ion.app.input

This module exposes the input devices the compositor currently knows about, one collection per kind. Each collection is a live view: devices appear and disappear as hardware is plugged and unplugged, so a device is looked up when it is needed rather than stored at config load.

Device handles

A device object is a handle that re-resolves on every access, not a snapshot. Holding one past the device’s removal is safe - is_valid reports the device is gone, and any other access raises. Two handles to one device compare equal and hash alike, so a device works as a dictionary key.

Looking a device up

A collection is indexed by name, by zero-based index (negative indices count from the end), or by slice, which yields a tuple. active is the device that most recently produced input, which is the one to reach for when responding to an event.

Names are unique within a collection: a device reporting a name already taken gets a .1, .2 … suffix. Which of two identical devices gets it follows the order they were added, which can change between sessions; port_id tells them apart when they are plugged into different ports.

One seat

Every device drives the same seat: there is one keyboard focus, one pointer and one clipboard for the session, whatever is plugged in. The collections enumerate devices rather than seats, so a second keyboard is another way to drive the one focus, not a focus of its own. The keyboard layout follows whichever device was last used, which is what active reports.

Settings and defaults

Writing a setting on a device changes only that device. On the active device the change reaches the seat when the current callback returns; on any other it is stored and applied when that device next becomes active. The matching ion.app.preferences.input defaults apply to every device of that kind, and writing one discards the per-device values, so declare the defaults first and override individual devices after.

import ion

for keyboard in ion.app.input.keyboards:
    print(keyboard.name, keyboard.layout)

Input device state.

Data

ion.app.input.keyboards

Collection of keyboard devices accessible as ion.app.input.keyboards.

Type:

ion.types.KeyboardCollection

ion.app.input.pointers

Collection of pointer devices accessible as ion.app.input.pointers.

Type:

ion.types.PointerCollection

ion.app.input.tablets

Collection of tablet devices accessible as ion.app.input.tablets.

Type:

ion.types.TabletCollection