import objectdraw.*;
import java.awt.*;

public class FallingLogoCallbackTimed extends ActiveObject {
    
    // the delay between successive moves of the ball
    private static final int DELAY_TIME = 33;
    // number of pixels ball falls in a single move
    private static final double Y_SPEED = 4;

    private static final double PIXEL_SPEED = Y_SPEED/DELAY_TIME;
    
    // the image of the logo
    private VisibleImage logoGraphic;
    // the canvas
    private DrawingCanvas canvas;
    
    private LogoControllerCallbackTimed myController;

    public FallingLogoCallbackTimed(LogoControllerCallbackTimed master, Image logo, 
	Location initialLocation, DrawingCanvas aCanvas) {
        canvas = aCanvas;
        logoGraphic = new VisibleImage(logo,initialLocation, canvas);
	myController = master;
        start();
    }
    
    public void run() {
	double prevClock, now, elapsed;
	prevClock = System.currentTimeMillis();
        while (logoGraphic.getY() < canvas.getHeight() ) {
	    now = System.currentTimeMillis();
 	    elapsed = now - prevClock;
	    prevClock =now; 

            logoGraphic.move(0, PIXEL_SPEED * elapsed);
            pause(DELAY_TIME);
        }
	myController.atBottom(this);
        logoGraphic.removeFromCanvas();
    }
}