MenuAction.java

/*
 * Copyright 2009-2012 Amazon Technologies, Inc. 
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); 
 * you may not use this file except in compliance with the License. 
 * You may obtain a copy of the License at:
 * 
 *    http://aws.amazon.com/apache2.0
 *
 * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES 
 * OR CONDITIONS OF ANY KIND, either express or implied. See the 
 * License for the specific language governing permissions and 
 * limitations under the License. 
 */

package com.amazonaws.eclipse.ec2.utils;

import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.ActionContributionItem;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuCreator;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Menu;

import com.amazonaws.eclipse.ec2.Ec2Plugin;
import com.amazonaws.eclipse.ec2.utils.IMenu.MenuItem;

/**
 * Action class to create static Menu objects
 */
public class MenuAction extends Action implements IMenuCreator {

	/** Holds MenuHandler object to process the menus */
	private MenuHandler menuHandler;
	
	/** Menu that gets displayed */
	protected Menu menu;

	/**
	 * Constructor
	 * 
	 * @param text
	 *            Text that gets displayed on the Menu
	 * @param toolTip
	 *            Tooltip that gets displayed for the menu
	 * @param imageDescriptor
	 *            The icon used for the menu
	 * @param menuHandler
	 *            The MenuHandler object used to manage actions
	 */
	public MenuAction(String text, String toolTip, 
				String imageDescriptor, MenuHandler menuHandler) {
		setText(text);
		setToolTipText(toolTip);
		setImageDescriptor(Ec2Plugin.getDefault().getImageRegistry().getDescriptor(imageDescriptor));
		this.menuHandler = menuHandler;
		setMenuCreator(this);
	}
	
	/**
	 * @see org.eclipse.jface.action.IMenuCreator#getMenu(Menu)
	 */
	public Menu getMenu(Menu parent) {
		return menu;
	}
	
	/**
	 * @see org.eclipse.jface.action.IMenuCreator#getMenu(Control)
	 */
	public Menu getMenu(Control parent) {
        if (menu != null) {
            return menu;
        }
        return constructMenu(parent);
	}

	/**
	 * Creates the menu dynamically
	 * 
	 * @param parent
	 *            Composite on which the menu is drawn
	 *
	 * @return The created menu
	 */
	protected Menu constructMenu(Control parent) {
        menu = new Menu(parent);

        for (final MenuItem menuItem : menuHandler.getMenuItems()) {
        	if (menuItem.equals(MenuItem.SEPARATOR)) {
        		new org.eclipse.swt.widgets.MenuItem(menu, SWT.SEPARATOR);        		
        	} else {
	        	IAction action = new Action(menuItem.getMenuText(), AS_RADIO_BUTTON) {
	        		@Override
	        		public void run() {
	        			if (isChecked()) {
	        				menuHandler.setCurrentSelection(menuItem);
	        			}
	        		}        		
	        	};
	        	
	        	addActionToMenu(action);
	        	
				// Every Time new object is created, so getMenuId is used for
				// determining the current selection
	        	action.setChecked(menuHandler.getCurrentSelection().getMenuId().equals(menuItem.getMenuId()));
        	}
        }
        
        return menu;
	}

	/**
	 * Use to add different MenuItems to the menu
	 * 
	 * @param action
	 *            The Action to be added
	 */
	protected void addActionToMenu(IAction action) {
		ActionContributionItem item = new ActionContributionItem(action);
		item.fill(menu, -1);
	}

	/**
	 * @see org.eclipse.jface.action.IMenuCreator#dispose()
	 */
	public void dispose() {
		if (menu != null) {
			menu.dispose();
		}
	}

	/**
	 * Used to popup the menu
	 * 
	 * @see org.eclipse.jface.action.Action#run()
	 */	
	@Override
	public void run() {
		if (menu != null)
			menu.setVisible(true);
	}
}