CanvasService.subscribeEditViewModeChanged Method
        
 Subscribe an event handler for View Mode Changed event.
 
         
        Parameters
        
            - callback
            
 
            - 
                
Type: function(isEditMode: Boolean)
The event handler 
            - unSubscribe
            
 
            - 
                
Type: Boolean - May be null
 (Optional) True to unsubscribe.