Re: Pango and text drawing confusion

[Sven Neumann <sven gimp org>]

Hi,

Mark Wheaton <mark wheaton ntlworld com> writes:

> 	I'm trying to draw some text onto a drawing area in GTK+2.0.
> 
> Now, the docs say I can't use gdk_draw_text() because it's
> deprecated. I have looked around for other ways of drawing text and it
> looks like I have to use gdk_draw_layout() instead, which means I have
> to get involved with Pango.
> 
> As far as I can tell, in order to get a PangoLayout I first need to
> make a PangoContext and then create a PangoLayout from this context.
> 
> kinda like this:
> 
> #include <pango.h>
> #include <gtk.h>
> {
> 	PangoContext *pContext;
> 	PangoLayout *pDrawingAreaLayout;
> 	
> 	pContext = pango_context_new();	
> 	pDrawingAreaLayout = pango_layout_new(Context);
> 	pango_layout_set_text(pDrawingAreaLayout, "Here is some text", -1);
> 	
> 	gdk_draw_layout(widget->window, NULL, 0, 0, pDrawingAreaLayout);
> }
> 
> The problem is that I can't call pango_context_new() because the
> compiler says it's an undeclared function. This seems to be because in
> pango-context.h there is this:
> 
> #ifdef PANGO_ENABLE_BACKEND
> PangoContext *pango_context_new           (void);
> void          pango_context_set_font_map  (PangoContext *context,
> 					   PangoFontMap                 *font_map);
> #endif /* PANGO_ENABLE_BACKEND */
> 
> Can anyone explain to me what is going on here?  Have I got it
> completely wrong or what?

you should let the drawing area create the layout for you; like this:

  layout = gtk_widget_create_pango_layout (drawing_area,
                                           "Here is some text");

Also, you should only draw the layout in the drawing_area's expose
handler but you probably know that already as it has been discussed
here every so often.


Salut, Sven