Add reverse functionality to repeat() of AnimationController#25125
Add reverse functionality to repeat() of AnimationController#25125HansMuller merged 14 commits intoflutter:masterfrom flschweiger:add_reverse_to_repeat
Conversation
|
Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA). 📝 Please visit https://cla.developers.google.com/ to sign. Once you've signed (or fixed any issues), please reply here (e.g. What to do if you already signed the CLAIndividual signers
Corporate signers
|
|
I signed it! |
|
CLAs look good, thanks! |
zoechi
added
framework
|
@HansMuller Can you review this? |
|
@goderbauer Looks like a nice enhancement. Will review this week. |
HansMuller
left a comment
HansMuller
left a comment
There was a problem hiding this comment.
This PR is pretty close to the finish line! Just a few more tweaks, mostly for the corner cases.
|
@HansMuller Reworked the PR again with a nicer implementation of the repeating mechanism. Would be cool if you could have a look 😃 |
HansMuller
left a comment
HansMuller
left a comment
There was a problem hiding this comment.
LGTM
If you could add just one last comment to the test, I can land this for you.
This is a nice new animation feature. Thanks for the contribution and thanks for hanging in there!
| expect(controller.value, 0.0); | ||
|
|
||
| controller.repeat(reverse: true); | ||
| tick(const Duration(milliseconds: 0)); |
There was a problem hiding this comment.
It's not clear why this first duration=0 tick is always needed. I assume it's to enable the simulation to figure out which way it's going. Might be helpful to include one comment at the beginning here, to explain what's going on.
There was a problem hiding this comment.
This can also be found in other tests (e.g. test('animateTo sets correct status') or test('after a reverse call animateTo sets correct status'). Every time when starting a new simulation, the first tick is used to initialise the simulation inside the AnimationController. When the line is removed, the elapsed time will always be 0 which means that the simulation will be evaluated at the time 0 and not after x milliseconds.
In the end I didn't comment on that because it is used quite often in the other tests already 😉
…r into add_reverse_to_repeat
6 participants
This PR adds a reverse flag to the
repeat()method of the AnimationController. With that feature it will be easier to create 'yoyo' animations like a glowing Flutter logo:AnimationController(vsync: this, duration: Duration(seconds: 1))..repeat(reverse: true);Also have a look at the following Stackoverflow question: https://stackoverflow.com/questions/49604221/how-to-do-yoyo-animation-in-flutter
So right now it's only possible to achieve this by listening to the current status of the AnimationController and alternating between calling
forward()andreverse()or through combining a fade-in animation with a fade-out animation.