Question

1. Create a simple Swing application that animates a square diagonally across its window once. You may set the size of the window and assume that it doesn’t change. Using Java swing using timers

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

// MovingSquare.java

import java.awt.Color;

import java.awt.Graphics;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JFrame;

import javax.swing.Timer;

public class MovingSquare extends JFrame {

      //declaring important attributes

      private int x, y; //current position of square

      private int size; //size of square

      private Color color; //square color

      private Timer timer; //timer for running animation

      public MovingSquare() {

            //will exit on close button click

            setDefaultCloseOperation(EXIT_ON_CLOSE);

            //using 500x500 size

            setSize(500, 500);

            //assigning values to instance variables

            x = 0;

            y = 0;

            size = 80;

            color = Color.BLUE;

            //initializing a timer that runs every 50 ms

            timer = new Timer(50, new ActionListener() {

                  @Override

                  public void actionPerformed(ActionEvent e) {

                        //updating x and y values by 5

                        x+=5;

                        y+=5;

                        //if the square goes out of bounds, stopping the timer

                        if ((x + size) >= getWidth() || (y + size) >= getHeight()) {

                              timer.stop();

                        }

                        //repainting to make things visible

                        repaint();

                  }

            });

            //starting timer

            timer.start();

            //making window visible

            setVisible(true);

      }

      @Override

      public void paint(Graphics g) {

            super.paint(g);

            //using the specified color

            g.setColor(color);

            //drawing a filled square

            g.fillRect(x, y, size, size);

      }

     

      public static void main(String[] args) {

            //initializing GUI

            new MovingSquare();

      }

}

/*OUTPUT*/