title: jquery UI draggable: control (pause) dragging when some condition is met
body: <p>when dragging an element I am doing some calculation and when a certain critaria is matched I'd like the dragging to <strong>pause</strong>.</p>
  
  <p>I don't want trigging a mouseup event, just pause.</p>
  
  <p>I have a perfect example set on this <a href="http://jsfiddle.net/bq7YP/" rel="nofollow">JS FIDDLE</a></p>
  
  <p>Please see a container and a list of rectangles.
  What I would like to achieve is somewhat the opposite as containment...</p>
  
  <p>If I would be to set the containment to be .draggable_wrapper, than my UL list would be constrained inside...I DON'T WANT THAT</p>
  
  <p>What I'd like is that when I drag the list, if the list position is more than zero (>0) TO pause dragging to the right and allow dragging only to the left (so to the negative position)...</p>
  
  <p>I don't want first LI's left border to ever get to the right of the container left border...</p>
  
  <p>and in the other side the exact same thing.... when draggin to the left... I want to stop when the 8. li's right border crossing the container's right border (this happens in the example where position is &lt; than -55px;</p>
  
  <p>so to make it more readable</p>
  
  <pre><code>$(....).draggable({
  ....
  drag: function(){
  var p_left = $(this).position().left;
  
  if(left &gt; 0) stop_dragging_right, allow only left;
  if(left &lt; -55px) sto_dragging_left, allow_only_right;
  
  });
  </code></pre>
  
  <p>How can I do that? similar is done when constraining</p>