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


public class Asst7 extends Applet {
    DrawingCanvas canvas;

    public void init() {
        GridLayout grid = new GridLayout(1,0);
        setLayout(grid);

	add (new DrawingCanvas());
	
        validate();
    }

}


class DrawingCanvas extends Canvas {
  // Shapes
  private static final int MAX_SHAPES=5;
  private static final int OVAL=0;
  private static final int SOLID_OVAL=1;
  private static final int RECTANGLE=2;
  private static final int SOLID_RECT=3;
  private static final int LINE=4;

  // Colors
  private static final int MAX_COLORS=4;
  private static final int RED=0;
  private static final int BLUE=1;
  private static final int GREEN=2;
  private static final int YELLOW=3;

  // States
  private static final int DRAWING=0;
  private static final int CHANGING_POSITION=1;

//  private Dimension shapeSize;
  private int pressedX;
  private int pressedY;
  private int color=BLUE;
  private int shape=OVAL;
  private int state=CHANGING_POSITION;

  //used for rubber shapes
  private int cursorX;
  private int cursorY;
  
  // constructor
  public DrawingCanvas() {
    super();
    pressedX = pressedY =-1;
    cursorX=cursorY=-1;
  }
  
  // called when mouse button is pressed
  // (x,y) is position of mouse press
  //   ignore the event parameter
  public boolean mouseDown(Event event, int x, int y) {
    
    // (for debugging purposes?)
    System.out.println ("mouse pressed at (" + x + ", " + y + ")");
    
    if (y<20 && x<40) {
      if (x <40) {
	if (x<20){
	  shape=(shape+1)%MAX_SHAPES;
	  drawMenu();
	  System.out.println ("Changing shape to " + shape);
	}
	else {
	  color=(color+1)%MAX_COLORS;
	  drawMenu();
	  System.out.println ("Changing color to " + color);
	}
      }
      return false;
    }
    pressedX = cursorX= x;
    pressedY = cursorY= y;
    return false;
  }
  
  
  // called when mouse is moved without holding down any button
  public boolean mouseMove(Event event, int x, int y) {
    drawMenu();
    return false;
  }

  // called when mouse is moved while holding down the button
  public boolean mouseDrag(Event event, int x, int y) {
    if ((x>=40) || (y>=20)) {
      drawRubber(cursorX, cursorY);
      drawRubber(x,y);
      cursorX=x;
      cursorY=y;
      state=DRAWING;
    }
    return false;
  }

  // called when mouse button is released
  public boolean mouseUp(Event event, int x, int y) {
    if (state==DRAWING) {
      drawRubber(cursorX, cursorY); /* delete the last rubber */
      Dimension d= new Dimension(x-pressedX, y-pressedY);
      Graphics g =getGraphics();
      drawShape(g, pressedX, pressedY, color, shape, d);
      state=CHANGING_POSITION;
      g.dispose();
    }
    return false;
  }

  public void drawShape(Graphics g, int x, int y, int color, int shape, Dimension d) {
     setColor(g, color);
     
     int ulX=d.width>0 ? x : x+d.width;
     int ulY=d.height>0 ? y : y+d.height;
     int w=d.width<0 ? -d.width:d.width;
     int h=d.height<0 ? -d.height:d.height;

     switch (shape) {
       case OVAL:
           g.drawOval(ulX,ulY,w,h);
           break;
       case SOLID_OVAL:
           g.fillOval(ulX,ulY,w,h);
           break;
       case RECTANGLE:
	   g.drawRect(ulX,ulY,w,h);
           break;
       case SOLID_RECT:
           g.fillRect(ulX,ulY,w,h);
           break;
       case LINE:
           g.drawLine(x, y , x+d.width, y+d.height);
           break;
     }
  }
  
  public void setColor(Graphics g, int color) {
    switch(color) {
    case RED:
      g.setColor(Color.red);
      break;
    case GREEN:
      g.setColor(Color.green);
      break;
    case BLUE:
      g.setColor(Color.blue);
      break;
    case YELLOW:
      g.setColor(Color.yellow);
      break;
    }
  }
  
  public void drawRubber(int x, int y) {
    Dimension d= new Dimension(x-pressedX, y-pressedY);
    drawXOR(pressedX, pressedY, color, shape, d);
  }

  public void drawMenu() {
    Dimension d = new Dimension(20,20);
    Graphics g = getGraphics();
    g.clearRect(0,0,40,20);
    Dimension shape_d = new Dimension(15,15);
    drawShape(g,3,3, color,shape,shape_d);
    drawShape(g,0,0,BLUE,RECTANGLE,d);
    drawShape(g,20,0,color,SOLID_RECT,d);
    drawShape(g,20,0,BLUE,RECTANGLE,d);
    g.dispose();      
  }

  public void drawXOR(int x, int y, int color, int shape, Dimension d) {
     Graphics g = getGraphics();
     g.setXORMode(getBackground());
     drawShape(g,x,y,color,shape, d);
     g.dispose();
  }
}