Flutter
  • Flutter Tutorials Handbook
  • 01 Flutter: Hello World
    • Related Article
  • 02 Flutter: Stateless Widgets
  • 03 Flutter: Buttons and Stateful widgets
  • 04 Flutter: Basic Navigation & Routes
    • Simple routes using StatelessWidget
    • Routes using StatefulWidget
  • 05 Flutter: Using onChanged to show input text
  • 06 Flutter: Using onSubmitted to show input text after submit
  • 07 Flutter: Adding-Deleting text in TextField
  • 08 Flutter: Tab Navigation
  • 09 Flutter: HTTP requests and Rest API
  • 10 Flutter: ListView with JSON or List Data
  • 11 Flutter: Sliding menu using a Drawer
    • Simple Drawer
    • Drawer using variables
  • 12 Flutter: Animations
  • 13 Flutter: JSON Storage
  • 14 Flutter: Friendly Chat App
  • 15 Flutter: Changing icon color onfocus
  • 16 Flutter: Horizontal ListView and Tabs
  • 17 Flutter: RaisedButton
  • 18 Flutter: RaisedButton with parameters
  • 19 Flutter: FlatButton
  • 20 Flutter: IconButton
  • 21 Flutter: Updating data in TextField
  • 22 Flutter: Checkbox
  • 23 Flutter: Radio with Functions
  • 24 Flutter: Switch
  • 25 Flutter: Slider
  • 26 Flutter: DatePicker
  • 27 Flutter: appBar
  • 28 Flutter: Floating Action Button
  • 29 Flutter: Drawer which shows Toggle Menu
  • 30 Flutter: Footer Buttons
  • 31 Flutter: BottomNavigationBar
  • 32 Flutter: Using BottomSheets
  • 33 Flutter: Using SnackBar
  • 34 Flutter: AlertDialog
  • 35 Flutter: SimpleDialog
  • 36 Flutter: Rows and Columns
  • 37 Flutter: Using Cards
  • 38 Flutter: Using Expanded
  • 39 Flutter: ListviewBuilder using Dart maps
  • 40 Flutter: ListviewBuilder using Dart lists
  • 41 Flutter: Using Custom Widgets
  • 42 Flutter: Using Image Assets
  • 43 Flutter: ListviewBuilder with Refresh Indicator
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15 Flutter: Changing icon color onfocus

main.dart
import 'package:flutter/material.dart';
import 'package:meta/meta.dart';

void main() {
  runApp(new MaterialApp(
    home: new MyApp()
  ));
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Custom Bottom Nav',
      home: new Scaffold(
        appBar: new AppBar(title: new Text('Custom Bottom Nav')),
        body: new Container(),
        bottomNavigationBar: new BottomNav(
          navCallback: (i) => print("Navigating to $i"),
        ),
      ),
    );
  }
}

class BottomNav extends StatefulWidget {
  final int initialIndex;
  final ValueChanged<int> navCallback;

  BottomNav({@required this.navCallback, this.initialIndex: 0});

  @override
  _BottomNavState createState() => new _BottomNavState();
}

class _BottomNavState extends State<BottomNav> {
  int _selected;

  @override
  void initState() {
    super.initState();
    _selected = widget.initialIndex;
    notifyCallback();
  }

  @override
  Widget build(BuildContext context) {
    return new Material(
      color: Colors.white,
      elevation: 8.0,
      child: new Container(
        height: 56.0,
        child: new Row(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            _buildButton(0, Icons.home, "Home"),
            _buildButton(1, Icons.book, "Bookmarks"),
            _buildButton(2, Icons.video_library, "Videos"),
          ],
        ),
      ),
    );
  }

  Widget _buildButton(int index, IconData data, String tooltip) {
    return new Flexible(
      flex: 1,
      child: new Tooltip(
        message: tooltip,
        child: new InkWell(
          onTap: () => onButtonTap(index),
          child: new Center(
            child: new Icon(data,
              color: _selected == index ? Colors.red : Colors.grey,
            ),
          ),
        ),
      ),
    );
  }

  onButtonTap(int index) {
    setState(() {
      _selected = index;
    });
    notifyCallback();
  }

  notifyCallback() {
    widget.navCallback(_selected);
  }
}
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Last updated 6 years ago