Frequently asked questions about libinput.
My mouse moves too fast, even at the slowest setting
This is a symptom of high-dpi mice (greater than 1000dpi). These devices need a udev hwdb entry to normalize their motion. See Normalization of relative motion for a detailed explanation.
Kinetic scrolling does not work
The X.Org synaptics driver implemented kinetic scrolling in the driver. It measures the scroll speed and once the finger leaves the touchpad the driver keeps sending scroll events for a predetermined time. This effectively provides for kinetic scrolling without client support but triggers an unfixable bug: the client cannot know that the events are from a kinetic scroll source. Scroll events in X are always sent to the current cursor position, a movement of the cursor after lifting the finger will send the kinetic scroll events to the new client, something the user does not usually expect. A key event during the kinetic scroll procedure causes side-effects such as triggering zoom.
libinput does not implement kinetic scrolling for touchpads. Instead it provides the libinput_event_pointer_get_axis_source() function that enables callers to implement kinetic scrolling on a per-widget basis, see Scroll sources.
Is libinput GPL-licensed?
No, libinput is MIT licensed. The Linux kernel header file linux/input.h in libinput's tree is provided to ensure the same behavior regardless of which kernel version libinput is built on. It does not make libinput GPL-licensed.
Where is the configuration stored?
libinput does not store configuration options, it is up to the caller to manage these and decide which configuration option to apply to each device. This must be done at startup, after a resume and whenever a new device is detected.
In a GNOME X.Org stack a user would usually toggle an option in the gnome-control-center which adjusts a gsettings entry. That change is picked up by gnome-settings-daemon and applied to the device by adjusting input device properties that the xf86-input-libinput driver provides. The input device property changes map to the respective libinput configuration options.
This has an effect on the availability of configuration options: if an option is not exposed by the intermediary, it cannot be configured by the client. Also some configuration options that are provided by the intermediary may not be libinput-specific configuration options.
