canvasb.java

很不错的一个获取html色彩值的Applet

/*	ColorPicker v1.0 by Toh Lik Khoong
	Please contact me at [e-mail] for any comments or suggestions
	The source code is strictly for educational purposes and cannot be modified
	or used without the express permission of the author
	Visit http://navsurf.com for the latest version and other useful applets
*/

import java.awt.*;
import java.awt.event.*;
import java.awt.image.MemoryImageSource;
import java.awt.image.PixelGrabber;

public class CanvasB extends Canvas{
	static final int HEIGHT = 256;
	static final int WIDTH = 30;

	private int[] colormap = new int[WIDTH*HEIGHT];
	private Image col_img = null;

	private Point cur_point = new Point();

	CanvasB(){
		super.setBackground(Color.white);
		super.resize(WIDTH + 10, HEIGHT);
		for (int x = 0; x < WIDTH; x++){
			for (int y = 1; y <= HEIGHT; y++){
				colormap[x + (HEIGHT - y)*WIDTH] = Color.HSBtoRGB((float) 0.0, (float) 0.0, ((float) y)/HEIGHT);
			}
		}
		col_img = createImage(new MemoryImageSource(WIDTH, HEIGHT, colormap, 0, WIDTH));
		mouseY = HEIGHT/2;
	}

	public void refresh(Color col){
		for (int x = 0; x < WIDTH; x++){
			for (int y = 1; y <= HEIGHT/2; y++){
				colormap[x + y * WIDTH] = 0xFF << 24 | (y*2*(col.getRed() - 255)/HEIGHT + 255) << 16 | (y*2*(col.getGreen() - 255)/HEIGHT + 255) << 8 | (y*2*(col.getBlue() - 255)/HEIGHT + 255);
			}
		}
		for (int x = 0; x < WIDTH; x++){
			for (int y = HEIGHT/2; y < HEIGHT; y++){
				colormap[x + y * WIDTH] = 0xFF << 24 | (col.getRed()*2*(HEIGHT-y)/HEIGHT) << 16 | (col.getGreen()*2*(HEIGHT-y)/HEIGHT) << 8 | (col.getBlue()*2*(HEIGHT-y)/HEIGHT);
			}
		}
		col_img = createImage(new MemoryImageSource(WIDTH, HEIGHT, colormap, 0, WIDTH));
		repaint();
	}

	int mouseY = 0;
	int prevY = 0;

	public void setCursor(int y){
		prevY = mouseY;
		mouseY = y;
	}

	public Color getColorAt(int x, int y){
		Color couleur = new Color(colormap[x + y*WIDTH]);
		return couleur;
	}

	public Color getColor(){
		Color couleur = new Color(colormap[mouseY*WIDTH]);
		return couleur;
	}

	public boolean mouseDrag( Event evt, int x, int y ){
		/*Color cur_color = cb.getColorAt(e.getX(), e.getY());
		tf_r.setText(Integer.toString(cur_color.getRed()));
		tf_g.setText(Integer.toString(cur_color.getGreen()));
		tf_b.setText(Integer.toString(cur_color.getBlue()));
		tf_hc.setText(Integer.toHexString(cur_color.getRGB() & 0xFFFFFF).toUpperCase());
		cb.setCursor(e.getY());
		cb.repaint();
		cc.setBackground(cur_color);*/
		System.out.println(evt.y);
		return true;
	}

	public void paint(Graphics g){
		int[] p_x = {0, 5, 0};
		int[] p_y = {mouseY - 5, mouseY, mouseY + 5};
		g.setColor(Color.black);
		g.fillPolygon(p_x, p_y, 3);
		p_x[0] = size().width - p_x[0];
		p_x[1] = size().width - p_x[1];
		p_x[2] = size().width - p_x[2];
		g.fillPolygon(p_x, p_y, 3);
		g.drawImage(col_img, 5, 0, this);
	}

	public void update(Graphics g){
		//g.clearRect(0, Math.max(0, prevY - 5), 5, Math.max(5, prevY + 5));
		//g.clearRect(size().width - 5, Math.max(0, prevY - 5), size().width, Math.max(5, prevY + 5));
		g.clearRect(0, 0, 5, size().height);
		g.clearRect(size().width - 5, 0, size().width, size().height);
		paint(g);
	}

}