Re: dashline migration from 0.14 to 2.0

[Damon Chaplin <damon karuna eclipse co uk>]

On Mon, 2013-07-01 at 20:54 +0200, Serge Noiraud wrote:
> Hi,
>
> I have a porting problem with dash lines.
> With goocanvas 0.14
> the python program used :
>
>              item = goocanvas.Path(parent = self.current_parent(),
>                                    data = p_data,
>                                    stroke_color = stroke_color,
>                                    line_width = 1,
>                                    line_dash = goocanvas.LineDash([5.0, 5.0]))
>
> Someone port it to :
>
>              item = GooCanvas.CanvasPath(parent = self.current_parent(),
>                                          data = p_data,
>                                          stroke_color = stroke_color,
>                                          line_width = 1,
>                                          line_dash = GooCanvas.LineDash([5.0, 5.0]))
>
> It crashed because GooCanvas.LineDash accept no argument.
> What is the best way to have the same functionality ?

I think the same problem occurred with GooCanvas.CanvasPoints.
Apparently boxed types do not allow arguments to constructors with
introspection. So the __new__ function was overridden. See
bindings/python/GooCanvas.py.

Maybe you can do the same thing for LineDash.

A long-term solution I guess would be to add a function like
goo_canvas_line_dash_set_dashes() to set the dash data after it has been
created. (We also need a set_dash_offset().)

Damon