How do I draw a string in Java 2D?

By I Wayan Saryada in 2D API, Core API 0 Comment

The code snippet below show you how to draw a string using Graphics2D. The drawString() method accept the string to be drawn and their x and y coordinate. Here you can also see how to set the antialiasing mode using the setRenderingHint() method.

package org.kodejava.awt.geom;

import javax.swing.*;
import java.awt.*;

public class DrawString extends JPanel {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setTitle("Draw String Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.add(new DrawString());
        frame.pack();
        frame.setSize(420, 300);
        frame.setVisible(true);
    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;

        // Define rendering hint, font name, font style and font size
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setFont(new Font("Segoe Script", Font.BOLD + Font.ITALIC, 40));
        g2.setPaint(Color.ORANGE);

        // Draw Hello World String
        g2.drawString("Hello World!", 50, 100);
    }
}

Run the snippet, and you’ll see the following screen:

Draw 2D String

Draw 2D String

How do I create a dashed stroke in Java 2D?

By I Wayan Saryada in 2D API, Core API 0 Comment 
package org.kodejava.awt.geom;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;

public class DrawDashedStroke extends JComponent {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Draw Dashed Stroke Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().add(new DrawDashedStroke());
        frame.pack();
        frame.setSize(new Dimension(420, 250));
        frame.setVisible(true);
    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        float[] dash = {10.0f, 5.0f, 3.0f};

        // Creates a dashed stroke
        Stroke dashed = new BasicStroke(2.0f, BasicStroke.CAP_BUTT,
                BasicStroke.JOIN_MITER, 10.0f, dash, 0.0f);

        g2.setStroke(dashed);
        g2.setPaint(Color.RED);
        g2.draw(new RoundRectangle2D.Double(50, 50, 300, 100, 10, 10));
    }
}

This code snippet produce the following output:

Draw 2D Dashed Stroke

Draw 2D Dashed Stroke

How do I define stroke when drawing a shape in Java 2D?

By I Wayan Saryada in 2D API, Core API 0 Comment 
package org.kodejava.awt.geom;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.Line2D;

public class DrawStrokeDemo extends JComponent {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Draw Stroke Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().add(new DrawStrokeDemo());
        frame.pack();
        frame.setSize(new Dimension(420, 200));
        frame.setVisible(true);
    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;

        float[] strokes = {1, 2, 3, 4, 5, 6};
        for (float stroke : strokes) {
            g2.setStroke(new BasicStroke(stroke));
            g2.draw(new Line2D.Float(50, stroke * 20, 350, stroke * 20));
        }
    }
}

This code snippet produce the following output:

Draw 2D Stroke

Draw 2D Stroke

How do I create a gradient paint in Java 2D?

By I Wayan Saryada in 2D API, Core API 0 Comment

To change the color of a graphics shape we can use the setPaint() method. For a simple coloring we can pass the color object into this method, such as Color.RED or Color.GREEN.

If you want to paint with a gradient paint you can use the GradientPaint class. This class provides a way to fill a shape with a linear color gradient pattern. To create a gradient color pattern you can pass the following parameter to the object constructor.

  • x1: x coordinate of the first specified point in user space
  • y1: y coordinate of the first specified point in user space
  • color1: color at the first specified point
  • x2: x coordinate of the second specified point in user space
  • y2: y coordinate of the second specified point in user space
  • color2: color at the second specified point
package org.kodejava.awt.geom;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.Rectangle2D;

public class GradientPaintDemo extends JComponent {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Gradient Paint Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().add(new GradientPaintDemo());
        frame.pack();
        frame.setSize(new Dimension(420, 350));
        frame.setVisible(true);
    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;

        GradientPaint blackToGray = new GradientPaint(50, 50, Color.BLACK,
                300, 100, Color.LIGHT_GRAY);
        g2.setPaint(blackToGray);
        g2.fill(new Rectangle2D.Double(50, 50, 300, 100));

        GradientPaint blueToBlack = new GradientPaint(0, 0, Color.BLUE,
                400, 400, Color.BLACK);
        g2.setPaint(blueToBlack);
        g2.fill(new Rectangle2D.Double(50, 160, 300, 100));
    }
}

This code snippet produce the following output:

2D Gradient Paint Demo

2D Gradient Paint Demo

How do I draw an arc in Java 2D?

By I Wayan Saryada in 2D API, Core API 0 Comment

Arc2D is the abstract superclass for all objects that store a 2D arc defined by a framing rectangle, start angle, angular extent (length of the arc), and a closure type (Arc2D.OPEN, Arc2D.CHORD, or Arc2D.PIE).

To constructs a new arc in double values, such as defining the specified location, size, angular extents, and closure type we can use the Arc2D.Double static-inner class.

package org.kodejava.awt.geom;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.Arc2D;

public class DrawArc extends JComponent {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Draw Arc Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().add(new DrawArc());
        frame.pack();
        frame.setSize(new Dimension(420, 450));
        frame.setVisible(true);
    }

    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;

        g2.setStroke(new BasicStroke(2.0f));
        g2.setPaint(Color.RED);
        g2.draw(new Arc2D.Double(50, 50, 300, 300, 0, 90, Arc2D.PIE));
        g2.setPaint(Color.GREEN);
        g2.draw(new Arc2D.Double(50, 50, 300, 300, 90, 90, Arc2D.PIE));
        g2.setPaint(Color.BLUE);
        g2.fill(new Arc2D.Double(50, 50, 300, 300, 180, 90, Arc2D.PIE));
    }
}

Here is the result you’ll get when you run the snippet:

Draw 2D Arc

Draw 2D Arc