bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/views/contentoutline/PropertyChangeUpdateActionContributionItem.java

/*******************************************************************************
 * Copyright (c) 2001, 2004 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/
package org.eclipse.wst.sse.ui.views.contentoutline;

import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.action.ActionContributionItem;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.ui.texteditor.IUpdate;

/**
 * A listener on the given action's PreferenceStore. It calls .update() on the
 * action when the given key changes value.
 */
public class PropertyChangeUpdateActionContributionItem extends ActionContributionItem {

	private class PreferenceUpdateListener implements IPropertyChangeListener {
		public void propertyChange(PropertyChangeEvent event) {
			if (event.getProperty().equals(fProperty)) {
				if (debug) {
					System.out.println(fProperty + " preference changed, updating " + getAction());
				}
				((IUpdate) getAction()).update();
			}
		}
	}

	static final boolean debug = "true".equalsIgnoreCase(Platform.getDebugOption("org.eclipse.wst.sse.ui/propertyChangeUpdateActionContributionItem")); //$NON-NLS-1$  //$NON-NLS-2$;

	private IPropertyChangeListener fListener = null;

	protected String fProperty = null;
	private IPreferenceStore fStore;

	public PropertyChangeUpdateActionContributionItem(PropertyChangeUpdateAction action) {
		super(action);
		fProperty = action.getPreferenceKey();
		fStore = action.getPreferenceStore();
		fListener = new PreferenceUpdateListener();
		connect();
	}

	public void connect() {
		if (debug) {
			System.out.println("PropertyChangeUpdateActionContributionItem started listening for " + fProperty);
		}
		if (fStore != null) {
			fStore.addPropertyChangeListener(fListener);
		}
	}

	public void disconnect() {
		if (debug) {
			System.out.println("PropertyChangeUpdateActionContributionItem stopped listening for " + fProperty);
		}
		if (fStore != null) {
			fStore.removePropertyChangeListener(fListener);
		}
	}

	public void dispose() {
		super.dispose();
		disconnect();
		fProperty = null;
		fStore = null;
	}

	public String toString() {
		if (getAction().getId() != null)
			return super.toString();
		else
			return getClass().getName() + "(text=" + getAction().getText() + ")"; //$NON-NLS-1$ //$NON-NLS-2$
	}
}