drag and drop code that uses a state machine to tame the madness

dragDrop.js

/**
 * I stumbled upon this solution while trying to help out a colleague. 
 *    I was studying a book on the theory of computation at the time
 *    which, coincidentally, talked about state machines, it then ocurred
 *    to me that a state machine could help solve the problems we were 
 *    having at the time.
 */
(function(){
    // 0 = not doing anything
    // 1 = is dragging
    // 2 = is dragging and entered different element
    var dragState = 0;

    document.addEventListener('dragstart', function(e){ console.log('starting drag'); });

    document.addEventListener('dragenter', function (e) {
      switch(dragState){
        // first time dragging
        case 0:
          dragState = 1;

          console.log('first drag');

          break;

        // is currently already dragging, and seems to be
        //    entering some other element
        case 1:
          dragState = 2;

          console.log('entered into another element');

          break;

        // undefined for this event
        default: case 2: break;
      }
    });

    document.addEventListener('dragover', function(e){ console.log('over an element'); });

    document.addEventListener('dragleave', function (e) {
      switch(dragState){
        // if you are here it means you left the first area which
        //    started the dragging process
        case 1:
          dragState = 0;

          console.log('abandoned dragging');

          break;

        // you just left some other element at this point
        case 2:
          dragState = 1;

          console.log('left an element');

          break;

        // undefined for this event
        default: case 0: break;
      }
    }, true); // can't remember why I needed to use true here...

    document.addEventListener('drag', function(e){ console.log('drag origin'); });

    document.addEventListener('drop', function(e){ console.log('drop'); });

    document.addEventListener('dragend', function(e){
      dragState = 0;
    });
}());