/*******************************************************************************
 * 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.core.runtime.IConfigurationElement;
import org.eclipse.ui.*;

/**
 * This class extends regular plugin action with the
 * additional requirement that the delegate has
 * to implement interface IViewActionDeelgate.
 * This interface has one additional method (init)
 * whose purpose is to initialize the delegate with
 * the view part in which the action is intended to run.
 */
public final class ViewPluginAction extends PartPluginAction {
	private IViewPart viewPart;

	/**
	 * This class adds the requirement that action delegates
	 * loaded on demand implement IViewActionDelegate
	 */
	public ViewPluginAction(IConfigurationElement actionElement, IViewPart viewPart, String id, int style) {
		super(actionElement, id, style);
		this.viewPart = viewPart;
		registerSelectionListener(viewPart);
	}

	/* (non-Javadoc)
	 * Method declared on PluginAction.
	 */
	protected IActionDelegate validateDelegate(Object obj) throws WorkbenchException {
		if (obj instanceof IViewActionDelegate)
			return (IViewActionDelegate)obj;
		else
			throw new WorkbenchException("Action must implement IViewActionDelegate"); //$NON-NLS-1$
	}

	/* (non-Javadoc)
	 * Method declared on PluginAction.
	 */
	protected void initDelegate() {
		super.initDelegate();
		((IViewActionDelegate)getDelegate()).init(viewPart);
	}

	/**
	 * Returns true if the view has been set
	 * The view may be null after the constructor is called and
	 * before the view is stored.  We cannot create the delegate
	 * at that time.
	 */
	public boolean isOkToCreateDelegate() {
		return super.isOkToCreateDelegate() && viewPart != null;
	}
}