Terminal doesn't respect trackpad inertia

[citelao]

Windows Terminal version

1.23.12681.0

Windows build number

10.0.26504.0 (ge_current_directwinai.251006-1819)

Other Software

No response

Steps to reproduce

On a recent build (later than Sept 2024's Beta KB5043166):

1. Begin scrolling with a trackpad, so there is inertia.
2. Press Ctrl.

The window zooms uncontrollably.

Expected Behavior

It's undocumented, but we made a change to the trackpad handler to cancel inertia upon keypresses (internal link).

Scrolling should stop & no zooming should occur.

Actual Behavior

However, Terminal seems to be handling scrolling differently and still seems to maintain this inertia.

---

BTW, this would have mitigated #5708 and similar.

[DHowett]

So! Terminal receives all scrolling as mouse wheel events (actually pointer wheel events, but who's counting?) through XAML. We subscribe to the standard PointerWheelChanged event, and only when we receive it do we actually do anything with it.

We aren't tracking inertia or accumulating wheel deltas over time. We're also not using DirectManipulation.

We may need to file a bug on the System XAML folks.

[citelao]

Oh goodness! This indeed reproes in WinUI Gallery:

1. On the ScrollView page (e.g.), scroll with a trackpad.
2. Press Ctrl.

Inertia doesn't stop.

Do we want to file this internally or externally?

[DHowett]

Weeellll... probably get the same response either way. I think Externally, but considering that Terminal is on WinUI 2 (rather than WinAppSDK/WinUI 3) both may be warranted. 🙂

[citelao]

Filed: microsoft/microsoft-ui-xaml#10830

[DHowett]

Thank you, @citelao! I'm gonna close this one out as a remote duplicate for now.