// Lab 3: WorldDemo.ijava sample program
// Show how to use the World class to produce an animation

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

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

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

  // start the world and the timer
  boolean go() { return this.bigBang(100,100,1.0); }
 
  // make the world grow with the timer
  World onTick() { return new MiniWorld(x + 2); }

  // decrease the size of the sun when "d" is pressed
  World onKeyEvent(String ke){
    if (ke.equals("d"))  // decrease the radius of the circle
      return new MiniWorld(this.x - 3);
    else if (ke.equals("i"))  // increase the radius of the circle
      return new MiniWorld(this.x + 3);
    else
      return this;
  }

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

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

class Examples{
  Examples() {}

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

  // test the method onTick in the class MiniWorld
  boolean testOnTick = 
    check this.mw.onTick() expect new MiniWorld(32);

  // test the method onKeyEvent in the class MiniWorld
  boolean testOnKeyEvent = 
    (check this.mw.onKeyEvent("x") expect this.mw) &&
    (check this.mw.onKeyEvent("d") expect new MiniWorld(27)) &&
    (check this.mw.onKeyEvent("i") expect new MiniWorld(33)) &&
    (check this.mw.onKeyEvent("left") expect this.mw);

  
  // start our world --- by displaying the canvas, 
  //                     starting the timer
  //                     and responding to key events
  boolean run = this.mw.go();
}