How to determine if an entity is going to be dragged or not?

By Gopinath Taget

Consider this: When you pick on an entity, the AcDbEntity::getGripPoints() function is invoked and the grip points are drawn. The grip points remain until any other AutoCAD command is issued or when Esc is pressed.

So, is there a way to check whether an entity is currently drawing its grip points or not?

One way of doing this is using acedSSGetFirst() and a Windows Hook.  Here’s the relevant ARX code:

BOOL ArxWinHookFct (MSG *pMsg)     {     // create a flag so that we don't call the function multiply     static bool flag = false;     // if not already processing     if (!flag)     {      // set that we are now processing      flag = true;      struct resbuf *grip_set = NULL, *ents = NULL;      // get the pick first selection set      int res = acedSSGetFirst(&grip_set, &ents);      // if ok      if (res == RTNORM)      {       long length = 0l;       // make sure we have some fata       if (ents != NULL)       {        // print out what we have        acedSSLength(ents->resval.rlname, &length);        acutPrintf (_T("nLength ents = %ld"), length);        acedSSFree (ents->resval.rlname);       }      }           // ok, now we can flag that we have finished      flag = false;     }          // Return TRUE to destroy the message     return (FALSE) ;    }