Conference bulova::decw_jan-89_to_nov-90

2663.0. "Not receiving all motion events - why?" by SAC::SNYDER_P (Pauline) Thu Apr 26 1990 05:04

  A customer of mine has a problem with receiving pointer motion events.
  
  Under VMS 5.2/DECwindows 1.0 he receives all pointer motion events or button
  1,2 and 3 motion events (depending on what events mask he uses). Recompiling/
  linking the same code under VMS 5.3/DECwindows 2.0 the pointer/button motion 
  events for buttons 2 and 3 are suppressed. It looks as if the event mask 
  bit PointerMotionHintMask is selected because the motion events received 
  fit exactly that description but only for button 2 and 3. Button 1 motion
  events are all received as before.

  This can be demonstrated by adding XtAddEventHandler call to the main 
  function of HelloWorld.c as issued, together with an appropriate event
  processing routine to identify the event type and do a printf.

  There are reasons why this customer cannot just use a translation table in
  a .uil file like everybody else.

     Is this a legitimate use of XtAddEventHandler ?

     If so, can anyone explain why it is not working as expected and 
     how to achieve the intended aim of receiving all motion events?

     If not can anyone explain the 'correct' way to add event handling
     capability to widgets created at runtime by an application.

  Thanks in advance for your help.    Pauline

>  Under VMS 5.2/DECwindows 1.0 he receives all pointer motion events or button
>  1,2 and 3 motion events (depending on what events mask he uses). Recompiling/
>  linking the same code under VMS 5.3/DECwindows 2.0 the pointer/button motion 
>  events for buttons 2 and 3 are suppressed. It looks as if the event mask 
>  bit PointerMotionHintMask is selected because the motion events received 
>  fit exactly that description but only for button 2 and 3. Button 1 motion
>  events are all received as before.

    An interesting "experiment" would be to try the DECWINDOWS V1.0 image
    against a DECWINDOWS V2.0 server, and vice-versa.  In that way you
    will be able to tell us whether the "client"-side or the server has
    changed the behavior.
    
>     Is this a legitimate use of XtAddEventHandler ?
    
    Yes.
    
>     If not can anyone explain the 'correct' way to add event handling
>     capability to widgets created at runtime by an application.
    
    Note that you can also use translation manager syntax on widgets
    created at run-time, but XtAddEventHandler is fine as well.
    
    Leo

    Execute a XQueryPointer() call after receiving the MotionNotify event.
    That function call tells Xlib that the program is now ready for another
    MotionNotify event.
    
    -Terry