evento 0.1.0

Dart/Flutter communication package based on events

Animo

Why this package exists?

Because I needed something simpler with greater control over my staggered animations. I needed an API to create multiple controllers in the context of a single widget. And of course the power to start/stop/reverse the animations when I want.

Usage

import 'package:flutter/material.dart';
import 'package:animo/animo.dart';

// Define a tween.
ATween myTween = ATween(
  begin: 0,
  end: 120,
  interval: Interval(0, 1, curve: Curves.easeOut)
);

class TestWidget extends StatelessWidget {
  Widget build(context) {
    return Animo((defineAnimation) {
      // When you have complex animation sequences you'll probably need
      // multiple controllers. `defineAnimation` spins up a new one every time
      // when it gets called.
      AAnimation anim = defineAnimation(duration: Duration(seconds: 1));
      
      // Attach multiple tweens to the created controller.
      anim.attach([myTween]);
      
      // ... and at the end control your animation directly by calling forward, reverse, stop
      // methods of the AnimationController instance
      anim.controller.forward();

      // It is important to return a function that returns your widget. This function gets
      // gets called on every tick of the animation.
      return () {
        return Text('value: ${myTween.value}');
      };
    });
  }
}

Additionally the package offers a few helper functions to apply scaling, translating and rotating:

• Widget withOpacity(Widget child, {double value = 1})
• Widget withScale(Widget child, {double value = 1})
• Widget withTranslate(Widget child, {double x = 0, double y = 0, double z = 0})
• Widget withRotation(Widget child, {double x = 0, double y = 0, double z = 0})

Padding(
  padding: EdgeInsets.only(bottom: 40),
  child: withTranslate(
    withScale(
      MyButton("Click me"),
      value: anotherTween.value
    ),
    y: myTween.value
  )
);

Also some common fading in and out (with possible position X and/or Y offset):

Widget fadeIn(
    child,
    {
      double offsetX = 0,
      double offsetY = 0,
      int duration = 800,
      int delay = 0,
      curve = Curves.easeOut
    }
)

and

Widget fadeOut(
    child,
    {
      double offsetX = 0,
      double offsetY = 0,
      int duration = 800,
      int delay = 0,
      curve = Curves.easeOut
    }
)