docs: function mxConstraintHandler(graph)
  {
  	this.graph = graph;
  	
  	// Adds a graph model listener to update the current focus on changes
  	this.resetHandler = mxUtils.bind(this, function(sender, evt)
  	{
  		if (this.currentFocus != null && this.graph.view.getState(this.currentFocus.cell) == null)
  		{
  			this.reset();
  		}
  		else
  		{
  			this.redraw();
  		}
  	});
  	
  	this.graph.model.addListener(mxEvent.CHANGE, this.resetHandler);
  	this.graph.view.addListener(mxEvent.SCALE_AND_TRANSLATE, this.resetHandler);
  	this.graph.view.addListener(mxEvent.TRANSLATE, this.resetHandler);
  	this.graph.view.addListener(mxEvent.SCALE, this.resetHandler);
  	this.graph.addListener(mxEvent.ROOT, this.resetHandler);
  }