A StyleAnimation is an immutable object used to track the state of CSS
values. I'd have liked to make it fully immutable - ie not have the
timestamp in there - but couldn't find a place to sanely store the
timestamp.
This is an abstract base class. Implementations for this will be added
later (for both CSS3 transitions and animations, potentially for
animated images).
Actually aplying the information in this object will be done by a
different object commtted later.
This has two goals:
1) Move invalidation code out of a nested if branch. Invalidation is
actually the most important thing this function does.
2) Have the changes bitmask available. It will needed for invalidate
calls to children later.
The design principles were:
- synchronized
If multiple style contexts are animating, they should all do an
animation step at the same time.
- degrades well
Even when there's thousands of style contexts all animating at the same
time, the animation steps don't starve the CPU. This is achieved by
making sure the timeout is really fast. It just sets a bunch of flags.
- no hidden bottlenecks
Turning animatability on or off on a style context is O(1).
So far it is unused.
This is only a small performance boost by itself, but it's necessary
for animations, so we need it.
Benchmark numbers for my Glade benchmark for interested people:
GTK 3.4.0 last commit this commit
Raleigh
real 0m41.879s 0m10.176s 0m9.900s
user 0m41.394s 0m9.895s 0m9.628s
sys 0m0.111s 0m0.096s 0m0.102s
Adwaita (*)
real 0m51.049s 0m13.432s 0m14.848s 0m12.253s
user 0m50.487s 0m13.034s 0m13.218s 0m11.927s
sys 0m0.117s 0m0.151s 0m0.147s 0m0.107s
Ambiance (patched to not use private GTK APIs)
real 0m52.167s 0m13.115s 0m13.117s 0m12.944s
user 0m51.576s 0m12.739s 0m12.768s 0m12.651s
sys 0m0.119s 0m0.137s 0m0.136s 0m0.118s
(*) Adwaita and unico currently use custom properties, and
_gtk_css_value_compare() for custom properties always returns FALSE,
which makes this optimization never trigger. So I modified
_gtk_css_value_compare() to return TRUE for these properties instead and
reran the benchmark. Those are the numbers.
Add an internal API that allows GtkStyleContext to create a widget path
for the widget and with that bypassing gtk_widget_get_path() and that
function caching the path.
Instead, look up the variable upon use. This is more correct (for when
the engine changes due to save/restore() shenanigans.
And it removes code that doesn't use the standard code paths.
Equality tests are done with _gtk_css_value_equal(). There is no need to
do it per-property, equal values will still be equal.
This essentially reverts 24f5d54329e028347bd76af42e86ed190c1229a2 and
92c7a7171e1240b6d961ee5b6f9ab6b596e98904.
... and Make this new value be a real GValue, as we don't need to save
performance for these anymore (it's just used for custom properties).
And I'd rather have code work for all values then be optimized for no
reason.
Deprecate public API where appropriate and make it no-ops.
Remove all calls to it.
Get rid of the 'transition' css property.
For now, this means spinners don't animate anymore.
Instead of keeping a custom GPtrArray, keep it as a GtkCssArrayValue of
GtkCssStringValue. This way, we gain equality comparisons and print
functions for free.
