Gradient Color Example

This section shows you the Gradient Color.

Gradient Color is a tool bar which consists of different shades of color. We are providing you an example which shows the Gradient Color.
The Ellipse2D.Float class provides an ellipse shape defining value of float type. Similarly the Rectangular2D.Float class provides a rectangle defining values of float type. We have defined the colors using Color class.

Following code shows all predefined colors:

for (int j = 0; j < color.length; j++) {
Ellipse2D shape = new Ellipse2D.Float(x + size * (float)i, y, size, size);
g2.setPaint(color[j]);}

To show a linear gradient, we have defined three colors red, green and blue of integer type. The red returns the red component of the two colors specified, the green returns the green component of the two colors specified and blue returns the blue component of two colors.

Following code shows the alpha Gradient:

int alpha = (int)(255 * (float)j / (float)color.length)

To draw the frame around all the colors, we have defined Rectangle2D class. The method g2.draw(frame) draws the frame.

Here is the code of ColorGradientExample.java


import java.awt.*;

import javax.swing.*;

import java.awt.geom.Ellipse2D;

import java.awt.geom.Rectangle2D;

      

public class ColorGradientExample extends JPanel{

    public void paint(Graphics g) {

        Graphics2D g2 = (Graphics2D)g;

        Dimension dim = getSize();

        g2.translate(dim.width / 2, dim.height / 2);

        Color[] color = {

        Color.white, Color.lightGray, Color.gray, Color.darkGray,

        Color.black, Color.red, Color.pink, Color.orange,

        Color.yellow, Color.green, Color.magenta, Color.cyan, Color.blue

        };

        float size = 30;

        float x = -size * color.length / 2;

        float y = -size * 3 / 2;

        for (int j = 0; j < color.length; j++) {

        Ellipse2D shape = new Ellipse2D.Float(x + size * (float)j, y, size, size);

          g2.setPaint(color[j]);

          g2.fill(shape);

        }

        y += size;

        Color color1 = Color.green;

        Color color2 = Color.blue;

        for (int j = 0; j < color.length; j++) {

        float num = (float)j / (float)color.length;

        int red = (int)(color2.getRed() * num + color1.getRed() * (1 - num));

        int green = (int)(color2.getGreen() * num +

                            color1.getGreen() * (1 - num));

        int blue = (int)(color2.getBlue() * num +

                           color1.getBlue() * (1 - num));

          Color co = new Color(red, green, blue);

         Ellipse2D shape = new Ellipse2D.Float(

              x + size * (float)j, y, size, size);

          g2.setPaint(co);

          g2.fill(shape);

        }

        y += size;

        color1 = Color.red;

        for (int j = 0; j < color.length; j++) {

          int alpha = (int)(255 * (float)j / (float)color.length);

          Color co = new Color(color1.getRed(), color1.getGreen(),

                              color1.getBlue(), alpha);

         Ellipse2D shape = new Ellipse2D.Float(

              x + size * (float)j, y, size, size);

          g2.setPaint(co);

          g2.fill(shape);

        }

   y -= size * 2;

   Rectangle2D frame = new Rectangle2D.Float(x, y, size * color.length, size * 3);

   g2.setPaint(Color.black);

   g2.draw(frame);

      }

   public static void main(String[] args) {

    JFrame frame = new JFrame("Color Gradient Example");

    frame.getContentPane().add(new ColorGradientExample());

    frame.setSize(450, 300);

    frame.show();

  }

}

Output will be displayed as:

Download Source Code