[Gtk-sharp-list] Gtk.Style vs Pango - I'm confused...
Federico Mena Quintero
Fri, 17 Sep 2004 20:59:21 -0500
On Thu, 2004-09-16 at 17:52 +0200, Anset wrote:
> I was looking for a way to change the font on a widget and I landed on these
label = new Gtk.Label ("Hello big bold world");
font_desc = Pango.FontDescription.FromString ("sans 50 bold");
> It looks like Style was there before Pango, but Pango does not replace it.
> Pango does "just text", if you allow the understatement. However Style does
> "text also"...
> One example of something that puzzles me:
> Gtk.Style has a Pango.FontDescription propperty.
> Pango.Context has a Pango.FontDesctiption propperty.
> A Gtk.Widget has both a Gtk.Style and a Pango.Context propperty.
> So which one do I use to change the Font?
A PangoFontDescription is an object that holds a tuplet with a
particular configuration of a typeface: ("sans", 10 points, bold).
A GtkStyle is an object that holds the style parameters for a widget.
These include some thickness parameters, colors to use for different
parts of the widget (shadow/normal/light), the font, etc.
Ignore the PangoContext for now; it's just a running instance of the
Pango engine for a particular output device. You would have a
PangoContext for an X11 display, another one for printing, etc.
You can't build a GtkStyle by hand, because its values come from a bunch
of places: user resource files, theme files, widget-specific code, etc.
Rather, you take an existing style and modify the bits you need. This
is nicely wrapped by Gtk.Widget.ModifyStyle(). The Gtk.RCStyle object
you pass to it represents a set of modifications. The example above is
equivalent to this C code:
label = gtk_label_new ("Hello big bold world");
rc_style = gtk_rc_style_new ();
rc_style->font_desc = pango_font_description_from_string ("sans 50 bold");
gtk_widget_modify_style (label, rc_style);
Right now there seems to be no way to modify the fields of a Gtk.RCStyle
in GTK#. Fortunately, for your specific needs you can use the