ProgressRing: Indeterminate ProgressRing being hidden and shown multiple times makes spinner jump

[warappa]

Describe the bug

If a ProgressRing is hidden and shown multiple times, then the spinner starts to jump every 2 seconds.

Interestingly, it effects all ProgressRing instances on the page which are always visible!

To Reproduce

<CheckBox IsChecked="{Binding IsProgressRingVisible}">Toggle</CheckBox>
<ui:ProgressRing Visibility="{Binding IsProgressRingVisible, Converter={StaticResource BoolToVisibilityConverter}}" IsIndeterminate="True" />

Expected behavior

It should not start jumping.

Screenshots

No response

OS version

Windows 10 22H2 19045.5371

.NET version

.NET 4.7.2

WPF-UI NuGet version

4.0.0

Additional context

Fix

The From is missing from the first DoubleAnimation. After adding this, you can toggle as many times you want and it will not start jumping around.

In the control template, replace this:

<DoubleAnimation
    RepeatBehavior="Forever"
    Storyboard.TargetName="Arc"
    Storyboard.TargetProperty="(Canvas.RenderTransform).(RotateTransform.Angle)"
    To="360"
    Duration="0:0:2" />

with this

<DoubleAnimation
    RepeatBehavior="Forever"
    Storyboard.TargetName="Arc"
    Storyboard.TargetProperty="(Canvas.RenderTransform).(RotateTransform.Angle)"
    From="0"
    To="360"
    Duration="0:0:2" />