Package: CompositionAnimatedControl

CompositionAnimatedControl is the reusable core for the repository's Skia-backed controls. It hosts a composition custom visual, renders into an SKCanvas, and exposes a playback model that higher-level controls can reuse.

Install

dotnet add package CompositionAnimatedControl

What it adds

Skia-based rendering through OnRender(SKCanvas canvas, Rect destRect, TimeSpan effectiveElapsed, bool isRunning)
Start(), Stop(), Pause(), Resume(), and Seek(...)
RepeatCount, PlaybackRate, Position
Redraw() for on-demand refresh
Update, Started, Stopped, and Disposed events
Stretch and StretchDirection support

Animated mode

The SimpleTimelineControl sample shows a looped time-based animation:

public sealed class SimpleTimelineControl : CompositionAnimatedControl
{
    protected override Size OnGetSourceSize() => new(300, 200);

    protected override NormalizeResult OnNormalizeElapsed(TimeSpan elapsed)
    {
        var loop = TimeSpan.FromSeconds(2);
        var remainder = TimeSpan.FromTicks(elapsed.Ticks % loop.Ticks);
        return new NormalizeResult(remainder, elapsed >= loop);
    }

    protected override void OnRender(SKCanvas canvas, Rect rect, TimeSpan t, bool running)
    {
        canvas.Clear(SKColors.White);
        var progress = (float)(t.TotalSeconds / 2.0);
        var x = (float)(rect.X + rect.Width * progress);
        using var paint = new SKPaint { Color = SKColors.CornflowerBlue, IsAntialias = true };
        canvas.DrawCircle(x, (float)rect.Center.Y, 20, paint);
    }
}

Static redraw mode

The same base class also supports redraw-on-demand content:

keep the control stopped,
update internal state from app events,
call Redraw() when the visual should refresh.

The StaticRedrawControl sample demonstrates this pattern.

When to use it

Choose this package when you need custom Skia rendering but do not want to build the scheduling and composition integration yourself.