The G_CONST_RETURN define in GLib is, and has always been, a bit fuzzy.
We always used it to conform to the platform, at least for public-facing
API.
At first I assumed it has something to do with brain-damaged compilers
or with weird platforms where const was not really supported; sadly,
it's something much, much worse: it's a define that can be toggled at
compile-time to remove const from the signature of public API. This is a
truly terrifying feature that I assume was added in the past century,
and whose inception clearly had something to do with massive doses of
absynthe and opium — because any other explanation would make the
existence of such a feature even worse than assuming drugs had anything
to do with it.
Anyway, and pleasing the gods, this dubious feature is being
removed/deprecated in GLib; see bug:
https://bugzilla.gnome.org/show_bug.cgi?id=644611
Before deprecation, though, we should just remove its usage from the
whole API. We should especially remove its usage from Cally's internals,
since there it never made sense in the first place.
ClutterInterval.compute_value() computes the new value given a progress
and copies it to a given GValue. Since most of the time we want to pass
that very same value to another function that copies it again, we should
have a compute_value() variant that stores that computed value inside
ClutterInterval and returns a pointer to it. This way we initialize the
result GValue just once and we never copy it, as long as the Interval
instance is valid.
A ClutterInterval can change the way the progress is computed
by subclassing and overriding the ::compute_value() virtual function.
It should also be possible to register a custom progress function
in the same way it is possible to register a custom transformation
function between two GValues.
This commit adds an internal, global hash table that maintains a
GType <-> progress function association; each ClutterInterval
will check if there is a progress function registered for the
GType of the initial and final values of the interval and, if
it has been found, it will call it to compute the value of the
interval depending on the progress factor.
If the computation of the interval value depending on the progress
was not successful, ClutterInterval::compute_value() should return
this information to the caller.
Bug 1014 - Clutter Animation API Improvements
* clutter/Makefile.am:
* clutter/clutter.h: Update the build
* clutter/clutter-types.h: Add AnimationMode, an enumeration
for easing functions.
* clutter/clutter-alpha.[ch]: Add the :mode property to
control the function bound to an Alpha instance using an
enumeration value. Also add six new alpha functions:
- ease-in, ease-out, ease-in-out
- sine-in, sine-out, sine-in-out
* clutter/clutter-deprecated.h: Deprecate the #defines for
the alpha functions. They will be replaced by entries in the
ClutterAnimationMode.
* clutter/clutter-interval.[ch]: Add ClutterInterval, an
object for defining, validating and computing an interval
between two values.
* clutter/clutter-animation.[ch]: Add ClutterAnimation, an
object responsible for animation the properties of a single
actor along an interval of values. ClutterAnimation memory
management is automatic. A simple wrapper method for
ClutterActor is provided:
clutter_actor_animate()
which will create, or update, an animation for the passed
actor.
* clutter/clutter-debug.h:
* clutter/clutter-main.c: Add a new 'animation' debug note.
* clutter/clutter-script.c: Clean up the alpha functions
whitelist, and add the new functions.
* doc/reference/clutter/Makefile.am:
* doc/reference/clutter/clutter-sections.txt: Update the
API reference.
* doc/reference/clutter/clutter-animation.xml: Renamed to
doc/reference/clutter/clutter-animation-tutorial.xml to
avoid clashes with the ClutterAnimation section.
* doc/reference/clutter/clutter-docs.sgml: Renamed to
doc/reference/clutter/clutter-docs.xml, as it was an XML
file and not a SGML file.
* tests/Makefile.am:
* tests/interactive/Makefile.am:
* tests/interactive/test-animation.c:
* tests/interactive/test-easing.c: Add two tests for the
new simple animation API and the easing functions.
* tests/interactive/test-actors.c:
* tests/interactive/test-behave.c:
* tests/interactive/test-depth.c:
* tests/interactive/test-effects.c:
* tests/interactive/test-layout.c:
* tests/interactive/test-multistage.c:
* tests/interactive/test-paint-wrapper.c:
* tests/interactive/test-rotate.c:
* tests/interactive/test-scale.c:
* tests/interactive/test-texture-quality.c:
* tests/interactive/test-threads.c:
* tests/interactive/test-viewport.c: Update interactive tests
to the deprecations and new alpha API.
