G(tk)Application support in gtk3reactor

[lucian]

GLib has a GApplication class that handles things like application uniqueness and a few other things, and provides its own .run() method. GtkApplication inherits from it and also does Gtk-specific things.

After installing the gtk3reactor, if I call reactor.run() the UI does show up, but the GApplication's 'activate' event never fires. At glyph's suggestion I explicitly set the reactor's mainloop to that of the GApplication's and 'activate' fired as expected.

The reactor also doesn't stop when I close the window, even with the hack.

[itamar]

Could you provide a minimal example?

[lucian]

Example of hanging reactor.

[lucian]

Perhaps something like the reactor.registerWxApp would work?

 http://twistedmatrix.com/documents/current/core/howto/choosing-reactor.html#auto12

[lucian]

Example with Window and a twisted callback

[lucian]

The sedonc minimal example doesn't hang when I close the window. I believe it happened because of my usage of IRCClient in my app.

I was wrong, I should've written the minimal example before filing the ticket.

[lucian]

If I start the reactor with .run(installSignalHandlers=False), the app responds to SIGTERM and dies correctly, and also responds to SIGINT (incorrectly, because of a GTK/py-gi bug  https://bugzilla.gnome.org/show_bug.cgi?id=622084)

[lucian]

Patch to replicate the _run=app.run and installSignalHandlersFalse=False workarounds

[lucian]

Default back to installing signal handlers by default, at exarkun's suggestion. Add docs.

[lucian]

Remove a useless method, add tests.

[itamar]

If possible the tests should use #5547. If #5547 isn't ready and we want to release 12.1, we should at a minimum make sure we do the SIGCHLD cleanup stuff that ReactorBuilder does since these tests create a new reactor instance and run it.

[itamarst]

(In [34040]) Branching to 'gtk-app-5492'

[itamar]

I made some fixes in the branch, in particular matching coding standard a bit better, and moving the code to gireactor instead of _glibbase.

[itamar]

OK, ready for final review assuming all tests are happy:

 http://buildbot.twistedmatrix.com/boxes-supported?branch=/branches/gtk-app-5492

[therve]

• I'm seeing test failures when using the gi and gtk3 reactor on the whole test suite. They got attached to random tests:

[ERROR]
Traceback (most recent call last):
  File "Twisted/trunk/twisted/internet/base.py", line 800, in runUntilCurrent
    call.func(*call.args, **call.kw)
  File "Twisted/trunk/twisted/internet/_glibbase.py", line 296, in stop
    posixbase.PosixReactorBase.stop(self)
  File "Twisted/trunk/twisted/internet/base.py", line 577, in stop
    "Can't stop reactor that isn't running.")
twisted.internet.error.ReactorNotRunning: Can't stop reactor that isn't running.

I think maybe overriding _run may not be enough?

• choosing-reactor.xhtml has some tabs in it. It'd be nice to wrap lines to 80 chars too.

Do we have a gtk3 slave somewhere too?

[itamar]

So in theory I fixed it. But I can't test it since it's not possible to do this correctly on older versions of gobject introspection, AFAICT. Removing from 12.1 milestone, though, this isn't really necessary for basic gtk3 support; if we make it in then fine, but doesn't seem like it should be a blocker.

[itamar]

Next step: run tests on e.g. Ubuntu 12.04. I will upgrade my system from 11.10 real soon now, but feel free to run on your system and if it looks good it's mergeable in theory.

[therve]

Looks good, tests are passing for me now. I think we can merge it as it is. Maybe the last question I have is whether we should raise an error when registerGApplication is called after reactor.run or called a second time.

[itamar]

OK, I added those two things, will merge once buildbot is happy.

[itamarst]

(In [34391]) Merge gtk-app-5492: Add support for Gio.Application instance registration.

Fixes: #5492 Author: lucian, itamar Review: itamar, therve