/** An example applet that wraps the Asteroids animation. */

// Comments in square brackets are general comments that hold true of
// any applet

import uwcse.graphics.*;
import uwcse.animation.*;

// [Each GWindow-based application should extend AppletGWindow, which
// is itself an extension of Applet]
public class AsteroidsApplet extends AppletGWindow {
    private Stage stage;
    private boolean animationStarted;

    // [code that should run when the applet is first loaded]
    public void init() {
	// [always do this first, to take care of any work that the
	// AppletGWindow needs]
	super.init();

	// create the window for the applet
	GWindow window = new GWindow(this);

	// create the stage
	this.stage = new Stage(window);

	// create the asteriods animation object
	Asteroids l = new Asteroids(this.stage);

	// create the handler for input & timer events; register it
	// with the stage
	AsteroidsEventHandler h = new AsteroidsEventHandler(this.stage);
	this.stage.registerEventHandler(h);

	// start sending timer events, one every three seconds
	this.stage.startTimerEvents(3000);

	this.animationStarted = false;
    }

    // [code that should run whenever the applet becomes visible (the
    // first time the applet runs, as well as any time that the web
    // page containing the applet is exposed)]
    public void start() {
	// [always do this first, to take care of any work that the
	// AppletGWindow needs]
	super.start();

	if (! this.animationStarted) {
	    // start up the animation now
	    this.animationStarted = true;
	    // do the animation in the background, so this start
	    // method finishes
	    this.stage.animateInBackground();
	} else {
	    // we're restarting the applet
	    this.stage.resumeAnimation();
	}
    }

    // [code that should run whenever the applet becomes (temporarily)
    // invisible, e.g. when the web page containing the applet is
    // hidden]
    public void stop() {
	// [always do this first, to take care of any work that the
	// AppletGWindow needs]
	super.stop();

	this.stage.suspendAnimation();
    }

    // [code that should run when the applet finishes]
    public void destroy() {
	this.stage.quitAnimation();

	// [always do this last, to finish with any work that the
	// AppletGWindow needs]
	super.destroy();
    }

}