Ring spinner

CompositionRingSpinner is an indeterminate progress indicator in RoyalApps.Community.Avalonia.Common.Controls. Its animation runs in a composition visual, independently of UI dispatcher work. Avoid blocking the dispatcher in application code: input and layout still need it.

Watch the spinner animation

The compositor-driven ring continues while the UI thread is blocked; the standard Avalonia progress bar pauses.

Try the sample

Choose Block UI thread for 5 seconds to compare the ring with the standard indeterminate Avalonia ProgressBar on the same page. After a short preparation delay, the dispatcher is deliberately blocked. The ring continues to animate while the progress bar and input pause; the UI resumes automatically after five seconds.

Standalone setup

Reference Common and include its optional standalone style in your application:

<StyleInclude Source="avares://RoyalApps.Community.Avalonia.Common/Controls/CompositionRingSpinner.Styles.axaml" />

Add the namespace and set a size in unbounded layouts:

<community:CompositionRingSpinner
    xmlns:community="clr-namespace:RoyalApps.Community.Avalonia.Common.Controls;assembly=RoyalApps.Community.Avalonia.Common"
    Width="24" Height="24"
    ForegroundColor="DodgerBlue" TrackColor="#30606060"
    StrokeThickness="2" IsActive="True" />

The control measures to the smaller available dimension. When both dimensions are unbounded its desired size is zero. The ring remains centered in rectangular bounds and uses their smaller dimension as its diameter.

Styling and animation

Property	Default	Behavior
IsActive	true	Shows and animates the foreground arc
ForegroundColor	DodgerBlue	Color of the animated arc
TrackColor	Transparent	Color of the stationary full ring
StrokeThickness	2	Finite DIP width, clamped to fit the ring when drawing

When inactive, only the track is drawn. Animation is also suspended when the control or an ancestor is hidden, its bounds are empty, or it is detached. Reattachment creates a fresh composition visual. The root rotation takes three seconds; the arc grows and shrinks between 10 and 280 degrees over 1.2 seconds.

The spinner does not read application-wide or operating-system motion settings. Bind IsActive to the state your application intends to display. RoyalConnect's UI.Core style supplies its dynamic application accent while standalone consumers retain DodgerBlue or their own explicit color.

Nonfinite stroke widths are rejected. Finite widths below one DIP are normally drawn at one DIP; bounds smaller than two DIPs reduce that minimum to half the available diameter. Large widths are clamped to half the diameter.

See the generated API reference for the complete public contract.