/*
*
*
* 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 defers the display decision to the user by choosing
* the foreground selector to be the next foreground.
* <p>
* From the user perspective when the last MIDlet the user launched sets its
* current displayable for the first time, 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 MVMDisplayController extends DisplayController {
/** Foreground Selector MIDlet. */
private MIDletProxy foregroundSelector;
/**
* Construct a DisplayController with a reference to the ProxyList.
*
* @param theMIDletProxyList reference to the MIDlet proxy list
* @param theForegroundSelector the proxy of foreground selector
*/
public MVMDisplayController(MIDletProxyList theMIDletProxyList,
MIDletProxy theForegroundSelector) {
super(theMIDletProxyList);
foregroundSelector = theForegroundSelector;
/*
* Ensure the foreground selector will get the foreground
* when requested.
*/
lastMidletCreated = foregroundSelector;
}
/**
* Handles MIDlet foreground requests.
* <p>
* If proxy being updated belongs last MIDlet created in the proxy list,
* then put the MIDlet in the foreground.
* <p>
* Otherwise, the request will not be granted. Foreground will not change.
*
* @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 foregroundRequest(MIDletProxy midlet) {
/*
* When the last MIDlet started wants the foreground automatically
* put in the foreground this time only.
*/
return (midlet == lastMidletCreated) ? midlet
: midletProxyList.getForegroundMIDlet();
}
/**
* Handles MIDlet background requests.
* <p>
* If the MIDlet is the foreground MIDlet, then bring the foreground
* selector to the foreground.
*
* @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;
}
/*
* Normal MVM mode case,
* Let the user choose the next foreground.
*/
return getForegroundSelector();
}
/**
* Preempt an Isolate's displays.
*
* @param preempting proxy of the preempting MIDlet to be put in the
* foreground when a preempted MIDlet gets the foreground
*
* @return Proxy of the next foreground MIDlet, may be the foreground
* MIDlet if the foreground should not change
*
*/
MIDletProxy startPreempting(MIDletProxy preempting) {
Enumeration midlets;
MIDletProxy preempted;
MIDletProxy foreground;
/*
* Preempt all of the MIDlets in the same Isolate as the preempting
* proxy.
*/
midlets = midletProxyList.getMIDlets();
while (midlets.hasMoreElements()) {
MIDletProxy current = (MIDletProxy)midlets.nextElement();
if (current.getIsolateId() != preempting.getIsolateId()) {
continue;
}
preempting.setPreemptedMidlet(current);
current.setPreemptingDisplay(preempting);
midletProxyList.notifyListenersOfProxyUpdate(current,
MIDletProxyListListener.PREEMPTING_DISPLAY);
}
foreground = midletProxyList.getForegroundMIDlet();
if (foreground == null) {
return preempting;
}
if (foreground.getIsolateId() == preempting.getIsolateId()) {
preempting.setPreemptedMidlet(foreground);
return preempting;
}
return foreground;
}
/**
* Called to process a select foreground event.
* Returns the foreground selector MIDlet in the foreground.
*
* @param onlyFromLaunchedList true if midlet should
* be selected from the list of already launched midlets,
* if false then possibility to launch midlet is needed.
* @return Proxy of the next foreground MIDlet, may be the foreground
* MIDlet if the foreground should not change
*/
MIDletProxy selectForeground(boolean onlyFromLaunchedList) {
notifyListenersOfSelectForeground(onlyFromLaunchedList);
return getForegroundSelector();
}
/**
* Returns the foreground selector MIDlet.
*
* @return Proxy of the foreground selector MIDlet
*/
private MIDletProxy getForegroundSelector() {
return foregroundSelector;
}
}
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