Re: Multi Thread applications with GNUstep

[Richard Frith-Macdonald]

On Wednesday, August 1, 2001, at 04:27 PM, Pierre-Yves Rivaille wrote:

> I'm developing a multithreaded application with GNUstep (i hope to
> release an alpha version soon), and I'm facing a few problems.
>
> There are two threasd: the main thread (with the AppKit runloop) and one
> worker thread. I want to display the progress of the work being done by
> the worker thread.
>
> The problem I face is that whenever the AppKit thread is in a
> NSEventTrackingRunLoopMode tracking loop (typically when you press
> the mouse button on a NSButton, NSSlider, NSMenu), I can not
> display the updates. (I've tried to do this using DO)
>
> It looks like the proper way to do this is just to use
> -setNeedsDisplay: in the working thread (at least, that is what I read 
> in
> MOSX doc:
> http://developer.apple.com/techpubs/macosx/ReleaseNotes/ThreadSupport.html)
> .
> But GNUstep does not seems to be supporting this.
>
> Do I miss something or should I try to implement this behaviour in
> GNUstep ?

The problem is most likely that the control you have clicked on has 
grabbed
things and *doesn't want* anything else messing with the display because 
it
is drawing directly (for efficiency) rather than using the auto-update
mechanism.  So I'm not sure that you should be able to update the display
elsewhere.  It should be quite easy to modify the event code to ensure 
that
the auto-update is done (so -setNeedsDisplay: would work), but I think 
careful
reading of the documentation and consideration should be applied before 
doing it.