Templates for Swing Graphics programs

Drawing on a JPanel — no animation or timers, but multiple panels and buttons

Note: This uses Graphics2D to get better graphics.
Buttons are added to the south panel, but no event listeners have been implemented, so the buttons do nothing.

import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class SwingGraphics {

	public static void main(String[] args) {
		new SwingGraphics(); 
	}
   
	//Constants
	//set the size of the drawing panel
	final static int panW = 800;
	final static int panH = 800;

	//Global variables
	GraphicsPanel panel;
	
	//Constructor - we'll put the main organization here
	SwingGraphics(){
		JFrame window = new JFrame("Drawing on a JPanel");
		window.setResizable(false);
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			
		panel = new GraphicsPanel();
		window.add(panel);  //defaults to BorderLayout.CENTER

		JPanel buttonPanel = new JPanel();
		buttonPanel.setBackground(Color.GRAY.darker());
		buttonPanel.add(new JButton("Jump"));
		buttonPanel.add(new JButton("Run"));
		buttonPanel.add(new JButton("Swing"));
		window.add(buttonPanel, BorderLayout.SOUTH);

		window.pack(); //needed in order to use the GraphicsPanel's size to set the JFrame size
		window.setLocationRelativeTo(null); //centre the window, must be after pack()

		window.setVisible(true); 	
	}

	
	//We extend JPanel so we can customize it. This is where the magic happens...
	private class GraphicsPanel extends JPanel {
		GraphicsPanel(){
			this.setBackground(Color.BLACK);
			this.setPreferredSize(new Dimension(panW, panH));
		}

		@Override
		public void paintComponent(Graphics g) {
			super.paintComponent(g); //erases screen and draws background colour
			Graphics2D g2 = (Graphics2D)g;
			g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
			g2.setStroke(new BasicStroke(3));
			//Do all your drawing here
			g2.setColor(Color.CYAN);
			g2.drawOval(100,100,100,100);
		}
	}
}

Simplest Drawing program

This just has a GraphicsPanel that you can draw on

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class SwingGraphics {

	public static void main(String[] args) {
		new SwingGraphics(); 
	}
   
	//Constants
	//set the size of the drawing panel
	final static int panW = 800;
	final static int panH = 700;

	//Global variables
	GraphicsPanel panel;
	
	SwingGraphics(){
		JFrame window = new JFrame("Drawing on a JPanel");
		window.setResizable(false);
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			
		panel = new GraphicsPanel();
		window.add(panel);  //defaults to BorderLayout.CENTER

		window.pack(); //needed in order to use the GraphicsPanel's size to set the JFrame size
		window.setLocationRelativeTo(null); //centre the window, must be after pack()

		window.setVisible(true); 	
	}

	private class GraphicsPanel extends JPanel {
		GraphicsPanel(){
			this.setBackground(Color.WHITE);
			this.setPreferredSize(new Dimension(panW, panH));
		}

		@Override
		public void paintComponent(Graphics g) {
			super.paintComponent(g);

			//Do all your drawing here
			g.setColor(Color.BLUE);
			g.fillOval(100,100,100,100);
		}
	}
}