The grab API is a relic of Clutter 0.6, and hasn't been through proper
vetting in a *long* time — mostly due to the fact that we don't really
like grabs, and point to the ::captured-event as a way to implement
"soft grabs" in toolkits and applications.
The implementation of full and device grabs uses weak references on
actors instead of using the ::destroy signal, which is meant exactly for
the case of releasing pointers to actors when they are disposed.
The API naming scheme is also fairly broken, especially for
device-related grabs.
Finally, keyboard device grabs are just not implemented.
We can, in one go, clean up this mess and deprecate a bunch of badly
named API by introducing generic device grab/ungrab methods on
ClutterInputDevice, and re-implement the current API on top of them.
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.
We keep the symbol in the public header, but the definition is now
private. You could not sub-class InputDevice anyway, without the
instance structure, and the lack of padding in the class made actually
implementing devices in backends really hard.
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.
This backend is a event backend that can be enabled for EGL (for now).
It uses udev (gudev) to query input devices on a linux system, listens to
keyboard events from input devices and xkbcommon to translate raw key
codes into key keysyms.
This commit only supports key events, more to follow.
