Stylus doesn't trigger PointerDownEvent

[RimaitosLab]

The main problem

When you use a stylus as an input device, sometimes a PointerDownEvent gets triggered and then for the next 5-30sec the application doesn't handle any pointer inputs(it probably just freezes). Then I get a notice from the system that the app isn't responding and in that moment everything works as it should. The Problem then only reoccurs after you restart the Application.

Note: As long as I don't use the stylus everything works fine.

The main strange thing about this is that it only happens sometimes.

The second problem

When I press the button on my SPen and then touch the display, no pointer down events are triggered at all.

Steps to Reproduce

1. Create a new Flutter Project and paste the content of the test application into main.dart (https://pastebin.com/PDuDVFQU)
2. Load the application onto your test device
3. Run the app (It seems to me, that this problem occurs with a higher probability if the data of the app is deleted beforehand, and the app is started from the device itself)

Target Platform: Android
Target OS version: 9
Devices: Samsung tab S4 (SM T830); Samsung Tab S3 (SM T820)

It seems like the problem occurs more frequently on the S4. But this could also be my imagination.

Logs

Log file: https://pastebin.com/9GFaVMUq
In line 1278 it says I didn't do anything for 20711 ms even though I instantly put the pen down again after I lifted it.

Flutter analyze doesn't return any issues (after you remove the curly brackets in the Strings which don't affect the problem)

[✓] Flutter (Channel beta, v1.10.7, on Linux, locale en_US.UTF-8)
    • Flutter version 1.10.7 at
      /home/ich/programming-libraries/flutter-sdk/flutter
    • Framework revision e70236e36c (2 weeks ago), 2019-10-02 09:32:30 -0700
    • Engine revision 9e6314d348
    • Dart version 2.6.0 (build 2.6.0-dev.4.0 1103600280)

 
[!] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at /home/ich/Android/Sdk
    • Android NDK location not configured (optional; useful for native profiling
      support)
    • Platform android-28, build-tools 28.0.3
    • Java binary at:
      /home/ich/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/191.59002
      03/jre/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_202-release-1483-b49-5587405)
    ! Some Android licenses not accepted.  To resolve this, run: flutter doctor
      --android-licenses

[!] Android Studio (version 3.5)
    • Android Studio at
      /home/ich/.local/share/JetBrains/Toolbox/apps/AndroidStudio/ch-0/191.59002
      03
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
    • Java version OpenJDK Runtime Environment (build
      1.8.0_202-release-1483-b49-5587405)

[!] VS Code (version 1.39.1)
    • VS Code at /usr/share/code
    ✗ Flutter extension not installed; install from
      https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[✓] Connected device (1 available)
    • SM T830                   • ce11182b6346556a1c7e • android-arm64 • Android
      9 (API 28)


! Doctor found issues in 3 categories.

Note: The doctor is wrong. I don't use VSCode and AndroidStudio is up to date with version 3.5.1

Thanks in advance for your help.

• Rimaito

[goderbauer]

/cc @dkwingsmt

[RimaitosLab]

Is this issue still being processed, or was it forgotten?
The Problem still exists as far as I can tell, and I would appreciate it if you would a least tell me whether it is my fault or an error in flutter.

[dkwingsmt]

Sorry, I did forget this issue. Thanks for the reminder.

I'll try to find a device to reproduce this issue.

[RimaitosLab]

Is there any update on this issue?

[RimaitosLab]

Just as a side note, this issue still seems to exist, and it has been 2 months since the last answer. I would like to know what the sate of this issue is...

[iapicca]

Hi @RimaitosLab
are you still experiencing the issue with the latest stable or above?
Thank you

[RimaitosLab]

I just tried the given example and at least on the Samsung tab S4 (SM T830), the behaviour hasn't changed. I haven't tested it on other devices yet.
The issue still doesn't appear consistently but out of 5 restarts, it froze 3 times.

flutter doctor output:

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel master, 1.20.0-3.0.pre.163, on Linux, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
[✓] Android Studio (version 4.0)
[✓] Connected device (1 available)

• No issues found!

Best Regards!

[iapicca]

I’m unable to reproduce the issue to pinpoint the cause. The issue needs further investigation.

[dkwingsmt]

@iapicca I suspect this issue only exists on certain device.

[iapicca]

@RimaitosLab
I see a PR landed in 1.22 to fix #67869
are you still experiencing the issue with the lasted stable?

tagging @TahaTesser for visibility

[RimaitosLab]

It took me almost 15min to be able to reproduce the issue again. Both issues still exist.

This time while testing I enabled "Pointer location" in the developer options of android. This lead to the discovery that the whole system doesn't register any pointer events in the timespan.

I still cannot reproduce this issue reliably. I just try it a few times (many few times) and wait till it occurs.

If there is anything I could provide to help to solve this issue, please let me know.

[wanjm]

I also come across this problem, use hand first , everything works well then . If i use pen first, then app blocked;

write a simple app to catch move event, will trigger this easier;

[wanjm]

bugreport-MRX-W29-HUAWEIMRX-W29-2021-01-15-20-18-51.zip
attaced is the log when app no respond;

[Y0ngg4n]

I could reproduce the second issue.

[wanjm]

many users use android pad + stylus now. more any more people come across such problem

[Teages]

The second issues is still exist on my test with Samsung Tab S6.

I use the example code of Listener for test.

1. Hover and press the eraser button: works well, PointerEvent.buttons == 2, console log:

I/ViewRootImpl( 4205): updatePointerIcon pointerType = 20001, calling pid = 4205
D/InputManager( 4205): setPointerIconType defaultIconType = 20001, callingPid = 4205

2. then, touch the screen with stylus, but not release the eraser button. The position frozen, and the Listener can not catch any event, console log:

I/[DWTE]  ( 4205): onPenEvent no editText
I/ViewRootImpl@ca24f60[MainActivity]( 4205): ViewPostIme pointer 0
I/ViewRootImpl( 4205): updatePointerIcon pointerType = 20001, calling pid = 4205
D/InputManager( 4205): setPointerIconType defaultIconType = 20001, callingPid = 4205

3. leave the screen, console log:

I/ViewRootImpl@ca24f60[MainActivity]( 4205): ViewPostIme pointer 1
I/ViewRootImpl( 4205): updatePointerIcon pointerType = 20001, calling pid = 4205
D/InputManager( 4205): setPointerIconType defaultIconType = 20001, callingPid = 4205

---

If I swap the sequence of operations, it works well

1. Hover but not press the eraser button
2. touch the screen with stylus, then hold the eraser button, The value of PointerEvent.buttons changed from 1 to 2. the position is still updating.

---

Well, give up the function like temporary eraser is easy, but when the users try to use the eraser like they did in Samsung Notes or other software but it doesn't work, they will get confused or even angry. So I hope this issue can be solve properly

[Marc-R2]

For me, this problem occurs as well.
A test app on my Galaxy Tab S7 (Android 12) detects the stylus itself when it hovers over the screen and when it touches the touchscreen.
When the function key is pressed, the stylus is also recognized as a stylus with pressed function key when hovering over the screen. However, as soon as I touch the touchscreen with the function key pressed, the PointerMoveEvents do not update and there is no PointerDownEvent.
Unfortunately I can't say more about this at the moment.

The previously mentioned bug, which caused the app to crash when touched with the stylus key pressed, has just been fixed.

[Nuckerr]

I just upgraded to master channel, the app no longer crashes when I press with the S-Pen with the side button pressed, however none of my tap functions work with gesture detectors etc.

[keev-LIM]

I just upgraded to master channel, the app no longer crashes when I press with the S-Pen with the side button pressed, however none of my tap functions work with gesture detectors etc.

I'm too

[WasteOfO2]

Although the issue with crashes has been fixed, the S Pen buttons still don't seem to work

Seeing the variety of devices reporting this, it is probably a Samsung-wide issue.

Tested on Samsung Galaxy Tab S6 Lite with the same result, dysfunctional S Pen buttons

[georgkrause]

I can confirm that the stylus button is not working on Galaxy Tab S6 Lite. If more debug information is needed, let me know!

[Iey4iej3]

Not working on Samsung S6 Lite under Lineage OS 20 as well.

[ceskyDJ]

The same problem is on Samsung Galaxy Tab S8.

[jaween]

I can confirm that the method posted by @Teagas still reproduces "the second problem" of this issue. I am using the latest Flutter stable with a Galaxy Tab S6 Lite and an S-Pen.

Scenario which fails:

1. Hold down the stylus button
2. Contact the screen
   (observe no pointer down/move events propagated to the app)
3. Remove the contact
   (observe no pointer up event propagated to the app)

Steps 2 and 3 should have had pointer events received by the app.

Scenario which succeeds:

1. Contact the screen
   (observe pointer down/move events received by the app)
2. Hold down the stylus button
   (observe pointer move events continue to be received by the app)
3. Release the contact
   (observe pointer up event received by the app)

Note, in the scenario that succeeds (and when the stylus is just hovering above the screen), the stylus button itself correctly appears in the PointerEvent.buttons bitmask as kPrimaryStylusButton. The problem is pressing the button before contacting the screen seems to disable all pointer events for this gesture.

Flutter doctor output

[✓] Flutter (Channel stable, 3.10.6, on Ubuntu 22.04.2 LTS 6.2.0-26-generic,
    locale en_AU.UTF-8)
    • Flutter version 3.10.6 on channel stable at /opt/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision f468f3366c (5 weeks ago), 2023-07-12 15:19:05 -0700
    • Engine revision cdbeda788a
    • Dart version 3.0.6
    • DevTools version 2.23.1

[!] Android toolchain - develop for Android devices (Android SDK version 33.0.2)
    • Android SDK at /home/jaween/Android/Sdk
    • Platform android-33-ext5, build-tools 33.0.2
    • Java binary at: /opt/android-studio/jbr/bin/java
    • Java version OpenJDK Runtime Environment (build
      11.0.15+0-b2043.56-8887301)
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/linux#android-setup for
      more details.

[✗] Chrome - develop for the web (Cannot find Chrome executable at
    google-chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[✓] Linux toolchain - develop for Linux desktop
    • Ubuntu clang version 14.0.0-1ubuntu1.1
    • cmake version 3.22.1
    • ninja version 1.10.1
    • pkg-config version 0.29.2

[✓] Android Studio (version 2022.1)
    • Android Studio at /opt/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
      11.0.15+0-b2043.56-8887301)

[✓] VS Code (version 1.81.0)
    • VS Code at /usr/share/code
    • Flutter extension version 3.70.0

[✓] Connected device (2 available)
    • SM P610 (mobile) • R52N70B0XPN • android-arm64 • Android 13 (API 33)
    • Linux (desktop)  • linux       • linux-x64     • Ubuntu 22.04.2 LTS
      8.2.0-26-generic

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

! Doctor found issues in 2 categories.

[tangclue]

is there any update? I have same problem. Is there any update plan?

[Italo-ols]

I am having the same issue on an app that is built using flutter on my Galaxy tab s6 lite (Android 13).

[raffaem]

Any news on this? This is affecting Saber and Butterfly as well.

[gggirlgeek]

samsung tab s8 plus:
Same eraser button issue for me.

Thank you @Teases: for the tip to workaround the issue by pressing the button after holding the tip down on the screen. It's usable but not intuitive. You're awesome.