/*
*
*
* 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
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*/
package javax.microedition.midlet;
import com.sun.midp.midlet.MIDletPeer;
import com.sun.midp.midlet.MIDletStateHandler;
import com.sun.midp.security.SecurityToken;
import com.sun.midp.security.SecurityInitializer;
import com.sun.midp.security.ImplicitlyTrustedClass;
import javax.microedition.lcdui.Display;
/**
* A <code>MIDlet</code> is a MID Profile application.
* The application must extend this class to allow the
* application management software to control the MIDlet and to be
* able to retrieve properties from the application descriptor
* and notify and request state changes.
* The methods of this class allow the application management software
* to create, start, pause, and destroy a MIDlet.
* A <code>MIDlet</code> is a set of classes designed to be run and
* controlled by the application management software via this interface.
* The states allow the application management software to manage
* the activities of multiple <CODE>MIDlets</CODE> within
* a runtime environment.
* It can select which <code>MIDlet</code>s are active at a given time
* by starting and pausing them individually.
* The application management software maintains the state of the
* <code>MIDlet</code> and
* invokes methods on the <code>MIDlet</code> to notify the MIDlet of
* change states.
* The <code>MIDlet</code>
* implements these methods to update its internal activities and
* resource usage as directed by the application management software.
* The <code>MIDlet</code> can initiate some state changes itself and
* notifies the application management software of those state changes
* by invoking the appropriate methods.<p>
*
* <strong>Note:</strong> The methods on this interface signal state
* changes. The state change is not considered complete until the state
* change method has returned. It is intended that these methods return
* quickly.<p>
*/
public abstract class MIDlet {
/**
* Inner class to request security token from SecurityInitializer.
* SecurityInitializer should be able to check this inner class name.
*/
static private class SecurityTrusted
implements ImplicitlyTrustedClass {}
/** Security token to allow access to implementation APIs */
private static SecurityToken classSecurityToken =
SecurityInitializer.requestToken(new SecurityTrusted());
/** Internal peer of this MIDlet */
private MIDletPeer peer;
/**
* Static initializer to set MIDletTunnel implementation
* in MIDletPeer class.
*/
static {
MIDletPeer.setMIDletTunnel(classSecurityToken,
new MIDletTunnelImpl());
}
/**
* Gets the MIDletPeer instance for this MIDlet.
*
* @return MIDletPeer instance for this midlet.
*/
MIDletPeer getMIDletPeer() {
return peer;
}
/**
* Protected constructor for subclasses.
* The application management software is responsible
* for creating MIDlets and creation of MIDlets is restricted.
* MIDlets should not attempt to create other MIDlets.
*
* @exception java.lang.SecurityException unless the application
* management software is creating the MIDlet.
*/
protected MIDlet() {
peer = MIDletStateHandler.newMIDletPeer(classSecurityToken, this);
// Ensure that a display for this midlet is created
Display d = Display.getDisplay(this);
}
/**
* Signals the <code>MIDlet</code> that it has entered the
* <em>Active</em> state.
* In the <em>Active</EM> state the <code>MIDlet</code> may
* hold resources.
* The method will only be called when
* the <code>MIDlet</code> is in the <em>Paused</em> state.
* <p>
* Two kinds of failures can prevent the service from starting,
* transient and non-transient. For transient failures the
* <code>MIDletStateChangeException</code> exception should be thrown.
* For non-transient failures the <code>notifyDestroyed</code>
* method should be called.
* <p>
* If a Runtime exception occurs during <code>startApp</code> the
* MIDlet will be
* destroyed immediately. Its <code>destroyApp</code> will be
* called allowing
* the MIDlet to cleanup.
*
* @exception MIDletStateChangeException is thrown
* if the <code>MIDlet</code>
* cannot start now but might be able to start at a
* later time.
*/
protected abstract void startApp() throws MIDletStateChangeException;
/**
*
* Signals the <code>MIDlet</code> to enter
* the <em>Paused</em> state.
* In the <em>Paused</em> state the <code>MIDlet</code> must
* release shared resources
* and become quiescent. This method will only be called
* called when the <code>MIDlet</code> is in the <em>Active</em> state. <p>
* <p>
* If a Runtime exception occurs during <code>pauseApp</code> the
* MIDlet will be destroyed immediately. Its
* <code>destroyApp</code> will be called allowing
* the MIDlet to cleanup.
*/
protected abstract void pauseApp();
/**
* Signals the <code>MIDlet</code> to terminate and enter the
* <em>Destroyed</em> state.
* In the destroyed state the <code>MIDlet</code> must release
* all resources and save any persistent state. This method may
* be called from the <em>Paused</em> or
* <em>Active</em> states. <p>
* <code>MIDlet</code>s should
* perform any operations required before being terminated, such as
* releasing resources or saving preferences or
* state. <p>
*
* <strong>Note:</strong> The <code>MIDlet</code> can request that
* it not enter the <em>Destroyed</em>
* state by throwing an <code>MIDletStateChangeException</code>. This
* is only a valid response if the <code>unconditional</code>
* flag is set to <code>false</code>. If it is <code>true</code>
* the <code>MIDlet</code> is assumed to be in the <em>Destroyed</em> state
* regardless of how this method terminates. If it is not an
* unconditional request, the <code>MIDlet</code> can signify that it
* wishes to stay in its current state by throwing the
* <code>MIDletStateChangeException</code>.
* This request may be honored and the <code>destroy()</code>
* method called again at a later time.
*
* <p>If a Runtime exception occurs during <code>destroyApp</code> then
* they are ignored and the MIDlet is put into the <em>Destroyed</em>
* state.
*
* @param unconditional If true when this method is called, the
* <code>MIDlet</code> must cleanup and release all resources. If
* false the <code>MIDlet</code> may throw
* <CODE>MIDletStateChangeException</CODE> to indicate it does not
* want to be destroyed at this time.
*
* @exception MIDletStateChangeException is thrown
* if the <code>MIDlet</code> wishes to continue to
* execute (Not enter the <em>Destroyed</em> state).
* This exception is ignored if <code>unconditional</code>
* is equal to <code>true</code>.
*/
protected abstract void destroyApp(boolean unconditional)
throws MIDletStateChangeException;
/**
*
* Used by an <code>MIDlet</code> to notify the application
* management software that it has entered into the
* <em>Destroyed</em> state. The application management software
* will not call the MIDlet's <code>destroyApp</code> method,
* and all resources
* held by the <code>MIDlet</code> will be considered eligible for
* reclamation.
* The <code>MIDlet</code> must have performed the same operations
* (clean up, releasing of resources etc.) it would have if the
* <code>MIDlet.destroyApp()</code> had been called.
*
*/
public final void notifyDestroyed() {
peer.notifyDestroyed();
}
/**
* Notifies the application management software that the MIDlet
* does not want to be active and has
* entered the <em>Paused</em> state. Invoking this method will
* have no effect if the <code>MIDlet</code> is destroyed, or if
* it has not yet been started. <p>
* It may be invoked by the <code>MIDlet</code> when it is
* in the <em>Active</em> state. <p>
*
* If a <code>MIDlet</code> calls <code>notifyPaused()</code>, in the
* future its <code>startApp()</code> method may be called make
* it active again, or its <code>destroyApp()</code> method may be
* called to request it to destroy itself. <p>
*
* If the application pauses itself it will need to call
* <code>resumeRequest</code> to request to reenter the
* <code>active</code> state.
*/
public final void notifyPaused() {
peer.notifyPaused();
}
/**
* Provides a <code>MIDlet</code> with a mechanism to retrieve named
* properties from the application management software.
* The properties are retrieved from the combination of
* the application descriptor file and the manifest.
* For trusted applications the values in the manifest MUST NOT
* be overridden by those in the application descriptor. If they
* differ, the MIDlet will not be installed on the device.
* For untrusted applications, if an attribute
* in the descriptor has the same name as an attribute in the
* manifest the value from the descriptor is used and the value
* from the manifest is ignored.
*
* @param key the name of the property
* @return A string with the value of the property.
* <code>null</code> is returned if no value is available for the
* key.
* @exception NullPointerException is thrown
* if key is <code>null</code>.
*/
public final String getAppProperty(String key) {
return peer.getMIDletSuite().getProperty(key);
}
/**
* Provides a <code>MIDlet</code> with a mechanism to indicate
* that it is interested in entering the <em>Active</em>
* state. Calls to this method can be used by the application
* management software to determine which applications to move to
* the <em>Active</em> state. <p> When the application management
* software decides to activate this application it will call the
* <code>startApp</code> method. <p> The application is generally
* in the <em>Paused</em> state when this is called. Even in the
* paused state the application may handle asynchronous events
* such as timers or callbacks.
*/
public final void resumeRequest() {
peer.resumeRequest();
}
/**
* <p>Requests that the device handle (for example, display or
* install) the indicated URL.</p>
*
* <p>If the platform has the appropriate capabilities and
* resources available, it SHOULD bring the appropriate
* application to the foreground and let the user interact with
* the content, while keeping the MIDlet suite running in the
* background. If the platform does not have appropriate
* capabilities or resources available, it MAY wait to handle the
* URL request until after the MIDlet suite exits. In this case,
* when the requesting MIDlet suite exits, the platform MUST then
* bring the appropriate application (if one exists) to the
* foreground to let the user interact with the content.</p>
*
* <p>This is a non-blocking method. In addition, this method does
* NOT queue multiple requests. On platforms where the MIDlet
* suite must exit before the request is handled, the platform
* MUST handle only the last request made. On platforms where the
* MIDlet suite and the request can be handled concurrently, each
* request that the MIDlet suite makes MUST be passed to the
* platform software for handling in a timely fashion.</p>
*
* <p>If the URL specified refers to a MIDlet suite (either an
* Application Descriptor or a JAR file), the application handling
* the request MUST interpret it as a request to install the named
* package. In this case, the platform's normal MIDlet suite
* installation process SHOULD be used, and the user MUST be
* allowed to control the process (including cancelling the
* download and/or installation). If the MIDlet suite being
* installed is an <em>update</em> of the currently running MIDlet
* suite, the platform MUST first stop the currently running
* MIDlet suite before performing the update. On some platforms,
* the currently running MIDlet suite MAY need to be stopped
* before any installations can occur.</p>
*
* <p>If the URL specified is of the form
* <code>tel:<number></code>, as specified in <a
* href="http://www.ietf.org/rfc/rfc2806.txt">RFC2806</a>, then the
* platform MUST interpret this as a request to initiate a voice
* call. The request MUST be passed to the "phone"
* application to handle if one is present in the platform. The
* "phone" application, if present, MUST be able to set
* up local and global phone calls and also perform DTMF post
* dialing. Not all elements of RFC2806 need be implemented,
* especially the area-specifier or any other requirement on the
* terminal to know its context. The isdn-subaddress,
* service-provider and future-extension may also be
* ignored. Pauses during dialing are not relevant in some
* telephony services.</p>
*
* <p>Devices MAY choose to support additional URL schemes beyond
* the requirements listed above.</p>
*
* <p>Many of the ways this method will be used could have a
* financial impact to the user (e.g. transferring data through a
* wireless network, or initiating a voice call). Therefore the
* platform MUST ask the user to explicitly acknowledge each
* request before the action is taken. Implementation freedoms are
* possible so that a pleasant user experience is retained. For
* example, some platforms may put up a dialog for each request
* asking the user for permission, while other platforms may
* launch the appropriate application and populate the URL or
* phone number fields, but not take the action until the user
* explicitly clicks the load or dial buttons.</p>
*
* @return true if the MIDlet suite MUST first exit before the
* content can be fetched.
*
* @param URL The URL for the platform to load. An empty string
* (not null) cancels any pending requests.
*
* @exception javax.microedition.io.ConnectionNotFoundException if
* the platform cannot handle the URL requested.
*
*/
public final boolean platformRequest(String URL)
throws javax.microedition.io.ConnectionNotFoundException {
return peer.platformRequest(URL);
}
/**
* Get the status of the specified permission.
* If no API on the device defines the specific permission
* requested then it must be reported as denied.
* If the status of the permission is not known because it might
* require a user interaction then it should be reported as unknown.
*
* @param permission to check if denied, allowed, or unknown.
* @return 0 if the permission is denied; 1 if the permission is allowed;
* -1 if the status is unknown
*
*/
public final int checkPermission(String permission) {
return peer.checkPermission(permission);
}
}
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