Karabiner-elements: FingerStatusManager.m: MultitouchExtension Ignored area detection is inconsistent

[aerobounce]

Env

• macOS 10.15.1 (19B88)
• MacBook Pro (15-inch, 2016)
• Karabiner 12.7.0

Steps to reproduce

1. Set whatever number to Ignored areas in Karabiner-MultitouchExtension
2. Touch ignored area repeatedly and you will find at some point, touch condition indicates that it is not ignored (Red coloured).

Points

• Seemingly, amount of ignored area of each side is not the key. Whatever it is, it works inconsistently.
• Ignore detection sometime works, sometimes not. Inconsistent.
• Not certain, but if touched point is at the edge of rect, more likely it will fail to ignore touch even the touched location is in ignored area.

Supposedly responsible file / method

https://github.com/pqrs-org/Karabiner-Elements/blob/b174d1e4274f9271a5b24fde1cf640305b12144a/src/apps/MultitouchExtension/src/FingerStatusManager.m#L35-L40

Problem

Karabiner organically blocks original key press event if the app has rules that utilizes multitouch-count. So when _touch-detection_ is not what a user is intended, that is quite annoying.

In my case

I use MacBook Pro the one with large trackpad.
When I'm typing, usually part of my palm is touching trackpad.

I have set T + 1 touch == CMD + T.
You know what will happen.
A new tab is opened when I type T when I'm not intended so. :(

[aerobounce]

And If I remember correctly, KeyRemap4MacBook and old Karabiner had the same bug.

[tekezo]

I confirmed this issue.
I'll investigate the detail of cause. Please wait for a while.

[tekezo]

I fixed this issue at the latest beta version (v12.7.4).
Please confirm it.

How to upgrade Karabiner-Elements to the latest beta version:
https://pqrs.org/osx/karabiner/document.html#check-for-updates

[aerobounce]

I appreciate your work @tekezo. 👍🏻 And wow that was quick!

I've installed v12.7.4 and so far, at least the bug is no more reproducible in Karabiner-MultitouchExtension app.
Let give me sometime to confirm that it is also okay in practice use / everyday use. I use multitouch rules intensively so it suppose won't take much time.

[aerobounce]

So it's been 2 or 3 days since I've installed v12.7.4 which includes fix for this issue. Tested on my MacBook Pro and on a machine at work too.

In a word, ROBUST 💪🏻.
I've had no mis-detection! NOT EVEN ONCE. 👍🏻

I'm sure this issue is fixed now. Thanks again, @tekezo !
I'm closing this issue now.

[tekezo]

Thank you for confirmation!