/*
*
*
* 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.suspend;
import com.sun.midp.main.*;
import com.sun.midp.security.SecurityToken;
import com.sun.midp.security.Permissions;
import java.util.Vector;
/**
* Main system of the current isolate that contains all
* suspendable subsystems in current isolate.
* There is a singleton instance in each isolate. The
* instance kept in the AMS isolate is a special one and
* belongs to <code>MIDPSystem</code> subtype.
*/
public class SuspendSystem extends AbstractSubsystem {
/**
* Listeners interested in suspend/resume operations.
*/
private final Vector listeners = new Vector(1, 2);
/**
* Main subsystem that implements suspend actions for
* whole MIDP system. It works in the AMS Isolate. There
* is the only instance for all isolates.
*/
private static class MIDPSystem extends SuspendSystem
implements MIDletProxyListListener {
/**
* A flag to determine if at least one MIDlet has been
* destroyed during last suspend processing.
*/
private boolean midletKilled = false;
/**
* A flag to determine if at least one MIDlet has been
* successfully paused during last suspend processing.
*/
private boolean midletPaused = false;
/**
* Stored foreground MIDlet.
*/
private MIDletProxy lastForeground;
/**
* The MIDlet proxy list.
*/
MIDletProxyList mpl =
MIDletProxyList.getMIDletProxyList(classSecurityToken);
/**
* Constructs the only instance.
*/
private MIDPSystem() {
state = ACTIVE;
mpl.addListener(this);
addListener(mpl);
}
/**
* Initiates MIDPSystem suspend operations.
*/
public synchronized void suspend() {
if (ACTIVE == state) {
SuspendTimer.start(mpl);
lastForeground = mpl.getForegroundMIDlet();
SuspendResumeUI.showSuspendAlert(classSecurityToken);
super.suspend();
}
}
/**
* Performs MIDPSystem-specific suspend operations.
*/
protected synchronized void suspendImpl() {
SuspendTimer.stop();
}
/**
* Performs MIDPSystem-specific resume operations.
*/
protected synchronized void resumeImpl() {
midletKilled = false;
midletPaused = false;
SuspendResumeUI.dismissSuspendAlert();
alertIfAllMidletsKilled();
if (null != lastForeground) {
mpl.setForegroundMIDlet(lastForeground);
lastForeground = null;
}
}
/**
* Shows proper alert if all user midlets were killed by a preceding
* suspend operation, and the event is not reported yet.
*/
private synchronized void alertIfAllMidletsKilled() {
if (allMidletsKilled()) {
SuspendResumeUI.showAllKilledAlert(classSecurityToken);
}
}
/**
* Notifies of system suspend.
*/
protected void suspended() {
super.suspended();
suspended0(!midletPaused && midletKilled);
}
/**
* Notifies native functionality that MIDP activities in java
* have been suspended.
* @param allMidletsKilled true to indicate that all user MIDlets
* were killed by suspend routines.
*/
protected native void suspended0(boolean allMidletsKilled);
/**
* Determines if at least one of preceding suspension operations
* killed all user MIDlets and the condition has not been checked
* since that time.
* @return true if a suspension operation killed all user MIDlets
* and the condition has not been checked yet, false
* otherwise. This method returns true only once for one
* event.
*/
protected native boolean allMidletsKilled();
/**
* Receives notifications on MIDlet updates and removes corresponding
* MIDlet proxy from suspend dependencies if required.
* @param midlet MIDletProxy that represents the MIDlet updated
* @param reason kind of changes that took place, see
*/
public void midletUpdated(MIDletProxy midlet, int reason) {
boolean amsMidlet =
(MIDletSuiteUtils.getAmsIsolateId() == midlet.getIsolateId());
if (reason == MIDletProxyListListener.RESOURCES_SUSPENDED) {
if (!amsMidlet) {
midletPaused = true;
}
removeSuspendDependency(midlet);
} else if (reason == MIDletProxyListListener.MIDLET_STATE &&
amsMidlet &&
midlet.getMidletState() == MIDletProxy.MIDLET_ACTIVE) {
/* An AMS midlet has been activated, checking if it is a
* result of abnormal midlet termination during suspend.
*/
alertIfAllMidletsKilled();
}
}
/**
* Receives MIDlet removal notification and removes corresponding
* MIDlet proxy from suspend dependencies.
* @param midlet MIDletProxy that represents the MIDlet removed
*/
public synchronized void midletRemoved(MIDletProxy midlet) {
midletKilled = true;
removeSuspendDependency(midlet);
if (midlet == lastForeground) {
lastForeground = null;
}
}
/**
* Not used. MIDletProxyListListener interface method.
*/
public void midletAdded(MIDletProxy midlet) {}
/**
* Not used. MIDletProxyListListener interface method.
*/
public void midletStartError(int externalAppId, int suiteId,
String className, int errorCode,
String errorDetails) {}
}
/**
* The singleton instance.
*/
private static SuspendSystem instance =
MIDletSuiteUtils.getIsolateId() == MIDletSuiteUtils.getAmsIsolateId()?
new MIDPSystem() : new SuspendSystem();
/**
* Retrieves the singleton instance.
* @param token security token that identifies caller permissions for
* accessing this API
* @return the singleton instance
*/
public static SuspendSystem getInstance(SecurityToken token) {
token.checkIfPermissionAllowed(Permissions.MIDP);
return instance;
}
/**
* Retrieves the singleton instance. The method is only available from
* this restricted package.
* @return the singleton instance
*/
static SuspendSystem getInstance() {
return instance;
}
/**
* Constructs an instance.
*/
private SuspendSystem() {}
/**
* Registers a listener interested in system suspend/resume operations.
* IMPL_NOTE: method for removing listeners is not needed currently.
*
* @param listener the listener to be added
*/
public void addListener(SuspendSystemListener listener) {
synchronized (listeners) {
listeners.addElement(listener);
}
}
/**
* Notifies listeners of system suspend.
*/
protected void suspended() {
synchronized (listeners) {
for (int i = listeners.size() - 1; i >= 0; i-- ) {
SuspendSystemListener listener =
(SuspendSystemListener)listeners.elementAt(i);
listener.midpSuspended();
}
}
}
/**
* Notifies listeners of system resume.
*/
protected void resumed() {
synchronized (listeners) {
for (int i = listeners.size() - 1; i >= 0; i-- ) {
SuspendSystemListener listener =
(SuspendSystemListener)listeners.elementAt(i);
listener.midpResumed();
}
}
}
}
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