import java.awt.*;
import java.applet.*;

public class teufel extends Applet implements Runnable{
	Thread moveThread;
	private static final int MOVEPAUSE = 100;
	public boolean myGo = false;
	public boolean inTow = false;
	public boolean halfkey = false;
	public boolean stopWatch = false;
	public Image offScreenImage;
	public int theW = 150;
	public int theH = 400;
	public int yBottle = 120;
	public int ytop = yBottle;
	public int theGap = 30;
	public int yHigh = 30;
	public int yLine = 2*theH/3;
	public int dy;
	public int it;
	public int dt;
	public double dytop = (double)ytop;
	public long t1;

	public void start()  {
		if(myGo) {
			if(moveThread == null){
				moveThread = new Thread(this);
				moveThread.start();
			}
		}
	}
	
	public void stop()  {
		if(moveThread != null){
			moveThread.stop();
			try {
				moveThread.join();
			}
			catch (InterruptedException e) { }
		}
		moveThread=null;
	}
		
	public void run() {
		while (true){
			try {
				moveThread.sleep(MOVEPAUSE);
			}catch(InterruptedException e) {
			}
			repaint();
		}
	}


	public void init() {
		super.init();
		offScreenImage = createImage(theW,theH);

		//{{INIT_CONTROLS
		setLayout(null);
		resize(150,400);
		setBackground(new Color(16777215));
		//}}
		
		repaint();
	}

	//{{DECLARE_CONTROLS
	//}}

	public void update(Graphics g){
		Graphics offg = offScreenImage.getGraphics();
		paint(offg);
		g.drawImage(offScreenImage, 0, 0, this);
	}
		
	public void paint(Graphics g){
		// calcs
		if (yHigh < 10) yHigh = 10;
		if (yHigh > 90) yHigh = 90;
		int yplate = yBottle - 10 + yHigh/10;
		theGap = 32 - yHigh/4;
		double diff = (32. - (double)yHigh/4.0) - 20.0;
		if (Math.abs(diff) < 0.1) {
			myGo = false;
			stop();
		} else {
			myGo = true;
			start();
		}
		// dytop is precise location of top of teufel, ytop its rounded value
		dytop = dytop - diff;
		if ((int)dytop < yplate+10) {
			dytop = (double)(yplate+10);
			if (!stopWatch) {
				myGo = false;
				stop();
			}
		}	
		if ((int)dytop > theH-110) {
			dytop = (double)(theH-110);
			if (!stopWatch) {
				myGo = false;
				stop();
			}
		}	
		ytop = (int)dytop;
		if (stopWatch) {
			myGo = true;
			start();
		}
		// Draw everything
		g.setColor(Color.white);
		g.fillRect(0, 0, theW, theH);
		g.setColor(Color.darkGray);
		g.fillRect(0,yBottle,theW,theH-yBottle);             // bottle
		g.setColor(Color.blue);
		g.fillRect(10,yBottle,theW-20,theH-yBottle-10);     // water
		g.setColor(Color.yellow);
		g.drawLine(0,yLine,theW,yLine);
		g.setColor(Color.black);
		g.fillRect(10,yplate,theW-20,10);                    // top plate
		g.setColor(Color.darkGray);
		g.fillRect(11,yplate+1,theW-22,8);                   
		g.setColor(Color.black);
		g.fillRect(30,ytop,theW-60,100);                      // teufel
		g.setColor(Color.white);
		g.fillRect(40,ytop+10,theW-80,theGap);                // air gap
		g.setColor(Color.blue);
		g.fillRect(40,ytop+10+theGap,theW-80,100-10-theGap);  // water
		g.setColor(Color.black);
		g.fillRect(40,ytop+60,25,40);                         // teufel - bottom
		g.fillRect(theW-65,ytop+60,25,40);
		drawVerticalSpring(5,theW-40,40,yHigh+5,yplate-1,g);
		drawVerticalSpring(5,theW-40,40,yHigh+6,yplate  ,g);
		g.setColor(Color.red);
		g.fillRect(40,yHigh-5,theW-80,10);                    // force plate
		if (stopWatch) {
			if (Math.abs(ytop-yLine) < 3 && Math.abs(diff) < 0.1) {
			} else {
				dt = (int)(System.currentTimeMillis() - t1);
			}
			g.setColor(Color.red);
			g.drawString(""+dt,20,15);
		}
	}

	public void drawVerticalSpring(int nt, int xhigh, int xlow, 
	                                         int yhigh, int ylow, Graphics g){
		double denom = 2.0*nt + 1.0;
		g.drawLine((xhigh+xlow)/2,ylow,xhigh,(int)(ylow+0.5*(yhigh-ylow)/denom));
		for (int i = 1; i < 2*nt; i=i+2){
			g.drawLine(xhigh,(int)(ylow+(i-0.5)*(yhigh-ylow)/denom),
					    xlow,(int)(ylow+(i+0.5)*(yhigh-ylow)/denom));
			g.drawLine(xhigh,(int)(ylow+(i+1.5)*(yhigh-ylow)/denom),
					    xlow,(int)(ylow+(i+0.5)*(yhigh-ylow)/denom));
		}
		g.drawLine(xhigh,(int)(ylow+(2.*nt+0.5)*(yhigh-ylow)/denom),(xhigh+xlow)/2,yhigh);
	}	

	public boolean handleEvent(Event evt){
		if (evt.key == Event.DOWN){
			halfkey = !halfkey;
			if (halfkey) yHigh++;
			repaint();
			return true;
		}
		if (evt.key == Event.UP){
			halfkey = !halfkey;
			if (halfkey) yHigh--;
			repaint();
			return true;
		}
		if (evt.id == Event.KEY_PRESS) {
			String thePressedKey = ""+(char)evt.key;
			if (thePressedKey.equalsIgnoreCase("s")) {
				stopWatch = !stopWatch;
	            t1 = System.currentTimeMillis();
	            repaint();
			}
		}
		if (evt.target == this && evt.id == Event.MOUSE_DOWN) {
			osc_MouseDown(evt);
			return true;
		}
		if (evt.target == this && evt.id == Event.MOUSE_DRAG) {
			osc_MouseDrag(evt);
			return true;
		}
		if (evt.target == this && evt.id == Event.MOUSE_UP) {
			osc_MouseUp(evt);
			return true;
		}
		return false;
	}
	
	void osc_MouseDrag(Event event) {
		if (inTow) {
			yHigh = event.y - dy;
			repaint();
			it = 0;
		}
	}

	void osc_MouseDown(Event event) {
		dy = event.y - yHigh;
		if ((int)Math.abs(dy) < 10) {
			inTow = true;
			//myGo = false;
		}
	}

	void osc_MouseUp(Event event) {
		inTow = false;
	}
}