bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/workbench/ui/internal/UIEventPublisher.java

/*******************************************************************************
 * Copyright (c) 2009 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.e4.workbench.ui.internal;

import java.util.HashMap;
import java.util.Map;
import org.eclipse.e4.core.services.context.IEclipseContext;
import org.eclipse.e4.ui.model.application.MApplicationElement;
import org.eclipse.e4.ui.model.application.MUIElement;
import org.eclipse.e4.ui.services.events.IEventBroker;
import org.eclipse.e4.workbench.ui.UIEvents;
import org.eclipse.e4.workbench.ui.UIEvents.EventTags;
import org.eclipse.e4.workbench.ui.UIEvents.EventTypes;
import org.eclipse.emf.common.notify.Notification;
import org.eclipse.emf.ecore.EClass;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.ecore.util.EContentAdapter;

/**
 * Transforms E4 MPart events into 3.x legacy events.
 */
public class UIEventPublisher extends EContentAdapter {

	private IEclipseContext context;

	/**
	 * Constructor.
	 * 
	 * @param e4Context
	 * @param partList
	 */
	public UIEventPublisher(IEclipseContext e4Context) {
		this.context = e4Context;
	}

	public void notifyChanged(Notification notification) {
		super.notifyChanged(notification);

		// Inhibit No-Ops
		if (notification.isTouch())
			return;

		// Format the event
		Map<String, Object> argMap = new HashMap<String, Object>();
		String topic = formatData(notification, argMap);

		if (topic != null) {
			//System.out.println("UI Model Event: " + topic + " args: " + argMap); //$NON-NLS-1$ //$NON-NLS-2$
			IEventBroker eventManager = (IEventBroker) context.get(IEventBroker.class.getName());
			eventManager.send(topic, argMap);
		} else {
			System.out.println("Event of unknown type received from the model"); //$NON-NLS-1$
		}
	}

	/**
	 * @param notification
	 * @param argMap
	 * @return
	 */
	private String formatData(Notification notification, Map<String, Object> argMap) {
		// The unchecked casts below represent 'asserts'
		MApplicationElement appElement = (MApplicationElement) notification.getNotifier();
		EStructuralFeature feature = (EStructuralFeature) notification.getFeature();

		argMap.put(EventTags.TYPE, getEventType(notification));
		argMap.put(EventTags.ELEMENT, appElement);
		argMap.put(EventTags.ATTNAME, feature.getName());

		if (notification.getEventType() == Notification.SET
				|| notification.getEventType() == Notification.ADD
				|| notification.getEventType() == Notification.REMOVE) {
			argMap.put(EventTags.NEW_VALUE, notification.getNewValue());
			argMap.put(EventTags.OLD_VALUE, notification.getOldValue());
		}

		if (appElement instanceof MUIElement) {
			argMap.put(EventTags.WIDGET, ((MUIElement) appElement).getWidget());
		}
		return getTopic(feature, getEventType(notification));
	}

	private String getEventType(Notification notification) {
		switch (notification.getEventType()) {
		case Notification.ADD:
			return EventTypes.ADD;
		case Notification.REMOVE:
			return EventTypes.REMOVE;
		case Notification.SET:
			return EventTypes.SET;
		}

		return "UNKNOWN"; //$NON-NLS-1$
	}

	/**
	 * Map the attribute back to the correct topic.
	 * 
	 * @param type
	 * @return fully qualified topic
	 */
	private String getTopic(EStructuralFeature eFeature, String type) {
		EClass eContainingClass = eFeature.getEContainingClass();
		return UIEvents.UITopicBase + UIEvents.TOPIC_SEP + eContainingClass.getEPackage().getName()
				+ UIEvents.TOPIC_SEP + eContainingClass.getName() + UIEvents.TOPIC_SEP
				+ eFeature.getName() + UIEvents.TOPIC_SEP + type;
	}
}