fdo-mirrors/xorg-xorgproto
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/xorg/proto/xorgproto.git synced 2026-05-07 03:48:00 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

specs: rewrite pointer emulation section

Browse source 
plus a fixme

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
This commit is contained in:
Peter Hutterer 2011-03-18 16:17:09 +10:00
parent 15e76dd365
commit ed840d79d3
1 changed files with 47 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

80
specs/XI2proto.txt
View file

@ -449,51 +449,65 @@ withheld.
5.3.2 Pointer emulation for direct touch devices
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In order to facilitate backwards compatibility with legacy clients, direct touch
devices will emulate pointer events. Pointer emulation events will only be
delivered through the attached master device; no pointer events will be emulated
for floating touch devices. Further, only one touch from any attached slave
direct touch device may be emulated per master device at any time.
Touch sequences from direct touch devices may emulation pointer events. Only
one touch sequence from a device may emulate pointer events at a time. Which
touch sequence emulates pointer events is implementation dependent.
FIXME:
Pointer emulation events will only be delivered through the attached
master device; no pointer events will be emulated for floating touch
devices.
why?
Pointer events are emulated as follows:
* Touch begin events generate a pointer motion event to the location of the
- TouchBegin events generate a pointer motion event to the location of the
touch, followed by a button press event for button 1.
* Touch update events generate a pointer motion event to update the location
- TouchUpdate events generate a pointer motion event to update the location
of the touch.
* Touch end events generate a pointer motion event to the location of the touch
- TouchEnd events generate a pointer motion event to the location of the touch
if the touch has moved, followed by a button release event for button 1.
A touch sequence may only be owned by one client at a time. When pointer events
are emulated from a touch sequence and delivered through a pointer grab, the
grabbing client implicitly becomes the owner of the touch sequence.
If a touch sequence emulates pointer events and an emulated pointer event
triggers the activation of a passive grab, the grabbing client becomes the
owner of this touch sequence.
A pointer grabbing client is considered to have accepted ownership of the touch
sequence when the following occurs:
The touch sequences is considered to have been accepted if
* The emulated button press event is delivered through an asynchronous grab.
* The emulated button press event is delivered through a synchronous grab and
further events are allowed through to the grabbing client.
* The emulated button press event is delivered through a synchronous grab and
then the grab is deactivated without replaying the button press event.
- the grab mode is asynchronous, or
- the grab mode is synchronous and the device is thawed as a result of
AllowEvents with any mode but ReplayPointer or ReplayDevice, or
- the grab mode is synchronous and the device remains frozen as a result of
AllowEvents with mode SyncPointer or SyncDevice
Touch and pointer grabs are mutually exclusive. For a given window, any touch
grab is activated first. If there is no touch grab or the touch grab is
rejected, any pointer grab is activated. If there is a pointer grab and the
grabbing client accepts ownership of the touch sequence as outlined above, the
touch sequence is ended for all other clients listening for touch events.
Otherwise, if there is no pointer grab or the grabbing client replays the
pointer events without accepting the touch sequence, the next window in the
window set is checked for grabs.
Otherwise, if the button press is replayed by the client, the touch sequence
is considered to be rejected.
If the touch sequence is not accepted by any client through a grab, the touch
and emulated pointer events may be delivered to a client selecting for them.
Event propagation for the touch sequence ends at the first client selecting for
touch or pointer events. If a window has both touch and pointer event
selections, only the touch events will be delivered.
Touch event delivery precedes pointer event delivery. A touch event event
emulating pointer events is delivered
Both the emulated pointer events and their associated touch events will have the
PointerEmulated flag set.
- as a touch event to the top-most window of the current window set if a
client has a touch grab on this window
- otherwise, as a pointer event to the top-most window of the current window
set if a client has a pointer grab on this window,
- otherwise, to the next window in the window set as in the same order as
until a grab has been found,
If no touch or pointer grab on any window was activated and the last window
in the window set has been reached, the event is delivered
- as a touch event to the window if a client has selected for touch events
on this window
- otherwise, as a pointer event to the window if a client has selected for
pointer events.
This sequence is repeated from the current window if the current owner of
the sequence rejects the sequence.
FIXME
Both the emulated pointer events and their associated touch events will
have the PointerEmulated flag set.
huh? we never get both events anyway
// ❧❧❧❧❧❧❧❧❧❧❧