// Lab 3: WorldDemo.bjava sample program
// Show how to use the Canvas class to display a drawing

import draw.*;
import colors.*;
import geometry.*;

// a class to represent a world with one dying red sun
class MiniWorld{
  int x;

  MiniWorld(int x){
    this.x = x;
  }

  // draw the sun
  boolean draw(Canvas c){
    return c.drawDisk(new Posn(100, 50), 
                      this.x, new Red());
  }

  // erase the sun - clear the canvas
  boolean erase(Canvas c){
    return c.drawRect(new Posn(0, 0), 
             200, 200, new White());
  }
}

class Examples{
  Examples() {}

  // define a new world
  MiniWorld mw = new MiniWorld(30);

  // define a new canvas
  Canvas c = new Canvas(200, 200);
  
  // display the canvas and draw a disk on the canvas
  boolean makeDrawing = 
    this.c.show() && 
    this.mw.draw(this.c);
  
/* Try the following in the Interactions window:
> Examples e = new Examples();
> e.mw.erase(e.c)
true
> e.mw.draw(e.c)
true
> 
*/
}