Action.overridable cannot be overridden by a DoNothingAction

Steps to reproduce

Wrap a TextField with Actions and use DoNothingAction for all text editing Intents (see code sample)
Run it, type in some text.
Do some text editing related shortcuts like arrow left, arrow up, ctrl + A, backspace etc.

Expected results

arrow up, arrow down, page up, page down, home and end or in other words ExtendSelectionVerticallyToAdjacentPageIntent and ExtendSelectionVerticallyToAdjacentLineIntent do nothing
for all other intents no assertion errors is thrown

Actual results

ExtendSelectionVerticallyToAdjacentPageIntent and ExtendSelectionVerticallyToAdjacentLineIntent moves caret to the start/end of the text
When all other intents are executed, the following assertion error is thrown (example for SelectAllTextIntent):

════════ Exception caught by services library ══════════════════════════════════
The following assertion was thrown while processing the key message handler:
SelectAllTextIntent cannot be handled by an Action of runtime type DoNothingAction.
'package:flutter/src/widgets/actions.dart':
Failed assertion: line 926 pos 9: 'false'

Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
  https://github.com/flutter/flutter/issues/new?template=02_bug.yml

When the exception was thrown, this was the stack:
#2      Actions._castAction (package:flutter/src/widgets/actions.dart:926:9)
actions.dart:926
#3      Actions._maybeFindWithoutDependingOn.<anonymous closure> (package:flutter/src/widgets/actions.dart:907:33)
actions.dart:907
#4      Actions._visitActionsAncestors (package:flutter/src/widgets/actions.dart:746:18)
actions.dart:746
#5      Actions._maybeFindWithoutDependingOn (package:flutter/src/widgets/actions.dart:905:5)
actions.dart:905
#6      _OverridableActionMixin.getOverrideAction (package:flutter/src/widgets/actions.dart:1637:19)
actions.dart:1637
#7      _OverridableActionMixin.isEnabled (package:flutter/src/widgets/actions.dart:1706:39)
actions.dart:1706
#8      Action._isEnabled (package:flutter/src/widgets/actions.dart:247:45)
actions.dart:247
#9      ActionDispatcher.invokeActionIfEnabled (package:flutter/src/widgets/actions.dart:664:16)
actions.dart:664
#10     ShortcutManager.handleKeypress (package:flutter/src/widgets/shortcuts.dart:935:9)
shortcuts.dart:935
#11     _ShortcutsState._handleOnKeyEvent (package:flutter/src/widgets/shortcuts.dart:1135:20)
shortcuts.dart:1135
#12     _HighlightModeManager.handleKeyMessage (package:flutter/src/widgets/focus_manager.dart:2244:72)
focus_manager.dart:2244
#13     KeyEventManager._dispatchKeyMessage (package:flutter/src/services/hardware_keyboard.dart:1119:34)
hardware_keyboard.dart:1119
#14     KeyEventManager.handleRawKeyMessage (package:flutter/src/services/hardware_keyboard.dart:1195:17)
hardware_keyboard.dart:1195
#15     BasicMessageChannel.setMessageHandler.<anonymous closure> (package:flutter/src/services/platform_channel.dart:259:49)
platform_channel.dart:259
#16     _DefaultBinaryMessenger.setMessageHandler.<anonymous closure> (package:flutter/src/services/binding.dart:665:35)
binding.dart:665
#17     _invoke2 (dart:ui/hooks.dart:388:13)
hooks.dart:388
#18     _ChannelCallbackRecord.invoke (dart:ui/channel_buffers.dart:45:5)
channel_buffers.dart:45
#19     _Channel.push (dart:ui/channel_buffers.dart:136:31)
channel_buffers.dart:136
#20     ChannelBuffers.push (dart:ui/channel_buffers.dart:344:17)
channel_buffers.dart:344

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(colorScheme: .fromSeed(seedColor: Colors.deepPurple)),
      home: Scaffold(
        body: Actions(
          actions: {
            DeleteCharacterIntent: DoNothingAction(),
            DeleteToNextWordBoundaryIntent: DoNothingAction(),
            DeleteToLineBreakIntent: DoNothingAction(),
            ExtendSelectionByCharacterIntent: DoNothingAction(),
            ExtendSelectionToNextWordBoundaryIntent: DoNothingAction(),
            ExtendSelectionToNextWordBoundaryOrCaretLocationIntent:
                DoNothingAction(),
            ExtendSelectionToLineBreakIntent: DoNothingAction(),
            ExtendSelectionVerticallyToAdjacentLineIntent: DoNothingAction(),
            ExtendSelectionVerticallyToAdjacentPageIntent: DoNothingAction(),
            ExtendSelectionToDocumentBoundaryIntent: DoNothingAction(),
            SelectAllTextIntent: DoNothingAction(),
            ReplaceTextIntent: DoNothingAction(),
            UpdateSelectionIntent: DoNothingAction(),
            CopySelectionTextIntent: DoNothingAction(),
            PasteTextIntent: DoNothingAction(),
          },
          child: const TextField(enableInteractiveSelection: false),
        ),
      ),
    );
  }
}

Screenshots or Video

No response

Logs

No response

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.38.5, on Pop!_OS 24.04 LTS 6.17.9-76061709-generic, locale en_US.UTF-8) [26ms]
    • Flutter version 3.38.5 on channel stable at /home/alexander/.develop/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision f6ff1529fd (3 weeks ago), 2025-12-11 11:50:07 -0500
    • Engine revision 1527ae0ec5
    • Dart version 3.10.4
    • DevTools version 2.51.1
    • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android, enable-ios,
      cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging

[✓] Android toolchain - develop for Android devices (Android SDK version 36.1.0) [998ms]
    • Android SDK at /home/alexander/.android/sdk/
    • Emulator version 36.3.10.0 (build_id 14472402) (CL:N/A)
    • Platform android-36, build-tools 36.1.0
    • Java binary at: /home/alexander/.local/android-studio/jbr/bin/java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.8+-14196175-b1038.72)
    • All Android licenses accepted.

[✓] Chrome - develop for the web [8ms]
    • Chrome at google-chrome

[✓] Linux toolchain - develop for Linux desktop [370ms]
    • Ubuntu clang version 18.1.3 (1ubuntu1)
    • cmake version 3.28.3
    • ninja version 1.11.1
    • pkg-config version 1.8.1
    • OpenGL core renderer: Mesa Intel(R) Iris(R) Xe Graphics (RPL-P)
    • OpenGL core version: 4.6 (Core Profile) Mesa 25.1.5-1pop0~1753463422~24.04~8af185e
    • OpenGL core shading language version: 4.60
    • OpenGL ES renderer: Mesa Intel(R) Iris(R) Xe Graphics (RPL-P)
    • OpenGL ES version: OpenGL ES 3.2 Mesa 25.1.5-1pop0~1753463422~24.04~8af185e
    • OpenGL ES shading language version: OpenGL ES GLSL ES 3.20
    • GL_EXT_framebuffer_blit: yes
    • GL_EXT_texture_format_BGRA8888: yes

[✓] Connected device (2 available) [125ms]
    • Linux (desktop) • linux  • linux-x64      • Pop!_OS 24.04 LTS 6.17.9-76061709-generic
    • Chrome (web)    • chrome • web-javascript • Google Chrome 143.0.7499.169

[✓] Network resources [363ms]
    • All expected network resources are available.

• No issues found!

It seems that DoNothingAction couldn't actually bind to any Intent in this case, despite the document saying it should be able to.
A possible workaround is to create your own Intent specific DoNothingAction.

import 'package:flutter/material.dart';

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

class MyDoNothingAction<T extends Intent> extends Action<T> {
  @override
  void invoke(T intent) {}
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple)),
      home: Scaffold(
        body: Actions(
          actions: {
            DeleteCharacterIntent: MyDoNothingAction<DeleteCharacterIntent>(),
            DeleteToNextWordBoundaryIntent: MyDoNothingAction<DeleteToNextWordBoundaryIntent>(),
            DeleteToLineBreakIntent: MyDoNothingAction<DeleteToLineBreakIntent>(),
            ExtendSelectionByCharacterIntent: MyDoNothingAction<ExtendSelectionByCharacterIntent>(),
            ExtendSelectionToNextWordBoundaryIntent:
                MyDoNothingAction<ExtendSelectionToNextWordBoundaryIntent>(),
            ExtendSelectionToNextWordBoundaryOrCaretLocationIntent:
                MyDoNothingAction<ExtendSelectionToNextWordBoundaryOrCaretLocationIntent>(),
            ExtendSelectionToLineBreakIntent: MyDoNothingAction<ExtendSelectionToLineBreakIntent>(),
            ExtendSelectionVerticallyToAdjacentLineIntent:
                MyDoNothingAction<ExtendSelectionVerticallyToAdjacentLineIntent>(),
            ExtendSelectionVerticallyToAdjacentPageIntent:
                MyDoNothingAction<ExtendSelectionVerticallyToAdjacentPageIntent>(),
            ExtendSelectionToDocumentBoundaryIntent:
                MyDoNothingAction<ExtendSelectionToDocumentBoundaryIntent>(),
            SelectAllTextIntent: MyDoNothingAction<SelectAllTextIntent>(),
            ReplaceTextIntent: MyDoNothingAction<ReplaceTextIntent>(),
            UpdateSelectionIntent: MyDoNothingAction<UpdateSelectionIntent>(),
            CopySelectionTextIntent: MyDoNothingAction<CopySelectionTextIntent>(),
            PasteTextIntent: MyDoNothingAction<PasteTextIntent>(),
          },
          child: const TextField(enableInteractiveSelection: false),
        ),
      ),
    );
  }
}

A possible workaround is to create your own Intent specific DoNothingAction.

Yes, that naturally fixes assertion errors. This does not fix ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent still running their default actions however.

I did some digging and I think I found the issue for why overriding ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent does not work.

Here is the code from editable_text.dart :

// line 5455
  late final _UpdateTextSelectionVerticallyAction<DirectionalCaretMovementIntent>
  _verticalSelectionUpdateAction =
      _UpdateTextSelectionVerticallyAction<DirectionalCaretMovementIntent>(this);
// ...

// line 5512
  late final Map<Type, Action<Intent>> _actions = <Type, Action<Intent>>{
// ...
// line 5570
    ExtendSelectionVerticallyToAdjacentLineIntent: _makeOverridable(_verticalSelectionUpdateAction),
    ExtendSelectionVerticallyToAdjacentPageIntent: _makeOverridable(_verticalSelectionUpdateAction),
// ...
}

Action used for both ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent is bound to DirectionalCaretMovementIntent, which I assume should not be the case.

And indeed overriding the DirectionalCaretMovementIntent itself like

DirectionalCaretMovementIntent: MyDoNothingAction<DirectionalCaretMovementIntent>()

fixes the issue and caret does not move anymore on arrow up and similar shortcuts.

Thanks for the report. Seeing the same behaviour with latest SDK versions.

stable : 3.38.5
master : 3.40.0-1.0.pre-413

Hmm maybe we can construct a const Function<T> in each Action<T> and does the type check like this:

mappedAction._functionSignature is Function<T>

But this means people won't be able to implement Action<T>. Let me try this out.

The above tricks seems to work but unforunately some of our public APIs return Action<T> and the language only allows for covariant type parameters so there's no way you can return a Action<Intent> when T is a more specialized type. And Function is final so we can't do Action<T> extends Function<T>, and also Function type literal has a special syntax Function(U).

I did some digging and I think I found the issue for why overriding ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent does not work.

Here is the code from editable_text.dart :

// line 5455
late final _UpdateTextSelectionVerticallyAction
_verticalSelectionUpdateAction =
_UpdateTextSelectionVerticallyAction(this);
// ...

// line 5512
late final Map<Type, Action> _actions = <Type, Action>{
// ...
// line 5570
ExtendSelectionVerticallyToAdjacentLineIntent: _makeOverridable(_verticalSelectionUpdateAction),
ExtendSelectionVerticallyToAdjacentPageIntent: _makeOverridable(_verticalSelectionUpdateAction),
// ...
}

Action used for both ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent is bound to DirectionalCaretMovementIntent, which I assume should not be the case.

And indeed overriding the DirectionalCaretMovementIntent itself like

DirectionalCaretMovementIntent: MyDoNothingAction()

fixes the issue and caret does not move anymore on arrow up and similar shortcuts.

Should I create a separate issue for this bug?

Action used for both ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent is bound to DirectionalCaretMovementIntent, which I assume should not be the case.

Hmm I'm not sure what you mean, it makes sense to me that ExtendSelectionVerticallyToX should be a subclass of DirectionalCaretMovementIntent?

Action used for both ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent is bound to DirectionalCaretMovementIntent, which I assume should not be the case.

Hmm I'm not sure what you mean, it makes sense to me that ExtendSelectionVerticallyToX should be a subclass of DirectionalCaretMovementIntent?

The issue is that you cannot override ExtendSelectionVerticallyToAdjacentPageIntent and ExtendSelectionVerticallyToAdjacentLineIntent individually even when using something likeMyDoNothingAction<ExtendSelectionVerticallyToAdjacentPageIntent>() and MyDoNothingAction<ExtendSelectionVerticallyToAdjacentLineIntent>(). You need to use MyDoNothingAction<DirectionalCaretMovementIntent>(), which will override them both.

And my guess is that this happens because action used in editable_text.dart for both these intents is defined bound to DirectionalCaretMovementIntent like this:

  late final _UpdateTextSelectionVerticallyAction<DirectionalCaretMovementIntent>
  _verticalSelectionUpdateAction =
      _UpdateTextSelectionVerticallyAction<DirectionalCaretMovementIntent>(this);

Action used for both ExtendSelectionVerticallyToAdjacentLineIntent and ExtendSelectionVerticallyToAdjacentPageIntent is bound to DirectionalCaretMovementIntent, which I assume should not be the case.

Hmm I'm not sure what you mean, it makes sense to me that ExtendSelectionVerticallyToX should be a subclass of DirectionalCaretMovementIntent?

The issue is that you cannot override ExtendSelectionVerticallyToAdjacentPageIntent and ExtendSelectionVerticallyToAdjacentLineIntent individually even when using something likeMyDoNothingAction<ExtendSelectionVerticallyToAdjacentPageIntent>() and MyDoNothingAction<ExtendSelectionVerticallyToAdjacentLineIntent>(). You need to use MyDoNothingAction<DirectionalCaretMovementIntent>(), which will override them both.

And my guess is that this happens because action used in editable_text.dart for both these intents is defined bound to DirectionalCaretMovementIntent like this:

late final _UpdateTextSelectionVerticallyAction
_verticalSelectionUpdateAction =
_UpdateTextSelectionVerticallyAction(this);

Ah I might have fixed that in #180883. It's probably because we were using the statically inferred type T extends Intent to find the override action instead of using the Intent's runtime type. Let me add a test for that later.

Update: Yeah I think I might have fixed that case in the said PR. But the limitation is that you won't be able to access callingAction, which is basically the equivalent of the super implementation when you're implementing the override.

I can reproduce this on master. The root cause is in Actions._castAction — it does mappedAction is Action? which fails for DoNothingAction because Dart's reified generics are invariant ( Action is not Action at runtime). I have a fix that wraps Action actions in a typed delegate when intentType == Intent. Would like to submit a PR — does this approach sound reasonable?

Fix DoNothingAction assertion when overriding Action.overridable

Fix some type checks in the `Actions` widget (flutter#180883)

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

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Action.overridable cannot be overridden by a DoNothingAction #180435

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Action.overridable cannot be overridden by a DoNothingAction #180435

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PurplePolyhedron commented on Jan 3, 2026

lebeshev commented on Jan 3, 2026

lebeshev commented on Jan 3, 2026

tirth-patel-nc commented on Jan 6, 2026

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LongCatIsLooong commented on Jan 9, 2026

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lebeshev commented on Jan 10, 2026

LongCatIsLooong commented on Jan 12, 2026

lebeshev commented on Jan 14, 2026

LongCatIsLooong commented on Jan 14, 2026

solvejet-team commented on Apr 11, 2026

github-actions commented on Jul 14, 2026

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