ProgressRing: Determinate with Lottie only works with increasing value

[jp-weber]

Describe the bug
ProgressRing with Lottie not working if the value is counted down. When the value is started for example with the maximum value and count down, the Lottie animation breaks.

Steps to reproduce the bug

Steps to reproduce the behavior:

1. Set the value (for example same as maximum)
2. Set IsIndeterminate to false
3. Count down the value (with timer or something else)

Expected behavior
The decreasing value should work with Lottie animation.

Version Info

NuGet package version:
Microsoft.UI.Xaml 2.5.0-prerelease.200812001

Windows app type:

UWP	Win32
Yes

Windows 10 version	Saw the problem?
Insider Build (xxxxx)
May 2020 Update (19041)	Yes
November 2019 Update (18363)
May 2019 Update (18362)
October 2018 Update (17763)
April 2018 Update (17134)
Fall Creators Update (16299)
Creators Update (15063)

Device form factor	Saw the problem?
Desktop	Yes
Xbox
Surface Hub
IoT

Additional context

[ranjeshj]

@karenbtlai any thoughts ?

[mdtauk]

@karenbtlai any thoughts ?

I assume the Lottie control allows playing animations forwards and backwards, as well as playing at increased and reduced speeds? (Issue #3134 may need it)

[marcelwgn]

I would like to look into this, if that's fine with everyone else.

[karkarl]

I believe it may be something to do with the playback rate for AnimatedVisualPlayer (toggle negative for counting down). Counting down is currently not a supported ProgressRing scenario, and will need to be implemented.

[marcelwgn]

So this isn't supported by the animation itsself? I was able to "support" this by setting the playback rate to -1 when decreasing, however the progress just jumps to the new value, it doesn't animate.

[jp-weber]

Any updates? For this problem only a new animation would have to be implemented, which is used when the new value of the property change is smaller than the old one.