Re: regarding all the possible functions that can be assigned to PangoCairoShapeRendererFunc func

[Parth Kanungo <kanungoparth gmail com>]

Thanks John.

 

Actually, my purpose of understanding pango_cairo_renderer_draw_shape() is that I should be able to implement pango_ft2_renderer_draw_shape() which does not exist as of now. For that,

 

1. I want to know what any callback function that matches the signature of PangoCairoShapeRendererFunc used in pango_cairo_renderer_draw_shape()  does.

2. Can you elaborate on the bigger picture as well ?

 

Having understood that, I shall write my own callbacks and also the function pango_ft2_renderer_draw_shape() (which is my intended goal).

And, Yes, I have some idea of what GObject does. I'll take another look into it.

 

Thanks again.

 

Regards,

--

PangoLearner

On Fri, Sep 7, 2012 at 6:06 AM, John Ralls <jralls ceridwen fremont ca us> wrote:

On Sep 6, 2012, at 7:29 AM, Parth Kanungo <kanungoparth gmail com> wrote:

Hello all,

 

 

We know that PangoCairoShapeRendererFunc is a function pointer.

 

The function pango_cairo_context_set_shape_renderer in pangocairo-context.h assigns a PangoCairoShapeRendererFunc func its value.

 

I want to know what all are the possible functions that can be assigned to PangoCairoShapeRendererFunc func ??

 

(My purpose is to understand the working of pango_cairo_renderer_draw_shape() function in pangocairo-renderer.h)

 

Any help/suggestion would be appreciated.

Thanks in advance

You write a callback function that matches the signature of PangoCairoShapeRendererFunc [1] and use pango_cairo_context_set_shape_renderer() to set it as the callback on your PangoContext. When the context needs to render a shape, it calls your callback function.

This is another standard GObject programming construct. You'll find it much easier to understand Pango -- and most of the other libraries in the Gtk stack -- if you start by studying GObject. Since the documentation is written at a rather high level, you'll find a good grounding in OO programming helpful.

Regards,

John Ralls

[1] http://developer.gnome.org/pango/stable/pango-Cairo-Rendering.html#PangoCairoShapeRendererFunc