TimingFramework triggers for Trident - Let's try again

[<remy.rakic@gmail.com>]

Sorry for the previous post, i hadn't finished wrting it ! That's
embarassing... damn kenai ui....

Here you go, the finished one: 

Hey Kirill, 

I was just testing Trident the other day, and thought the trigger
feature from the TimingFramework would be interesting to have (In case
you're not familiar with it, it's basically a way to start and reverse
an animation when specific events occur, ie it's a nice high level
concept that adds listeners for you - kinda neat).

So i "ported" them to Trident. It removes the some of needs for final
timelines and the associated anonymous listeners, etc.

It's not deeply tested, and moreover i have close to zero experience
with either library. That being said, i did eyeball that the included
triggers worked obviously.

You can find it here
http://lqd.hybird.org/files/trident/trident-triggers-0.1-src.zip , i
also added a modified ButtonFg demo, that exercises most, if not all,
of the included triggers. (note: I added a Timeline constructor that
took a duration in my test version, so the demo won't compile out of
the box, but it's a trivial change and a not so subtle feature request
:). I also modified one or two things i didn't like in the original
API, very limited and subjective changes i can back out if need be.

I decided not to port the animation triggers (triggers on an
animation's start and stop events), because from my limited
understanding of both libraries, this feature seems to be supported in
Trident with TimelineScenarios, and parallel and sequential animations
is what i think those triggers were meant to help achieve. It could be
nice to have in order to have a more unified triggers api, or some
feature i don't know about for which it's useful, but i think it would
clash with trident's regular way of doing that. So in the end i don't
really know, it's probably trivial to add anyway, so no biggie here.

Let me know what you think.

ps: Developing this, i think i got bitten by this: is the timeline
state change totally asynchronous and in another thread ? in my first
trials i suspended, played, resumed in a sequence quite fast, and at
some point i thought the state was not the one i was expecting. Is
there a way to get state changes from a timeline other than adding a
callback to it os is this the preferred way to go ?
Unrelated to this, is there a way to start a timeline/timeline scenario
at a specific point in time ? That would be useful for scrubbing the
timeline, extracting frame data, or using trident timelines just fot
its interpolation features (which would be weird but i don't judge :)
Maybe those questions are better suited for the users list anyway...

Cheers
Rémy Rakic