Remove the Refresh Button from Grid Panel in Extjs (Extended javaScript Library)

When you add a toolbar at the bottom of the Grid Panel, you can observe the Refresh icon.
If you wish to hide this refresh button you can do the following

listeners: {
          
/* FIRES AFTER THE COMPONENT RENDERING IS FINISHED.
  THE AFTERRENDER EVENT IS FIRED AFTER THIS COMPONENT HAS BEEN RENDERED
*/                                      
afterrender : function(component){                    
component.getBottomToolbar().refresh.hideParent = true;
component.getBottomToolbar().refresh.hide();                
}
}

This will simply hide the Refresh Icon.