This has several possible answers, depending on what exactly you want to
achieve. One option is gtk_widget_modify_font(). Note that this function
can be used to change only the font size, as in the following example:
-<programlisting>
+<informalexample><programlisting>
PangoFontDesc *font_desc = pango_font_description_new (<!-- -->);
pango_font_description_set_size (font_desc, 40);
gtk_widget_modify_font (widget, font);
pango_font_description_free (font_desc);
-</programlisting>
+</programlisting></informalexample>
</para>
<para>
If you want to make the text of a label larger, you can use
gtk_label_set_markup():
-<programlisting>
+<informalexample><programlisting>
gtk_label_set_markup (label, "<big>big text</big>");
-</programlisting>
+</programlisting></informalexample>
This is preferred for many apps because it's a relative size to the
user's chosen font size. See g_markup_escape_text() if you are
constructing such strings on the fly.
</para></listitem>
<listitem><para>
Create the cairo context inside the expose handler. If you do this,
-gdk_create_cairo() arranges for it to be backed by the double-buffering
+gdk_cairo_create() arranges for it to be backed by the double-buffering
pixmap. This is the preferred solution, and is used throughout GTK+
itself.
</para></listitem>