Re: Help for an extension: Call a function when switch workspace in overview

["Jasper St. Pierre" <jstpierre mecheye net>]

Whoa. Thanks for this, even I learned some things!

On Tue, Sep 4, 2012 at 8:25 AM, Amy <mathematical coffee gmail com> wrote:
> Forgot to reply on-list; storing this in the archives for posterity
> (some future person might want to know about looking up gir
> files/converting typelib files/generating docs from them).
>
>
> ---------- Forwarded message ----------
> From: Amy <mathematical coffee gmail com>
> Date: 4 September 2012 15:32
> Subject: Re: Help for an extension: Call a function when switch
> workspace in overview
> To: Bazon Bloch <bazonbloch arcor de>
>
>
> On 4 September 2012 15:00, Bazon Bloch <bazonbloch arcor de> wrote:
>> Is there a way how to find out which connect events are available? I
>> searched /usr/share/gnome-shell/* for a file including "workspace-switched",
>> but found nothing.
>
> Ahh, I remember going through the same pain as you when I first
> started developing extensions!
>
> Here is stuff I've learned along the way:
>
> A good place to look is documentation online, if you can find any.
> Most of it lives on developer.gnome.org. For example:
>
> * http://developer.gnome.org/st/stable/ for imports.gi.St
> * http://developer.gnome.org/shell/unstable/ for imports.gi.Shell (<--
> I found that one hard to find, since it's in unstable instead of
> stable!)
>
> These pages will give lists of signals available for each class.
>
> If you can't find the documents (Meta doesn't have them), you can look
> in the *.gir files, which define how the C functions map to the JS
> functions for each library (imports.gi.Meta, imports.gi.Gtk, ...). You
> can find the signals quickly by grepping for 'signal':
>
> grep 'glib:signal' Meta-3.0.gir
> # will give me a list of signals in the Meta library.
> # ... (lots of signals)
>       <glib:signal name="workspace-changed" when="last">
>       </glib:signal>
> # ... (lots more signals)
>
> When you find the signal you're interested in you can go into the .gir
> file and see what it is owned by (in this case Meta.Screen), so you
> know that if you want to listen to the 'workspace-changed' signal you
> will have to connect to a Meta.Screen (global.screen in this case).
>
> In terms of finding the gir files, I found some in /usr/share/gir-1.0.
>
> I think some of them only appear there if you install either the
> relevant -dev package, or perhaps a gir package.
>
> Some of them I couldn't find at all (e.g. Meta, Shell, St) because
> they are considered "private", but you can find these here:
>
> * /usr/lib/gnome-shell (Shell, St)
> * /usr/lib/mutter (Meta)
>
> However these are .typelib files, which is like a compiled version of the gir.
>
> To conver the .typelibs into readable .gir files you can use
>
> g-ir-generate /usr/lib/mutter/Meta-3.0.typelib > Meta-3.0.gir
>
> (the g-ir-* tools are provided by package gobject-introspection on
> ubuntu; I think you can install them from a repository on the web
> somewhere too).
>
> Sometimes g-ir-generate will complain about not being able to find
> various other typelibs, for example if you try to generate Shell.gir
> from the typelib:
>
> g-ir-generate /usr/lib/gnome-shell/Shell-0.1.typelib
> ** (g-ir-generate:9599): ERROR **: failed to load typelib: Typelib
> file for namespace 'St', version '1.0' not found
> Trace/breakpoint trap (core dumped)
>
> In this case it's trying to find St-1.0.typelib, which is in
> /usr/lib/gnome-shell, so you can include it using --includedir like so
> (it also needs to find Meta-3.0.typelib in /usr/lib/mutter, I think by
> default just /usr/lib/girepository-1.0 is included):
>
> g-ir-generate --includedir=/usr/lib/gnome-shell
> --includedir=/usr/lib/mutter /usr/lib/gnome-shell/Shell-0.1.typelib
>
> and then it will work.
>
> (Note - there are many .typelib files in
> /usr/lib(64?)/girepository-1.0, more than there are .gir files in
> /usr/share/gir-1.0).
>
> Then if you like you can even generate HTML documentation from the
> .gir files (but if you can find documentation online use that instead,
> it looks better):
>
> mkdir mutter-docs
> g-ir-doc-tool Meta-3.0.gir -o mutter-docs
>
> Then turn the output (yelp files) into HTML:
>
> yelp-build html mutter-docs
>
> And then load index.html in a browser and you have some basic
> browsable documentation, complete with a list of signals (so if you
> click on the Meta.Screen page it has a list of signals you can connect
> to, although it is a bit sparse on explanation).
>
> PS - re closing a window through the hover X button in the overview,
> you'll probably have to monkey patch that. See
> /usr/share/gnome-shell/js/ui/workspace.js - the code to do with
> this.closeButton, and in particular, WindowOverlay._closeWindow
> appears to handle the closing of a window when the button is clicked.
>
> PPS if you really did want to look up a list of signals, you can do it
> with GObject, but I think it is much much more helpful to browse the
> documentation/girs:
>
> const GObject = imports.gi.GObject;
> GObject.signal_list_ids(GObject.type_from_name('MetaScreen')).map(function
> (id) { return GObject.signal_name(id); });
>
> where signal_list_ids lists all the ids belonging to class MetaScreen,
> and signal_name(id) gets the name for that signal (documentation:
> http://developer.gnome.org/gobject/stable/gobject-Signals.html).
>
> Hope that helps! (And the mailing list is a great way to ask questions
> when you get fed up of wading through documentation, I still do heaps
> of that :))
>
>> Entering global.screen.connect in looking glass didn't help either, and
>> unfortunately, I wasn't successful in finding the source code for
>> global.screen (that's what I tried as a beginner.)
>>
>> (Specific I would be interested in the events:
>>  * show overview
>>  * close a window through the hover x-Button in the overview)
>>
>>
>> _______________________________________________
>> gnome-shell-list mailing list
>> gnome-shell-list gnome org
>> https://mail.gnome.org/mailman/listinfo/gnome-shell-list
>>
> _______________________________________________
> gnome-shell-list mailing list
> gnome-shell-list gnome org
> https://mail.gnome.org/mailman/listinfo/gnome-shell-list



-- 
  Jasper