Download 09F-NoteSet21

CSE 1341 Honors
Professor Mark Fontenot
Southern Methodist University
Note Set 21
Drawing In Java
• Background
– Windowed applications in Java use the Swing
framework
• Swing – part of the Java Foundation Classes that
provide a (nearly) platform independent way of making
GUI applications
• Provides things like windows, buttons, text fields, radio
buttons, etc.
– Apps with 2D graphics use the 2DGraphics API
– All of this is object oriented
• a button is an object, etc.
Let’s Make a Window
import javax.swing.*;
Where lots of GUI stuff lives in the Java API
public class SimpleJFrame extends JFrame {
public SimpleJFrame () {
this.setTitle("This is Awesome!");
this.setSize(500, 500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main (String [] args) {
SimpleJFrame s = new SimpleJFrame();
}
}
Let’s Make a Window
import javax.swing.*;
public class SimpleJFrame extends JFrame {
We’re extending the
functionality of the JFrame
class
public SimpleJFrame () {
this.setTitle("This is Awesome!");
this.setSize(500, 500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main (String [] args) {
SimpleJFrame s = new SimpleJFrame();
}
}
Create a new SimpleJFrame
Object
Let’s Make a Window
import javax.swing.*;
public class SimpleJFrame extends JFrame {
public SimpleJFrame () {
this.setTitle("This is Awesome!");
this.setSize(500, 500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main (String [] args) {
SimpleJFrame s = new SimpleJFrame();
}
}
Calling superclass
methods that are part
of JFrame…
Let’s Make a Window
import javax.swing.*;
public class SimpleJFrame extends JFrame {
We’re extending the
functionality of the JFrame
class
public SimpleJFrame () {
this.setTitle("This is Awesome!");
this.setSize(500, 500);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main (String [] args) {
SimpleJFrame s = new SimpleJFrame();
}
}
Create a new SimpleJFrame
Object
Now, with a button
//New Import
import java.awt.*;
import javax.swing.*;
public class SimpleFrameWithComponents extends JFrame {
public SimpleFrameWithComponents () {
this.setTitle("This is more Awesome!");
this.setSize(500, 500);
this.setLayout(new FlowLayout());
JButton jb = new JButton("Press me!");
this.getContentPane().add(jb);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public static void main (String [] args) {
SimpleFrameWithComponents s = new SimpleFrameWithComponents();
}
}
Coordinates in a Window
[0,0]
x
Pixel
y
Let’s Draw
import
import
import
import
java.awt.Color;
java.awt.Graphics;
java.awt.Graphics2D;
javax.swing.JFrame;
Some new Imports for
graphics and drawing
public class SimpleDraw extends JFrame{
SimpleDraw() {
Calling superclass methods
this.setSize(300, 300);
this.setVisible(true);
to set up the window
this.setBackground(Color.BLUE);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.RED);
g2.fillOval(50, 50, 20, 20);
g2.setColor(Color.MAGENTA);
g2.drawString("Hello There", 100, 100);
}
public static void main (String [] args) {
SimpleDraw s = new SimpleDraw();
}
}
Let’s Draw
import
import
import
import
java.awt.Color;
java.awt.Graphics;
java.awt.Graphics2D;
javax.swing.JFrame;
public class SimpleDraw extends JFrame{
Sets the background
color of the frame. Color
options:
SimpleDraw() {
this.setSize(300, 300);
Some color
this.setVisible(true);
this.setBackground(Color.BLUE);
Color.BLUE
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Color.RED
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.RED);
g2.fillOval(50, 50, 20, 20);
g2.setColor(Color.MAGENTA);
g2.drawString("Hello There", 100, 100);
}
public static void main (String [] args) {
SimpleDraw s = new SimpleDraw();
}
}
options:
Color.MAGENTA
Color.PINK
Color.BLACK
etc.
Let’s Draw
import
import
import
import
java.awt.Color;
java.awt.Graphics;
java.awt.Graphics2D;
javax.swing.JFrame;
public class SimpleDraw extends JFrame{
SimpleDraw() {
this.setSize(300, 300);
this.setVisible(true);
this.setBackground(Color.BLUE);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.RED);
g2.fillOval(50, 50, 20, 20);
g2.setColor(Color.MAGENTA);
g2.drawString("Hello There", 100, 100);
}
public static void main (String [] args) {
SimpleDraw s = new SimpleDraw();
}
}
method that is part being
overridden in our class.. From
the super class.
Let’s Draw
import
import
import
import
java.awt.Color;
java.awt.Graphics;
java.awt.Graphics2D;
javax.swing.JFrame;
public class SimpleDraw extends JFrame{
SimpleDraw() {
this.setSize(300, 300);
this.setVisible(true);
this.setBackground(Color.BLUE);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.RED);
g2.fillOval(50, 50, 20, 20);
g2.setColor(Color.MAGENTA);
g2.drawString("Hello There", 100, 100);
}
public static void main (String [] args) {
SimpleDraw s = new SimpleDraw();
}
}
Turns the graphic object parameter
into a 2D graphics object
Paints an oval, then a string
Some Options of what you can draw
• void drawRect(int x, int y, int width, int height);
• void drawOval(int x, int y, int width, int height)
• void drawLine(int x1, int y1, int x2, int y2)
• void fillOval(int x, int y, int width, int height)
• void fillRect(int x, int y, int width, int height)
Can You Draw This?
Can You Draw This?
Breakout:
Use the graphics drawing functionality to draw
a picture of the playing field including the boundaries,
lines, center line, box and robot!