/*******************************************************************************
* Copyright (c) 2006 IBM Corporation and others.
* 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.ui.internal.texteditor;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
public final class PropertyEventDispatcher {
private final Map fHandlerMap= new HashMap();
private final Map fReverseMap= new HashMap();
private final IPreferenceStore fStore;
private final IPropertyChangeListener fListener= new IPropertyChangeListener() {
public void propertyChange(PropertyChangeEvent event) {
firePropertyChange(event);
}
};
public PropertyEventDispatcher(IPreferenceStore store) {
Assert.isLegal(store != null);
fStore= store;
}
public void dispose() {
if (!fReverseMap.isEmpty())
fStore.removePropertyChangeListener(fListener);
fReverseMap.clear();
fHandlerMap.clear();
}
private void firePropertyChange(PropertyChangeEvent event) {
Object value= fHandlerMap.get(event.getProperty());
if (value instanceof IPropertyChangeListener)
((IPropertyChangeListener) value).propertyChange(event);
else if (value instanceof Set)
for (Iterator it= ((Set) value).iterator(); it.hasNext(); )
((IPropertyChangeListener) it.next()).propertyChange(event);
}
public void addPropertyChangeListener(String property, IPropertyChangeListener listener) {
Assert.isLegal(property != null);
Assert.isLegal(listener != null);
if (fReverseMap.isEmpty())
fStore.addPropertyChangeListener(fListener);
multiMapPut(fHandlerMap, property, listener);
multiMapPut(fReverseMap, listener, property);
}
private void multiMapPut(Map map, Object key, Object value) {
Object mapping= map.get(key);
if (mapping == null) {
map.put(key, value);
} else if (mapping instanceof Set) {
((Set) mapping).add(value);
} else {
Set set= new LinkedHashSet();
set.add(mapping);
set.add(value);
map.put(key, set);
}
}
private void multiMapRemove(Map map, Object key, Object value) {
Object mapping= map.get(key);
if (mapping instanceof Set) {
((Set) mapping).remove(value);
} else if (mapping != null) {
map.remove(key);
}
}
public void removePropertyChangeListener(IPropertyChangeListener listener) {
Object value= fReverseMap.get(listener);
if (value == null)
return;
if (value instanceof String) {
fReverseMap.remove(listener);
multiMapRemove(fHandlerMap, value, listener);
} else if (value instanceof Set) {
fReverseMap.remove(listener);
for (Iterator it= ((Set) value).iterator(); it.hasNext();)
multiMapRemove(fHandlerMap, it.next(), listener);
}
if (fReverseMap.isEmpty())
fStore.removePropertyChangeListener(fListener);
}
}