Overlapping of drag and drop puzzle pieces

There is a much easier way to do activities where the user has to drag something to its correct location. Instead of having the objects already in random places, and then some sort of logic to figure out if they are in the destination location (which might involve an array of destinations, one of which applies to the object you're dragging), you could start the puzzle with everything already in the destination position.

When the activity starts, each piece would make a note of its current location, then would place itself somewhere random. That would all happen before the user sees the pieces. As any piece is being dragged you only have to use Pythagorus to decide whether it's in the destination position. Something on these lines (the code would go on each piece):

var myX:Number = x;

var myY:Number = y;

var solved:Boolean = false;

x = Math.random()*500;

y = Math.random()*400;

addEventListener(MouseEvent.MOUSE_DOWN,drag);

function drag(e:MouseEvent){

  addEventListener(MouseEvent.MOUSE_MOVE,dragging);

  addEventListener(MouseEvent.MOUSE_UP,drop); 

}

function drop(e:MouseEvent){

  removeEventListener(MouseEvent.MOUSE_MOVE,dragging);

  removeEventListener(MouseEvent.MOUSE_UP,drop); 

}

function dragging(e:MouseEvent){

  var dx:Number = e.stageX - myX;

  var dy:Number = e.stageY - myY;

  var d:Number = Math.sqrt(dx*dx+dy*dy);

  if(d<10){

    removeEventListener(MouseEvent.MOUSE_MOVE,dragging);

    removeEventListener(MouseEvent.MOUSE_UP,drop); 

   removeEventListener(MouseEvent.MOUSE_DOWN,drag);

   x = myX;

   y = myY;

   checkSolved();

  }else{

   x = e.stageX;

   y = e.stageY;

}

}

I didn't test that, I just typed it here! It might work though.

The checkSolved function would be one that went around all of the pieces to see if they are all solved, and if they are then the puzzle is complete. Something like:

function checkSolved(){

var i:int;

var total:int = 20;//the number of pieces, named "piece1", etc, in this example

var allsolved = true;

for(i=0;i<total;i++){

   if(!this["piece"+(i+1)].solved){

     allsolved = false;

    break;

}

  if(allsolved){

     //puzzle is completed

  }

}

I didn't test that either! Hopefully you get the general idea.