/*
 * Copyright 2003 Smithvalley. All rights reserved.
 * 
 * THIS CODE AND INFORMATION ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
 * KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
 */
 
package com.smithvalley.samples.demos;

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

/**
 * This is a static class used for enabling anti-aliased text in a way
 * that works both in 1.1.4 Microsoft VM's and modern VM's.
 * 
 * Make the call as follows:
 * AntiAliasEnabler.setAntiAlias(g, true); // to enable anti-aliasing
 * AntiAliasEnabler.setAntiAlias(g, false); // to disable anti-aliasing
 * 
 * This call should be made somewhere in your paint() method, generally
 * the first line.
 * 
 * If you make the call from more than one location in your code you
 * will need to bottleneck all your calls though one static method which
 * is in a class which is NOT this class.  Here is an example:
 * 
 * public MyMainClass {
 * 
 * 		public static void setAntiAlias(Graphics g, boolean enable) {
 * 			AntiAliasEnabler.setAntiAlias(g, enable);
 * 		}
 * }
 * 
 * Now you may use MyMainClass.setAntiAlias(g, true/false) from anywhere
 * in your applet or application to turn anti-aliasing on and off.  If
 * you call AntiAliasEnabler.setAntiAlias() directly from more than one
 * location you will get a class not found exception after the first time
 * it is called.  This is due to an anomaly in the JIT and how it handles
 * calls to alien classes.
 * 
 * When you include this class you must have the Java2 libraries in your
 * classpath so this might not work for those of you using older IDE's.
 * I sugest using Eclipse becuase it makes it really easy to run your IDE
 * under a modern Java library and compile for 1.1.4.  You simply go to
 * Preference -> Java -> Compiler and under "JDKCompilance" choose 1.3.
 * If the VM you are using is too new it may no longer support the
 * backwards compatibility feature.  I use the IBM 1.3.1 JDK and it
 * compiles 1.1.4 code with no problems.
 * 
 * @author Mike Smith (michael@smithvalley.com)
 */
public class AntiAliasEnabler {
	private static final String javaVersion = System.getProperty("java.version");
	public static final float javaVersNum;
	static  {
		float version = 0;
		try {
			version = Float.valueOf(javaVersion.substring(0, 3)).floatValue();
		} catch (NumberFormatException e) {
		}
		javaVersNum = version;
	}
	private static boolean canAntiAlias = true;
	
	private AntiAliasEnabler() {}
		
	public static void setAntiAlias(Graphics g, boolean enable) {
		if (canAntiAlias) {
			if (javaVersNum < 1.2F) {
				canAntiAlias = false;
			} else {
				try {
					setRenderingHits(g, enable);
				} catch(Exception e) {
					canAntiAlias = false;
				}
			}
		}
	}
	
	private static void setRenderingHits(Graphics g, boolean enable) {
		Object o;
		if (enable) {
			o = RenderingHints.VALUE_ANTIALIAS_ON;
		} else {
			o = RenderingHints.VALUE_ANTIALIAS_OFF;
		}
		Graphics2D gg = (Graphics2D)g;
		gg.setRenderingHint(RenderingHints.KEY_ANTIALIASING, o);
	}
	
}