hoe event set in ExoActionEvent

[m.heidari@xxxxxxxxxxxxx]

hello,
in Ecm Admin when i select Manage NodeType and view NodeType List how event 
set in 
the following code.

static public class ViewActionListener extends ExoActionListener {
    public void execute(ExoActionEvent event) throws Exception {
      UINodeTypeList uicomp = (UINodeTypeList) event.getComponent() ;
      String nodeName = event.getParameter(OBJECTID) ;
      NodeType nodeType = uicomp.ntManager_.getNodeType(nodeName) ;
      UINodeTypeForm nodeTypeForm =      
(UINodeTypeForm)uicomp.getSibling(UINodeTypeForm.class) ;      
      String[] namespaces = 
uicomp.repository_.getNamespaceRegistry().getPrefixes() ;      
      nodeTypeForm.update(uicomp.session_, nodeType, uicomp.ntManager_, 
namespaces, true) ;      
      uicomp.setRenderedSibling(UINodeTypeForm.class) ;
    }
  }
Regards,
M.Heidari