Re: Odd Linux behavior

[Lindley M French <lfrench1 gmu edu>]

I'll try to throw something basic together. Until I have time for that, however, a few more details have emerged.

I have code which requests that my GUI take a screenshot of one of its windows. So it needs to generate an expose event for that window whether it's visible or not. To this end, I use gdk_window_process_updates() to force an expose event.

The problem is that I have several windows arranged in an hbox, and they aren't all visible 100% of the time. There's a scroll bar, and you can scroll to the various windows.

When a window is scrolled into view as far as the hbox is concerned, gdk_window_process_events() works as expected even if the entire GUI is minimized. But when a window is *not* scrolled into view, it doesn't----the expose handler is never called.

I wondered if maybe this was a result of the window being unmapped when it's scrolled out of view, but this doesn't seem to be the case as far as I can tell.

----- Original Message -----
From: richard boaz <ivor boaz gmail com>
Date: Thursday, August 20, 2009 1:31 pm
Subject: Re: Odd Linux behavior

> hi,
> 
> when you first reported this, i tried re-creating with my own 
> program, but
> couldn't.
> 
> the lack of response you've received is only most likely due to no 
> one else
> having experienced this.
> 
> which suspiciously points to the code.
> 
> i think you might make progress on this if you:
> 
>   1. reduce your problem to a simple "hollow world" example
>   2. that continues to demonstrate the problem
>   3. if possible, test as well on a different platforms (not sure 
> if you've
>   demonstrated this on more than one already)
>   4. re-submit the worldly code to the list
> 
> having actual code is sometimes critical, especially when the 
> behavior is
> unfamiliar.
> 
> cheers,
> 
> richard
> 
> On Thu, Aug 20, 2009 at 6:55 PM, Lindley M French 
> <lfrench1 gmu edu> wrote:
> 
> > Okay, I've determined that this new behavior is still just a 
> symptom of
> > expose events not occurring.
> >
> > Still curious why expose events don't happen when the program is 
> bg'd but
> > on-screen, though.
> >
> > ----- Original Message -----
> > From: Lindley M French <lfrench1 gmu edu>
> > Date: Thursday, August 20, 2009 12:07 pm
> > Subject: Odd Linux behavior
> >
> > > About a month ago I posted that my GTK+ app stopped getting expose
> > > events when I bg'd the app in Linux. Got no response, though.
> > >
> > > Well, it seems to be worse than that.
> > >
> > > I'm running the program through Putty from a Windows machine. 
> If I
> > > minimize the main window, or even just lock the screen,
> > > *something* stops working. Can't say for sure what it is, but I've
> > > got a console program which periodically sends the GUI updates via
> > > pipes, and I left the combo running last night with the screen
> > > locked.....and zero progress was made. I get in this morning,
> > > unlock the screen, and it starts going again.
> > >
> > > This can only mean that the pipes are filling up and not being
> > > emptied, which means that *something* is blocking unexpectedly in
> > > the GUI.
> > >
> > > Does anyone have the first clue what I should be looking for to
> > > fix this? I'm using GTK+ 2.12.
> > >
> > _______________________________________________
> > gtk-list mailing list
> > gtk-list gnome org
> > http://mail.gnome.org/mailman/listinfo/gtk-list
> >
>