Octave/backend interface proposal

[Shai Ayal]

On Jan 20, 2008 11:31 PM, Michael Goffioul <michael.goffioul at gmail.com> wrote:
> Hi,
>
> Following a chat I had with Shai, we though we would need at some
> point in time some kind of interaction between octave and any
> graphics backend (to exchange some information). After some
> discussions, we agreed on a scheme, whose skeleton would
> be something like in the attached files.
>
> The idea is to define a graphics_backend interface (that the
> actual backend would implement) and attach to a figure the
> backend to which it belongs, which serves as an entry point
> for octave/backend interaction. This scheme should allow
> multiple backends running at the same time.
>
> Example of possible interaction are:
> - closing a figure window
> - getting font metric information
> - getting drawing canvas size (useful to deal with normalized
> units)
> - other things we didn't think about yet
>
> For the moment, only a gnuplot backend is defined and will
> be used as default.
>
> If you're OK with the concept (and the implementation), please
> commit.

I'm OK with the concept and implementation, however do we really need
to get the figure position from the backend this way? Can't the
backend just update the figure.position property? is this a
multithreading related problem?
Unless there is some real problem, I think this data exchange
mechanism should be only for things that have no corresponding
property -- i.e. font metrics

Shai