This protocol is wayland-like though it uses a slightly different
message format. The XML file uses the same structure, except for the
"fixed" type which is "float" here.
The scanner uses a jinja template to generate source and header files
for ei and eis which are now used instead of the protobuf-generated
objects. Note that the scanner is a minimal working version, some
features like enum value checks are not yet implemented.
Unlike wayland we do not need to generate the libwayland-like library,
we only need the wire protocol parser - some shortcuts can thus be taken.
To keep the changes simple, the protocol currently is a flat protocol
with only one interface and all messages copied over from the previous
ei.proto file. In future commits, this will be moved to the respective
interfaces instead.
The check is currently missing from a number of libeis APIs but in most
cases we can blame the EIS implementation and say "don't do this".
Device removal is an exception since that is still required.
With the planned switch to a protocol supporting multiple interfaces
(a la wayland), a single version number is no longer useful. Remove this
API, we can add something more specific later if we need to.
This makes it easier to correlate a particular input transaction
(whether there are events or not) with out-of-band information like the
planned portal InputCapture::Activated signal's "activation-id".
The primary use-case for these properties in libei itself was to send
some fixed information (pid, cmdline and conection type). In the portal
case, these can be obtained out-of-band via the portal. In the
non-portal case these can be obtained from the socket itself (fetch pid,
look up /proc/pid/cmdline) which is just as reliable as trusting
whatever libei sends.
The only other use-case for the properties was the activation id in the
InputCapture::Activated portal signal. This can be achieved with a
serial in the START_EMULATING event.
libreis was intended for an intermediary to set some information that
the libei client cannot be entrusted with. In particular this was the
application name, the allowed capabilities, and some properties that -
once set - the client could no longer change (appid as probably the only
really useful one). The price for this was a rather complicated version
negotiation dance before the initial CONNECT request.
Now that we have a clear view of what's going to happen -
RemoteDesktop.ConnectToEIS and the InputCapture portal - there is no
longer any need for libreis. The extra information that libreis would've
sent is communicated out-of-band in both portals and are known to the
compositor at the time the connection is being established.
So we can simply drop this, it's no longer required and dropping it
makes the protocol significantly simpler anyway.
The default behaviour of a peck context is to handle the CONNECT event.
Let's disable that.
No effect on the test, the client cannot receive the connect event until
it's been accepted, but it's better form anyway.
libei used to have direct portal support code (see the git history) but:
- that code was a custom proposed portal that never went anywhere
- libei has slowly changed to be more an input event transport layer since
it is now also used sending events *to* a libei context
- a number of libei users will never need the DBus code, either because they
don't want it or because they talk Dbus themselves na ddon't need this
abstraction.
Luckily, it's quite easy to move this into a separate library with a
simple API that does, effectively, the same trick as the old portal backend.
This API is aiming to be as simple as possible because the tools that
require anything more complex should talk to DBus directly.
An example tool that uses the API to retrieve an EIS fd over the
RemoteDesktop portal is included in this patch.
"Öffis" is a German word meaning public transport. It also sounds like the
French Œuf, the word for egg.
Co-authored-by: Olivier Fourdan <ofourdan@redhat.com>
Let the client set the version number it wants on Connect. There is new
public API to query the client/server's version as set once the connect
finished (eis_client_get_version() and ei_get_version()) but there is
currently no public API for the client to select the version it actually
wants, other than whatever both support. IOW, it's not possible for the
client to say "I want version 8 but if that's not supported, use version
5".
For all but the simplest loggers, the current approach of "this is a
continuation of the previous message" doesn't work well. The caller
cannot know whether the *current* message is complete until it receives
the next message - but that message may never come.
Drop this approach, if we need to compile multiple messages into one,
we can handle this internally and then pass it all as one message to the
caller.
The basic set of functions and macros to have access to a libreis
context for our to-be-client.
Since we connect the ei context to a backend during peck_new(), we need
a new function for the case where we do want to have libreis in the
mix.
All we do here is decide whether the connect event gets handled, clients
are always effectively connected (i.e. the client does send the connect
request) since we set up the backend during init.
Incoming device events are now added to a device-internal queue. Once
the frame event comes in, that queue is shuffled over to the main event
queue. For libei/the EIS implementation this means that device events
are seen only once the frame event appears from the sender (or it is
emulated by other means).
Currently only implemented for frame events, the vague plan for the
future is to merely queue the device events internally and "release"
them once a frame event was received, retrofitting the timestamp to the
C event struct (i.e. making ei_event_get_time() available on all device
events).
Meanwhile, the frame event it is.
Because we're doing this per dispatch call (rather than a device state)
we need to ensure that the various tests gobble up all pending frame
events - the assert_no_events helpers do this.
If we only check for specific events, a frame event may still be pending
from one interaction. This causing the assertion to fail on the
subsequent dispatch call.
We only need frame events after device events (pointer, touch,
keyboard). In some cases, the library prevents an event from being
written to the wire, e.g. if the coordinates are out of region, but the
client will still call ei_device_frame() for that now-filtered event.
Keep a boolean to remember if we have sent something that requires a
frame event and filter accordingly.
Note that this currently filters the *sender* side only, not the
receiver side. A sender that gets an empty frame event onto the wire
will still get that into the other side.
This also doesn't handle the flushing of frame events before other
events, ideally we should enforce a frame event before e.g. stop
emulating.
Destroying a touch causes ei_touch_up if the touch is still down. But
for the event sequence to be correct we also need to add a frame event
here, otherwise the touch up may be "pending" on the remote until the
next actual event happens and a frame is added.
A client that doesn't want this should just call ei_touch_up()
Some of the behaviors we enable trigger others (none that we use here
though), so let's use the helper function to get the same behavior sets
as if we set those in the tests.
With passive libei contexts receiving events sent by the EIS
implementation, the type of device changes significantly. While a
relative input device could still send data in logical pixels,
absolute devices may not have that luxury.
Best example here is an external tablet (think: Wacom Intuos): that
tablet has no built-in mapping to a screen and thus cannot capture input
events in logical pixels.
Address this by adding a device type, either virtual or physical.
In terms of functionality, the device's type decides:
- only virtual devices have regions
- only physical devices have a size
The event API remains as-is but the event data not represents either
logical pixels (virtual devices) or mm (physical device).
An EIS implementation connected to a passive libei context would likely
create:
- a virtual relative device (sending deltas in logical pixels)
- one or more physical absolute devices (sending deltas in mm)
Previously, a client could only bind to a capability immediately after
SEAT_ADDED and with a rather awkward API to confirm the capabilities.
Change this to allow for dynamic binding of capabilities, i.e. a client
calls ei_bind_capability() or ei_unbind_capability() whenever it feels
like, causing the respective devices of this capabilty to be added or
removed.
This allows for clients that are temporarily disinterested in a
capability but may require said capability later.
The default function takes one capability, a helper for enable/disable
multiple capabilities in one go is provided as well. On the protocol,
only the "bind" request exists which always represents the currently
wanted set of capabilities.
Note that the helper functions for multiple capabilities require NULL
(not zero) as sentinel, thanks to gcc.
This is a leftover from an earlier implementation that didn't get
removed in time. This extends to a macro that was using the context flag
(rather than the client flag) and in turn caused a bunch of false
positives on the tests.
This way eis_seat_has_capability() returns the effective capabilities
the server can actually use - no point creating touch devices when the
client has not confirmed that.
In theory we should have a eis_seat_get_effective_capabilities() to
differ between configured and effective capabilities, but I'm having a
hard time thinking of a use-case where the implementation forgets
which caps it enabled.
The side-effect of this patch is that adding a device without
capabilities requested by the client now produces warning.
Our API requires a client to know which capability to pass into the
drop_capabilities function. This doesn't work for capabilities newer
than the client's version so they do not get disabled. The client will
thus receive devices it didn't ask for and doesn't know how to handle.
Let's invert the requirement and require the caller to confirm the
capabilities it wants - all others are dropped.
This is an API break but also requires updates of all clients, the
previous simple case of just calling ei_seat_bind() will now result in
zero capabilities.
A libei context can be initialized as active or passive context -
an "active" context sends events, a "passive" context receives events.
The EIS context supports both simultaneously, it is up to the
implementation to disconnect libei clients that it does not want to
suppport.
For example, the xdotool use-case creates an active libei context. The
EIS implementation controls and sets up the devices, but libei
sends the events.
In an input-capturing use-case, the EIS implementation controls
and sets up the devices **and** sends the events. libei is merely the
receiver for any event, it cannot send events. Thus this use-case
requires a passive libei context.
Most of this code is copy/paste with minor modifications - libei already
had the code to send events, libeis had the code to receive events, so
the vast majority of this patch is copying the code into the respective
other library, swap "ei" and "eis" and then apply the various minor
modifications needed to hook into the existing library.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
One macro that also defines the cleanup function, one macro that only
defines the unref. This is required for any place where we want to
use cleanup from multiple source files - like the test suite.
