MenuHandler.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 java.util.ArrayList;
import java.util.List;

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

/**
 * Handler to process Menu selections
 */
public class MenuHandler {

	/** Holds the currently selected Menu Item */
	private MenuItem currentSelection;
	
	/** Holds all the Menu Items that needs to be displayed */
	private List<MenuItem> menuItems;
	
	/** Holds the client from which the Menu is invoked */
	private IMenu observer;
	
	/**
	 * Constructor
	 */
	public MenuHandler() {
		menuItems = new ArrayList<MenuItem>();
	}

	/**
	 * Creates a MenuItem for the menu
	 * 
	 * @param menuId
	 *            An Id for the menu
	 * @param menuText
	 *            The text that gets displayed
	 * @return Created MenuItem
	 * 
	 * @see MenuHandler#add(String, String, boolean)
	 */
	public MenuItem add(String menuId, String menuText) {
		return add(menuId, menuText, false);
	}

	/**
	 * Creates a MenuItem for the menu
	 * 
	 * @param menuId
	 *            An Id for the menu
	 * @param menuText
	 *            The text that gets displayed
	 * @param boolean The current MenuItem is marked for selection
	 *
	 * @return Created MenuItem
	 */	
	public MenuItem add(String menuId, String menuText, boolean selected) {
		MenuItem menuItem = new MenuItem(menuId, menuText);
		menuItems.add(menuItem);
		currentSelection = selected ? menuItem : currentSelection;
		return menuItem;
	}

	/**
	 * Adds a MenuItem to the current MenuList
	 * 
	 * @param menuItem
	 *            MenuItem to be added
	 */
	public void add(MenuItem menuItem) {
		menuItems.add(menuItem);
	}

	/**
	 * Clears the MenuItem list. Used when Menu needs to be refreshed with new
	 * data
	 */
	public void clear() {
		menuItems.clear();
	}

	/**
	 * Returns the current MenuItem selected
	 * 
	 * @return MenuItem selected
	 */
	public MenuItem getCurrentSelection() {
		return currentSelection;
	}

	/**
	 * Sets the current selection of the MEnuItem
	 * 
	 * @param currentSelection
	 *            Current selected MenuItem
	 */
	public void setCurrentSelection(MenuItem currentSelection) {
		this.currentSelection = currentSelection;
		
		if (observer != null)
			observer.menuClicked(currentSelection);
	}

	/**
	 * Returns the list of MenuItems
	 * 
	 * @return List The menu list
	 */
	public List<MenuItem> getMenuItems() {
		return menuItems;
	}

	/**
	 * Registers the client as the listener, which will be notified using
	 * callback
	 * 
	 * @param observer
	 *            The client which wishes to get notified for every MenuItems
	 *            selected
	 */
	public void addListener(IMenu observer) {
		this.observer = observer;
	}
}