%%%
%%% Authors:
%%%   Michael Mehl (mehl@dfki.de)
%%%   Gert Smolka (smolka@dfki.de)
%%%   Christian Schulte <schulte@ps.uni-sb.de>
%%%   Joerg Wuertz (wuertz@dfki.de)
%%%
%%% Copyright:
%%%   Michael Mehl, 1998
%%%   Gert Smolka, 1998
%%%   Christian Schulte, 1998
%%%   Joerg Wuertz, 1998
%%%
%%% Last change:
%%%   $Date: 1999-10-05 18:18:26 +0200 (Tue, 05 Oct 1999) $ by $Author: kornstae $
%%%   $Revision: 12123 $
%%%
%%% This file is part of Mozart, an implementation
%%% of Oz 3
%%%    http://www.mozart-oz.org
%%%
%%% See the file "LICENSE" or
%%%    http://www.mozart-oz.org/LICENSE.html
%%% for information on usage and redistribution
%%% of this file, and for a DISCLAIMER OF ALL
%%% WARRANTIES.
%%%


functor

import
   Tk
   Application(exit)

define

   CanvasWidth  = 400.0
   CanvasHeight = 400.0
   BallRadius   = 50.0
   XDelta       = 5.0
   YDelta       = 5.0
   Gravity      = 3.0
   Fraction     = 0.9
   RepeatTime   = 100
   Mouth        = 30
   MouthDelta   = 5
      
   BackColor    = '#fffff0'
   BallColors   = if Tk.isColor then
		     red  | blue | yellow | green  |
		     plum | cyan | tan    | bisque | BallColors
		  else
		     black | BallColors
		  end
   
   class Ball
      from Time.repeat Tk.canvasTag
      prop final
	 
      attr
	 x:      0.0
	 xd:     XDelta
	 y:      0.0
	 yd:     YDelta
	 mouth:  Mouth
	 d:      ~MouthDelta
	 
      meth init(X Y Canvas Color)
	 Tk.canvasTag,tkInit(parent:Canvas)
	 {Canvas tk(crea arc X Y X+BallRadius Y+BallRadius
		    fill:Color start:30 extent:300 tag:self)}
	 x <- X
	 y <- Y
	 Time.repeat, setRepAll(action:bounce delay:RepeatTime)
	 
	 thread
	    try {self go}
	    catch _ then skip
	    end
	 end
      end
      
      meth bounce
	 %% increment @x and @d
	 x <- @x + @xd
	 if @x =< 0.0 then
	    x  <- 0.0
	    xd <- ~@xd
	 elseif @x>=CanvasWidth-BallRadius then
	    x  <- CanvasWidth-BallRadius
	    xd <- ~@xd
	 end
	 %% increment @y and @yd
	 y  <- @y - @yd
	 yd <- @yd - Gravity
	 if @y>=CanvasHeight-BallRadius then
	    y  <- CanvasHeight-BallRadius
	    yd <- Fraction * ~@yd
	 end
	 Tk.canvasTag,tk(coords @x @y @x+BallRadius @y+BallRadius)
	 %% set the new mouth
	 mouth <- @mouth+@d
	 if @mouth>=Mouth          then mouth <- Mouth      d <- ~@d
	 elseif @mouth=<MouthDelta then mouth <- MouthDelta d <- ~@d
	 end
	 Tk.canvasTag,tk(itemconfigure start:@mouth extent:360-2*@mouth)
      end
      
      meth close
	 Time.repeat, stop
	 Tk.canvasTag, tkClose
      end
   end
   
   class Manager
      from Tk.canvas
      prop final locking
      attr
	 Balls:  nil
	 Colors: BallColors
	 
      meth init(parent:P)
	 {self tkInit(parent:P bg:BackColor bd:3 relief:sunken
		      width:CanvasWidth height:CanvasHeight)}
	 {self tkBind(action: self # NewBall
		      event:  '<1>'
		      args:   [float(x) float(y)])}
	 {self tkBind(action: self # KillBall
		      event:  '<3>')}
      end
      
      meth NewBall(X Y)
	 lock
	    C|Cr  = @Colors
	 in
	    Balls  <- {New Ball init(X Y self C)}|@Balls
	    Colors <- Cr
	 end
      end
      
      meth KillBall
	 lock
	    case @Balls of nil then skip
	    [] B|Br then {B close} Balls <- Br
	    end
	 end
      end
   end
   

   Top = {New Tk.toplevel tkInit(title:  'Oz Bouncer'
				 delete: Application.exit # 0)}
			     
   {Tk.send pack({New Manager init(parent:Top)})}
   
end