org.eclipse.mylyn.context.core/src/org/eclipse/mylyn/context/core/ContextChangeEvent.java

package org.eclipse.mylyn.context.core;

import java.util.Collections;
import java.util.List;

import org.eclipse.core.runtime.Assert;

/**
 * @author Shawn Minto
 * @since 3.2
 */
public class ContextChangeEvent {

	/**
	 * @author Shawn Minto
	 * @since 3.2
	 */
	public enum ContextChangeKind {
		PRE_ACTIVATED, ACTIVATED, DEACTIVATED, CLEARED, INTEREST_CHANGED, LANDMARKS_ADDED, LANDMARKS_REMOVED, ELEMENTS_DELETED;
	}

	private final String contextHandle;

	private final IInteractionContext context;

	private final ContextChangeKind eventKind;

	private final List<IInteractionElement> elements;

	public ContextChangeEvent(ContextChangeKind eventKind, String contextHandle, IInteractionContext context,
			List<IInteractionElement> elements) {
		Assert.isNotNull(eventKind);
		this.contextHandle = contextHandle;
		this.context = context;
		this.eventKind = eventKind;
		if (elements == null) {
			this.elements = Collections.emptyList();
		} else {
			this.elements = elements;
		}
	}

	/**
	 * The Type of context event that occurred
	 * 
	 * @since 3.2
	 */
	public ContextChangeKind getEventKind() {
		return eventKind;
	}

	/**
	 * The elements that were manipulated for the event (may be empty)
	 * 
	 * @since 3.2
	 */
	public List<IInteractionElement> getElements() {
		return elements;
	}

	/**
	 * The handle of the context that was changed (Can be null if a composite context with multiple
	 * IInteractionContext's is changed)
	 * 
	 * @since 3.2
	 */
	public String getContextHandle() {
		return contextHandle;
	}

	/**
	 * The context that was changed (Can be null e.g. context deleted)
	 * 
	 * @since 3.2
	 */
	public IInteractionContext getContext() {
		return context;
	}

	/**
	 * Utility for whether the manipulated context is the active one
	 * 
	 * @since 3.2
	 */
	public boolean isActiveContext() {
		IInteractionContext activeContext = ContextCore.getContextManager().getActiveContext();
		return activeContext != null && activeContext.getHandleIdentifier() != null
				&& activeContext.getHandleIdentifier().equals(contextHandle);
	}
}