Pango + Cairo + Xcb

["Matthew Allen" <fret memecode com>]

Hi,

I'm writing a backend for a widget set using Pango + Cairo + Xcb. And I've got some text showing up on the screen but I think I still have some misconceptions about how things should be done.

First I'm starting with this in my singleton font engine class:

	Map = pango_cairo_font_map_get_default();
	Ctx = pange_cairo_font_map_create_context((PangoCairoFontMap*)Map);

Then to load a font I do:

	Desc = pango_font_description_new();
	pango_font_description_set_family(...);
	pango_font_description_set_size(...);
	Hnd = pango_font_map_load_font(Map, Ctx, Desc);
	pango_font_description_free(Desc);

That 'Hnd' is stored in a font object. Thats then passed to a "DisplayString" class which maps to a pango layout, which draws a peice of text on the screen. So in there I do:

	Layout = pango_layout_new(Ctx);
	pango_layout_set_text(Layout, ...);
	pango_layout_get_size(Layout, ...);

But it also has a Draw method to put that layout on screen:

	Surface = cairo_xcb_surface_create(...);
	Cr = cairo_create(Surface);
	cairo_set_source_rgb(Cr, ...);
	pango_cairo_show_layout(Cr, Layout);
	cairo_destroy(Cr);
	cairo_surface_destroy(Surface);

However I suspect the load font call should be somewhere else, because when I load several fonts I can't draw with the first one anymore... the last one is cached. So should I be doing the load font just before drawing? Is it an expensive call time wise?

Are these calls in the right order?
Maybe I have to select the font into the context before drawing with it?

Thanks for any comments or direction you can provide.
--
Matthew Allen