DevicePresenceNotify event. This event is sent when the list of
input devices changes, in which case devchange will be false, and
no information about the change will be contained in the event;
the client should use XListInputDevices() to learn what has changed.
If devchange is true, an attribute that the server believes is
important has changed on a device, and the client should use
XGetDeviceControl to examine the device. If control is non-zero,
then that control has changed meaningfully.
DevicePresenceNotify event. This event is sent when the list of input devices changes, in which case devchange will be false, and no information about the change will be contained in the event; the client should use XListInputDevices() to learn what has changed.
If devchange is true, an attribute that the server believes is important has changed on a device, and the client should use XGetDeviceControl to examine the device. If control is non-zero, then that control has changed meaningfully.