AnimationController

snippet.packages.flutter.lib.src.animation.animation_controller.20.

  

// ignore_for_file: directives_ordering
// ignore_for_file: unnecessary_import
// ignore_for_file: unused_import
// ignore_for_file: unused_element
// ignore_for_file: unused_local_variable
import 'dart:async';
import 'dart:convert';
import 'dart:math' as math;
import 'dart:typed_data';
import 'dart:ui' as ui;
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/painting.dart';
import 'package:flutter/physics.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/semantics.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/scheduler.dart';
import 'package:flutter/animation.dart';
import 'package:flutter/services.dart';

// From: packages/flutter/lib/src/animation/animation_controller.dart:20
late AnimationController _controller, fadeAnimationController, sizeAnimationController;
late bool dismissed;
void setState(VoidCallback fn) { }
class Foo extends StatefulWidget {
  const Foo({ Key? key, required this.duration }) : super(key: key);

  final Duration duration;

  @override
  State createState() => _FooState();
}

class _FooState extends State with SingleTickerProviderStateMixin {
  late AnimationController _controller;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this, // the SingleTickerProviderStateMixin
      duration: widget.duration,
    );
  }

  @override
  void didUpdateWidget(Foo oldWidget) {
    super.didUpdateWidget(oldWidget);
    _controller.duration = widget.duration;
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Container(); // ...
  }
}
Future fadeOutAndUpdateState() async {
  try {
    await fadeAnimationController.forward().orCancel;
    await sizeAnimationController.forward().orCancel;
    setState(() {
      dismissed = true;
    });
  } on TickerCanceled {
    // the animation got canceled, probably because we were disposed
  }
}