Re: [orca-list] Geany, SciTE and other Scintilla based applications

[Mike Ray <mike raspberryvi org>]

Mike,

Thanks for a few pointers and places to look.

Looking at the Scintilla source and some of the gtk stuff it looks like
it's a matter of sub-classing the scintilla class, or making the
scintilla class itself a sub-class of some atk object.

And then doing something positive with the different signals which
scintilla emits to interface to atk.

I am familiar with how MSAA works on Windows and of course the gtk
signals are somewhat different to Windows messages but it can't be that
hard if I can find some examples.

There seems to be a lot of talk now about vala but I don't know if
that's at all relevant.  I suspect it will just hide some of the
lower-level gtk stuff from view.

Mike

On 15/07/2014 19:50, Mike Gorse wrote:
> Hi Mike,
>
> Unfortunately, we don't really have a good tutorial for building
> custom atk classes (I thought there was one around somewhere, but now
> I can't find it, and it would be outdated anyhow). My suggestion would
> be to look through gtk's accessibility code (in gtk/a11y for gtk 3)
> and look at the atk documentation as a reference:
>
> https://developer.gnome.org/atk/unstable/
>
> For the stable gtk+ sources:
> ftp://ftp.gnome.org/pub/gnome/sources/gtk+/3.12
>
> If you only need to support gtk 3.8 or later, then you can derive your
> classes from the relevant Gtk*Accessible classes and call
> gtk_widget_class_set_accessible_type in the custom widget's class init
> function. If you also need to support earlier versions of gtk, then it
> is a bit of a mess, and your best bet is probably to override
> get_accessible in the class init function and create a base class
> adapted from, say, GtkWidgetAccessible. For an example of how to do
> this, you could look at my patch on
> https://bugzilla.gnome.org/show_bug.cgi?id=669441 (the patch in
> comment 7, not the much cleaner patch in comment 4, but the latter is
> a good example if you only need to support gtk+ 3.8 and later). One
> option might be to encapsulate the accessibility code with #if
> GTK_CHECK_VERSION(3.8.0), depending on whether it's important to make
> it work for gtk 2 as well.
>
> Feel free to write if you have other questions. Sorry for not being
> able to suggest anything more straight-forward in terms of
> documentation, but, anyway, it would be good for more people to
> understand how all of this works.
>
> Thanks,
> -Mike
>
> On Tue, 15 Jul 2014, Mike Ray wrote:
>
> > He also said that if I add atk accessibility to it he will incorporate
> > the changes.
> >
> > But as I don't currently know how to do this, it is likely to take me a
> > while.
> >
> > If anybody can point me at atk tutorials and tips I'd like to have a go
> > as I am a big fan of SciTE on Windows.
> >
> > Mike
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-- 
Michael A. Ray
Analyst/Programmer
Witley, Surrey, South-east UK

The box said: 'install Windows XP, 7 or better'. So I installed Linux

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