path: root/doc
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authorPeter Hutterer <>2015-12-15 08:39:56 +1000
committerPeter Hutterer <>2016-01-11 15:17:46 +1000
commit1a99977ca027962824cc93be851508c5eeee19d5 (patch)
tree689039a2381fba4e171c6935bbfa5b6256be7f3d /doc
parent96fbf848625c0fb2eb53bd7e55664a96155c46ed (diff)
tablet: a tip event can replace an axis event
When we're only dealing with BTN_TOUCH we can make the tip event independent of the axis event. Now that we handle pressure thresholds to trigger tip state this does not work, we'd have to send an axis event with the new pressure and then a tip event. Since the pressure triggers the tip event this seems disconnected. Make the tip event officially capable of carrying axes. A caller can then decide how to forward this to the next layer. Signed-off-by: Peter Hutterer <> Acked-by: Jason Gerecke <>
Diffstat (limited to 'doc')
1 files changed, 2 insertions, 1 deletions
diff --git a/doc/tablet-support.dox b/doc/tablet-support.dox
index 5e6f3932..7207a473 100644
--- a/doc/tablet-support.dox
+++ b/doc/tablet-support.dox
@@ -45,7 +45,8 @@ pressure value while the tip is logically up. Most application can and
should ignore pressure information until they receive the event of type @ref
LIBINPUT_EVENT_TABLET_TOOL_TIP. Applications that require extremely
fine-grained pressure sensitivity should use the pressure data instead of
-the tip events.
+the tip events to determine a logical tip down state and treat the tip
+events like axis events otherwise.
Note that the pressure threshold to trigger a logical tip event may be zero
on some devices. On tools without pressure sensitivity, determining when a