https://bugzilla.gnome.org/show_bug.cgi?id=654656
Clutter may be used together with GTK+, which indirectly may use
XInput2 too, so the cookie data must persist when both are handling
events.
What happens now in a nutshell is, Clutter is only guaranteed to allocate
the cookie itself after XNextEvent(), and only frees the cookie if its
XGetEventData() call allocated the cookie data.
The X[Get|Free]EventData() calls happen now in clutter-event-x11.c as
hypothetically different event translators could also handle other set
of X Generic Events, or other libraries handling events for that matter.
Creating a synthetic event requires direct access to the ClutterEvent
union members; this access does not map in bindings to high-level
languages, especially run-time bindings using GObject-Introspection.
It's also midly annoying from C, as it unnecessarily exposes the guts of
ClutterEvent - something we might want to fix in the future.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2575
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.
Since the XI2 device manager code is going to be compiled only on
POSIX compliant systems, we can safely assume the presence of stdint.h
and include it unconditionally.
Hierarchy and Device changed events come through with the X window set
to be the root window, not the stage window. We need to whitelist them
so that we can actually support hotplugging and device changes.
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.
We ask XI2 to get the client pointer for CLUTTER_POINTER_DEVICE, and
we use the attached keyboard device for CLUTTER_KEYBOARD_DEVICE. For
everything else, we return NULL.
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.
