Re: [gtk-osx-users] trying to integrate an eventtrap into gtk-osx-application

[John Ralls <jralls ceridwen us>]

On Oct 8, 2014, at 7:32 AM, Eric Le Lay <kerik-sf users sourceforge net> wrote:

> Hello John,
>
> I'd like to respond to multimedia keys (play-pause, next, previous)
> in a Gtk application bundle for OSX.
>
> It seems to be possible using quartz events (see CGEventTapCreate).
> I've gone so far as to get running code (attached as a diff).
>
> I register the event trap in an applicationDidFinishLaunching delegate
> handler added to GtkApplicationDelegate.c.
> I do intercept multimedia key and can swallow them at will.
> Now there is a little problem: when I close the gtk window, the
> whole screen freezes. I have to ssh from another computer and kill the
> app. It would indicate that the event tap is no more processing
> events. 
> Is there any chance of fixing my code or is it a doomed path anyway
> and I should use a separate helper app with its own pure quartz event
> loop?

That’s not something I’ve ever played with, but perhaps your event tap isn’t getting disabled. It’s possible 
for a Gtk application to end without getting the ApplicationWillTerminate notification, so make sure that the 
tap is actually getting removed. I have trouble believing that’s really the problem, though, because when the 
program terminates the run loop will be destroyed and that should take the event tap with it.

I don’t see how a helper app would make any difference: You have to inject the events into the g_main_loop 
somehow in order to respond to them.

Regards,
John Ralls