Re: Get the default font in Gtk3

[Emmanuele Bassi <ebassi gmail com>]

On 29 March 2018 at 15:12, rastersoft <raster rastersoft com> wrote:

> [get the Gtk font type and size]
> > > Ops, sorry: I'm reworking a backup utility that I wrote (cronopete), and
> > > I added a timeline with the backups (you can see an screenshot at
> > > http://www.rastersoft.com/cronopete_screenshot.png ). As you can see, at
> > > the left is the timeline and it has the days, months and years. I think
> > > those should use the same typography than the standard Gtk widgets, but
> > > reducing the size to 2/3. The same for the titles in each "pseudowindow"
> > > (they have a visual effect: they go forward and backwards when you move
> > > through the timeline).
> > >
> > > ...I must be missing something here...
> > You can change font size in a layout. The scrolling might be tricky, but
> > just eyeballing it, sounds like something that can be done by showing
> > the layout twice at different coords in different clips
> > (cairo_save/cairo_restore brackets).
> >
> > So...?
> >
> > (Only thing I'm not quite sure about right now is if gtk fully initializes
> > font description in a layout, cause I vaguely recall that it might
> > not... though maybe that was just wrt. theming API...)
> Mainly the problem is that I'm using cairo_show_text...


That's the Cairo toy text API; you should only use it for tests or small
examples; it's basically useless for anything user-facing.


> I presume that what you say is that I should replace all that with
> Pango... Now I have some problems: first, I'm using vala and I can't find
> the "get_pango_layout" from a widget. It exists "create_pango_layout", so I
> suppose that this is the call I need to create a layout.


Yes, the function is `gtk_widget_create_pango_layout()`:
https://developer.gnome.org/gtk3/stable/GtkWidget.html#gtk-widget-create-pango-layout


> Now the big question is: does ANY widget return the right layout, or I
> must use a widget designed to contain text (like a Gtk.Label) to get that
> layout, paint into it, and paste it in the final Cairo canvas (which won't
> be the same canvas than the Gtk.Label from which I created the layout)?

All widgets that need to render text call gtk_widget_create_pango_layout()
internally, including GtkLabel.

Ciao,
 Emmanuele.

-- 
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