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Firefox skips key events

  • 3 پاسخ
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  • آخرین پاسخ توسّط !evil

!evil
!evil
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Hi,

I'm on Arch Linux and use uinput to create key events. It works reliably for >12months in all applications and under all circumstances except in Firefox where some key events are skipped non-deterministically. My test case is:

in a text field, emit `<ctrl down>a<ctrl up>123456789987654321<left>...<left>` with 9 times `<left>`. Sometimes a 9 is missing and sometimes the cursor is further to the right than expected.

This happens every 8th try or so, which is too frequent to not break the user experience.

What I have tried: - multiple PCs (2 with this issue and 1 without) - Troubleshoot Mode - `window.onkeydown=(e)=>console.log(e)` (events are missing)

Since I've only ever seen repeated characters/keys disappear and never when writing manually, I would guess there is some kind of event cleanup algorithm kicking in. (the events are emitted without any delays)

I would really like to fix this issue because Firefox is my favorite browser. Any idea how to track it down?

Maybe related: https://support.mozilla.org/en-US/questions/1363234

Hi, I'm on Arch Linux and use uinput to create key events. It works reliably for >12months in all applications and under all circumstances except in Firefox where some key events are skipped non-deterministically. My test case is: in a text field, emit `<ctrl down>a<ctrl up><del>123456789987654321<left>...<left>` with 9 times `<left>`. Sometimes a 9 is missing and sometimes the cursor is further to the right than expected. This happens every 8th try or so, which is too frequent to not break the user experience. What I have tried: - multiple PCs (2 with this issue and 1 without) - Troubleshoot Mode - `window.onkeydown=(e)=>console.log(e)` (events are missing) Since I've only ever seen repeated characters/keys disappear and never when writing manually, I would guess there is some kind of event cleanup algorithm kicking in. (the events are emitted without any delays) I would really like to fix this issue because Firefox is my favorite browser. Any idea how to track it down? Maybe related: https://support.mozilla.org/en-US/questions/1363234

All Replies (3)

!evil
!evil Question owner
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after `<ctrl up>` there is a `<d e l>`

Helpful?

zeroknight
zeroknight
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X11 or Wayland? Does setting the environment variable MOZ_ENABLE_WAYLAND=1 make any difference?

This is a good site for testing: https://w3c.github.io/uievents/tools/key-event-viewer.html

Helpful?

!evil
!evil Question owner
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Thanks for the reply! Its Wayland and MOZ_ENABLE_WAYLAND=1 doesn't.

The event viewer showed that keydown are missing (two keyup back to back). I've did some more testing:

- if JS is idle, I can't reproduce - if JS is busy, it happens ever so often (I created a minimal page with a busy loop on "input" of the input element) - it really only affects consecutive events of the same key. For instance, emitting 12121212112121212121 only hicks up exactly at 11 (one of them ends up missing)

Btw, can't reproduce in Chrome

Helpful?

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