AnimationRx.Wpf 2.0.2

AnimationRx.Wpf

AnimationRx.Avalonia

AnimationRx

Reactive, composable animation primitives for WPF and Avalonia. Extends ReactiveUI for Schedulers and Rx conventions.

AnimationRx exposes animations as IObservable<Unit> (for effects that complete) and value streams like IObservable<double> (for interpolated values). This makes animations easy to compose, sequence, run in parallel, cancel (dispose), and bind to reactive view-models.

• AnimationRx.Wpf: targets .NET Framework 4.6.2, 4.7.2, 4.8 and .NET 8/9/10 (windows).
• AnimationRx.Avalonia: targets .NET 8/9/10.

Cancellation model: every animation is an IObservable. Dispose the subscription returned by Subscribe() to cancel mid-flight.

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Packages

AnimationRx.Wpf

NuGet:

• Package: AnimationRx.Wpf

Package Manager:

• Install-Package AnimationRx.Wpf

AnimationRx.Avalonia

NuGet:

• Package: AnimationRx.Avalonia

Package Manager:

• Install-Package AnimationRx.Avalonia

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Quick start

WPF

using CP.AnimationRx;
using System.Reactive.Disposables;

// Fade in over 300ms using Sine ease
var d = someElement
    .OpacityTo(300, 1.0, Ease.SineInOut)
    .Subscribe();

// later => cancel if needed
// d.Dispose();

Avalonia

using CP.AnimationRx;

// Fade out over 250ms
someVisual
    .OpacityTo(250, 0.0, Ease.SineOut)
    .Subscribe();

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Core concepts

Duration

Animations are driven by a Duration value stream, where:

• Duration.Percent is always in [0..1]
• DurationPercentage(...) produces the progress stream
• EaseAnimation(...) reshapes the progress curve
• Distance(...) maps progress into a delta (e.g., pixels, degrees)

Easing

Easing is provided by:

• Ease enum (selects common easings)
• Eases extension methods (e.g., BackIn, SineOut) on IObservable<Duration>

Threading & schedulers

Both libraries separate:

• time source (defaults to RxSchedulers.TaskpoolScheduler)
• UI updates (defaults to RxSchedulers.MainThreadScheduler)

All built-in UI animations marshal reads/writes to the UI thread.

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API reference

In the sections below:

• rx<T> means IObservable<T>
• methods returning rx<Unit> represent animations that complete

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AnimationRx.Wpf API

Namespace: CP.AnimationRx

Setup

Add these usings:

using CP.AnimationRx;
using System.Reactive;
using System.Reactive.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

---

Frames & timing (WPF)

Animations.AnimateFrame(double framesPerSecond, IScheduler? scheduler = null) → rx<long>

Emits an increasing tick at approximately the requested FPS.

var frames = Animations.AnimateFrame(60)
    .Subscribe(i => Debug.WriteLine($"tick {i}"));

Animations.AnimateFrame(TimeSpan period, IScheduler? scheduler = null) → rx<long>

Emits ticks on a fixed period.

var frames = Animations.AnimateFrame(TimeSpan.FromMilliseconds(33))
    .Subscribe(i => Debug.WriteLine(i));

Animations.RenderFrames() → rx<long>

Emits one tick per WPF CompositionTarget.Rendering (synchronized to the UI rendering loop).

var renderLoop = Animations.RenderFrames()
    .Subscribe(_ =>
    {
        // do per-render work here
    });

Animations.MilliSecondsElapsed(IScheduler scheduler) → rx<double>

Emits elapsed milliseconds since subscription (starting with 0.0).

var ms = Animations.MilliSecondsElapsed(RxSchedulers.TaskpoolScheduler)
    .Subscribe(t => Debug.WriteLine($"elapsed {t:0}ms"));

Animations.DurationPercentage(double milliSeconds, IScheduler? scheduler = null) → rx<Duration>

Produces progress from 0..1 over the duration, always emitting a final 1.0 and then completing.

Animations.DurationPercentage(500)
    .Subscribe(d => Debug.WriteLine(d.Percent));

Animations.DurationPercentage(rx<double> milliSeconds, IScheduler? scheduler = null) → rx<Duration>

Same as above, but the duration can change dynamically.

var durationMs = Observable.Return(750.0);
Animations.DurationPercentage(durationMs)
    .Subscribe(d => Debug.WriteLine(d.Percent));

Animations.ToDuration(this rx<double>) → rx<Duration>

Maps raw [0..1] values to Duration.

Observable.Return(0.25)
    .Concat(Observable.Return(0.5))
    .Concat(Observable.Return(1.0))
    .ToDuration()
    .Subscribe(d => Debug.WriteLine(d.Percent));

Animations.TakeOneEvery<T>(this rx<T>, TimeSpan interval, IScheduler? scheduler = null) → rx<T>

Back-pressure helper that delays each element by interval and concatenates (one “in flight” at a time).

var throttled = Observable.Range(1, 5)
    .TakeOneEvery(TimeSpan.FromMilliseconds(200));

throttled.Subscribe(Console.WriteLine);

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Easing (WPF)

Ease enum

Use Ease.None for linear or pick from: BackIn, BackOut, BackInOut, BounceIn, BounceOut, BounceInOut, CircIn, CircOut, CircInOut, CubicIn, CubicOut, CubicInOut, ElasticIn, ElasticOut, ElasticInOut, ExpoIn, ExpoOut, ExpoInOut, QuadIn, QuadOut, QuadInOut, QuarticIn, QuarticOut, QuarticInOut, QuinticIn, QuinticOut, QuinticInOut, SineIn, SineOut, SineInOut.

Eases.EaseAnimation(this rx<Duration> progress, Ease ease) → rx<Duration>

Applies the selected ease to a duration stream.

Animations.DurationPercentage(400)
    .EaseAnimation(Ease.ExpoOut)
    .Subscribe(d => Debug.WriteLine(d.Percent));

Specific easing functions on rx<Duration>

Each method below reshapes Duration.Percent:

• BackIn(), BackOut(), BackInOut()
• BounceIn(), BounceOut(), BounceInOut()
• CircIn(), CircOut(), CircInOut()
• CubicIn(), CubicOut(), CubicInOut()
• ElasticIn(), ElasticOut(), ElasticInOut()
• ExpoIn(), ExpoOut(), ExpoInOut()
• QuadIn(), QuadOut(), QuadInOut()
• QuarticIn(), QuarticOut(), QuarticInOut()
• QuinticIn(), QuinticOut(), QuinticInOut()
• SineIn(), SineOut(), SineInOut()

Example of using a specific easing method directly:

Animations.DurationPercentage(300)
    .SineInOut()
    .Subscribe(d => Debug.WriteLine(d.Percent));

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Value animation (WPF)

Animations.AnimateValue(double ms, double from, double to, Ease ease = Ease.None, IScheduler? scheduler = null) → rx<double>

Creates a numeric interpolation stream from from to to.

Animations.AnimateValue(600, from: 0, to: 100, Ease.SineInOut)
    .ObserveOn(RxSchedulers.MainThreadScheduler)
    .Subscribe(v => viewModel.Progress = v);

Animations.Distance(this rx<Duration> progress, double distance) → rx<double>

Converts progress to progress.Percent * distance.

Animations.DurationPercentage(300)
    .Distance(200) // 0..200
    .Subscribe(px => Debug.WriteLine(px));

Animations.Distance(this rx<Duration> progress, rx<double> distance) → rx<double>

Same as above, but distance is dynamic.

var distance = Observable.Return(150.0);
Animations.DurationPercentage(300)
    .Distance(distance)
    .Subscribe(px => Debug.WriteLine(px));

Animations.PixelsPerSecond(this rx<double> milliSeconds, double velocity) → rx<double>

Converts milliseconds to pixels at a constant velocity (px/s): velocity * ms / 1000.

Animations.MilliSecondsElapsed(RxSchedulers.TaskpoolScheduler)
    .PixelsPerSecond(velocity: 200)
    .Subscribe(px => Debug.WriteLine($"{px:0.0}px"));

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Element property animation (WPF)

All methods below return rx<Unit>.

OpacityTo(this UIElement element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates UIElement.Opacity to to.

myPanel
    .OpacityTo(250, 0.0, Ease.SineOut)
    .Concat(myPanel.OpacityTo(250, 1.0, Ease.SineIn))
    .Subscribe();

WidthTo(this FrameworkElement element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Width (falls back to ActualWidth if Width is NaN).

myControl.WidthTo(400, 320, Ease.ExpoOut).Subscribe();

HeightTo(this FrameworkElement element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Height (falls back to ActualHeight if Height is NaN).

myControl.HeightTo(400, 80, Ease.ExpoOut).Subscribe();

MarginTo(this FrameworkElement element, double ms, Thickness to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Margin to to.

myControl.MarginTo(300, new Thickness(10), Ease.SineInOut).Subscribe();

PaddingTo(this Control element, double ms, Thickness to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Padding to to.

myButton.PaddingTo(300, new Thickness(24, 8, 24, 8), Ease.SineOut).Subscribe();

CanvasLeftTo(this FrameworkElement element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates the Canvas.Left attached property.

myItem.CanvasLeftTo(350, 120, Ease.ExpoOut).Subscribe();

CanvasTopTo(this FrameworkElement element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates the Canvas.Top attached property.

myItem.CanvasTopTo(350, 40, Ease.ExpoOut).Subscribe();

BrushColorTo(this SolidColorBrush brush, double ms, Color to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates a SolidColorBrush.Color.

If the brush might be frozen, clone it first and assign a non-frozen brush instance to your element.

var brush = new SolidColorBrush(Colors.OrangeRed);
myBorder.Background = brush;

brush.BrushColorTo(500, Colors.SteelBlue, Ease.SineInOut).Subscribe();

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Margin edge animation (WPF)

These helpers animate individual Thickness components per-frame.

LeftMarginMove(this FrameworkElement element, double ms, double position, Ease ease = Ease.None, IScheduler? scheduler = null)

Moves Margin.Left to an absolute position.

myControl.LeftMarginMove(400, 100, Ease.ExpoOut).Subscribe();

RightMarginMove(this FrameworkElement element, rx<double> ms, rx<double> position, Ease ease = Ease.None, IScheduler? scheduler = null)

Dynamic duration + dynamic position.

var ms = Observable.Return(250.0);
var pos = Observable.Return(30.0);

myControl.RightMarginMove(ms, pos, Ease.SineInOut).Subscribe();

TopMarginMove(this FrameworkElement element, double ms, double position, Ease ease = Ease.None)

Moves Margin.Top to position.

myControl.TopMarginMove(300, 12, Ease.SineOut).Subscribe();

BottomMarginMove(this FrameworkElement element, double ms, double position, Ease ease = Ease.None, IScheduler? scheduler = null)

Moves Margin.Bottom to position.

myControl.BottomMarginMove(300, 12, Ease.SineOut).Subscribe();

Observable overloads also exist for LeftMarginMove, RightMarginMove, TopMarginMove, BottomMarginMove where ms, position, and/or ease can be IObservable.

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Transforms (WPF)

Transform helpers will add the required transform into RenderTransform using a TransformGroup if needed.

TranslateTransform(this FrameworkElement element, rx<double> ms, rx<Point> position, Ease xease = Ease.None, Ease yease = Ease.None)

Animates translate using dynamic duration and a dynamic target point.

var ms = Observable.Return(400.0);
var pos = Observable.Return(new Point(120, 40));

myControl.TranslateTransform(ms, pos, Ease.ExpoOut, Ease.SineIn).Subscribe();

TranslateTransform(this FrameworkElement element, double ms, double xPosition, double yPosition, Ease xease = Ease.None, Ease yease = Ease.None, IScheduler? scheduler = null)

Animates translate to (xPosition,yPosition).

myControl.TranslateTransform(400, 120, 40, Ease.ExpoOut, Ease.SineIn).Subscribe();

RotateTransform(this FrameworkElement element, double ms, double angle, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates rotation by delta (angle - initialAngle internally).

myControl.RotateTransform(300, 45, Ease.SineOut).Subscribe();

ScaleTransform(this FrameworkElement element, double ms, double scaleX, double scaleY, Ease easeX = Ease.None, Ease easeY = Ease.None, IScheduler? scheduler = null)

Animates scale by delta.

myControl.ScaleTransform(250, 1.2, 1.2, Ease.SineInOut, Ease.SineInOut).Subscribe();

SkewTransform(this FrameworkElement element, double ms, double angleX, double angleY, Ease easeX = Ease.None, Ease easeY = Ease.None, IScheduler? scheduler = null)

Animates skew by delta.

myControl.SkewTransform(250, 10, 0, Ease.SineOut, Ease.SineOut).Subscribe();

Absolute transform helpers (WPF)

These are convenience helpers that animate to absolute targets:

• TranslateTo(this FrameworkElement element, double ms, double toX, double toY, ...)
• ScaleTo(this FrameworkElement element, double ms, double toScaleX, double toScaleY, ...)
• RotateTo(this FrameworkElement element, double ms, double toAngle, ...)
• SkewTo(this FrameworkElement element, double ms, double toAngleX, double toAngleY, ...)

TranslateTo example:

myControl.TranslateTo(300, toX: 0, toY: 0, Ease.ExpoOut, Ease.ExpoOut).Subscribe();

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“Effects” helpers (WPF)

ShakeTranslate(this FrameworkElement element, double ms, double amplitude, int shakes = 6, Ease ease = Ease.None, IScheduler? scheduler = null)

Shakes horizontally using TranslateTransform and returns to the original position.

myControl.ShakeTranslate(600, amplitude: 12, shakes: 8, ease: Ease.SineOut).Subscribe();

PulseOpacity(this UIElement element, double milliSecondsPerHalf, double low = 0.2, double high = 1.0, int pulses = 1, Ease ease = Ease.None, IScheduler? scheduler = null)

Pulses opacity between low and high for pulses cycles.

myControl.PulseOpacity(150, low: 0.3, high: 1.0, pulses: 3, ease: Ease.SineInOut).Subscribe();

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Composition helpers (WPF)

Sequence(this IEnumerable<rx<Unit>> animations) → rx<Unit>

Concatenates animations in-order.

var anim = new[]
{
    myControl.OpacityTo(150, 0.0),
    myControl.OpacityTo(150, 1.0),
    myControl.ScaleTransform(200, 1.1, 1.1, Ease.SineOut, Ease.SineOut),
    myControl.ScaleTransform(200, 1.0, 1.0, Ease.SineIn, Ease.SineIn)
}.Sequence();

anim.Subscribe();

Parallel(this IEnumerable<rx<Unit>> animations) → rx<Unit>

Merges animations and completes when the last one finishes.

new[]
{
    myControl.OpacityTo(250, 1.0, Ease.SineOut),
    myControl.TranslateTransform(250, 120, 0, Ease.ExpoOut, Ease.ExpoOut)
}.Parallel().Subscribe();

RepeatAnimation(this rx<Unit> animation, int? count = null) → rx<Unit>

Repeats an animation. If count is null, repeats forever until disposed.

var pulseOnce = myControl.PulseOpacity(120, pulses: 1);

pulseOnce.RepeatAnimation(count: 5).Subscribe();
// pulseOnce.RepeatAnimation().Subscribe(); // infinite until disposed

Stagger(this IEnumerable<rx<Unit>> animations, TimeSpan staggerBy, IScheduler? scheduler = null) → IEnumerable<rx<Unit>>

Delays each animation by an incremental amount.

var items = listBox.Items.Cast<FrameworkElement>();

var anims = items.Select(el => el.TranslateTransform(300, -40, 0, Ease.SineOut, Ease.SineOut)
    .Concat(el.TranslateTransform(250, 0, 0, Ease.ExpoOut, Ease.ExpoOut)));

anims.Stagger(TimeSpan.FromMilliseconds(80))
    .Parallel()
    .Subscribe();

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AnimationRx.Avalonia API

Namespace: CP.AnimationRx

Setup

Add these usings:

using CP.AnimationRx;
using System.Reactive;
using System.Reactive.Linq;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Media;

---

Frames & timing (Avalonia)

Animations.AnimateFrame(double framesPerSecond, IScheduler? scheduler = null) → rx<long>

Frames on an interval (default uses taskpool scheduler).

Animations.AnimateFrame(60)
    .Subscribe(i => Debug.WriteLine(i));

Animations.AnimateFrame(TimeSpan period, IScheduler? scheduler = null) → rx<long>

Fixed-period ticker.

Animations.AnimateFrame(TimeSpan.FromMilliseconds(16))
    .Subscribe(_ => { /* timer */ });

Animations.MilliSecondsElapsed(IScheduler scheduler) → rx<double>

Elapsed milliseconds since subscription.

Animations.MilliSecondsElapsed(RxSchedulers.TaskpoolScheduler)
    .Subscribe(ms => Debug.WriteLine(ms));

Animations.DurationPercentage(double ms, IScheduler? scheduler = null) → rx<Duration>

Progress [0..1] over a fixed duration.

Animations.DurationPercentage(500)
    .EaseAnimation(Ease.SineInOut)
    .Subscribe(d => Debug.WriteLine(d.Percent));

Animations.DurationPercentage(rx<double> ms, IScheduler? scheduler = null) → rx<Duration>

Progress [0..1] over a dynamic duration.

var durationMs = Observable.Return(350.0);
Animations.DurationPercentage(durationMs)
    .Subscribe(d => Debug.WriteLine(d.Percent));

Animations.TakeOneEvery<T>(this rx<T>, TimeSpan interval, IScheduler? scheduler = null) → rx<T>

Delays each element by interval and sequences them.

Observable.Range(1, 3)
    .TakeOneEvery(TimeSpan.FromMilliseconds(250))
    .Subscribe(Console.WriteLine);

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Easing (Avalonia)

Eases.EaseAnimation(this rx<Duration> progress, Ease ease) → rx<Duration>

Applies a selected ease.

Animations.DurationPercentage(300)
    .EaseAnimation(Ease.ExpoOut)
    .Subscribe(d => Debug.WriteLine(d.Percent));

Eases.ToDuration(this rx<double>) → rx<Duration>

Maps raw [0..1] values to Duration.

Observable.Return(0.0)
    .Concat(Observable.Return(1.0))
    .ToDuration()
    .Subscribe(d => Debug.WriteLine(d.Percent));

Specific easing functions on rx<Duration>

Same list as WPF (BackIn, BounceOut, SineInOut, etc.).

Animations.DurationPercentage(300)
    .BounceOut()
    .Subscribe(d => Debug.WriteLine(d.Percent));

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Value animation (Avalonia)

Animations.AnimateValue(double ms, double from, double to, Ease ease = Ease.None, IScheduler? scheduler = null) → rx<double>

Interpolates numeric values.

Animations.AnimateValue(400, 0, 100, Ease.SineInOut)
    .Subscribe(v => Debug.WriteLine(v));

Animations.Distance(this rx<Duration>, double distance) → rx<double>

Progress to delta.

Animations.DurationPercentage(200)
    .Distance(50)
    .Subscribe(v => Debug.WriteLine(v));

Animations.Distance(this rx<Duration>, rx<double> distance) → rx<double>

Dynamic distance.

var distance = Observable.Return(180.0);
Animations.DurationPercentage(200)
    .Distance(distance)
    .Subscribe(v => Debug.WriteLine(v));

---

Visual / control property animation (Avalonia)

All methods below return rx<Unit>.

OpacityTo(this Visual element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Visual.Opacity.

myVisual.OpacityTo(250, 0.0, Ease.SineOut).Subscribe();

WidthTo(this Control element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Control.Width (falls back to Bounds.Width if Width is NaN).

myControl.WidthTo(300, 240, Ease.ExpoOut).Subscribe();

HeightTo(this Control element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Control.Height.

myControl.HeightTo(300, 90, Ease.ExpoOut).Subscribe();

MarginTo(this Control element, double ms, Thickness to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates Control.Margin.

myControl.MarginTo(300, new Thickness(12), Ease.SineInOut).Subscribe();

PaddingTo(this TemplatedControl element, double ms, Thickness to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates TemplatedControl.Padding.

myTemplatedControl.PaddingTo(200, new Thickness(16, 8), Ease.SineOut).Subscribe();

CanvasLeftTo(this Control element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates the Canvas.Left attached property.

myControl.CanvasLeftTo(250, 120, Ease.ExpoOut).Subscribe();

CanvasTopTo(this Control element, double ms, double to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates the Canvas.Top attached property.

myControl.CanvasTopTo(250, 40, Ease.ExpoOut).Subscribe();

BrushColorTo(this SolidColorBrush brush, double ms, Color to, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates a SolidColorBrush.Color.

var brush = new SolidColorBrush(Colors.OrangeRed);
myBorder.Background = brush;

brush.BrushColorTo(500, Colors.SteelBlue, Ease.SineInOut).Subscribe();

ColorTo(this SolidColorBrush brush, double ms, Color to, Ease ease = Ease.None, IScheduler? scheduler = null)

Alias for BrushColorTo.

brush.ColorTo(500, Colors.LimeGreen, Ease.ExpoOut).Subscribe();

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Transforms (Avalonia)

Transform helpers will add the required transform to Visual.RenderTransform using a TransformGroup if needed.

TranslateTransform(this Visual element, double ms, double xPosition, double yPosition, Ease xease = Ease.None, Ease yease = Ease.None, IScheduler? scheduler = null)

Animates translation.

myVisual.TranslateTransform(400, 120, 40, Ease.ExpoOut, Ease.SineIn).Subscribe();

TranslateTo(this Visual element, double ms, double toX, double toY, ...)

Alias for TranslateTransform.

myVisual.TranslateTo(300, 0, 0, Ease.ExpoOut, Ease.ExpoOut).Subscribe();

RotateTransform(this Visual element, double ms, double angle, Ease ease = Ease.None, IScheduler? scheduler = null)

Animates rotation to the target angle.

myVisual.RotateTransform(300, 45, Ease.SineOut).Subscribe();

RotateTo(this Visual element, double ms, double toAngle, ...)

Alias for RotateTransform.

myVisual.RotateTo(300, 0, Ease.ExpoOut).Subscribe();

ScaleTransform(this Visual element, double ms, double scaleX, double scaleY, Ease easeX = Ease.None, Ease easeY = Ease.None, IScheduler? scheduler = null)

Animates scale.

myVisual.ScaleTransform(250, 1.2, 1.2, Ease.SineInOut, Ease.SineInOut).Subscribe();

ScaleTo(this Visual element, double ms, double toScaleX, double toScaleY, ...)

Alias for ScaleTransform.

myVisual.ScaleTo(250, 1.0, 1.0, Ease.SineOut, Ease.SineOut).Subscribe();

SkewTransform(this Visual element, double ms, double angleX, double angleY, Ease easeX = Ease.None, Ease easeY = Ease.None, IScheduler? scheduler = null)

Animates skew.

myVisual.SkewTransform(250, 10, 0, Ease.SineOut, Ease.SineOut).Subscribe();

SkewTo(this Visual element, double ms, double toAngleX, double toAngleY, ...)

Alias for SkewTransform.

myVisual.SkewTo(250, 0, 0, Ease.ExpoOut, Ease.ExpoOut).Subscribe();

---

“Effects” helpers (Avalonia)

ShakeTranslate(this Visual element, double ms, double amplitude, int shakes = 6, Ease ease = Ease.None, IScheduler? scheduler = null)

Shakes horizontally and returns to the original position.

myVisual.ShakeTranslate(600, amplitude: 12, shakes: 8, ease: Ease.SineOut).Subscribe();

PulseOpacity(this Visual element, double milliSecondsPerHalf, double low = 0.2, double high = 1.0, int pulses = 1, Ease ease = Ease.None, IScheduler? scheduler = null)

Pulses opacity between low and high for pulses cycles.

myVisual.PulseOpacity(150, low: 0.3, high: 1.0, pulses: 3, ease: Ease.SineInOut).Subscribe();

---

Composition helpers (Avalonia)

Sequence(this IEnumerable<rx<Unit>> animations) → rx<Unit>

Sequences animations.

new[]
{
    myVisual.OpacityTo(150, 0.0),
    myVisual.OpacityTo(150, 1.0),
}.Sequence().Subscribe();

Parallel(this IEnumerable<rx<Unit>> animations) → rx<Unit>

Runs animations in parallel.

new[]
{
    myVisual.OpacityTo(250, 1.0),
    myVisual.TranslateTransform(250, 120, 0)
}.Parallel().Subscribe();

RepeatAnimation(this rx<Unit> animation, int? count = null) → rx<Unit>

Repeats an animation.

var pulse = myVisual.PulseOpacity(120, pulses: 1);

pulse.RepeatAnimation(5).Subscribe();

DelayBetween(this IEnumerable<rx<Unit>> animations, TimeSpan delay, IScheduler? scheduler = null) → rx<Unit>

Inserts a delay between each animation in a sequence.

new[]
{
    myVisual.OpacityTo(100, 0.0),
    myVisual.OpacityTo(100, 1.0),
}
.DelayBetween(TimeSpan.FromMilliseconds(200))
.Subscribe();

Stagger(this IEnumerable<rx<Unit>> animations, TimeSpan staggerBy, IScheduler? scheduler = null) → IEnumerable<rx<Unit>>

Delays each animation by an incremental stagger.

var anims = items.Select(v => v.OpacityTo(250, 1.0, Ease.SineOut));

anims.Stagger(TimeSpan.FromMilliseconds(60))
    .Parallel()
    .Subscribe();

---

Patterns & tips

• Prefer composing animations with Rx (Concat, Merge, Sequence, Parallel) rather than timers.
• Always dispose subscriptions for:
  • cancellation
  • preventing leaks if element lifetime is shorter than the animation
• For smooth per-frame loops you can build a dt stream from AnimateFrame(...) (or RenderFrames() in WPF).

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License

MIT License. © Chris Pulman

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