The pivot point is a point in normalized coordinates space around which
all transformations revolve.
It supercedes the anchor point and the per-transformation center points
as well as the gravity settings, and tries to sort out the mess that
is the modelview matrix set up in ClutterActor.
https://bugzilla.gnome.org/show_bug.cgi?id=677853
The ClutterActor:depth property has always been a bit of a misnomer:
actors are 2D flat surfaces, so they cannot have "depth"; the property
defines the position on the Z axis.
Another side effect of the :depth property is that it decides the
default paint and allocation order on insertion, and that setting it
will call the ClutterContainer.sort_depth_order() method. This has
proven to be a fairly bad design decision that we strung along from the
0.x days, as it gives a false impression of being able to change the
paint and allocation order simply by changing the position on the Z
axis — something that, in reality, requires depth testing to be enabled
during the paint sequence of an actor's parent.
For 2.0 we need a clean break from the side effects, and a better
defined interface.
ClutterActor:z-position is essentially what ClutterActor:depth is, but
doesn't call into ClutterContainer, and has a more apt name.
https://bugzilla.gnome.org/show_bug.cgi?id=679465
It can be useful to check whether a ClutterActorIter is currently valid,
i.e. if the iterator has been initialized *and* if the actor to which it
refers to hasn't been updated.
We can also use the is_valid() method in the conformance test suite to
check that initialization has been successful, and that changing the
children list through the ClutterActorIter API leaves the iterator in a
valid state.
ClutterContent implementations may allow repeating their contents when
painting; we should provide the repeat policy on the actor, like we do
for scaling filters and content gravity.
ClutterGridLayout is port of GtkGrid to a Clutter layout manager. All
the logic is taken from gtkgrid.c, so all the credits should go to
Matthias Clasen for writing this nice piece of code.
ClutterGridLayout supports adding children with it's own methods
GridLayout.attach() and GridLayout.attach_next_to() as well as
Actor.add_child() and friends. The latter adds children in a similar
fashion to ClutterBoxLayout
https://bugzilla.gnome.org/show_bug.cgi?id=677372
The plain C bytes array, while convenient from a C perspective, is not
well handled by language bindings: the length of the array is not
specified, and it's only just implied by the image data size, rowstride,
and pixel format.
GBytes is a read-only bytes buffer that has an implicit length; we can
use it as the storage medium so that language bindings can actually
function correctly.
It's similar to to the implicit animation API of ClutterActor and
compatible to deprecated API of ClutterBoxLayout and
ClutterTableLayout.
It adds :use-animations, :easing-mode, :easing-duration and
:easing-delay properties to control animations when allocation of a
child has changed. Layout manager implementers should call
use_animations = clutter_layout_manager_get_easing_state (manager,
&mode,
&duration,
&delay);
from the allocate() virtual function to access these values.
https://bugzilla.gnome.org/show_bug.cgi?id=676827
Instead of going through clutter_event_get_state() and checking if the
modifier mask is set, we can provide simple convenience functions to do
it for us.
The :x-expand and :y-expand flags on ClutterActor are used to signal
that an actor should expand horizontally and/or vertically - i.e. that
its parent's layout management policy should try to assign extra space
to the actor when allocating it.
The expand flags are automatic: when set on a leaf node in the actor
tree, they will bubble up through the parent and grandparents up to the
top level actor; during allocation, the actors with children will lazily
compute whether their children needs to expand.
The TransitionGroup class is a logical container for running multiple
transitions.
TransitionGroup is not a Score: it is a Transition that advances each
Transition it contains using the delta between frames, and ensures that
all transitions are in a consistent state; these transitions are not
advanced by the master clock.
Instead of a single new() constructor that both allocates and
initializes, split the allocation and initialization into two separate
functions for types that are typically used on the stack, and rarely
allocated on the heap, like ClutterPoint and friends.
This is also applied retroactively to ClutterActorBox and ClutterVertex,
given that the same considerations on usage apply to them as well; we
can add a return value to clutter_actor_box_init() and
clutter_vertex_init() in an ABI-compatible way, so that
clutter_actor_box_new() and clutter_vertex_new() can be effectively
reimplemented as "init (alloc ())".
The ClutterCanvas content implementation should be used instead, to
avoid stringing along the ClutterTexture API and implementation.
This change requires some minor surgery, as the deprecated section
already contains an header for the previously deprecated methods; plus,
we don't want to deprecate clutter_cairo_set_source_color(). This means
creating a new header to be used for Cairo-related API.
Some events may contain precise scrolling information coming from
devices like trackpads and touchscreens. ClutterEvent should allow
setting and getting this information.
At least for the time being, we only expose the parts of the API that we
want to use internally and for new, out-of-tree Content implementations.
The full PaintNode tree API will be made public in 1.12 once we branch
master.
ClutterActor should be able to hold all transitions, even the ones that
have been explicitly created.
This will allow to add new transitions types in the future, like the
keyframe-based one, or the transition group.
It should be possible to ask a timeline what is its duration, taking
into account eventual repeats, and which repeat is the one currently
in progress.
These two functions allow writing animations that depend on the current
state of another timeline.
It should be possible to set up the delay of a transition, but since
we start the Transition instance before returning control to the caller,
we cannot use clutter_actor_get_transition() to do it without something
extra-awkward, like:
transition = clutter_actor_get_transition (actor, "width");
clutter_timeline_stop (transition);
clutter_timeline_set_delay (transition, 1000);
clutter_timeline_start (transition);
for each property involved. It's much easier to add a delay to the
easing state of an actor.
The ClutterBrightnessContrastEffect effect class allows changing the
brightness and contrast levels of an actor.
Modified-by: Emmanuele Bassi <ebassi@linux.intel.com>
Modified-by: Neil Roberts <neil@linux.intel.com>
https://bugzilla.gnome.org/show_bug.cgi?id=656156
It is sometimes useful to be able to have better control on when a
repaint function is called. Currently, all repaint functions are called
prior to the stages update phase of the frame processing.
We can introduce flags to represent the point in the frame update
process in which we wish Clutter called the repaint function.
As a bonus, we can also add a flag that causes adding a repaint function
to spin the master clock.
Now that ClutterActor has a default paint volume, subclasses may wish
to retrieve it without chaining up to the parent's implementation of
the get_paint_volume() function.
The get_default_paint_volume() returns a ClutterPaintVolume pointer
to the paint volume as computed by the default implementation of the
get_paint_volume() virtual function; it can only be used immediately,
as it's not guaranteed to survive across multiple frames.
Creating PaintVolume instances is not possible, and it's not recommended
anyway. It is, though, necessary to union paint volumes, especially with
2D boxes, in some cases.
Clutter should provide a simple convenience function that allows
unioning volumes to boxes in a moderately efficient way.
https://bugzilla.gnome.org/show_bug.cgi?id=670021
There are times when we don't want to remove all children and count of
the reference count to drop to 0 to ensure destruction; there are cases,
such as managed environments, where it's preferable to ensure that the
children of an actor get actually destroyed.
