Crate openlogi_hook 

OS-level mouse-event hook for OpenLogi.

Platform	Implementation
macOS	CGEventTap (same primitive used by Logi Options+)
Linux	evdev grab + uinput re-injection
Windows	WH_MOUSE_LL low-level mouse hook (motion is edge-clamped)

Usage

use openlogi_hook::{Hook, MouseEvent, EventDisposition};

if !Hook::has_accessibility() {
    eprintln!("grant Accessibility access first");
    return;
}

let hook = Hook::start(|event| {
    println!("{event:?}");
    EventDisposition::PassThrough
}).unwrap();

// … later, on shutdown:
hook.stop();

Structs

CursorPosition

Cursor position in the operating system’s global screen coordinate space, scaled so it lines up with GPUI’s own logical (DIP) display bounds — the Windows backend divides physical GetCursorPos pixels by the cursor’s monitor DPI scale to match; macOS CGEvent points and Linux root-window coordinates are already resolution-independent.

EventDevice

Best-effort identity for the physical device that produced an OS event.

EventTapInfo

A live event tap installed somewhere in the system, as reported by Hook::list_event_taps. Read-only diagnostic snapshot — enumerating taps needs no Accessibility grant and any process in the session sees them all.

ForegroundApp

One application, named the way a per-app profile names it.

ForegroundApplicationObserver

RAII owner of the current platform’s foreground-application observer.

Hook

A running OS-level mouse hook. Call Hook::stop to tear down.

KeyEvent

A keyboard event observed by the hook.

KeyModifiers

Which modifier keys were held when a key event fired — the same type a KeyTrigger is written with, so an event’s modifiers compare against a binding’s without a conversion. Detectable modifier state: what a keyboard trigger requires, and what the OS hook reports with each key event (openlogi-hook re-exports this type). Fn is absent: firmware-internal, never reported on non-function-row keys, and so unusable as a trigger (function-key-remapper spec, Appendix A).

PointerContext

Application identity and native window captured by one pointer lookup.

Enums

ButtonId

One of the user-rebindable controls on a Logi device: a mouse hotspot, or a keyboard key addressed by its HID++ 0x1b04 control ID.

EventDisposition

What the hook callback wants the OS to do with the captured event.

ForegroundApplicationObserverError

Failure to install or operate a native foreground-application observer.

HookError

Errors that Hook::start and related functions can produce.

HookEvent

Anything the OS hook can observe. Mouse preserves the existing callback payload; Key is the keyboard path added by the function-key remapper. Wrapping both in a union means Hook::start’s callback widens once and stays stable as further event classes arrive.

MouseEvent

An event captured at the OS layer.

PointerTarget

Native window identity under the pointer, or an explicit non-window outcome.

ScrollDelta

A signed two-axis scroll distance with an explicit unit.

TapLocation

Where in the event stream a tap is inserted (macOS CGEventTapLocation).

Constants

LOGITECH_VENDOR_ID

Logitech’s USB/Bluetooth vendor id (0x046D), widened from openlogi_core::hid::LOGITECH_VENDOR_ID because the hook’s identity sources (IOKit, evdev) hand it back as a u32.

SOFTWARE_SCROLL_INVERSION

Whether this platform can invert the wheel in software.

Functions

cursor_position

Return the current global cursor position without installing an input hook.

frontmost_application

Return the currently frontmost application.

frontmost_safari_pid

Return the Safari process captured by the latest macOS foreground-app observation without querying AppKit on the caller’s thread.

pointer_context

Query the window currently under the pointer, without activating anything.

pointer_context_supported

Whether this session has a pointer-window backend; does not probe permissions or connect to the window server. Unsupported Wayland never falls back to X11.

pointer_target_is_focused

Verify that this exact window, not merely another window of its application, is focused now. Returns false on any lookup failure or non-window target.

scroll_inversion

Whether set_scroll_inversion is currently on.

set_scroll_inversion

Turn software scroll inversion on or off for the captured pointers.

source_is_remappable

Whether the OS hook may suppress/remap a button event from this source.

watch_frontmost_application_changes

Observe native foreground-application changes.