RoundedLoadingButton is a Flutter package with a simple implementation of an animated loading button, complete with success and error animations.

Add this to your pubspec.yaml:

dependencies:
    rounded_loading_button: ^2.0.8

import 'package:rounded_loading_button/rounded_loading_button.dart';

final RoundedLoadingButtonController _btnController = RoundedLoadingButtonController();
void _doSomething() async {
    Timer(Duration(seconds: 3), () {
        _btnController.success();
    });
}
RoundedLoadingButton(
    child: Text('Tap me!', style: TextStyle(color: Colors.white)),
    controller: _btnController,
    onPressed: _doSomething,
)

The Rounded Loading Button has many configurable properties, including:

• duration - The duration of the button animation
• loaderSize - The size of the CircularProgressIndicator
• animateOnTap - Whether to trigger the loading animation on the tap event
• resetAfterDuration - Reset the animation after specified duration, defaults to 15 seconds
• errorColor - The color of the button when it is in the error state
• successColor - The color of the button when it is in the success state
• successIcon - The icon for the success state
• failedIcon - The icon for the failed state

All contributions are welcome!