/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.driver.input;
import java.nio.ByteBuffer;
import java.nio.channels.ByteChannel;
import java.util.ArrayList;
import org.jnode.driver.Driver;
import org.jnode.system.event.SystemEvent;
import org.jnode.util.Queue;
import org.jnode.util.QueueProcessor;
import org.jnode.util.QueueProcessorThread;
public abstract class AbstractInputDriver<E extends SystemEvent> extends Driver {
private final ArrayList<SystemListener> listeners = new ArrayList<SystemListener>();
private QueueProcessorThread<E> eventQueueThread;
private Queue<E> eventQueue = new Queue<E>();
private InputDaemon daemon;
protected final void startDispatcher(String id) {
this.eventQueue = new Queue<E>();
this.daemon = new InputDaemon(id + "-daemon");
this.daemon.start();
this.eventQueueThread = new QueueProcessorThread<E>(id + "-dispatcher",
eventQueue, new SystemEventDispatcher());
this.eventQueueThread.start();
}
protected final void stopDispatcher() {
if (eventQueueThread != null) {
eventQueueThread.stopProcessor();
}
this.eventQueueThread = null;
InputDaemon daemon = this.daemon;
this.daemon = null;
if (daemon != null) {
daemon.setRunningState(false);
daemon.interrupt();
}
}
class SystemEventDispatcher implements QueueProcessor<E> {
/**
* @see org.jnode.util.QueueProcessor#process(java.lang.Object)
*/
public void process(E event) throws Exception {
for (SystemListener l : listeners) {
sendEvent(l, event);
if (event.isConsumed()) {
break;
}
}
}
}
protected abstract void sendEvent(SystemListener<E> l, E e);
/**
* Add a pointer listener
*
* @param l
*/
public final synchronized void addListener(SystemListener<E> l) {
listeners.add(l);
}
/**
* Remove a pointer listener
*
* @param l
*/
public final synchronized void removeListener(SystemListener<E> l) {
listeners.remove(l);
}
/**
* Claim to be the preferred listener.
* The given listener must have been added by addKeyboardListener.
* <b>This is not checked by a security manager</b>
*
* @param l
*/
protected final synchronized void setPreferredListener(SystemListener<E> l) {
if (listeners.remove(l)) {
listeners.add(0, l);
}
}
protected abstract E handleScancode(byte b);
/**
* Gets the byte channel. This is implementation specific
*
* @return The byte channel
*/
protected abstract ByteChannel getChannel();
/**
* InputDaemon that translates scancodes to SystemEvents and dispatches those events.
*/
class InputDaemon extends Thread {
private boolean runningState;
public InputDaemon(String name) {
super(name);
}
public void run() {
processChannel();
}
/**
* Read scancodes from the input channel and dispatch them as events.
*/
final void processChannel() {
final ByteBuffer buf = ByteBuffer.allocate(1);
final ByteChannel channel = getChannel();
setRunningState(true);
while ((channel != null) && channel.isOpen() && isRunningState()) {
try {
buf.rewind();
if (channel.read(buf) != 1) {
continue;
}
final byte scancode = buf.get(0);
E event = handleScancode(scancode);
if ((event != null) && !event.isConsumed()) {
if (eventQueue.isClosed()) {
// the queue is closed : it usually happen while JNode is halting
// simply stop processing the events
break;
}
eventQueue.add(event);
}
} catch (Throwable ex) {
ex.printStackTrace();
}
}
}
public synchronized boolean isRunningState() {
return runningState;
}
public synchronized void setRunningState(boolean runningState) {
this.runningState = runningState;
}
}
}