Using Thread in Java to Create Animation, Example 5

I said we use the paint() method to have a corner to creat my objects. Further I can have a class for my objects and create images there and bring them on my frame. I need only to pass the graphic of canvas to that class. Then I can even create more than one similar objects on the canvas and put them next together. I can have them resized and rotated and deformed. Now, I use some simple drawings and my aircraft bomber looks more real. I create it in a small sub-class to my canvas. Then I can call it from my paint() method. From this point you can use formalities of object-oriented languages for data encapsulations. But I prefer to experience with animations and put details of software engineering aside until I become fully fluent and in command of more basic details.

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package animation; /** * * author Peter Jones */ public class Ex5Thread extends javax.swing.JFrame implements java.lang.Runnable { /** * Creates new form Ex5Thread */ public Ex5Thread() { super("Example 5!"); // A title for the frame x = X0; y = Y0; aPanel = new javax.swing.JPanel(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); setPreferredSize(new java.awt.Dimension(840, 400)); add(aPanel); pack(); start(); } /** * Start when browser is loaded or button pushed. * */ public void start() { if (fThread == null) { fThread = new java.lang.Thread(this); fThread.start(); } } // start /** * The thread loops to draw each frame.* */ public void run() { //j=0; // Loop through animation frames while (fThread != null) { // Sleep between frames try { Thread.sleep(10); //build the first image java.awt.Graphics gr = getGraphics(); paint(gr); //next, move coordinates //such that incoming image won't overlap t += 1; x = +(int) (V0 * t); y = Y0 + (int) (G * t * t / 2);//y-coordinate of bomb } catch (InterruptedException e) { break; } //break stops the loop // Now go to other frame other(); } }// run ends // Your other frame comes here. public void other() { // check for the end of panel isDone(); // Sleep between frames try { Thread.sleep(490); aPanel.repaint(); // meanwhile repaint the panel. } catch (InterruptedException e) { } } /* Boolean allows you to terminate this thread, if you like, and go to other tasks. * I used it to provide a flag for counting. */ public boolean isDone() { boolean temp = false; if (x > 840) {//if reaches end of panel temp = true; t = 0; //initial t x = X0; //initial x y = Y0; //initial y aPanel.repaint(); //reset the panel } return temp; } //Create some graphic public void paint(java.awt.Graphics gr) { //Next, create object from sub-class! new airCraft().paint(gr, x, y, Y0); /* gr.setColor(java.awt.Color.green); gr.fillOval(x, Y0+10, 100, 20);//fuselage gr.setColor(java.awt.Color.red); gr.fillArc(x-20, Y0+5, 40, 20, 0, 100);//tail gr.fillArc(x+10, Y0+3, 60, 15, 0, 135);//far wing gr.fillArc(x+35, Y0+10, 35, 20, 0, -135);//front wing gr.setColor(java.awt.Color.gray); gr.fillArc(x+55, Y0+10, 40, 10, 0, 100);//cockpit gr.setColor(java.awt.Color.red); gr.fillOval(x+30, Y0+y, 10, 5);//bomb*/ } public static void main(String args[]) { new Ex5Thread().setVisible(true); } /* Variables declaration - do not modify * For simple GUI * For thread animation */ private javax.swing.JPanel aPanel; private Thread fThread; /* Variables declaration - do not modify * */ long t = 0; //seconds int x = 20; // X-coordinate of a point final int X0 = 20; // pixels int y = 50; // Y-coordinate of a point final int Y0 = 50; // pixels final int V0 = 60; // pixels/second final double G = 2.45; //pixels/second/second // End of variables declaration //sub-class creates some graphical object class airCraft { airCraft() {//Constructor } protected void paint(java.awt.Graphics gr, int x, int y, int Y) { gr.setColor(java.awt.Color.green); gr.fillOval(x, Y + 10, 100, 20);//fuselage gr.setColor(java.awt.Color.red); gr.fillArc(x - 20, Y + 5, 40, 20, 0, 100);//tail gr.fillArc(x + 10, Y + 3, 60, 15, 0, 135);//far wing gr.fillArc(x + 35, Y + 10, 35, 20, 0, -135);//front wing gr.setColor(java.awt.Color.gray); gr.fillArc(x + 55, Y + 10, 40, 10, 0, 100);//cockpit gr.setColor(java.awt.Color.red); gr.fillOval(x + 30, Y + y, 10, 5);//bomb } } }

Click here to see the application. If you save the "jar" file in your computer you can use "7z" decompression utility to extract source file and image files.

As you see this is not a smooth animation. To make it smooth, you need to calculate different timings such as effect of a frame on human eyes, rendering a nice artistic image with software, or use pictures instead, using Java Beans to dispatch property changes, using JavaFX and create scenes. When you become familiar with basics that I put here, you can discover further.