// File:  DrawCanvas.java

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

public class DrawCanvas 
		extends Canvas 
{

	Graphics g;
	String curMode="Rect";
	mPoint curObj;
	public boolean fill=true;
	mPoint objList[]=new mPoint[100];
	int index=0;


	public DrawCanvas() {
		
		setBackground(Color.blue);
		setForeground(Color.yellow);
		
		// Notice the construction of two listener objects, ourMouseListener
		// and ourMotionListener. Both are constructed from the class 
		// definitions, called anonymous classes.

		// "You should consider using an anonymous class instead of
		// [a top level class or] a local class if:
		// . The class has a very short body.
		// . Only one instance of the class is needed.
		// . The class is used right after it is defined.
		// . The name of the class does not make your code any easier to understand."
		// [Java in a Nutshell, pg. 119]
		
		// We define our version of mouse adapters here 
		// because we will not use all of the MouseListener methods.

		// MouseListener is an interface and all of its methods are defined abstract.
		// This forces us to overwrite all the methods even though we do not need some.
		// To overcome this problem, adapter classes are developed. These are 
		// classes implementing interfaces with empty method bodies. Hence, we only
		// overwrite those methods that we need. 

		// In this case, we need mousePressed and mouseReleased.
		MouseListener ourMouseListener = new MouseAdapter() {
			// from MouseAdapter
			public void mousePressed(MouseEvent e) {
				int x=e.getX();
				int y=e.getY();
				if (curMode.equals("Rect")) curObj=new mRectangle(x, y, x, y);
				else if (curMode.equals("Circ")) curObj=new mCircle(x, y, x, y);
				else if (curMode.equals("Line")) curObj=new mLine(x, y, x+1, y+1);
				else if (curMode.equals("Round")) curObj=new mRound(x, y, x, y);
			}
		
			// from MouseAdapter
			public void mouseReleased(MouseEvent e) {
				g=getGraphics();
				g.setPaintMode();
				curObj.setEnds(e.getX(), e.getY());
				curObj.setFill(fill);
				objList[index++]=curObj;
				curObj.draw(g);
				if(index>=100) index=100;
			}
		};
		
		// We also need mouseDragged from MouseMotionListener.
		MouseMotionListener ourMotionListener = new MouseMotionAdapter() {
			public void mouseDragged(MouseEvent e) {
				g=getGraphics();
				g.setXORMode(Color.black);
				curObj.draw(g);
				curObj.setEnds(e.getX(), e.getY());
				curObj.draw(g);
			}
		};
		
		addMouseListener( ourMouseListener );
		addMouseMotionListener( ourMotionListener );
	}

	public void setDrawMode(String s) {
		if(s.equals("Clear")) {
			index=0;
			repaint();
		} 
		else if(s.equals("Redraw")) repaint();
		else curMode=s;
	}

	public void paint(Graphics g) {

		g.setColor(Color.yellow);
		super.paint(g);
		for(int i=0; i<index; i++)
			objList[i].draw(g);
	}
}

class mPoint {

	
	int x,y,x2,y2;
	boolean fill=false;

	public mPoint(int _x, int _y, int _x2, int _y2) {

		x=_x;
		y=_y;
		x2=_x2;
		y2=_y2;
	};

	public void draw(Graphics g) {
	}

	public void setFill(boolean _fill) {
		fill=_fill;
	}

	public boolean isIn(int _x, int _y) {
		return _x == x && _y == y;
	}

	public void setEnds(int _x, int _y) {
		x2=_x;
		y2=_y;
	}
}

class mLine extends mPoint {

	public mLine(int _x, int _y, int _x2, int _y2) {
		super(_x, _y, _x2, _y2);
	};

	public void draw(Graphics g) {
		g.drawLine(x, y, x2, y2);
	}
}

class mRectangle extends mPoint {

	public mRectangle(int _x, int _y, int _x2, int _y2) {
		super(_x, _y, _x2, _y2);
	};

	public void draw(Graphics g) {
		if (fill) {
			g.setColor(Color.black);
			g.fillRect(x, y, x2-x, y2-y);
			g.setColor(Color.yellow);
		}
		g.drawRect(x, y, x2-x, y2-y);
	}

	public boolean isIn(int _x, int _y) {
		Rectangle r=new Rectangle(x, y, x2-x, y2-y);
		return r.inside(_x, _y);
	}
}

class mRound extends mRectangle {

	public mRound(int _x, int _y, int _x2, int _y2) {
		super(_x, _y, _x2, _y2);
	};

	public void draw(Graphics g) {
		if (fill) {
			g.setColor(Color.black);
			g.fillRoundRect(x, y, x2-x, y2-y, 100, 50);
			g.setColor(Color.yellow);
		}
		g.drawRoundRect(x, y, x2-x, y2-y, 100, 50);
	}
}

class mCircle extends mRectangle {

	public mCircle(int _x, int _y, int _x2, int _y2) {
		super(_x, _y, _x2, _y2);
	};

	public void draw(Graphics g) {
		if (fill) {
			g.setColor(Color.black);
			g.fillOval(x, y, x2-x, y2-y);			
			g.setColor(Color.yellow);
		}
		g.drawOval(x, y, x2-x, y2-y);
	}
}