Responding to Changes in Parameters

3ds Max SDK Programmer's Guide > Writing Plug-ins > Writing Animation Controller Plug-ins >

When the position target weight parameter is changed for the Position Constraint controller, the list box must be redrawn. To do this the Position Constraint controller implements ReferenceMaker::NotifyRefDependent(). The message parameters passed into this method is the specific message which needs to be handled. The hTarget parameter is a pointer to the reference target that sent the message. The reference maker uses this handle to know specifically which reference target sent the message.

Example

RefResult PosConstPosition::NotifyRefChanged(
  Interval iv, RefTargetHandle hTarg, PartID& partID, RefMessage msg)
 {
   switch (msg)
   {
     case REFMSG_CHANGE:
      if (hTarg == pblock) {
         ParamID changing_param = pblock->LastNotifyParamID();
         switch (changing_param)
         {
          case position_target_weight:
            RedrawListbox(GetCOREInterface()->GetTime());
            break;
          default:
            pos_const_paramblk.InvalidateUI(changing_param);
            break;
         }
         ivalid.SetEmpty();
       }
      break;
 
     case REFMSG_OBJECT_CACHE_DUMPED:    
       return REF_STOP;
      break;
     }
   returnREF_SUCCEED;
   }
};