bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/PluginActionContributionItem.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ui.internal;

import org.eclipse.jface.action.ActionContributionItem;
import org.eclipse.ui.IActionDelegate2;
import org.eclipse.ui.IPluginContribution;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.activities.ActivityManagerEvent;
import org.eclipse.ui.activities.IActivityManagerListener;
import org.eclipse.ui.activities.IIdentifier;
import org.eclipse.ui.activities.IIdentifierListener;
import org.eclipse.ui.activities.IWorkbenchActivitySupport;
import org.eclipse.ui.activities.IdentifierEvent;
import org.eclipse.ui.activities.WorkbenchActivityHelper;

/**
 * Contribution item for actions provided by plugins via workbench action
 * extension points.
 */
public class PluginActionContributionItem extends ActionContributionItem implements IIdentifierListener, IActivityManagerListener {

	private IIdentifier identifier = null;
	
	/**
	 * Creates a new contribution item from the given action. The id of the
	 * action is used as the id of the item.
	 * 
	 * @param action
	 *            the action
	 */
	public PluginActionContributionItem(PluginAction action) {
		// dynamic UI (DDW) - this constructor has changed since 1113
		super(action);

		PlatformUI
			.getWorkbench()
			.getActivitySupport()
			.getActivityManager()
			.addActivityManagerListener(this);		
		
		// set up the identifier if necessary
		if (WorkbenchActivityHelper.isFiltering()) {			
			createIdentifier();
		}
	}
	
	/**
	 * Create the IIdentifier reference for this item.
     *
	 * @sicne 3.0
	 */
	private void createIdentifier() {
		IWorkbenchActivitySupport workbenchActivitySupport =
			PlatformUI.getWorkbench().getActivitySupport();
		IPluginContribution contribution = (IPluginContribution) getAction();
		// no need to check if contribution.getPluginId() == null - plugin actions are always from plugins.
		identifier =
			workbenchActivitySupport
				.getActivityManager()
				.getIdentifier(
				WorkbenchActivityHelper.createUnifiedId(contribution));
		identifier.addIdentifierListener(this);
	}

	/**
	 * Dispose of the IIdentifier if necessary.
	 * 
	 * @since 3.0
	 */
	private void disposeIdentifier() {
		if (identifier != null) {
			identifier.removeIdentifierListener(this);
			identifier = null;
		}
	}

	/**
	 * The default implementation of this <code>IContributionItem</code>
	 * method notifies the delegate if loaded and implements the <code>IActionDelegate2</code>
	 * interface.
	 */
	public void dispose() {
		PluginAction proxy = (PluginAction) getAction();
		if (proxy != null) {
			if (proxy.getDelegate() instanceof IActionDelegate2) {
				((IActionDelegate2) proxy.getDelegate()).dispose();
			}
		}
		
		PlatformUI
			.getWorkbench()
			.getActivitySupport()
			.getActivityManager()
			.removeActivityManagerListener(this);	
		
		disposeIdentifier();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.action.ActionContributionItem#isVisible()
	 */
	public boolean isVisible() {
		if (identifier != null && !identifier.isEnabled()) 
			return false;
		return super.isVisible();
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.ui.activities.IIdentifierListener#identifierChanged(org.eclipse.ui.activities.IdentifierEvent)
	 */
	public void identifierChanged(IdentifierEvent identifierEvent) {
		getParent().markDirty();
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.activities.IActivityManagerListener#activityManagerChanged(org.eclipse.ui.activities.ActivityManagerEvent)
	 */
	public void activityManagerChanged(ActivityManagerEvent activityManagerEvent) {
		// ensure that if we're going from a non-filtering state that we get an identifier
		// and vice versa.
		if (WorkbenchActivityHelper.isFiltering() && identifier == null) {
			createIdentifier();
			getParent().markDirty();
		}
		else if (!WorkbenchActivityHelper.isFiltering() && identifier != null) {
			disposeIdentifier();
			getParent().markDirty();
		}		
	}
}