/*
 *  JFLAP - Formal Languages and Automata Package
 * 
 * 
 *  Susan H. Rodger
 *  Computer Science Department
 *  Duke University
 *  August 27, 2009

 *  Copyright (c) 2002-2009
 *  All rights reserved.

 *  JFLAP is open source software. Please see the LICENSE for terms.
 *
 */





package gui.action;

import java.awt.event.InputEvent;

/**
 * The <TT>MenuConstants</TT> class is a simple class for retrieving
 * information universally important to menu items.
 * 
 * @author Thomas Finley
 */

public class MenuConstants {
	/**
	 * This is a singleton class; the information present is universal.
	 */
	private MenuConstants() {
	}

	/**
	 * Returns the main mask for menu items. The main mask is the mask of keys
	 * that are held down to typically invoke a menu item. This varies from
	 * platform to platform. On Windows it's the control key, and on everything
	 * else (presumably either Mac OS or some other Unix based system) it's meta
	 * (on the MacOS this is interpreted as the command key).
	 * 
	 * @return the main modifier for menu items
	 */
	public static int getMainMenuMask() {
		return MAIN_MENU_MASK;
	}

	/**
	 * Initializes the value for the main menu mask.
	 */
	private static void initMainMenuMask() {
		String s = System.getProperty("os.name");
		if ((s.lastIndexOf("Windows") != -1)
				|| (s.lastIndexOf("windows") != -1))
			MAIN_MENU_MASK = InputEvent.CTRL_MASK;
		else
			MAIN_MENU_MASK = InputEvent.META_MASK;
	}

	/** The main mask for keystrokes in a menu. */
	private static int MAIN_MENU_MASK;

	/**
	 * The static initializer initializes the information present in this class.
	 */
	static {
		initMainMenuMask();
	}
}