code: function mxGraphHandler(graph)
  {
  	this.graph = graph;
  	this.graph.addMouseListener(this);
  	
  	// Repaints the handler after autoscroll
  	this.panHandler = mxUtils.bind(this, function()
  	{
  		this.updatePreviewShape();
  		this.updateHint();
  	});
  	
  	this.graph.addListener(mxEvent.PAN, this.panHandler);
  	
  	// Handles escape keystrokes
  	this.escapeHandler = mxUtils.bind(this, function(sender, evt)
  	{
  		this.reset();
  	});
  	
  	this.graph.addListener(mxEvent.ESCAPE, this.escapeHandler);
  }
docs: Copyright (c) 2006-2015, JGraph Ltd
  Copyright (c) 2006-2015, Gaudenz Alder
   
  Class: mxGraphHandler
  
  Graph event handler that handles selection. Individual cells are handled
  separately using <mxVertexHandler> or one of the edge handlers. These
  handlers are created using <mxGraph.createHandler> in
  <mxGraphSelectionModel.cellAdded>.
  
  To avoid the container to scroll a moved cell into view, set
  <scrollAfterMove> to false.
  
  Constructor: mxGraphHandler
  
  Constructs an event handler that creates handles for the
  selection cells.
  
  Parameters:
  
  graph - Reference to the enclosing <mxGraph>.