[comp.sys.sgi] X-window expose event question..

dan@doctor.chem.yale.edu (Dan Severance) (05/16/91)

  Hi,
    Perhaps I don't understand how X works too well yet, but...
    I have a program that uses and event loop.  One of the events
    that I trap is an expose event.  If I compile and run the code
    on either a SUN or SGI, it works differently depending on which
    machine I display it on.   
       If I uncover or resize the window, whenever the SGI is the DISPLAY
    device, _TWO_ expose events are generated, while only one is generated
    when the window is moved from point A to point B.. 
       When the SUN is the DISPLAY device (openwindows) only 1 expose
    event is generated by resizing or unconvering the window.  Is there
    something I'm missing here??
       If someone has a piece of test code that demonstrates correct
    behavior, I can figure out what I'm doing wrong, or if you know what
    would cause this, just tell me..
       Thanks in advance.
         Dan Severance
         dan@omega.chem.yale.edu

    Machines:
      SUN SparcStation 1, color
      SGI 4D-25G (still waiting for 4D-35 upgrade)

karlton@fudge.wpd.sgi.com (Phil Karlton) (05/17/91)

Let me guess that you are running on top of 3.3.x and that you are not
using an X window manager. When this happens the NeWS server is really
in charge and doesn't give enough information to the X server for it to
tell the complete truth to the clients. The X server is sending the
extra event.

What you have here is a feature that will be (thankfully) withdrawn when
there is a native X server.

PK