animatedcanvas.java.svn-base

来自「example2 众多JAVA实例源码...学习java基础的好帮手」· SVN-BASE 代码 · 共 45 行

package opusmicro.demos.animate;

import java.util.*;
import javax.microedition.lcdui.*;
// A canvas to which you can attach one or more
// animated images. When the canvas is painted,
// it cycles through the animated images and asks
// them to paint their current image.
public class AnimatedCanvas extends Canvas {;
	private Display display;
	private Image offscreen;
	private Vector images = new Vector();
	public AnimatedCanvas( Display display ){
		this.display = display;
// If the canvas is not double buffered by the
// system, do it ourselves...
		if( !isDoubleBuffered() ){
			offscreen = Image.createImage( getWidth(), getHeight() );
		}
	}
// Add an animated image to the list.
	public void add( AnimatedImage image ){
		images.addElement( image );
	}
// Paint the canvas by erasing the screen and then
// painting each animated image in turn. Double
// buffering is used to reduce flicker.
	protected void paint( Graphics g ){
		Graphics saved = g;
		if( offscreen != null ){
			g = offscreen.getGraphics();
		}
		g.setColor( 255, 255, 255 );
		g.fillRect( 0, 0, getWidth(), getHeight() );
		int n = images.size();
		for( int i = 0; i < n; ++i ){
			AnimatedImage img = (AnimatedImage)images.elementAt( i );
			img.draw( g );
		}
		if( g != saved ){
			saved.drawImage( offscreen, 0, 0, Graphics.LEFT | Graphics.TOP );
		}
	}
}