/* Author: Gerard Whyte */
/* AKA: Gearóid Dé Faoite */
/* Date: 3/5/01 */
/* Copyright (C) 2001 Gerard Whyte */

//Importing in all the classes, that will be used in the applet, provided by the Java Libraries

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


///////////////////////////////////////////////////////////////////////////////////////////////////////////////
/*********** This is the class that defines the Pad, where most of the events in the applet will occur *******/
///////////////////////////////////////////////////////////////////////////////////////////////////////////////

class Pad extends Canvas
{

	private Dimension size;
	private int startX;
	private int startY;
	private int endX;
	private int endY;
	private Color darkPurple = new Color(117, 115, 145);

	public Pad(int width, int height)
	{

		size = new Dimension(width, height);
		setSize(size);

	}

	public void paint(Graphics g)
	{
		this.drawLine(this.getGraphics(), 0, 0, 549, 0, darkPurple);
		this.drawLine(this.getGraphics(), 0, 0, 0, 300, darkPurple);
		this.drawLine(this.getGraphics(), 549, 0, 549, 299, darkPurple);
		this.drawLine(this.getGraphics(), 0, 299, 549, 299, darkPurple);
	}

	public void drawLine(Graphics g, int x1, int y1, int x2, int y2)
	{

		g.drawLine(x1, y1, x2, y2);

	}

	public void drawLine(Graphics g, int x1, int y1, int x2, int y2, Color c)
	{

		g.setColor(c);
		g.drawLine(x1, y1, x2, y2);
		g.setColor(Color.black);

	}

	public void setStart(int x1, int y1)
	{

		startX = x1;
		startY = y1;

	}

	public void setEnd(int x1, int y1)
	{

		endX = x1;
		endY = y1;

	}

	public int getStartX()
	{

		return this.startX;
	}

	public int getStartY()
	{

		return this.startY;
	}

	public int getEndX()
	{

		return this.endX;

	}

	public int getEndY()
	{

		return this.endY;

	}

	public void drawDot(Graphics g, int x, int y, int w, Color c)
	{
		g.setColor(c);
		g.fillOval(x, y, w, w);
		g.setColor(Color.black);

	}
}



//////////////////////////////////////////////////////////////////////////////////////
/************ Applet Class - This is the class which defines the applet *************/
//////////////////////////////////////////////////////////////////////////////////////

public class VectorLaws extends Applet implements ActionListener, MouseListener, MouseMotionListener
{

//Attributes

	/* Components */
	private Label modeTitle;
	private Pad pad;
	private Button triangle;
	private Button parallel;
	private Button game;
	private Button go;
	private Button reset;
	
	/* Non-changed Attributes */
	private Graphics p;
	private Color lightPurple = new Color(160, 160, 183);
	private Color darkPurple = new Color(117, 115, 145);
	private Color blue = new Color(0, 64, 128);
	private Font arial = new Font("Arial", Font.PLAIN, 12);

	/* Local Variables */
	int mode = 0;
	boolean ready = false;
	int point = 0;
	int lastX;
	int lastY;
	int[] paraArray = new int[6];



//Methods


	/* Initialiser */

	public void init()
	{

		this.setBackground(Color.white);

		modeTitle = new Label("Triangle and Parallelogram Laws: Please select a mode.");
		modeTitle.setFont(arial);
		add(modeTitle);

		pad = new Pad(550, 300);
		pad.addMouseListener(this);
		add(pad);
		p = pad.getGraphics();

		triangle = new Button("Triangle Law");
		triangle.addActionListener(this);
		triangle.setFont(arial);
		add(triangle);

		parallel = new Button("Parallelogram Law");
		parallel.addActionListener(this);
		parallel.setFont(arial);
		add(parallel);

		game = new Button("Game");
		game.addActionListener(this);
		game.setFont(arial);
		add(game);

		go = new Button("Go");
		go.addActionListener(this);
		go.setFont(arial);
		add(go);

		reset = new Button("Reset");
		reset.addActionListener(this);
		reset.setFont(arial);
		add(reset);

	}


	/* Method that decides what happens when an action is performed on a component */

	public void actionPerformed(ActionEvent e)
	{

		if (e.getSource() == triangle)
		{

			mode = 1;	// Mode set to Triangle Law
			modeTitle.setText("Triangle Law");
			pad.repaint();
			point = 0;
			ready = false;

		}

		if (e.getSource() == parallel)
		{

			mode = 2;	// Mode set to Parallelogram Law
			modeTitle.setText("Parallelogram Law");
			pad.repaint();
			point = 0;
			ready = false;

		}

		if (e.getSource() == game)
		{

			mode = 3;	// Mode set to Game
			modeTitle.setText("Parallelogram Law Game");
			pad.repaint();
			point = 0;
			ready = false;

		}

		if (e.getSource() == go)
		{

			if (ready)
			{

				if (mode == 1) // Triangle Law
				{
					/* Draw Equivalent vector */
					pad.drawLine(p, pad.getStartX(), pad.getStartY(), pad.getEndX(), pad.getEndY(), 														Color.red);
					/* Draw dot at the end of the equivalent vector */
					pad.drawDot(p, pad.getEndX() - 3, pad.getEndY(), 5, Color.red);
					mode = 0; //reset mode
				}

				if (mode == 2 || mode == 3) // Parallogram Law or Game
				{
					/* Draw Parallelogram */
					
					pad.drawLine(p, paraArray[2], paraArray[3], 
						paraArray[4] + (paraArray[2] - paraArray[0]),
						  paraArray[5] + (paraArray[3] - paraArray[1]), lightPurple);

					pad.drawLine(p, paraArray[4], paraArray[5],
						paraArray[4] + (paraArray[2] - paraArray[0]),
						  paraArray[5] + (paraArray[3] - paraArray[1]), lightPurple);
					
					/* Draw Resultant vector */

					pad.drawLine(p, pad.getStartX(), pad.getStartY(), 
					  paraArray[4] + (paraArray[2] - paraArray[0]), 
					    paraArray[5] + (paraArray[3] - paraArray[1]), Color.red);

					/* Draw dot at the end of the resultant vector */
					pad.drawDot(p, (paraArray[4] + (paraArray[2] - paraArray[0])) - 3,
						paraArray[5] + (paraArray[3] - paraArray[1]), 5, Color.red);

					mode = 0; // reset mode
				}

			}

		}

		if (e.getSource() == reset)
		{
			
			mode = 0;	// Mode reset to nothing
			point = 0;
			ready = false;
			pad.repaint();
			modeTitle.setText("Triangle and Parallelogram Laws: Please select a mode.");

		}

	}


	/* Method that decides what happens when the mouse button is pressed */

	public void mousePressed(MouseEvent e)
	{

		if (e.getSource() == pad)
		{

			if (mode == 1)		// Triangle Law Mode
			{

				if (point == 0) // Set Starting Point
				{

					pad.setStart(e.getX(), e.getY());
					point += 1;

				}

				else if (point == 1) // Draw First Vector
				{

					lastX = e.getX();
					lastY = e.getY();
					pad.drawLine(p, pad.getStartX(), pad.getStartY(), lastX, lastY);
					pad.drawDot(p, lastX - 3, lastY, 5, blue);
					point += 1;

				}

				else if (point == 2) // Draw Second and up Vectors
				{

					pad.drawLine(p, lastX, lastY, e.getX(), e.getY());
					lastX = e.getX();
					lastY = e.getY();
					pad.drawDot(p, lastX - 3, lastY, 5, blue);
					pad.setEnd(lastX, lastY);
					ready = true;

				}

			}

			if (mode == 2)		// Parallelogram Law Mode
			{

				if (point == 0) // Set Starting Point
				{

					pad.setStart(e.getX(), e.getY());
					paraArray[0] = e.getX();
					paraArray[1] = e.getY();
					point += 1;

				}

				else if (point == 1) // Draw First Vector
				{
					pad.drawLine(p, pad.getStartX(), pad.getStartY(), e.getX(), e.getY());
					pad.drawDot(p, e.getX() - 3, e.getY(), 5, blue);
					paraArray[2] = e.getX();
					paraArray[3] = e.getY();
					point += 1;
								
				}

				else if (point == 2) // Draw Second Vector
				{

					pad.drawLine(p, pad.getStartX(), pad.getStartY(), e.getX(), e.getY());
					pad.drawDot(p, e.getX() - 3, e.getY(), 5, blue);
					paraArray[4] = e.getX();
					paraArray[5] = e.getY();
					ready = true;
					point += 1;

				}

			}

			if (mode == 3)		// Game Mode
			{

				if (point == 0) // Set Starting Point
				{

					pad.setStart(e.getX(), e.getY());
					paraArray[0] = e.getX();
					paraArray[1] = e.getY();
					point += 1;

				}

				else if (point == 1) // Draw First Vector
				{

					pad.drawLine(p, pad.getStartX(), pad.getStartY(), e.getX(), e.getY());
					pad.drawDot(p, e.getX() - 3, e.getY(), 5, blue);
					paraArray[2] = e.getX();
					paraArray[3] = e.getY();
					point += 1;
								
				}

				else if (point == 2) // Draw Second Vector
				{

					pad.drawLine(p, pad.getStartX(), pad.getStartY(), e.getX(), e.getY());
					pad.drawDot(p, e.getX() - 3, e.getY(), 5, blue);
					paraArray[4] = e.getX();
					paraArray[5] = e.getY();
					point += 1;

				}

				else if (point == 3) // Guess correct end point
				{

					pad.drawDot(p, e.getX() - 3, e.getY(), 5, darkPurple);

					if (((e.getX() < (paraArray[4] + (paraArray[2] - paraArray[0]) + 5)) &&
					    (e.getX() > (paraArray[4] + (paraArray[2] - paraArray[0]) - 5))) &&
					    ((e.getY() < (paraArray[5] + (paraArray[3] - paraArray[1]) + 5)) &&
					    (e.getY() > (paraArray[5] + (paraArray[3] - paraArray[1]) - 5))))
					{
						
						pad.drawLine(p, paraArray[2], paraArray[3], 
						  paraArray[4] + (paraArray[2] - paraArray[0]),
						    paraArray[5] + (paraArray[3] - paraArray[1]), lightPurple);

						pad.drawLine(p, paraArray[4], paraArray[5],
						  paraArray[4] + (paraArray[2] - paraArray[0]),
						    paraArray[5] + (paraArray[3] - paraArray[1]), lightPurple);

						pad.drawLine(p, pad.getStartX(), pad.getStartY(), 
						  paraArray[4] + (paraArray[2] - paraArray[0]), 
						    paraArray[5] + (paraArray[3] - paraArray[1]), Color.red);

						pad.drawDot(p, (paraArray[4] + (paraArray[2] - paraArray[0])) - 3,
						  paraArray[5] + (paraArray[3] - paraArray[1]), 5, Color.red);

						modeTitle.setText("Correct. Press Game to play again.");
						point += 1;
						mode = 0;
					}

					else // Guessed incorrectly
					{
						modeTitle.setText("Incorrect. Please try again");
						ready = true;
					}

				}
	
			}

		}

	}
	

	/* Methods to deal with other Mouse Events, none of these are used */

	public void mouseReleased(MouseEvent e){ }
	public void mouseEntered(MouseEvent e){ }
	public void mouseExited(MouseEvent e){ }
	public void mouseClicked(MouseEvent e){ }
	public void mouseMoved(MouseEvent e){ }
	public void mouseDragged(MouseEvent e){ }

}