/*
* Copyright (c) 2011, grossmann
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the jo-widgets.org nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.jowidgets.spi.impl.controller;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.Set;
import org.jowidgets.common.widgets.controller.IKeyEvent;
import org.jowidgets.common.widgets.controller.IKeyListener;
import org.jowidgets.common.widgets.controller.IKeyObservable;
import org.jowidgets.util.Assert;
import org.jowidgets.util.event.IObservableCallback;
public class KeyObservable implements IKeyObservable {
private static final IEventInvoker KEY_PRESSED_INVOKER = new KeyPressedInvoker();
private static final IEventInvoker KEY_RELEASED_INVOKER = new KeyReleasedInvoker();
private final Set<IKeyListener> listeners;
private final IObservableCallback observableCallback;
private boolean onFire;
public KeyObservable(final IObservableCallback observableCallback) {
Assert.paramNotNull(observableCallback, "observableCallback");
this.listeners = new LinkedHashSet<IKeyListener>();
this.observableCallback = observableCallback;
this.onFire = false;
}
@Override
public final void addKeyListener(final IKeyListener listener) {
Assert.paramNotNull(listener, "listener");
listeners.add(listener);
if (!onFire && listeners.size() == 1) {
observableCallback.onFirstRegistered();
}
}
@Override
public final void removeKeyListener(final IKeyListener listener) {
Assert.paramNotNull(listener, "listener");
listeners.remove(listener);
if (!onFire && listeners.size() == 0) {
observableCallback.onLastUnregistered();
}
}
public final void fireKeyPressed(final ILazyKeyEventContentFactory contentFactory) {
fireKeyEvent(contentFactory, KEY_PRESSED_INVOKER);
}
public final void fireKeyReleased(final ILazyKeyEventContentFactory contentFactory) {
fireKeyEvent(contentFactory, KEY_RELEASED_INVOKER);
}
private void fireKeyEvent(final ILazyKeyEventContentFactory contentFactory, final IEventInvoker eventInvoker) {
if (listeners.size() > 0) {
final int lastSize = listeners.size();
onFire = true;
try {
final IKeyEvent event = new KeyEvent(contentFactory);
for (final IKeyListener listener : new LinkedList<IKeyListener>(listeners)) {
eventInvoker.fireEvent(listener, event);
}
}
finally {
onFire = false;
if (lastSize > 0 && listeners.size() == 0) {
observableCallback.onLastUnregistered();
}
else if (lastSize == 0 && listeners.size() > 0) {
observableCallback.onFirstRegistered();
}
}
}
}
private interface IEventInvoker {
void fireEvent(IKeyListener listener, IKeyEvent event);
}
private static final class KeyReleasedInvoker implements IEventInvoker {
@Override
public void fireEvent(final IKeyListener listener, final IKeyEvent event) {
listener.keyReleased(event);
}
}
private static final class KeyPressedInvoker implements IEventInvoker {
@Override
public void fireEvent(final IKeyListener listener, final IKeyEvent event) {
listener.keyPressed(event);
}
}
}