demo_toggle_buttons.dart

import 'package:flutter/material.dart';

class DemoToggleButtons extends StatefulWidget {
  @override
  _DemoToggleButtonsState createState() => _DemoToggleButtonsState();
}

class _DemoToggleButtonsState extends State<DemoToggleButtons> {
  List<bool> isSelected = [false, true, false];
  FocusNode focusNodeButton1 = FocusNode();
  FocusNode focusNodeButton2 = FocusNode();
  FocusNode focusNodeButton3 = FocusNode();
  List<FocusNode> focusToggle;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    focusToggle = [focusNodeButton1, focusNodeButton2, focusNodeButton3];
  }

  @override
  void dispose() {
    // Clean up the focus node when the Form is disposed.
    focusNodeButton1.dispose();
    focusNodeButton2.dispose();
    focusNodeButton3.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      darkTheme: ThemeData.dark(),
      theme: ThemeData(brightness: Brightness.dark),
      home: Scaffold(
        appBar: AppBar(
          title: const Text('ToggleButtons'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              ToggleButtons(
                color: Colors.greenAccent,
                selectedColor: Colors.amberAccent,
                fillColor: Colors.purple,
                splashColor: Colors.lightBlue,
                highlightColor: Colors.lightBlue,
                borderColor: Colors.white,
                borderWidth: 5,
                selectedBorderColor: Colors.greenAccent,
                renderBorder: true,
                borderRadius: BorderRadius.only(
                    topLeft: Radius.circular(25),
                    bottomRight: Radius.circular(25)),
                disabledColor: Colors.blueGrey,
                disabledBorderColor: Colors.blueGrey,
                focusColor: Colors.red,
                focusNodes: focusToggle,
                children: <Widget>[
                  Icon(Icons.format_bold),
                  Icon(Icons.format_italic),
                  Icon(Icons.link),
                ],
                isSelected: isSelected,
                onPressed: (int index) {
                  setState(() {
                    isSelected[index] = !isSelected[index];
                  });
                },
              ),
              SizedBox(
                height: 50,
              ),
              Container(
                decoration: BoxDecoration(
                  color: Colors.black,
                ),
                child: Column(
                  children: <Widget>[
                    Text('TV remote'),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: <Widget>[
                        RaisedButton(
                          child: Text('Previous'),
                          onPressed: () {
                            FocusScope.of(context)
                                .requestFocus(focusNodeButton1);
                          },
                        ),
                        SizedBox(
                          width: 20,
                        ),
                        RaisedButton(
                          child: Text('Next'),
                          onPressed: () {
                            FocusScope.of(context)
                                .requestFocus(focusNodeButton2);
                          },
                        ),
                      ],
                    ),
                  ],
                ),
              )
            ],
          ),
        ),
      ),
    );
  }
}