1 / 15

Java: Animation

Java: Animation. Chris North cs3724: HCI. Animation?. Changing graphics over time Examples: cartoons Clippy, agents/assistants Hour glass Save dohicky Progress bar Copy file Amit’s pulsating plot. Purvi. Algorithm Animation. Java Graphics Review. Extend JPanel

rudolph
Download Presentation

Java: Animation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Java:Animation Chris North cs3724: HCI

  2. Animation? • Changing graphics over time • Examples: • cartoons • Clippy, agents/assistants • Hour glass • Save dohicky • Progress bar • Copy file • Amit’s pulsating plot

  3. Purvi • Algorithm Animation

  4. Java Graphics Review • Extend JPanel • Override paintComponent( ) method public class MyPanel extends JPanel { public void paintComponent(Graphics g){ super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; // my graphics here: g2.drawString("Hello World", 10, 10); } }

  5. Ticker

  6. Animating the ticker text • Keep repainting graphics using different x public class MyPanel extends JPanel { int x; public void paintComponent(Graphics g){ super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; // my graphics here: g2.drawString("Hello World", x, 10); } }

  7. Animation Loop • Update x location (member variable) • Repaint While(true){ //infinite loop x = x – 1; repaint(); //calls paintComponent() Thread.sleep(10); //slow down animation } • Problem?

  8. Multi-Threading • Loop prevents other parts of code from executing • User events pile up • Multiple threads let multiple methods execute simultaneously (multi-tasking) • Threads = lightweight processes, shared memory Main thread User interaction Anim thread Update graphics

  9. Java Threads • implement Runnable interface • Override run( ) method • Put animation loop here • new Thread(runnable) • Thread.start( ) • Calls runnable.run( )in new thread My Panel Runnable run( ) Thread start( )

  10. Simplifying • MyPanel implements Runnable My Panel Runnable run( ) My Panel Runnable run( ) Thread start( ) Thread start( )

  11. Threaded Ticker public class MyPanel extends JPanel implements Runnable { int x = 100; Thread mythread; public MyPanel(){ // constructor mythread = new Thread(this); mythread.start(); } public void run(){ while(true){ // animation loop x = x – 5; repaint(); Thread.sleep(100); } } public void paintComponent(Graphics g){ super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.drawString("Hello World", x, 10); // my graphics } } or in button code that starts animation

  12. Stopping a Thread • Stop animation loop with a flag • mythread = null; will cleanup thread object Boolean runMyAnimation; While(runMyAnimation){ //flag stops loop x = x – 5; repaint(); //calls paintComponent() Thread.sleep(100); //slow down animation }

  13. Controlling Animation Speed While(true){ x = x – 5; //animation step size repaint(); Thread.sleep(100); //delay between steps } Milliseconds 1000 = 1 second

  14. Animation Summary • In a secondary thread: • Make changes to global state • Repaint • Sleep delay • Repeat • Use double buffering as needed

  15. JBuilder Example

More Related