Java Tutorial/2D Graphics/Gradient Paint

Acyclic Gradient Paint

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.geom.Line2D; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; import javax.swing.JComponent; import javax.swing.JFrame; class GradientPane extends JComponent {

 public void paint(Graphics g) {
   Graphics2D g2D = (Graphics2D) g;
   Point2D.Float p1 = new Point2D.Float(150.f, 75.f); // Gradient line start
   Point2D.Float p2 = new Point2D.Float(250.f, 75.f); // Gradient line end
   float width = 300;
   float height = 50;
   Rectangle2D.Float rect1 = new Rectangle2D.Float(p1.x - 100, p1.y - 25, width, height);
   GradientPaint g2 = new GradientPaint(p1, Color.WHITE, p2, Color.DARK_GRAY, false); // Acyclic
                                                                                       // gradient
   rect1.setRect(p1.x - 100, p1.y - 25, width, height);
   g2D.setPaint(g2); // Gradient color fill
   g2D.fill(rect1); // Fill the rectangle
   g2D.setPaint(Color.BLACK); // Outline in black
   g2D.draw(rect1); // Fill the rectangle
   g2D.draw(new Line2D.Float(p1, p2));
 }

} public class AcyclicGradientPaint {

 public static void main(String[] a) {
   JFrame window = new JFrame("Acyclic Gradient Paint");
   window.setBounds(30, 30, 300, 300);
   window.getContentPane().add(new GradientPane());
   window.setVisible(true);
 }

}</source>

A non-cyclic gradient

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import javax.swing.JComponent; import javax.swing.JFrame; public class BasicDraw {

 public static void main(String[] args) {
   new BasicDraw();
 }
 BasicDraw() {
   JFrame frame = new JFrame();
   frame.add(new MyComponent());
   frame.setSize(300, 300);
   frame.setVisible(true);
 }

} class MyComponent extends JComponent {

 public void paint(Graphics g) {
   Graphics2D g2d = (Graphics2D) g;
   Color startColor = Color.red;
   Color endColor = Color.blue;
   int startX = 10, startY = 20, endX = 30, endY = 40;
   
   GradientPaint gradient = new GradientPaint(startX, startY, startColor, endX, endY, endColor);
   g2d.setPaint(gradient);
   g2d.draw(new Rectangle(20,20,200,200));
 }

}</source>

Control the direction of Gradients

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class GradientsDirection extends JPanel {

 public void paint(Graphics g) {
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;
   GradientPaint gp1 = new GradientPaint(5, 25, Color.yellow, 20, 2, Color.black, true);
   g2d.setPaint(gp1);
   g2d.fillRect(20, 80, 300, 40);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("GradientsDirection");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.add(new GradientsDirection());
   frame.setSize(350, 350);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}</source>

Cyclic Gradient Paint

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.geom.Line2D; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; import javax.swing.JComponent; import javax.swing.JFrame; class GradientPane extends JComponent {

 public void paint(Graphics g) {
   Graphics2D g2D = (Graphics2D) g;
   Point2D.Float p1 = new Point2D.Float(150.f, 75.f); // Gradient line start
   Point2D.Float p2 = new Point2D.Float(250.f, 75.f); // Gradient line end
   float width = 300;
   float height = 50;
   GradientPaint g1 = new GradientPaint(p1, Color.WHITE, p2, Color.DARK_GRAY, true); // Cyclic
                                                                                     // gradient
   Rectangle2D.Float rect1 = new Rectangle2D.Float(p1.x - 100, p1.y - 25, width, height);
   g2D.setPaint(g1); // Gradient color fill
   g2D.fill(rect1); // Fill the rectangle
   g2D.setPaint(Color.BLACK); // Outline in black
   g2D.draw(rect1); // Fill the rectangle
   g2D.draw(new Line2D.Float(p1, p2));
 }

} public class CyclicGradientPaint {

 public static void main(String[] a) {
   JFrame window = new JFrame("Cyclic Gradient Paint");
   window.setBounds(30, 30, 300, 300);
   window.getContentPane().add(new GradientPane());
   window.setVisible(true);
 }

}</source>

Drawing with a Gradient Color

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import javax.swing.JComponent; import javax.swing.JFrame; public class BasicDraw {

 public static void main(String[] args) {
   new BasicDraw();
 }
 BasicDraw() {
   JFrame frame = new JFrame();
   frame.add(new MyComponent());
   frame.setSize(300, 300);
   frame.setVisible(true);
 }

} class MyComponent extends JComponent {

 public void paint(Graphics g) {
   Graphics2D g2d = (Graphics2D) g;
   Color startColor = Color.red;
   Color endColor = Color.blue;
   int startX = 10, startY = 20, endX = 30, endY = 40;
   
   GradientPaint gradient = new GradientPaint(startX, startY, startColor, endX, endY, endColor);
   g2d.setPaint(gradient);
   g2d.draw(new Rectangle(20,20,200,200));
 }

}</source>

Gradients: a smooth blending of shades from light to dark or from one color to another

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class GradientsRedYellow extends JPanel {

 public void paint(Graphics g) {
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;
   GradientPaint gp1 = new GradientPaint(5, 5, Color.red, 20, 20, Color.yellow, true);
   g2d.setPaint(gp1);
   g2d.fillRect(20, 20, 300, 40);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("GradientsRedYellow");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.add(new GradientsRedYellow());
   frame.setSize(350, 350);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}</source>

Gradients in the middle

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class GradientsMiddle extends JPanel {

 public void paint(Graphics g) {
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;
   GradientPaint gp1 = new GradientPaint(0, 0, Color.orange, 0, 20, Color.black, true);
   g2d.setPaint(gp1);
   g2d.fillRect(20, 260, 300, 40);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("GradientsMiddle");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.add(new GradientsMiddle());
   frame.setSize(350, 350);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}</source>

Horizontal Gradients

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class GradientsLine extends JPanel {

 public void paint(Graphics g) {
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;
   GradientPaint gp1 = new GradientPaint(5, 25, Color.green, 2, 2, Color.black, true);
   g2d.setPaint(gp1);
   g2d.fillRect(20, 140, 300, 40);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("GradientsLine");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.add(new GradientsLine());
   frame.setSize(350, 350);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}</source>

String gradient paint

   <source lang="java">

import java.awt.Color; import java.awt.Font; import java.awt.FontMetrics; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class StringGraidentPaint extends JFrame {

 public StringGraidentPaint() {
   getContentPane().add(new DrawingCanvas());
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   setSize(500, 500);
   setVisible(true);
 }
 public static void main(String arg[]) {
   new StringGraidentPaint();
 }

} class DrawingCanvas extends JPanel {

 Font font = new Font("Dialog", Font.BOLD, 40);
 FontMetrics fontMetrics;
 
 DrawingCanvas() {
   setSize(300, 300);
   setBackground(Color.white);
   fontMetrics = getFontMetrics(font);
 }
 public void paint(Graphics g) {
   Graphics2D g2D = (Graphics2D) g;
   int w = getSize().width;
   int h = getSize().height;
   g2D.setFont(font);
   GradientPaint gp = new GradientPaint(
                           30.0f, 50.0f,
                           Color.blue,
                           fontMetrics.stringWidth("Hello!"),
                           fontMetrics.getHeight(),
                           Color.red);             
   g2D.setPaint(gp);
   g2D.drawString("Hello!", 20,200);                                                 

 }

}</source>

Vertical Gradient Paint

   <source lang="java">

import java.awt.Color; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class GradientsVertical extends JPanel {

 public void paint(Graphics g) {
   super.paint(g);
   Graphics2D g2d = (Graphics2D) g;
   GradientPaint gp1 = new GradientPaint(25, 25, Color.blue, 15, 25, Color.black, true);
   g2d.setPaint(gp1);
   g2d.fillRect(20, 200, 300, 40);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("GradientsVertical");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.add(new GradientsVertical());
   frame.setSize(350, 350);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}</source>