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cbd4f35442
This is a large commit because it's difficult to split this up and we don't care about bisecting here anyway. doxygen is going to produce the API documentation only sphinx is going to produce the prose user (and a bit of developer) documentation. The source split is doc/api and doc/user. Steps performed: - run the doxygen-to-sphinx.sh script to convert all .dox sources to .rst - manually fixed the .rst to render correctly - add a few extra .rst documents to generate the right hierarchy - hook up sphinx-build in meson - add a new @mainpage for doxygen more aimed at developers For the build directory: - sphinx produces /Documentation - doxygen now produces /api/ These need to be manually combined in the wayland-web repo, meson doesn't support subdirectories as output paths within the build dir and the documentation doesn't need to be installed anywhere. Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
85 lines
3.6 KiB
ReStructuredText
85 lines
3.6 KiB
ReStructuredText
.. _seats:
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==============================================================================
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Seats
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==============================================================================
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Each device in libinput is assigned to one seat.
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A seat has two identifiers, the physical name and the logical name. The
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physical name is summarized as the list of devices a process on the same
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physical seat has access to. The logical seat name is the seat name for a
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logical group of devices. A compositor may use that to create additional
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seats as independent device sets. Alternatively, a compositor may limit
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itself to a single logical seat, leaving a second compositor to manage
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devices on the other logical seats.
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.. _seats_overview:
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------------------------------------------------------------------------------
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Overview
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------------------------------------------------------------------------------
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Below is an illustration of how physical seats and logical seats interact:
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.. graphviz:: seats-sketch.gv
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The devices "Foo", "Bar" and "Spam" share the same physical seat and are
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thus available in the same libinput context. Only "Foo" and "Bar" share the
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same logical seat. The device "Egg" is not available in the libinput context
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associated with the physical seat 0.
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The above graph is for illustration purposes only. In libinput, a struct
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**libinput_seat** comprises both physical seat and logical seat. From a
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caller's point-of-view the above device layout is presented as:
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.. graphviz:: seats-sketch-libinput.gv
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Thus, devices "Foo" and "Bar" both reference the same struct
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**libinput_seat**, all other devices reference their own respective seats.
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.. _seats_and_features:
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------------------------------------------------------------------------------
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The effect of seat assignment
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------------------------------------------------------------------------------
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A logical set is interpreted as a group of devices that usually belong to a
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single user that interacts with a computer. Thus, the devices are
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semantically related. This means for devices within the same logical seat:
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- if the same button is pressed on different devices, the button should only
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be considered logically pressed once.
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- if the same button is released on one device, the button should be
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considered logically down if still down on another device.
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- if two different buttons or keys are pressed on different devices, the
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logical state is that of both buttons/keys down.
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- if a button is pressed on one device and another device moves, this should
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count as dragging.
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- if two touches are down on different devices, the logical state is that of
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two touches down.
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libinput provides functions to aid with the above:
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**libinput_event_pointer_get_seat_button_count()**,
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**libinput_event_keyboard_get_seat_key_count()**, and
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**libinput_event_touch_get_seat_slot()**.
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Internally, libinput counts devices within the same logical seat as related.
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Cross-device features only activate if all required devices are in the same
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logical seat. For example, libinput will only activate the top software
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buttons (see :ref:`t440_support`) if both trackstick and touchpad are assigned
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to the same logical seat.
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.. _changing_seats:
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------------------------------------------------------------------------------
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Changing seats
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------------------------------------------------------------------------------
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A device may change the logical seat it is assigned to at runtime with
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**libinput_device_set_seat_logical_name()**. The physical seat is immutable and
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may not be changed.
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Changing the logical seat for a device is equivalent to unplugging the
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device and plugging it back in with the new logical seat. No device state
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carries over across a logical seat change.
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