/*******************************************************************************
* Copyright (c) 2007 cnfree.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* cnfree - initial API and implementation
*******************************************************************************/
package org.sf.feeling.swt.win32.extension.sound.hook;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.internal.Callback;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.sf.feeling.swt.win32.extension.Win32;
import org.sf.feeling.swt.win32.internal.extension.Extension;
import org.sf.feeling.swt.win32.internal.extension.callback.WNDCallback;
import org.sf.feeling.swt.win32.internal.extension.callback.WNDCallbackManager;
/**
* <b>Important</b>: Vista doesn't support it.
*
* @author <a href="mailto:cnfree2000@hotmail.com">cnfree</a>
*
*/
public class MixerMsgHook
{
private static final int MM_MIXM_CONTROL_CHANGE = 0x3D1;
private int oldAddress;
private Shell shell;
private Callback windowMsgCallback;;
private int newAddress;
private WNDCallback callback;
public MixerMsgHook(Shell shell)
{
this.shell = shell;
}
public void installHook()
{
if (callback == null)
{
windowMsgCallback = new Callback(this, "WindowMsgProc", 4);
newAddress = windowMsgCallback.getAddress();
oldAddress = Extension.SetWindowLong(shell.handle, Win32.GWL_WNDPROC, newAddress);
callback = new WNDCallback(shell, oldAddress, newAddress)
{
public void dispose()
{
disposeCallback();
}
};
WNDCallbackManager.addCallback(shell, callback);
shell.addDisposeListener(new DisposeListener()
{
public void widgetDisposed(DisposeEvent e)
{
unInstallHook();
}
});
}
}
public void unInstallHook()
{
if (callback != null) WNDCallbackManager.disposeCallback(shell, callback);
}
private void disposeCallback()
{
if (callback != null)
{
Extension.SetWindowLong(shell.handle, Win32.GWL_WNDPROC, callback.getOldAddress());
windowMsgCallback.dispose();
windowMsgCallback = null;
newAddress = 0;
callback = null;
}
}
int WindowMsgProc(int handle, int msg, int wParam, int lParam)
{
if (msg == MM_MIXM_CONTROL_CHANGE)
{
Event event = new Event();
event.type = wParam;
event.detail = lParam;
event.widget = shell;
event.time = Extension.GetTickCount();
fireChangedEvent(event);
}
return Extension.CallWindowProc(oldAddress, handle, msg, wParam, lParam);
}
private List listeners;
public void addChangeListener(Listener listener)
{
if (listener == null) return;
if (listeners == null) listeners = new ArrayList();
if (!listeners.contains(listener)) listeners.add(listener);
}
public void removeChangeListener(Listener listener)
{
if (listener == null) return;
listeners.remove(listener);
if (listeners != null && listeners.size() == 0) listeners = null;
}
void fireChangedEvent(final Event event)
{
if (listeners != null)
{
for (int i = 0; i < listeners.size(); i++)
{
final Listener listener = (Listener) listeners.get(i);
Display.getDefault().asyncExec(new Runnable()
{
public void run()
{
listener.handleEvent(event);
}
});
}
}
}
}