x11rubberband.java

定要上载质量高而定要上载质量高而定要上载质量高而定要上载质量高而定要上载质量高而

/*
 * Created on Aug 29, 2004
 */
package org.flexdock.docking.drag.outline.x11;

import java.awt.Rectangle;

import org.flexdock.docking.drag.effects.RubberBand;

/**
 * @author marius
 */
public class X11RubberBand extends RubberBand {
	private static final Graphics X11_GRAPHICS = Graphics.getGraphics();
	private static X11RubberBand SINGLETON;
	private static final Object LOCK = new Object();
	
	private Graphics graphics;
	private Rectangle currentRect;

	
	public static X11RubberBand getInstance() {
		synchronized(LOCK) {
			return SINGLETON==null? new X11RubberBand(): SINGLETON;			
		}
	}
	
	public X11RubberBand() {
		synchronized(LOCK) {
			if(SINGLETON!=null)
				throw new IllegalStateException("There may only be one singleton X11RubberBand.  Use X11RubberBand.getInstance() instead.");
			
			this.graphics = X11_GRAPHICS;
			graphics.setForeground(graphics.getWhitePixel());
			graphics.setSubWindowMode(Graphics.SUBWIN_MODE_INCLUDE_INFERIORS);
			graphics.setXor();			
		}
	}
	
	public void paint(java.awt.Graphics g, Rectangle rect) {
		clear();
		currentRect = rect;
		drawImpl();
	}
	
	private void drawImpl() {
		if(currentRect==null)
			return;
		
		graphics.drawRectangle(currentRect);
	}
	
	public void clear() {
		if(currentRect!=null)
			drawImpl();
		currentRect = null;
	}
}