WorkingSetElementUpdater.java

/*******************************************************************************
 * Copyright (c) 2011 Wind River Systems, Inc. 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:
 * Wind River Systems - initial API and implementation
 *******************************************************************************/
package org.eclipse.tm.te.ui.views.workingsets;

import java.util.ArrayList;
import java.util.EventObject;
import java.util.List;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExecutableExtension;
import org.eclipse.tm.te.runtime.events.EventManager;
import org.eclipse.tm.te.ui.events.AbstractEventListener;
import org.eclipse.tm.te.ui.views.events.ViewerContentChangeEvent;
import org.eclipse.ui.IWorkingSet;
import org.eclipse.ui.IWorkingSetUpdater;
import org.eclipse.ui.navigator.CommonViewer;

/**
 * Working set element updater implementation.
 */
public class WorkingSetElementUpdater extends AbstractEventListener implements IWorkingSetUpdater, IExecutableExtension {
	// List of working sets managed by this updater
	private final List<IWorkingSet> workingSets = new ArrayList<IWorkingSet>();

	/* (non-Javadoc)
	 * @see org.eclipse.core.runtime.IExecutableExtension#setInitializationData(org.eclipse.core.runtime.IConfigurationElement, java.lang.String, java.lang.Object)
	 */
	@Override
	public void setInitializationData(IConfigurationElement config, String propertyName, Object data) throws CoreException {
		// Register ourself as ViewContentChangeEvent listener
		EventManager.getInstance().addEventListener(this, ViewerContentChangeEvent.class);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkingSetUpdater#add(org.eclipse.ui.IWorkingSet)
	 */
	@Override
	public void add(IWorkingSet workingSet) {
		synchronized (workingSets) {
			workingSets.add(workingSet);
        }
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkingSetUpdater#remove(org.eclipse.ui.IWorkingSet)
	 */
	@Override
	public boolean remove(IWorkingSet workingSet) {
		synchronized (workingSets) {
			return workingSets.remove(workingSet);
        }
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkingSetUpdater#contains(org.eclipse.ui.IWorkingSet)
	 */
	@Override
	public boolean contains(IWorkingSet workingSet) {
		synchronized (workingSets) {
			return workingSets.contains(workingSet);
        }
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IWorkingSetUpdater#dispose()
	 */
	@Override
	public void dispose() {
		synchronized (workingSets) {
			workingSets.clear();
        }

		// Remove ourself as event listener
		EventManager.getInstance().removeEventListener(this);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.tm.te.runtime.interfaces.events.IEventListener#eventFired(java.util.EventObject)
	 */
	@Override
	public void eventFired(EventObject event) {
		if (!(event instanceof ViewerContentChangeEvent) && !(((ViewerContentChangeEvent)event).getSource() instanceof CommonViewer)) {
			return;
		}

		// Create a snapshot of the working sets
		final IWorkingSet[] snapshot;
		synchronized (workingSets) {
			snapshot = workingSets.toArray(new IWorkingSet[workingSets.size()]);
        }

		// Update the working sets
		onUpdateWorkingSets((CommonViewer)((ViewerContentChangeEvent)event).getSource(), snapshot);
	}

	/**
	 * Update the managed working sets based on the content of the given viewer.
	 *
	 * @param viewer The viewer. Must not be <code>null</code>.
	 * @param workingsets The working sets. Must not be <code>null</code>.
	 */
	protected void onUpdateWorkingSets(CommonViewer viewer, IWorkingSet[] workingsets) {
		Assert.isNotNull(viewer);
		Assert.isNotNull(workingsets);
	}
}