animated_bottom_navigation_bar 1.0.0

Animated Bottom Navigation Bar Widget implementation inspired by https://dribbble.com/shots/7134849-Simple-Tab-Bar-Animation

example/lib/main.dart

import 'dart:async';

import 'package:animated_bottom_navigation_bar/animated_bottom_navigation_bar.dart';
import 'package:auto_size_text/auto_size_text.dart';
import 'package:circular_reveal_animation/circular_reveal_animation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/services.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        scaffoldBackgroundColor: Colors.white,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Animated Navigation Bottom Bar'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
  final autoSizeGroup = AutoSizeGroup();
  var _bottomNavIndex = 0; //default index of a first screen

  late AnimationController _fabAnimationController;
  late AnimationController _borderRadiusAnimationController;
  late Animation<double> fabAnimation;
  late Animation<double> borderRadiusAnimation;
  late CurvedAnimation fabCurve;
  late CurvedAnimation borderRadiusCurve;
  late AnimationController _hideBottomBarAnimationController;

  final iconList = <IconData>[
    Icons.brightness_5,
    Icons.brightness_4,
    Icons.brightness_6,
    Icons.brightness_7,
  ];

  @override
  void initState() {
    super.initState();
    final systemTheme = SystemUiOverlayStyle.light.copyWith(
      systemNavigationBarColor: HexColor('#373A36'),
      systemNavigationBarIconBrightness: Brightness.light,
    );
    SystemChrome.setSystemUIOverlayStyle(systemTheme);

    _fabAnimationController = AnimationController(
      duration: Duration(milliseconds: 500),
      vsync: this,
    );
    _borderRadiusAnimationController = AnimationController(
      duration: Duration(milliseconds: 500),
      vsync: this,
    );
    fabCurve = CurvedAnimation(
      parent: _fabAnimationController,
      curve: Interval(0.5, 1.0, curve: Curves.fastOutSlowIn),
    );
    borderRadiusCurve = CurvedAnimation(
      parent: _borderRadiusAnimationController,
      curve: Interval(0.5, 1.0, curve: Curves.fastOutSlowIn),
    );

    fabAnimation = Tween<double>(begin: 0, end: 1).animate(fabCurve);
    borderRadiusAnimation = Tween<double>(begin: 0, end: 1).animate(
      borderRadiusCurve,
    );

    _hideBottomBarAnimationController = AnimationController(
      duration: Duration(milliseconds: 200),
      vsync: this,
    );

    Future.delayed(
      Duration(seconds: 1),
      () => _fabAnimationController.forward(),
    );
    Future.delayed(
      Duration(seconds: 1),
      () => _borderRadiusAnimationController.forward(),
    );
  }

  bool onScrollNotification(ScrollNotification notification) {
    if (notification is UserScrollNotification &&
        notification.metrics.axis == Axis.vertical) {
      switch (notification.direction) {
        case ScrollDirection.forward:
          _hideBottomBarAnimationController.reverse();
          _fabAnimationController.forward(from: 0);
          break;
        case ScrollDirection.reverse:
          _hideBottomBarAnimationController.forward();
          _fabAnimationController.reverse(from: 1);
          break;
        case ScrollDirection.idle:
          break;
      }
    }
    return false;
  }

  @override
  Widget build(BuildContext context) {
    return Theme(
      data: ThemeData.dark(),
      child: Scaffold(
        extendBody: true,
        appBar: AppBar(
          title: Text(
            widget.title,
            style: TextStyle(color: Colors.white),
          ),
          backgroundColor: HexColor('#373A36'),
        ),
        body: NotificationListener<ScrollNotification>(
          onNotification: onScrollNotification,
          child: NavigationScreen(iconList[_bottomNavIndex]),
        ),
        floatingActionButton: FloatingActionButton(
          backgroundColor: HexColor('#FFA400'),
          child: Icon(
            Icons.brightness_3,
            color: HexColor('#373A36'),
          ),
          onPressed: () {
            _fabAnimationController.reset();
            _borderRadiusAnimationController.reset();
            _borderRadiusAnimationController.forward();
            _fabAnimationController.forward();
          },
        ),
        floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
        bottomNavigationBar: AnimatedBottomNavigationBar.builder(
          itemCount: iconList.length,
          tabBuilder: (int index, bool isActive) {
            final color = isActive ? HexColor('#FFA400') : Colors.white;
            return Column(
              mainAxisSize: MainAxisSize.min,
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(
                  iconList[index],
                  size: 24,
                  color: color,
                ),
                const SizedBox(height: 4),
                Padding(
                  padding: const EdgeInsets.symmetric(horizontal: 8),
                  child: AutoSizeText(
                    "brightness $index",
                    maxLines: 1,
                    style: TextStyle(color: color),
                    group: autoSizeGroup,
                  ),
                )
              ],
            );
          },
          backgroundColor: HexColor('#373A36'),
          activeIndex: _bottomNavIndex,
          splashColor: HexColor('#FFA400'),
          notchAndCornersAnimation: borderRadiusAnimation,
          splashSpeedInMilliseconds: 300,
          notchSmoothness: NotchSmoothness.defaultEdge,
          gapLocation: GapLocation.center,
          leftCornerRadius: 32,
          rightCornerRadius: 32,
          onTap: (index) => setState(() => _bottomNavIndex = index),
          hideAnimationController: _hideBottomBarAnimationController,
          shadow: BoxShadow(
            offset: Offset(0, 1),
            blurRadius: 12,
            spreadRadius: 0.5,
            color: Colors.grey,
          ),
        ),
      ),
    );
  }
}

class NavigationScreen extends StatefulWidget {
  final IconData iconData;

  NavigationScreen(this.iconData) : super();

  @override
  _NavigationScreenState createState() => _NavigationScreenState();
}

class _NavigationScreenState extends State<NavigationScreen>
    with TickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> animation;

  @override
  void didUpdateWidget(NavigationScreen oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.iconData != widget.iconData) {
      _startAnimation();
    }
  }

  @override
  void initState() {
    _controller = AnimationController(
      vsync: this,
      duration: Duration(milliseconds: 1000),
    );
    animation = CurvedAnimation(
      parent: _controller,
      curve: Curves.easeIn,
    );
    _controller.forward();
    super.initState();
  }

  _startAnimation() {
    _controller = AnimationController(
      vsync: this,
      duration: Duration(milliseconds: 1000),
    );
    animation = CurvedAnimation(
      parent: _controller,
      curve: Curves.easeIn,
    );
    _controller.forward();
  }

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

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.white,
      child: ListView(
        children: [
          SizedBox(height: 64),
          Center(
            child: CircularRevealAnimation(
              animation: animation,
              centerOffset: Offset(80, 80),
              maxRadius: MediaQuery.of(context).size.longestSide * 1.1,
              child: Icon(
                widget.iconData,
                color: HexColor('#FFA400'),
                size: 160,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class HexColor extends Color {
  HexColor(final String hexColor) : super(_getColorFromHex(hexColor));

  static int _getColorFromHex(String hexColor) {
    hexColor = hexColor.toUpperCase().replaceAll('#', '');
    if (hexColor.length == 6) {
      hexColor = 'FF' + hexColor;
    }
    return int.parse(hexColor, radix: 16);
  }
}