skyjake/lagrange Issue #493: External scrolling devices doesn't work on the iPad Pro

2022-05-06 14:33:33 necopinus

Lagrange on iPadOS doesn't seem to detect / work with external scrolling devices. Scrolling using the keyboard or by dragging the page (either with a finger or with click-and-drag) works, but neither scroll wheels nor two fingered scrolling using the iPad Pro Magic Keyboard works.

Tested on 15.4.1 with Lagrange 1.12 (2) 2022-04-05. Tested devices:

• iPad Pro Magic Keyboard (1st Gen)
• Logitech MX Ergo Trackball

For all devices, scrolling works as expected in all other apps. Lagrange on the desktop seems to work fine.

• Might* be the same issue as #301, though that seems to have resolved itself for the author.

Comments (4)

2022-05-07 03:05:34 skyjake

I think these external devices either don't produce input events via SDL, or if they now do, I'm not handling them.

It could be worth adding native iOS code to handle these input events directly. I already have some of this code on macOS for scroll events.

2024-06-01 14:01:49 antanst

Can confirm this still happens in latest iOS testflight version 1.17 (9)

2025-09-23 15:23:37 dariolob

Came here to open an issue for this, but noticed I wasn't the first. External devices still can't control scrolling as of now (Logitech Combo Touch - latest TestFlight build [1.19 (6)]

Thanks @skyjake for all the effort you put into Lagrange :)

2025-09-24 08:14:01 skyjake

I investigated this for a while, but couldn't get it working. This may be a case where SDL2 isn't quite up to the challenge and some custom input event handling will be required, or I just didn't find the right combination of hints/settings.