Like Microsoft Paint-is it possible to display the color panel

Question

My project requires whiteboard facility also....If i used JcolorChooser all the colors are displayed...If u see in Microsoft paint only 20 colors are displayed...How can we do using java?Please help me

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class ColorChart extends JPanel
    int[] colorInts;
    BufferedImage image;
    Color foregroundColor;
    Color backgroundColor;
    double x0;
    final int SIDE = 13;
    final int PAD = 3;
    public ColorChart()
        colorInts = new int[]
            0x000000, 0x808080, 0x800000, 0x808000, 0x008000, 0x008080, 0x000080,
            0x800080, 0x808040, 0x004040, 0x0080ff, 0x004080, 0x8000ff, 0x804000,
            0xffffff, 0xc0c0c0, 0xff0000, 0xffff00, 0x00ff00, 0x00ffff, 0x0000ff,
            0xff00ff, 0xffff80, 0x00ff80, 0x80ffff, 0x8080ff, 0xff0080, 0xff8040
        createImage();
        foregroundColor = Color.black;
        backgroundColor = Color.white;
    protected void paintComponent(Graphics g)
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        double w = getWidth();
        double h = getHeight();
        int cols = colorInts.length/2;
        // demo image area
        // darker highlight adjacent to black shadow
        g2.setPaint(UIManager.getColor("Panel.background").darker());
        g2.draw(new Line2D.Double(0, PAD-1.0, image.getWidth()+1.0, PAD-1.0));
        g2.draw(new Line2D.Double(0, PAD, 0, PAD+image.getHeight()));
        g2.drawImage(image, 1, PAD, this);
        double x = 1.0 + image.getWidth() + 1.0;
        double y = PAD + image.getHeight() + 1.0;
        // white highlight
        g2.setPaint(Color.white);
        g2.draw(new Line2D.Double(x, PAD-1.0, x, y));
        g2.draw(new Line2D.Double(0, y, x, y));
        // foreground/background tiles over image
        g2.setPaint(backgroundColor);
        Rectangle2D.Double bg = new Rectangle2D.Double(12.0, PAD+12.0, 12.0, 12.0);
        g2.fill(bg);
        g2.setPaint(UIManager.getColor("Panel.background"));
        g2.draw(bg);
        g2.setPaint(foregroundColor);
        Rectangle2D.Double fg = new Rectangle2D.Double(5.0, PAD+5.0, 12.0, 12.0);
        g2.fill(fg);
        g2.setPaint(UIManager.getColor("Panel.background"));
        g2.draw(fg);
        // darker shadow outlines
        g2.setPaint(UIManager.getColor("Panel.background").darker());
        g2.draw(new Line2D.Double(bg.x+bg.width+1.0, bg.y,
                                  bg.x+bg.width+1.0, bg.y+bg.height));
        g2.draw(new Line2D.Double(bg.x, bg.y+bg.height+1.0,
                                  bg.x+bg.width + 1.0, bg.y+bg.height+1.0));
        g2.draw(new Line2D.Double(fg.x+fg.width+1.0, fg.y,
                                  fg.x+fg.width+1.0, fg.y+fg.height));
        g2.draw(new Line2D.Double(fg.x, fg.y+fg.height+1.0,
                                  fg.x+fg.width + 1.0, fg.y+fg.height+1.0));
        // color swatches
        x0 = x;
        for(int row = 0; row < 2; row++)
            y = PAD + row*(SIDE+PAD);
            for(int col = 0; col < cols; col++)
                int index = row*cols + col;
                g2.setPaint(new Color(colorInts[index]));
                x = x0 + PAD + col*(SIDE+PAD);
                g2.fill(new Rectangle2D.Double(x, y, SIDE, SIDE));
                g2.setPaint(Color.black);
                g2.draw(new Line2D.Double(x, y, x+SIDE-1.0, y));
                g2.draw(new Line2D.Double(x, y, x, y+SIDE-1.0));
        // darker highlight trim that borders black shadow
        g2.setPaint(UIManager.getColor("Panel.background").darker());
        // inter-cell vertical trim
        y = 2*(PAD + SIDE);
        for(int col = 0; col < cols; col++)
            x = x0 + col*(SIDE+PAD) + 1.0;
            g2.setPaint(UIManager.getColor("Panel.background").darker());
            g2.draw(new Line2D.Double(x+1.0, PAD-1.0, x+1.0, y));
        x = x0 + cols*(SIDE+PAD) + 1.0;
        // top trim
        g2.draw(new Line2D.Double(x0+PAD, PAD-1.0, x-1.0, PAD-1.0));
        // horizontal center trim
        y = PAD + SIDE + 1.0;
        g2.draw(new Line2D.Double(x0+PAD, y+1.0, x-1.0, y+1.0));
        // white highlight trim
        g2.setPaint(Color.white);
        y = 2*(PAD + SIDE);
        // inter-cell vertical trim
        for(int col = 0; col < cols; col++)
            x = x0 + col*(SIDE+PAD) + 1.0;
            g2.draw(new Line2D.Double(x, PAD-1.0, x, y));
        // horizontal center trim
        x = x0 + cols*(SIDE+PAD) + 1.0;
        y = PAD + SIDE + 1.0;
        g2.draw(new Line2D.Double(x0+PAD, y, x-1.0, y));
        // bottom trim
        y = 2*(PAD + SIDE);
        g2.draw(new Line2D.Double(x0+PAD, y+1.0, x, y+1.0));
        // right side trim
        g2.draw(new Line2D.Double(x, PAD, x, y));
    public Dimension getPreferredSize()
        return new Dimension(260, 36);
    public void setBackgroundColor(int index)
        backgroundColor = new Color(colorInts[index]);
        repaint();
    public void setForegroundColor(int index)
        foregroundColor = new Color(colorInts[index]);
        repaint();
    private void createImage()
        int w = 27, h = 29;
        image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        int white = Color.white.getRGB();
        int bg = UIManager.getColor("Panel.background").getRGB();
        int[] data = new int[w*h];
        for(int j = 0; j < data.length; j++)
            data[j] = j%2 == 0 ? white : bg;
        image.setRGB(0, 0, w, h, data, 0, w);
        Graphics2D g2 = image.createGraphics();
        g2.setPaint(Color.black);
        g2.draw(new Line2D.Double(0,0,w,0));
        g2.draw(new Line2D.Double(0,0,0,h));
        g2.dispose();
    public static void main(String[] args)
        ColorChart colorChart = new ColorChart();
        colorChart.addMouseListener(new ColorSelector(colorChart));
        JFrame f = new JFrame("mimics v5.1");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setContentPane(colorChart);
        f.pack();
        f.setLocation(200,200);
        f.setVisible(true);
class ColorSelector extends MouseAdapter
    ColorChart chart;
    public ColorSelector(ColorChart cc)
        chart = cc;
    public void mousePressed(MouseEvent e)
        Point p = e.getPoint();
        Dimension d = chart.getPreferredSize();
        if(p.x > d.width || p.y > d.height)
            return;
        int x = (int)(p.x - chart.x0);
        int col = x / (chart.SIDE + chart.PAD);
        int row = p.y / (chart.SIDE + chart.PAD);
        int cols = chart.colorInts.length/2;
        if(row < 0 || row > 2 || col < 0 || col > cols-1 || x < 0 ||
                      row*col > chart.colorInts.length-1)
            return;
        int index = row*cols + col;
        //System.out.printf("p.x %d p.y %d x %d row %d col %d index %d\n",
        //                   p.x, p.y, x, row, col, index);
        if(SwingUtilities.isLeftMouseButton(e))
            chart.setForegroundColor(index);
        else if(SwingUtilities.isRightMouseButton(e))
            chart.setBackgroundColor(index);
}