TextField onChanged called twice after typing a letter followed by three digits on Android

[PerLycke]

Steps to Reproduce

1. Use a real device (tested on a Nexus 6P running Android 8.1.0 and a Samsung running Android 13 beta) and execute flutter run on the code sample
2. Type a111

Expected results:

onChanged should be called once

Actual results:

onChanged will be called twice after you typed a111, watch console print value twice as in

I/flutter ( 5033): a
I/flutter ( 5033): a1
I/flutter ( 5033): a11
2 I/flutter ( 5033): a111

Code sample

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const TextFieldTest(),
    );
  }
}

class TextFieldTest extends StatelessWidget {
  const TextFieldTest({super.key});

  @override
  Widget build(BuildContext context) {
    return Material(
      child: Center(
        child: TextField(
          onChanged: (value) => print(value),
        ),
      ),
    );
  }
}

Logs

[✓] Flutter (Channel stable, 3.3.2, on macOS 12.6 21G115 darwin-arm, locale en-GB)
    • Flutter version 3.3.2 on channel stable at /Users/per/dev/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision e3c29ec00c (19 hours ago), 2022-09-14 08:46:55 -0500
    • Engine revision a4ff2c53d8
    • Dart version 2.18.1
    • DevTools version 2.15.0

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/per/Library/Android/sdk
    • Platform android-33, build-tools 31.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 14.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 14A309
    • CocoaPods version 1.11.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)

[✓] VS Code (version 1.71.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.48.0

[✓] Connected device (3 available)
    • Nexus 6P (mobile) • ENU7N15B05017943 • android-arm64  • Android 8.1.0 (API 27)
    • macOS (desktop)   • macos            • darwin-arm64   • macOS 12.6 21G115 darwin-arm
    • Chrome (web)      • chrome           • web-javascript • Google Chrome 105.0.5195.102

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!

[PerLycke]

Sorry to say but this is a bad bug and it's a pity we need to add logic to handle this specific issue. My guess is we are not alone as I can't see it being very rare to rely on a TextField's onChanged in bigger production apps.

[exaby73]

Triage report

I can reproduce the issue. Doesn't reproduce on an emulator. My device is an Android 12, Vivo V21.

Related issues

• [Android 12] Textfield onchanged callback triggered twice on emulator #92782
• TextField onChanged called multiple times when selectiong text suggestions on iOS #82887

Versions reproducible on

• Stable (3.3.2)
• Master (3.4.0-19.0.pre.272)

Info

Logs

D/InsetsController(25666): show(ime(), fromIme=true)
I/flutter (25666): a
I/flutter (25666): a1
D/InsetsController(25666): show(ime(), fromIme=true)
I/flutter (25666): a11
D/InsetsController(25666): show(ime(), fromIme=true)
I/flutter (25666): a111
D/InsetsController(25666): show(ime(), fromIme=true)
I/flutter (25666): a111

Code Sample

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const TextFieldTest(),
    );
  }
}

class TextFieldTest extends StatelessWidget {
  const TextFieldTest({super.key});

  @override
  Widget build(BuildContext context) {
    return const Material(
      child: Center(
        child: TextField(onChanged: print),
      ),
    );
  }
}

Flutter Doctor

flutter doctor -v (Stable)

[✓] Flutter (Channel stable, 3.3.2, on Microsoft Windows [Version 10.0.22000.978], locale en-US)
    • Flutter version 3.3.2 on channel stable at C:\Users\Nabeel\fvm\versions\stable
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision e3c29ec00c (17 hours ago), 2022-09-14 08:46:55 -0500
    • Engine revision a4ff2c53d8
    • Dart version 2.18.1
    • DevTools version 2.15.0

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0)
    • Android SDK at C:\android-sdk
    • Platform android-33, build-tools 33.0.0
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 11.0.12+7-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = C:\Program Files\BraveSoftware\Brave-Browser\Application\brave.exe

[✓] Visual Studio - develop for Windows (Visual Studio Community 2022 17.3.2)
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.3.32819.101
    • Windows 10 SDK version 10.0.19041.0

[✓] Android Studio (version 2021.2)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.12+7-b1504.28-7817840)

[✓] VS Code (version 1.71.0)
    • VS Code at C:\Users\Nabeel\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.46.0

[✓] Connected device (3 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.22000.978]
    • Chrome (web)      • chrome  • web-javascript • unknown
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 105.0.1343.27

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!

flutter doctor -v (Master)

[✓] Flutter (Channel master, 3.4.0-19.0.pre.272, on Microsoft Windows [Version 10.0.22000.978], locale en-US)
    • Flutter version 3.4.0-19.0.pre.272 on channel master at C:\Users\Nabeel\fvm\versions\master
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 2262892e3b (2 hours ago), 2022-09-15 00:44:22 -0400
    • Engine revision 63cc5ea2b1
    • Dart version 2.19.0 (build 2.19.0-201.0.dev)
    • DevTools version 2.17.0

[✓] Windows Version (Installed version of Windows is version 10 or higher)

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0)
    • Android SDK at C:\android-sdk
    • Platform android-33, build-tools 33.0.0
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 11.0.12+7-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = C:\Program Files\BraveSoftware\Brave-Browser\Application\brave.exe

[✓] Visual Studio - develop for Windows (Visual Studio Community 2022 17.3.2)
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.3.32819.101
    • Windows 10 SDK version 10.0.19041.0

[✓] Android Studio (version 2021.2)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.12+7-b1504.28-7817840)

[✓] VS Code (version 1.71.0)
    • VS Code at C:\Users\Nabeel\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.46.0

[✓] Connected device (3 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.22000.978]
    • Chrome (web)      • chrome  • web-javascript • unknown
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 105.0.1343.27

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!

[justinmc]

CC @LongCatIsLooong from triage