Re: GtkCanvas requirements?

["Marco Pesenti Gritti" <mpgritti gmail com>]

On 4/19/07, Carlos Garnacho <carlosg gnome org> wrote:

Hi all!,

After reading Tim's mail about volunteer tasks [1], I've bitten the
bullet and will try to help out fostering the GtkCanvas discussion, so
here it goes!

There have been several discussions about getting a canvas into GTK+,
being the last one in the GTK+ meeting at Fosdem [2], where one of the
conclusions was that we needed to gather the candidates on one side and
the desired feature set for a GtkCanvas on another.

First of all we need to specify the feature requirements for the
canvas. The following is a list of features I think we should
consider, hope it's a good start, please add to it if there are others:

- GTK+ suitable API.
- a11y support.
- Model/View split.
- Size negociation, height for width, width for height and natural size.
- object shapes, collision detection.
- animation framework (perhaps should be more tied to GTK+, GtkTimeLine
maybe?).
- get the offscreen rendering patch in.
- GtkPrint* integration.
- grouping/ungrouping.
- extensibility, being able to create new canvas elements with little
effort.
- DnD support.
- Integrate tightly GTK+ and the canvas, even making GtkWidgets
specialized canvas elements drawn with a certain layout in a canvas, see
Havoc's proposal [3]

A couple of features which we are really missing in hippo-canvas:

* Key navigation (which is obviously also a prerequisite for a11y)
* Ability to set a global scaling factor for the canvas and support for units.

Marco