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.
