
* A MIDlet that is paused or destroyed is treated as if it has requested the
* background as described above.
*/
public class SMMDisplayController extends DisplayController {
/** Suite ID of the last MIDlet in foreground. */
private int lastMidletSuiteId;
/** Class name of the last MIDlet in foreground. */
private String lastMidletClassName;
/** This MIDlet should only get the foreground if it is the last MIDlet. */
private MIDletProxy lastMidletInForeground;
/**
* Construct a DisplayController with a reference to the ProxyList.
*
* @param theMIDletProxyList reference to the MIDlet proxy list
* @param suiteId the suiteId of the last MIDlet in the foreground
* @param classname classname of the last MIDlet in the foreground
*/
public SMMDisplayController(MIDletProxyList theMIDletProxyList,
int suiteId, String classname) {
super(theMIDletProxyList);
midletProxyList = theMIDletProxyList;
lastMidletSuiteId = suiteId;
lastMidletClassName = classname;
}
/**
* Handles MIDlet background requests.
* <p>
* If the MIDlet requesting to be put in the background is the foreground
* MIDlet, then find a MIDlet to bring to the foreground (see the
* findNextForeground method).
*
* @param midlet The proxy of the MIDlet that was updated
*
* @return Proxy of the next foreground MIDlet, may be the foreground
* MIDlet if the foreground should not change
*/
MIDletProxy backgroundRequest(MIDletProxy midlet) {
MIDletProxy foreground = midletProxyList.getForegroundMIDlet();
if (midlet != foreground) {
// not in the foreground, so don't change the foreground
return foreground;
}
return findNextForegroundMIDlet();
}
/**
* Find a MIDlet that wants the foreground. If none wants the foreground
* then find one that is not paused, if no find one that is paused
* and wants the foreground, then find one that is paused. Only return the
* "last MIDlet to have the foreground" if there are not other MIDlets.
*
* @return new foreground task or null
*/
private MIDletProxy findNextForegroundMIDlet() {
Enumeration midlets;
// find the first task that is active and wants foreground
midlets = midletProxyList.getMIDlets();
while (midlets.hasMoreElements()) {
MIDletProxy current = (MIDletProxy)midlets.nextElement();
if (current.getMidletState() != MIDletProxy.MIDLET_ACTIVE) {
continue;
}
if (current.wantsForeground() &&
current != getLastMidletInForeground()) {
return current;
}
}
// find the first task that is active
midlets = midletProxyList.getMIDlets();
while (midlets.hasMoreElements()) {
MIDletProxy current = (MIDletProxy)midlets.nextElement();
if (current.getMidletState() != MIDletProxy.MIDLET_ACTIVE &&
current != getLastMidletInForeground()) {
return current;
}
}
// find the first task that is paused and wants the foreground
midlets = midletProxyList.getMIDlets();
while (midlets.hasMoreElements()) {
MIDletProxy current = (MIDletProxy)midlets.nextElement();
if (current.getMidletState() != MIDletProxy.MIDLET_PAUSED &&
current != getLastMidletInForeground()) {
continue;
}
if (current.wantsForeground() &&
current != getLastMidletInForeground()) {
return current;
}
}
// find the first task that is paused
midlets = midletProxyList.getMIDlets();
while (midlets.hasMoreElements()) {
MIDletProxy current = (MIDletProxy)midlets.nextElement();
if (current.getMidletState() != MIDletProxy.MIDLET_PAUSED &&
current != getLastMidletInForeground()) {
return current;
}
}
return getLastMidletInForeground();
}
/**
* Returns the last MIDlet to that should get the foreground.
*
* @return last MIDlet in foreground
*/
private MIDletProxy getLastMidletInForeground() {
if (lastMidletInForeground == null) {
lastMidletInForeground =
midletProxyList.findMIDletProxy(lastMidletSuiteId,
lastMidletClassName);
}
return lastMidletInForeground;
}
}
|