Clutter should just require that the windowing system used by a backend
adds a device to the stage when the device enters, and removes it from
the stage when the device leaves; with this information, we can
synthesize every crossing event and update the device state without
other intervention from the backend-specific code.
The generation of additional crossing events for actors that are
covering the stage at the coordinates of the crossing event should be
delegated to the event processing code.
The x11 and win32 backends need to be modified to relay the enter and
leave events from the windowing system.
Slave and floating devices should always be disabled, and not deliver
events to the scene. It is up to the user to enable non-master devices
and handle events coming from them.
ClutterInputDevice gets a new :enabled property, defaulting to FALSE;
when a device manager creates a new device it has to set it to TRUE if
the :device-mode property is set to CLUTTER_INPUT_MODE_MASTER.
The main event queue entry point, _clutter_event_push(), will
automatically discard events coming from disabled devices.
This is a lump commit that is fairly difficult to break down without
either breaking bisecting or breaking the test cases.
The new design for handling X11 event translation works this way:
- ClutterBackend::translate_event() has been added as the central
point used by a ClutterBackend implementation to translate a
native event into a ClutterEvent;
- ClutterEventTranslator is a private interface that should be
implemented by backend-specific objects, like stage
implementations and ClutterDeviceManager sub-classes, and
allows dealing with class-specific event translation;
- ClutterStageX11 implements EventTranslator, and deals with the
stage-relative X11 events coming from the X11 event source;
- ClutterStageGLX overrides EventTranslator, in order to
deal with the INTEL_GLX_swap_event extension, and it chains up
to the X11 default implementation;
- ClutterDeviceManagerX11 has been split into two separate classes,
one that deals with core and (optionally) XI1 events, and the
other that deals with XI2 events; the selection is done at run-time,
since the core+XI1 and XI2 mechanisms are mutually exclusive.
All the other backends we officially support still use their own
custom event source and translation function, but the end goal is to
migrate them to the translate_event() virtual function, and have the
event source be a shared part of Clutter core.
Discarding the event without any warning when the device has no
associated stage makes it hard to find the bug for people implementing
new event backends. We should really warn for that abnormal condition in
_clutter_input_device_update().
This adds a wrapper macro to clutter-private that will use
g_object_notify_by_pspec if it's compiled against a version of GLib
that is sufficiently new. Otherwise it will notify by the property
name as before by extracting the name from the pspec. The objects can
then store a static array of GParamSpecs and notify using those as
suggested in the documentation for g_object_notify_by_pspec.
Note that the name of the variable used for storing the array of
GParamSpecs is obj_props instead of properties as used in the
documentation because some places in Clutter uses 'properties' as the
name of a local variable.
Mose of the classes in Clutter have been converted using the script in
the bug report. Some classes have not been modified even though the
script picked them up as described here:
json-generator:
We probably don't want to modify the internal copy of JSON
behaviour-depth:
rectangle:
score:
stage-manager:
These aren't using the separate GParamSpec* variable style.
blur-effect:
win32/device-manager:
Don't actually define any properties even though it has the enum.
box-layout:
flow-layout:
Have some per-child properties that don't work automatically with
the script.
clutter-model:
The script gets confused with ClutterModelIter
stage:
Script gets confused because PROP_USER_RESIZE doesn't match
"user-resizable"
test-layout:
Don't really want to modify the tests
http://bugzilla.clutter-project.org/show_bug.cgi?id=2150
If we do not unset the Stage we will have stale data, and the Crossing
event when re-entering a Stage will not be emitted, as the actor under
the pointer might be the same as before.
If an actor is on the boundary of a Stage and the pointer for a device
enters the Stage over that actor, the sequence of events currently is:
➔ ENTER (source: actor, related: NULL)
➔ MOTION
Thus the Stage never gets an ENTER event. This is a regression from
Clutter 1.0.
The correct sequence is:
➔ ENTER (source: stage, related: NULL)
➔ ENTER (source: actor, related: stage)
➔ MOTION
This also maps to the sequence of events sythesized by Clutter when
leaving the Stage through an actor overlapping the Stage boundary.
http://bugzilla.moblin.org/show_bug.cgi?id=9781
Embedding toolkits should benefit from a proper documentation of
clutter_input_device_update_from_event(): its meaning, its use and
the caveats for the "update_stage" argument.
Embedding toolkits most likely will disable the event handling, so all
the input device code will not be executed. Unfortunately, the newly
added synthetic event generation of ENTER and LEAVE event pairs depends
on having input devices.
In order to unbreak things without reintroducing the madness of the
previous code we should allow embedding toolkits to just update the
state of an InputDevice by using the data contained inside the
ClutterEvent. This strategy has two obvious reasons:
• the embedding toolkit is creating a ClutterEvent by translating
a toolkit-native event anyway
• this is exactly what ClutterStage does when processing events
We are, essentially, deferring input device handling to the embedding
toolkits, just like we're deferring event handling to them.
If an actor is lying on the border of the Stage it might miss the LEAVE
event when the pointer of a device leaves the Stage window. Since the
backend is unsetting the Stage back pointer on the InputDevice we can
queue the emission of a LEAVE event on the pointer actor as well.
http://bugzilla.moblin.org/show_bug.cgi?id=9677
If the stage associated to the InputDevice is not set we should
short-circuit out and return NULL. This will result in a pick()
done on the event's stage - if applicable.
http://bugzilla.moblin.org/show_bug.cgi?id=9602
When an InputDevice leaves a stage we set the stage member of
InputDevice to NULL. We should also unset the cursor_actor (as the
device is obviously not on an actor any more).
When the device re-enters the Stage the ENTER/LEAVE event generation
machinery will then be able to emit the ENTER event on the Stage.
The previous state for the device is used by the click count machinery
and we should not be overwriting it at every event; instead, we should
use a parallel storage for the current state coming from the windowing
system.
The LEAVE/ENTER event pairs should be queued during the InputDevice
update process, when we change the actor under the device pointer.
This commit cleans up the event emission code inside clutter-main.c
and the logic of the event processing.
The InputDevice objects stores pointer coordinates, state, stage and
the actor under the cursor, so if the current backend provides us with
one attached to the Event structure then we want the InputDevice itself
to update its state and give us the ClutterActor underneath the
pointer's cursor.
