From 6ba45a0006b30cb5285b32ad8a9593854011def2 Mon Sep 17 00:00:00 2001 From: Peter Hutterer Date: Thu, 6 Mar 2014 12:38:47 +1000 Subject: [PATCH] Add a documentation note to update the slot after syncing Clients may not care about the events generated during SYN_DROPPED, but the current slot must be updated to avoid a client being out-of-date. Same with tracking IDs, if they changed, the caller will likely have to update some internal states. Signed-off-by: Peter Hutterer Reviewed-by: Benjamin Tissoires --- libevdev/libevdev.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libevdev/libevdev.h b/libevdev/libevdev.h index 6920a76..481e378 100644 --- a/libevdev/libevdev.h +++ b/libevdev/libevdev.h @@ -707,7 +707,11 @@ enum libevdev_read_status { * If a device needs to be synced by the caller but the caller does not call * with the @ref LIBEVDEV_READ_FLAG_SYNC flag set, all events from the diff are * dropped after libevdev updates its internal state and event processing - * continues as normal. + * continues as normal. Note that the current slot and the state of touch + * points may have updated during the SYN_DROPPED event, it is strongly + * recommended that a caller ignoring all sync events calls + * libevdev_get_current_slot() and checks the ABS_MT_TRACKING_ID values for + * all slots. * * If a device has changed state without events being enqueued in libevdev, * e.g. after changing the file descriptor, use the @ref