[Graphics] More convenient backend access

[Shai Ayal]

On Jan 24, 2008 1:24 PM, Michael Goffioul <michael.goffioul at gmail.com> wrote:
> The attached patch allows a more convenient backend access from any
> graphics_object (by delegating to the parent object). It's not heavily
> used for the moment, but I'm sure it'll be convenient for future development.
>
> Michael.
>
> src/ChangeLog
>
> 2008-01-23  Michael Goffioul <michael.goffioul at gmail.com>
>
>     * graphics.h.in (base_properties::get_backend,
>     base_graphics_object::get_backend, graphics_backend::get_backend):
>     New methods for convenient access to the backend.
>     (figure::get_backend, figure::set_backend): Remove.
>     * graphics.cc (base_properties::get_backend): New method.
>     (Fdrawnow): Use graphics_object::get_backend to simplify code.
>

Michael, I'm not sure I understand how this works:
How does a new backend register?
How can the backend for a figure be set (by the user)?
How can the backend for a figure be read (get) by the user?

Shai