플러터챌린지 4일차 기본문제 - 신현호

readme.md

플러터챌린지 4일차 기본문제 - 신현호

Created with <3 with dartpad.dev.

main.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';


void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'HelloTextField',
      debugShowCheckedModeBanner: false,
      home: HelloTextFieldScreen(),
    );
  }
}

class HelloTextFieldScreen extends StatefulWidget {
  @override
  State<HelloTextFieldScreen> createState() => _HelloTextFieldScreenState();
}

class _HelloTextFieldScreenState extends State<HelloTextFieldScreen> {
  late final FocusNode leftFocusNode;
  late final FocusNode rightFocusNode;
  late final TextEditingController leftController;
  late final TextEditingController rightController;
  
  KeyEventResult _onKey(FocusNode node, RawKeyEvent event, TextEditingController controller) {
    if (event is RawKeyDownEvent) {
      FocusNode oppNode = (node == leftFocusNode) ? rightFocusNode : leftFocusNode;
      bool isBackSpace = (event.logicalKey == LogicalKeyboardKey.backspace);
      bool isTextEmpty = (controller.text.isEmpty == true);
      if (isBackSpace && isTextEmpty) {
        oppNode.requestFocus();
        return KeyEventResult.handled;
      }
      return KeyEventResult.ignored;
    }
    return KeyEventResult.ignored;
  }
  
  @override
  void initState() {
    super.initState();
    
    leftController = TextEditingController(text: "Hello");
    rightController = TextEditingController(text: "FlutterBoot!");
    leftFocusNode = FocusNode(onKey: (node, event) => _onKey(leftFocusNode, event, leftController));
    rightFocusNode = FocusNode(onKey: (node, event) => _onKey(rightFocusNode, event, rightController));
    
    WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
      rightFocusNode.requestFocus();
    });
  }

  @override
  void dispose() {
    leftController.dispose();
    rightController.dispose();
    leftFocusNode.dispose();
    rightFocusNode.dispose();
    super.dispose;
  }

  @override
  Widget build(BuildContext context) {
    InputBorder border = UnderlineInputBorder(
      borderSide: BorderSide(color: Theme.of(context).colorScheme.primary, width: 1.5),
    );
    
    return Scaffold(
      appBar: AppBar(
        title: const Text('Hello TextField!'),
      ),
      body: Center(
        child: Row(
          children: [
            const SizedBox(width: 10),
            Flexible(
              child: TextField(
                focusNode: leftFocusNode,
                controller: leftController,
                onEditingComplete: () {
                  rightFocusNode.requestFocus();
                },
              ),
            ),
            const SizedBox(width: 20),
            Flexible(
              child: TextField(
                autofocus: true,
                focusNode: rightFocusNode,
                controller: rightController,
                onEditingComplete: () {
                  leftFocusNode.requestFocus();
                },
                decoration: InputDecoration(
                  focusedBorder: border,
                  enabledBorder: border,
                  disabledBorder: border,
                  errorBorder: border,
                  focusedErrorBorder: border,
                ),
              ),
            ),
            const SizedBox(width: 10),
          ],
        ),
      ),
    );
  }
}