AnimatedBuilder Explained | Flutter for Android Developers

What’s AnimatedBuilder?

The AnimatedBuilder class is a general-purpose widget in Flutter for building animations. It is particularly useful for more complex widgets that need to include an animation as part of a larger build function. Key properties include ‘animation’, which is the Listenable that triggers rebuilds, and ‘builder’, which is a function called every time the animation notifies about a change.

Check the official documentation for more.

AnimatedBuilder explained for Android Developers

For Android developers, the AnimatedBuilder can be compared to the ViewPropertyAnimator in Android, which allows for smooth animations on views. Similar to how you would use an Animator in Android to animate properties of a view, the AnimatedBuilder allows you to animate properties of widgets in Flutter. It can also be likened to Kotlin’s Coroutines for managing state changes in a more readable way, as it allows for a clean separation of animation logic from the widget tree.

Example Code

Here is an example of how to use AnimatedBuilder:

AnimatedBuilder(
  animation: animation,
  builder: (context, child) {
    return Transform.rotate(
      angle: animation.value,
      child: child,
    );
  },
  child: Container(
    width: 100,
    height: 100,
    color: Colors.green,
  ),
);

AnimatedBuilder Remarks

In conclusion, the AnimatedBuilder class is a powerful tool for Flutter developers looking to implement animations in their applications. By understanding its properties and how it interacts with the widget tree, developers can create more dynamic and visually appealing user interfaces.