import java.awt.*;
import fallingletter;
import java.awt.event.*;
//This version implements the interface Runnable
public class HelloRunnable extends java.applet.Applet implements Runnable, MouseListener, MouseMotionListener
{
	fallingletter[] letters;
	int count, draggingletter;
	Thread animator;
	String greeting;
	//same as before
	public void init()
	{
		greeting = "Hello, World!";		
		letters = new fallingletter[greeting.length()];
		for (int i=0; i<greeting.length(); i++)
			letters[i]=new fallingletter(greeting.charAt(i), 20+20*i, 0);
		setBackground(Color.black);
		count=0;
		draggingletter=-1;
		addMouseListener(this);
		addMouseMotionListener(this);
	}
	//same as before
	public void paint(Graphics g)
	{
		g.setFont(new Font("Serif", Font.BOLD, 20));
		for (int i = 0; i<greeting.length() && i<count/20; i++)
			letters[i].draw(g);
	}
	//This is where to start taking notes:  start() creates the animation thread and starts it (like Timer.start()), don't call this method start() if you don't want it to start with the applet, though
	public void start()
	{
		animator = new Thread(this);	//Thread can be constructed by passing in a Runnable
		animator.start();
	}
	//The stop() method can stop the animation and make it freeze- I don't call this, but I could have used it to make it stop any time I want.  It's synchronized so it can happen at the same time as other synchronized methods like run()
	public synchronized void stop()
	{
		animator = null;
		notify();
	}
	//run() is the method in Runnable I have to define.  It executes automatically when a thread is started
	public synchronized void run()
	{
		while (Thread.currentThread() == animator)	//this is a key line for the while loop
		{						//do the stuff you need to in animation
			for (int i=0; i<greeting.length() && i<count/20; i++)
				if (i!=draggingletter)
					letters[i].update();
			count++;
			repaint();
			try					//you'll talk about what try and catch statements do later in the semester, just trust me for now
			{
				wait (40);			//wait about 40 milliseconds
			}
			catch (InterruptedException e)
			{
				break;				//if run is interrupted, stop this loop
			}
		}
	}
	//mouse functionality like before
	public void mouseClicked(MouseEvent event)
	{
		for (int i=0; i<greeting.length(); i++)
			if (letters[i].clickedin(event.getPoint()))
				letters[i].changeColor();
	}
	public void mousePressed(MouseEvent event)
	{
		for (int i=0; i<greeting.length(); i++)
			if (letters[i].clickedin(event.getPoint()))
			{
				draggingletter=i;
				break;
			}
	}
	public void mouseReleased(MouseEvent event)
	{
		draggingletter=-1;
	}
	public void mouseEntered(MouseEvent event){}
	public void mouseExited(MouseEvent event){}
	public void mouseMoved(MouseEvent event){}
	public void mouseDragged(MouseEvent event)
	{
		if (draggingletter>=0)
			letters[draggingletter].update(event.getX(), event.getY());
	}
}