Bounce Balls Animation

Bounce Balls Animation#

Initial Setup:

It imports necessary libraries for Swing components, random number generation, timers, and colors.
The Frame1 class inherits from javax.swing.JFrame which represents the main window of the application.

Global Variables:

panelTimer: A timer object to control repainting of the panel where balls bounce.
TimerStatus: Boolean flag to track if the timer is running.
RNG: Instance of Random class to generate random values.
Initial ball properties like x, y, radius.
clockTick: Time interval between timer ticks (in milliseconds).
alBalls: An ArrayList to store bouncing ball objects.
RNG2: Another random number generator (potentially for future use).

Constructor (Frame1):

Initializes the frame and sets its layout.
Sets TimerStatus to false initially.
Creates another random number generator (RNG2).
Positions the frame in the center of the screen.

PanelClock method:

Creates a new Timer object with clockTick interval and an anonymous ActionListener.
The actionPerformed method of the listener iterates through alBalls, calling their moveBall method to update their positions.
It then loops through all components in jPanel1 (which should be the balls), retrieves their objects using casting, and sets their locations based on their xpos and ypos values in the Ball class.
It repaints the panel (jPanel1) and reduces the timer delay to a smaller value (presumably for smoother animation).
Finally, starts the timer.

Event Handlers:

```
jbttnAddBallActionPerformed
```
: triggered when the “Add Ball” button is clicked.
- Creates a new Ball object.
- Sets random ball properties like radius, speed, color, and initial position.
- Adds the ball to the jPanel1 panel and the alBalls list.
- Starts the timer (PanelClock) if it’s not already running.
```
jbttnDeleteBallActionPerformed
```
: triggered when the “Delete Ball” button is clicked.
- Tries to remove the first ball from jPanel1 and alBalls
- Repaints the panel.
```
jbttnClearAllActionPerformed
```
: triggered when the “Clear All” button is clicked.
- Removes all components from jPanel1.
- Clears the alBalls list.

This code demonstrates how to create a simple bouncing ball animation with Swing. The balls update their positions based on random directions and repaint themselves within the panel.

Project File#

J2_Bounce_Rev24.java

/*
Project: Bounce
Description: Animate Bouncing Balls
Programmer: James Goudy
Date: April, 2024
 */
package j2_bounce_rev24;

/**
 *
 * @author jgoudy
 */
public class J2_Bounce_Rev24 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        // Instatiate a new frame
        Frame1 myFrame = new Frame1();
        myFrame.setVisible(true);
        myFrame.setSize(730,575);
        
        
    }
    
}/*
Project: Bounce
Description: Animate Bouncing Balls
Programmer: James Goudy
Date: April, 2024
 */
package j2_bounce_rev24;

/**
 *
 * @author jgoudy
 */
public class J2_Bounce_Rev24 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        
        // Instatiate a new frame
        Frame1 myFrame = new Frame1();
        myFrame.setVisible(true);
        myFrame.setSize(730,575);
        
        
    }
    
}

Frame1.java#

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/GUIForms/JFrame.java to edit this template
 */
package j2_bounce_rev24;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.Timer;
import java.awt.Color;
import javax.swing.JComponent;

/**
 *
 * @author jgoudy
 */
public class Frame1 extends javax.swing.JFrame {

    // Global Variables
    Timer panelTimer;  //this will control the repaint of the panel
    boolean TimerStatus;
    
    
    Random RNG = new Random();
    // Setup to show one can instantiate an object later
    Random RNG2;
    
    
    // initial ball info
    int x = 1;
    int y = 1;
    int radius = 25;

    // Timer Tick
    int clockTick = 100;
    
    // Arraylist to hold the balls
    ArrayList<Ball> alBalls = new ArrayList();


    // constructor
    public Frame1() {
        initComponents();

        TimerStatus = false;

        RNG2 = new Random();

        this.setLocationRelativeTo(null);

    }

    private void PanelClock() {

        panelTimer = new Timer(clockTick, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {

                for (Ball item : alBalls) {
                    item.moveBall();
                }

                for (int i = 0; i < jPanel1.getComponentCount(); i++) {
                    Ball js = (Ball) jPanel1.getComponent(i);
                    jPanel1.getComponent(i).setLocation(js.getXpos(), js.ypos);
                }


                jPanel1.repaint();
                panelTimer.setDelay(20);
            }
        });

        panelTimer.start();

    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jbttnAddBall = new javax.swing.JButton();
        jbttnDeleteBall = new javax.swing.JButton();
        jbttnClearAll = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 591, Short.MAX_VALUE)
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 364, Short.MAX_VALUE)
        );

        jLabel1.setFont(new java.awt.Font("Segoe UI", 1, 24)); // NOI18N
        jLabel1.setText("Bounce");

        jbttnAddBall.setText("Add Ball");
        jbttnAddBall.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jbttnAddBallActionPerformed(evt);
            }
        });

        jbttnDeleteBall.setText("Delete Ball");
        jbttnDeleteBall.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jbttnDeleteBallActionPerformed(evt);
            }
        });

        jbttnClearAll.setText("Clear All");
        jbttnClearAll.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jbttnClearAllActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(62, 62, 62)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel1)
                    .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jbttnAddBall, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(jbttnDeleteBall, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(jbttnClearAll, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(69, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(42, 42, 42)
                .addComponent(jLabel1)
                .addGap(18, 18, 18)
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jbttnAddBall)
                    .addComponent(jbttnDeleteBall)
                    .addComponent(jbttnClearAll))
                .addContainerGap(15, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>                        

    private void jbttnAddBallActionPerformed(java.awt.event.ActionEvent evt) {                                             

        // create a ball
        Ball aball = new Ball();

        // ball characteristics
        aball.setVisible(true);
        aball.setRadius(RNG.nextInt(40) + 10);
        aball.setBallspeed(RNG.nextInt(50) + 5);
        aball.setCompHeight(jPanel1.getHeight());
        aball.setCompWidth(jPanel1.getWidth());
        aball.setXpos(1);
        aball.setYpos(1);
        aball.setSlopeRun(RNG.nextInt(10) + 1);
        aball.setSlopeRise(RNG.nextInt(10));
        aball.setBallColor(new Color(RNG.nextInt(256),
                RNG.nextInt(256), RNG.nextInt(256)));

        // area where we bounce the balls
        //aball.setSize(jPanel1.getWidth(), jPanel1.getHeight());
        aball.setSize(2 * radius, 2 * radius);

        // add the ball to the panel
        jPanel1.add(aball);
        alBalls.add(aball);

       // aball.startBall();

        if (!TimerStatus) {
            PanelClock();
            TimerStatus = true;
        }
    }                                            

    private void jbttnDeleteBallActionPerformed(java.awt.event.ActionEvent evt) {                                                

        try {

            // uncomment to remove the last ball added
            //    jPanel1.remove(jPanel1.getComponentCount() - 1);
            
            // remove first ball added
            jPanel1.remove(alBalls.get(0));
            alBalls.remove(0);
            
            jPanel1.repaint();

        } catch (Exception e) {
        }


    }                                               

    private void jbttnClearAllActionPerformed(java.awt.event.ActionEvent evt) {                                              
        
        // Remove all balls from the pannel
        jPanel1.removeAll();
        
        // Reset the arraylist
        alBalls.clear();
       
        
    }                                             

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(Frame1.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Frame1.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Frame1.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Frame1.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Frame1().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JLabel jLabel1;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JButton jbttnAddBall;
    private javax.swing.JButton jbttnClearAll;
    private javax.swing.JButton jbttnDeleteBall;
    // End of variables declaration                   
}

BALL#

/*
Bounce Balls
Programmer: James Goudy
Rev: April, 2024
 */
package j2_bounce_rev24;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JComponent;
import javax.swing.Timer;

/**
 *
 * @author jgoudy
 */
public class Ball extends JComponent {

    // private members
    // position of the ball
    int xpos = 1;
    int ypos = 1;

    // direction of the ball - forward or backwards
    int xdir = 1;
    int ydir = 1;

    // size of the panel: these are going to be defaults
    int compWidth = 500;
    int compHeight = 500;

    // angle of the ball
    int slopeRun = 1;
    int slopeRise = 1;

    // speed
    int ballspeed = 2;

    // radius of the ball
    int radius = 25;

    // Timer
    Timer bTimer;

    // ball color
    Color ballColor;

    Random RNG;

    boolean wasReversed = false;

    //-------------------------------------------------------
    
    // Constructor
    public Ball() {

        RNG = new Random();
        ballColor = Color.blue;

    }

    // Setters
    public void setXpos(int xpos) {
        this.xpos = xpos;
    }

    public void setYpos(int ypos) {
        this.ypos = ypos;
    }

    public int getXpos() {
        return xpos;
    }

    public int getYPos() {
        return ydir;
    }


    //-------------------------------------------------------
    
    public void setCompWidth(int compWidth) {
        this.compWidth = compWidth - (radius);
    }

    public void setCompHeight(int compHeight) {
        this.compHeight = compHeight - (radius);
    }

    public void setSlopeRun(int slopeRun) {
        this.slopeRun = slopeRun;
    }

    public void setSlopeRise(int slopeRise) {
        this.slopeRise = slopeRise;
    }

    public int getSlopeRise() {
        return slopeRise;
    }

    public void setBallspeed(int ballspeed) {
        this.ballspeed = ballspeed;
    }

    public void setRadius(int radius) {
        this.radius = radius;
    }

    public void setBallColor(Color ballColor) {
        this.ballColor = ballColor;
    }

    //-------------------------------------------------------
    
    // Draw the ball
    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        g.setColor(Color.white);

        // un comment below to visualize the bounding box
        //g.fillRect(0, 0, radius, radius);
        g.setColor(ballColor);
        g.fillOval(0, 0, radius, radius);
    }

    
    //-------------------------------------------------------
    
    public void moveBall() {

        // check for collision on the left and right of the panel
        if (xpos > compWidth) {
            xdir = xdir * -1;
            xpos = compWidth - 1 - (radius);
        } else if (xpos < -1) {
            xdir = xdir * -1;
            xpos = 0 + (RNG.nextInt(10));
        }

        // check for collision on the top and bottom of the panel
        if (ypos > compHeight) {
            ydir = ydir * -1;
            ypos = compHeight - 1 - (radius);
        } else if (ypos < -1) {
            ydir = ydir * -1;
            ypos = 0 + (RNG.nextInt(10));
        }

        //System.out.println(radius);
        // increment the x and y positions
        ypos = ypos + (ydir * slopeRise);
        xpos = xpos + (xdir * slopeRun);

        // System.out.println(xpos + " " + ypos);
    }

    //-------------------------------------------------------
    
    
    //--- USED IF COLLISION IS PROGRAMMED ON FRAME 1---------
    
    // Used for collision if frame 1 is coded for collision
    public boolean getWasReversed() {
        return wasReversed;
    }

    public void setWasReversed() {
        this.wasReversed = true;
    }

    public void resetWasReversed() {
        this.wasReversed = false;
    }
    
    public void reverse() {

        xdir = xdir * -1;
        ydir = ydir * -1;

    }

}

Bounce Balls Animation

Contents

Bounce Balls Animation#

Project File#

Frame1.java#

BALL#