animated_bottom_navigation_bar 1.2.0

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:lanarsnavbarflutter/theme/app_theme.dart';
import 'package:lanarsnavbarflutter/theme/custom_colors_theme.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Demo',
      theme: AppTheme.get(isLight: true),
      darkTheme: AppTheme.get(isLight: false),
      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();

    _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) {
    final colors = Theme.of(context).extension<CustomColorsTheme>()!;
    return Scaffold(
      extendBody: true,
      appBar: AppBar(
        title: Text(
          widget.title,
          style: TextStyle(color: Colors.white),
        ),
      ),
      body: NotificationListener<ScrollNotification>(
        onNotification: onScrollNotification,
        child: NavigationScreen(iconList[_bottomNavIndex]),
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(
          Icons.brightness_3,
          color: AppTheme.colorGray,
        ),
        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 ? colors.activeNavigationBarColor : colors.notActiveNavigationBarColor;
          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: colors.bottomNavigationBarBackgroundColor,
        activeIndex: _bottomNavIndex,
        splashColor: colors.activeNavigationBarColor,
        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.activeNavigationBarColor,
        ),
      ),
    );
  }
}

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) {
    final colors = Theme.of(context).extension<CustomColorsTheme>()!;
    return Container(
      color: Theme.of(context).colorScheme.background,
      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: colors.activeNavigationBarColor,
                size: 160,
              ),
            ),
          ),
        ],
      ),
    );
  }
}