oracle.wireless.me.drm
Class DRMAgent

java.lang.Object
  oracle.wireless.me.drm.DRMAgent

public abstract class DRMAgent

extends java.lang.Object

Implementation of DRMAgent receives notification of lifecycle methods of a context MIDlet. The context MIDlet is also referred to as subject MIDlet here. The implementation class will be registered automatically with the MIDlet at the time of application provisioning or delivery. It is guaranteed that its onStartApp(), onPauseApp() and onDestroyApp(boolean) methods will be called before peer methods (startApp(), pauseApp() and destroyApp(boolean) respectively) of the context MIDlet are execuated. Thus, DRMAgent may check the execution of subject MIDlet's lifecycle. It is anticipated that the implementation of onStartApp() will be the principal mechanism for checking subject MIDlet, while onPauseApp() and onDestroyApp(boolean) should be used for book-keeping chores. Depending on implementation business rules, onStartApp() may either execute headless or display UI widgets. Semantics of javax.microedition.midlet.MIDlet.startApp() method also applies to DRMAgent.onStartApp() for displaying UI widgets. The implemenation of DRMAgent can use context midlet to obtain the javax.microedition.lcdui.Display using following code snippet.

 Display d = Display.getDisplay(context);
 d.setCurrent(....);
 

It is noteworthy that completion of DRMAgent.onStartApp() allows UI components to be made visible even before startApp() method of context MIDlet completes. In effect, DRMAgent implementation must call DRMAgent.resumeStartApp() so long the peer MIDlet.startApp() should resume normally. Should DRMAgent determines to veto the normal execution of the context MIDlet, it may call MIDlet.notifyDestroy() or may throw Exception.

A well behaved DRMAgent should provide a public constructor with a single argument of type MIDlet. The general contract of the constructor implemenation is to call super class constructor with super(context). As far as reasonably practical, implementations are encouraged to use obscure resource names like RMS store and keep the implementation compact. There may only be a single DRMAgent implmentation per Midlet Suite. The overhead of multiple DRMAgent classes is not deemed pragmatic for MIDP devices. At runtime, there will be exactly one instance of DRMAgent per MIDlet in a Midlet Suite.

Version:

1.0 10/10/2002 2:28AM

Method Summary

java.lang.String	getProperty(java.lang.String name) Returns the value of the named property.
java.lang.String	getProperty(java.lang.String name, java.lang.String defaultValue) Returns the value of the named property, if the value is not found, specified default value is returned.
void	onDestroyApp(boolean unconditional) Notifies that destroyApp method of peer MIDlet has been called.
void	onPauseApp() Notifies that pauseApp method of context MIDlet has been called.
void	onStartApp() Notifies that startApp method of context MIDlet has been called.
void	resumeStartApp() This policy must call resumeStartApp() method should startApp() method of context MIDlet resume normally.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getProperty

public final java.lang.String getProperty(java.lang.String name)

Returns the value of the named property. The behaviour of this method is not defined if the delivery of an application has not occurred.

getProperty

public final java.lang.String getProperty(java.lang.String name,
                                          java.lang.String defaultValue)

Returns the value of the named property, if the value is not found, specified default value is returned. The behaviour of this method is not defined if the delivery of an application has not occurred.

resumeStartApp

public final void resumeStartApp()

This policy must call resumeStartApp() method should startApp() method of context MIDlet resume normally.

onStartApp

public void onStartApp()

Notifies that startApp method of context MIDlet has been called. Any unchecked exception will be propogated to startApp() method of context MIDlet. By default, this implementation of onStartApp() calls resumeStartApp() to preserve the execution continuity of the context MIDlet's startApp() method.

onPauseApp

public void onPauseApp()

Notifies that pauseApp method of context MIDlet has been called. Any unchecked exception will be propogated to pauseApp() method of context MIDlet. This class provides no-op implementation.

onDestroyApp

public void onDestroyApp(boolean unconditional)

Notifies that destroyApp method of peer MIDlet has been called. Any unchecked exception will be propogated to destoyApp(boolean) method of context MIDlet. This class provides no-op implementation.