animate*AsState for Simple Tweens
Animate a single value automatically.
animate*AsState for Simple Tweens is a free Jetpack Compose Academy lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Jetpack Compose Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Animation, the Easy Way
Compose can animate changes for you. The simplest tool is the animate*AsState family, which smoothly moves a value from old to new. ✨
What animateDpAsState Does
When your target value changes, animateDpAsState returns a State that glides toward it over a few frames instead of jumping.
val size by animateDpAsState(targetValue = if (big) 200.dp else 100.dp)Read It Like Normal State
The animated value is just a State you read with by. Use it in a Modifier and the UI follows the animation every frame.
Box(Modifier.size(size).background(Color.Blue))A Whole Family of Helpers
There is one per type: animateFloatAsState, animateColorAsState, animateDpAsState, and more. Pick the one matching the value you want to tween.
Animate a Color
Use animateColorAsState to fade between colors. Toggle a boolean and watch the background shift smoothly from one tint to another. 🎨
val color by animateColorAsState(if (on) Color.Green else Color.Gray)Animate Transparency
For fade in and out, animate a float and feed it to alpha. A value of 0f is invisible, 1f is fully opaque.
val a by animateFloatAsState(if (visible) 1f else 0f)
Box(Modifier.alpha(a))Choose the Pace
Pass an animationSpec to control timing. A tween lets you set the duration in milliseconds and an easing curve.
animateDpAsState(target, animationSpec = tween(durationMillis = 500))Spring for Bounce
Swap in a spring spec for natural, physics-based motion. Tune dampingRatio and stiffness to add a little playful bounce.
animateDpAsState(target, animationSpec = spring(dampingRatio = 0.4f))It Reacts to State
You never call start or stop. When the target value changes during recomposition, the animation restarts toward the new goal automatically.
Smooth, Not Linear
Default easing makes motion feel alive by speeding up then slowing down. Easing curves like FastOutSlowInEasing avoid robotic, constant-speed movement.
Listen When It Finishes
Need to react when motion ends? Pass a finishedListener lambda, which fires once with the final value after the animation settles.
animateDpAsState(target) { final -> /* done */ }Quick Check
Which spec gives motion a natural, bouncy physics feel?
Recap: One Value at a Time
You learned animate*AsState: change a target, read the animated State, and pick tween or spring. It is the quickest way to add smooth single-value motion. 🎉
Frequently asked questions
Is the “animate*AsState for Simple Tweens” lesson free?
Yes — the full text of “animate*AsState for Simple Tweens” is free to read here on the web, and the Jetpack Compose Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Jetpack Compose Academy course, upgrade to CoddyKit PRO.
What will I learn in “animate*AsState for Simple Tweens”?
Animate a single value automatically. You practise Jetpack Compose Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Jetpack Compose Academy?
No prior experience is required. Jetpack Compose Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “animate*AsState for Simple Tweens” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Jetpack Compose Academy lesson?
Yes. Every Jetpack Compose Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- animate*AsState for Simple Tweens
- AnimatedVisibility & Crossfade
- updateTransition for Coordinated Motion
- Gesture-Driven Animations