[Sugar-devel] Physics activity (Was: Release v3 tonight?)

[Gary C Martin]

Hi Asaf,

On 20 Jul 2009, at 06:16, Asaf Paris Mandoki wrote:

> Hi,
> Thanks for the feedback. The save/load functionality is ready and I'll
> be committing soon to elements.

:-)

> Brian: What is the status of the library handling? I'll have to update
> elements after I commit to enable the new functions and commit
>
> BTW, the pickling function I added to elements was almost copy n'
> paste from the pybox2d testbed. I'm new to python but I think there is
> something that is not finished or maybe it wasn't cleaned up about the
> additional_vars in the pickle_load function. I'm not sure if that
> argument should be removed.

When I'm doing my testing on your commits, I'll try and take a look  
and see.

> I also have other modification suggestions that I wanted to run by you
> before creating the tickets.
>
> 1. It IS possible to pin/link objects to the background (It just needs
> a 2 line hack). Should we enable this feature?

By background, I'm assuming you mean the current solid ground. I tried  
to link some contraptions to the ground to act as foundations, though  
just pinning them to the background is a fine work around. Happy to  
see the feature enabled if it seems safe to you, it might enable some  
more possibilities if we add the option of different world  
environments (solid ground only, no ground, closed box), e.g. in a  
closed box environment kids might want to link objects hanging from  
the ceiling.

> 2. Modify the polygon tool icon. I suggest changing it for an
> irregular polygon. The icon gives the idea of a different behavior.

Sure, seems like a good change (assign ticket to me if you want).

> 3. Modify the grab tool icon. Maybe put a hand shape. The current icon
> is not really descriptive.

Sure, seems like a good change (assign ticket to me if you want).

> 4. Make the Play/Stop button more conspicuous, maybe change its  
> color(s).

Not so hot on this one :-) It breaks the Sugar design guidelines  
(colour represents user identity). Now I know Walter has quite  
seriously gone and broken these guidelines with some of his  
technicolor tool icons in TurtleArt... The shock, the horror... But  
not sure we should continue that slide in Sugar guideline standards ;-)

Pro: Yes, black and white for Stop, and colour for Play is quite  
visually effective.

Con: Once we start to creep into colour tool icons they'll start  
appearing all over the place and the collaboration colour == identity  
metaphor will start to break down. The high contrast silhouette of  
icon shapes is a strong component and differentiator of the Sugar UI  
design.

The current 'Play' and 'Stop' icons are from the standard Sugar  
artwork set, perhaps we should just improve them. I was never  
completely keen on both their silhouette shapes being round, or  
perhaps it would be enough for the fill/stroke to be inverted between  
stop & play shapes?

Eben: maybe there is some design middle ground for having some tool  
icon colour in the HIG? Perhaps with a strict specification, say like  
a single colour (different brightness allowed) may be used in addition  
to white & transparent, but only for toggle or radio buttons to  
indicate important active vs inactive states? But I'm not convinced.  
It feels like an erosion of a strong design principle.

Regards,
--Gary