Re: Copying widget layout into a cairo layout

[Zoltan Boszormenyi <zboszor freemail hu>]

Zoltan Boszormenyi írta:
> Hi,
>
> I need to create a scrolling label widget.
> I already succeeded marrying gtklabel and gtkimage,
> I use a Cairo surface and created PangoLayout out of it,
> I render the label text into the Cairo+Pango layout,
> I use the expose method used by GtkImage to display
> the pixbuf in the widget, and added a timer so the
> pixbuf is scrolled in a double buffered way.
>
> Now, the problem is that the text rendered into the pixbuf
> is much larger than the usual widget texts, like on stock
> GtkButton and GtkLabel. I attached the screenshot from
> my example application.
>
> How can I copy the PangoContext that a plain widget use?
> E.g. the following code doesn't seem to work:
>
> =================================
>   label->surface = cairo_image_surface_create_for_data(cairo_data,
>                         CAIRO_FORMAT_ARGB32, width, height, rowstride);
>
>   label->cairo = cairo_create (label->surface);
>   
>   label->layout = pango_cairo_create_layout(label->cairo);
>
>   /* This is the layout used by GtkLabel, etc. */
>   layout = gtk_widget_create_pango_layout (GTK_WIDGET (label),
>                               "This long string gives a good enough
> length for any line to have.");
>
>   pango_cairo_context_set_font_options(
>             pango_layout_get_context(label->layout),
>            
> pango_cairo_context_get_font_options(pango_layout_get_context(layout)));
>
>   pango_cairo_update_context(label->cairo,
> pango_layout_get_context(layout));
>   pango_layout_context_changed(label->layout);
>
>   g_object_unref (layout);
> =================================
>
> What is the proper way to get the same font, fontsize, etc. on a Cairo
> layout?
>
> Thanks in advance,
> Zoltán Böszörményi
>   

The following code also doesn't work, I get the same large font
for my GtkScrollLabel that my previously attached screenshot showed:

  label->cairo = cairo_create (label->surface);
  pango_cairo_update_context(label->cairo, gtk_widget_get_pango_context
(GTK_WIDGET(label)));
  label->layout = pango_cairo_create_layout(label->cairo);

Is there and easy way to render the text in the same size as
GtkLabel's default?

Thanks in advance,
Zoltán Böszörményi