bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/actions/HelpContentsAction.java

/*******************************************************************************
 * Copyright (c) 2004 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.actions;

import org.eclipse.jface.action.Action;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.ui.IWorkbenchPreferenceConstants;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.ActionFactory.IWorkbenchAction;
import org.eclipse.ui.help.WorkbenchHelp;
import org.eclipse.ui.internal.IHelpContextIds;
import org.eclipse.ui.internal.IWorkbenchGraphicConstants;
import org.eclipse.ui.internal.WorkbenchImages;
import org.eclipse.ui.internal.WorkbenchMessages;
import org.eclipse.ui.internal.util.PrefUtil;

/**
 * Action to open the help contents.
 * 
 * @since 3.0
 */
public class HelpContentsAction extends Action implements IWorkbenchAction {
	/**
	 * The workbench window; or <code>null</code> if this
	 * action has been <code>dispose</code>d.
	 */
	private IWorkbenchWindow workbenchWindow;

	/**
	 * Zero-arg constructor to allow cheat sheets to reuse this action.
	 */
	public HelpContentsAction() {
	    this(PlatformUI.getWorkbench().getActiveWorkbenchWindow());
	}

	/**
	 * Constructor for use by ActionFactory.
	 */
	public HelpContentsAction(IWorkbenchWindow window) {
		if (window == null) {
			throw new IllegalArgumentException();
		}
		this.workbenchWindow = window;
		setActionDefinitionId("org.eclipse.ui.help.helpContents"); //$NON-NLS-1$
		
		// support for allowing a product to override the text for the action
		String overrideText = PrefUtil.getAPIPreferenceStore().getString(IWorkbenchPreferenceConstants.HELP_CONTENTS_ACTION_TEXT);
		if ("".equals(overrideText)) { //$NON-NLS-1$
		    setText(WorkbenchMessages.getString("HelpContentsAction.text")); //$NON-NLS-1$ 
			setToolTipText(WorkbenchMessages.getString("HelpContentsAction.toolTip")); //$NON-NLS-1$
		}
		else {
		    setText(overrideText);
		    setToolTipText(Action.removeMnemonics(overrideText));
		}
		setImageDescriptor(WorkbenchImages.getImageDescriptor(IWorkbenchGraphicConstants.IMG_ETOOL_HELP_CONTENTS));
		WorkbenchHelp.setHelp(this, IHelpContextIds.HELP_CONTENTS_ACTION);
	}
	
	/* (non-Javadoc)
	 * Method declared on IAction.
	 */
	public void run() {
		if (workbenchWindow == null) {
			// action has been disposed
			return;
		}
		//This may take a while, so use the busy indicator
		BusyIndicator.showWhile(null, new Runnable() {
			public void run() {
				WorkbenchHelp.displayHelp();
			}
		});
	}
	
	/* (non-Javadoc)
	 * Method declared on ActionFactory.IWorkbenchAction.
	 */
	public void dispose() {
		workbenchWindow = null;
	}

}