01: /*
02: *
03: *
04: * Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
05: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
06: *
07: * This program is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU General Public License version
09: * 2 only, as published by the Free Software Foundation.
10: *
11: * This program is distributed in the hope that it will be useful, but
12: * WITHOUT ANY WARRANTY; without even the implied warranty of
13: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14: * General Public License version 2 for more details (a copy is
15: * included at /legal/license.txt).
16: *
17: * You should have received a copy of the GNU General Public License
18: * version 2 along with this work; if not, write to the Free Software
19: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA
21: *
22: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
23: * Clara, CA 95054 or visit www.sun.com if you need additional
24: * information or have any questions.
25: */
26:
27: package com.sun.midp.events;
28:
29: /**
30: * A listener interface for preprocessing and receiving MIDP events.
31: * <p>
32: * Each system that wants to receive events implements an EventListener and
33: * registers the listener with the EventQueue for each event type to be
34: * received. Registration will require a system issued security token to
35: * prevent unauthorized registrations, to get this token the system will
36: * implement a static method to be called at VM startup. The EventListener
37: * interface has methods for pre-processing
38: * an event and receiving an event. The pre-processing method gets
39: * called in the Java thread that is inserting an event when the event is the
40: * type that it was registered for with a reference to the event to inserted
41: * and the previously inserted event (if there is one). If the pre-processing
42: * method merges the events and does not want does not want the new event
43: * inserted into the queue, then it will return false. The receiving method
44: * gets called in the event delivery thread with the first event of the type
45: * of it registered for in the queue.</p>
46: */
47: public interface EventListener {
48: /**
49: * Preprocess an event that is being posted to the event queue.
50: * This method will get called in the thread that posted the event.
51: *
52: * @param event event being posted
53: *
54: * @param waitingEvent previous event of this type waiting in the
55: * queue to be processed
56: *
57: * @return true to allow the post to continue, false to not post the
58: * event to the queue
59: */
60: public boolean preprocess(Event event, Event waitingEvent);
61:
62: /**
63: * Process an event.
64: * This method will get called in the event queue processing thread.
65: *
66: * @param event event to process
67: */
68: public void process(Event event);
69: }
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