1. Recitation 12
November 18, 2011

2. Today’s Goals:
Use Threads to animate changes.

3. Creating a thread } Creates a new Command Creates a new Java thread
public void animateFromOrigin() {
Runnable animateCommand = new AnimationCommand(…);
Thread thread = new Thread(animateCommand);
thread.setName(“Shuttle Animation”);
thread.start(); }
Invokes the run method on the command object passed to constructor.

4. Pausing a thread void sleep(int pauseTime) { try {
// OS suspends program for pauseTime
Thread.sleep(pauseTime);
} catch (Exception e) {
// program may be forcibly interrupted while sleeping
e.printStackTrace(); }; }

5. java.lang.Runnable Interface
Command Object
run ()
package java.lang;
public interface Runnable {
public void run(); }

6. Runnable Implementation
public class AShuttleAnimationCommand implements Runnable{
Shuttle shuttle;
int animationStep, animationPauseTime;
public AShuttleAnimationCommand (Shuttle shuttle, int step, int pause) {
this.shuttle = shuttle;
animationStep = step;
animationPauseTime = pause; }
public void run() { shuttle.animateFromOrigin(animationStep,animationPauseTime);
Note: Will likely need to
specify additional parameters
(e.g. where to move to!)
Parameters
Target Object

7. Recitation Specification
Goal: Animate the changes to a Triangle’s x and y position.
Tasks:
Implement animateSetX/Y methods in CartesianLine.java
Implement run() in both ASetXCommand and ASetYCommand
Bonus:
Animate push and pop onto shape stack, using code from Recitation 11

8. Setup and Submission Work with a single partner!
Please follow the instructions on the course website to set up and submit your projects!
Set up your project:
Submit an assignment:
Work with a single partner!