Faster Launch of Activities

[Tomeu Vizoso]

Hi Greg,

On Mon, Jul 14, 2008 at 5:35 PM, Greg Smith <gregsmitholpc at gmail.com> wrote:
> Hi Tomeu et al,
>
> One persistent request from the users is for "faster" response of the XO
> (e.g.
> http://sextosdela37.blogspot.com/2008/04/analizando-el-uso-de-las-laptop-en-el.html)
>
> I believe the new Sugar GUI in 8.2.0 may help with that by launching
> activities faster. I'm told you may know more about that.

Well, the GUI changes won't make activities launch faster, it even may
make them launch a bit slower! Although I hope it shouldn't be
noticeable, we should measure it. I'm thinking here about the pulsing
icon that appears now in the middle of the screen, it's a bigger area
that gets redrawn, so in theory it should make things slower. But
tuning the frequency at which it is redrawn and making sure we are not
doing unneeded work should be quite easy, if the need arise.

The changes that improve activity startup time are:

1. preloading expensive python modules in rainbow
2. smarter refreshing of the journal, so we don't steal cpu cycles
from the starting up activity

2 affects all activities, but 1 only affects to activities written in
python with the exception of Terminal, Log, Analyze and Journal (as
are not currently launched via rainbow).

> I put a place holder for this in the release notes:
> http://wiki.laptop.org/go/Release_Notes/8.2.0#Home_View_and_Frame_Redesign
>
> Can you give a little more detail (targeted at end users) that explains what
> they will see and maybe a little technical background (or a link) on how we
> did it?
>
> Just edit it right in to the release notes and we can review from there.

The changes explained above are not related to the GUI improvements
mentioned in the wiki, so I think they should be noted in a separate
section. I think that Eben is the best suited person to explain how
those changes improve usability.

> Is there anything else in the 8.2.0 release which will improve
> responsiveness of the XO in general?

Don't think so, we worked on that during this release, but decided to
delay this work for the 9.1.0 release. We have been experimenting with
the Composite X extension, which will avoid many redraws in the UI,
giving a much more responsive experience.

Regards,

Tomeu