Animate AI Assistant button and panel

[lukemelia]

Screen.Recording.2024-03-20.at.4.03.35.PM.mov

[github-actions]

Test Results

    1 files  ±0      1 suites  ±0   8m 4s ⏱️ +24s
535 tests ±0  406 ✔️  - 125  4 💤 ±0      0 ❌ ±    0  125 🔥 +125 
535 runs  ±0  281 ✔️  - 250  4 💤 ±0  125 ❌ +125  125 🔥 +125 

For more details on these errors, see this check.

Results for commit df61a89. ± Comparison against base commit f76bbd3.

♻️ This comment has been updated with latest results.

[nickschot]

https://www.loom.com/share/cd5d9bdc3e194ecba4b6a1fb83bc1e6b

I remember that this was still something we have to finalise after finishing the implementation of the scale correction/transform based animating. I don't think the current version has a fill: forwards style thing going on by default (if I remember correctly), so it's likely related to sprite.lockStyles which locks position and width with inline CSS. Apparently that isn't currently automatically cleaned up after an animation, though we do have an unlockStyles function as well. This is called within the transitionRunner. You could see if calling it after the animation promise resolves works (for now?). I don't remember if it may have unexpected side effects at this point.

edit: to add to that, I think with the current timeline functionality (animating every sprite for the entire duration instead of just when it's animated), anchoring, padding etc. we may be able to get rid of lockStyles by integrating it into the keyframes.

[lukemelia]

Thanks @nickschot. I updated this PR to use a StaticBehavior to fix the width during the animation. I generalized the fill behavior so that you can opt StaticBehavior into forward filling like the other behaviors (except Wait) already did by default.

Integrating the lockStyles into the timeline is an interesting idea that likely simplifies the overall code and mental model.

[lukemelia]

After discussion with the team and with Chris, we decided to defer animation work on host, so I'll close this PR after extracting the non-animation changes from it into new PRs