GLib introduced macros that allows defining the lower and upper bounds
of the API to be used by application code.
The lower bound allows to define the minimum version that will trigger
deprecation warnings; the upper bound defines the maximum version that
will trigger compiler warnings for unavailable symbols.
This scheme allows gradually porting application code to a new version
of the API, especially in case of resynchronization after multiple
development cycles.
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
It should be possible to adapt the abicheck.sh script so that it
actually tests the ABI of libclutter-1.0.so taking into account
the backends that were compiled into Clutter, and avoid expected
failures if Clutter was not built with a specific backend.
https://bugzilla.gnome.org/show_bug.cgi?id=670680
We cannot deprecate ClutterAlpha yet. We cannot also implement
ClutterAlpha in terms of ClutterTimeline, because multiple Alpha
instances can be attached to the same Timeline. So we can start
with a "soft" deprecation: just a warning in the documentation
stating that ClutterAlpha will be deprecated, and removed, in the
future, and that newly-written code should use ClutterTimeline
instead.
We can use ClutterTimeline and its progress mode inside
ClutterAnimation; obviously, we have to maintain the invariants because
of the ClutterAnimation:alpha property, but if all you set is the :mode
property using one of the Clutter animation modes then we can skip the
ClutterAlpha entirely.
Instead of having the easing functions be dependent of ClutterAlpha, and
static to the clutter-alpha.c source file, we should make them generic
and move them to their own internal header and source files. This will
allow to re-use them in the near future.
Since Cogl has started restricting what cogl 1.x api is exposed when
COGL_ENABLE_EXPERIMENTAL_2_0_API is defined and since we build all
Clutter internals with COGL_ENABLE_EXPERIMENTAL_2_0_API defined this
patch makes a first pass at reducing our internal use of the Cogl 1.x
api.
The most notable api that's no longer exposed to us internally is
the cogl_material_ api so this switches all Clutter internals to use the
cogl_pipeline_ api instead. This patch also makes quite a bit of
progress removing internal uses of CoglHandle although there is still
more to go.
The experimental cogl_texture_pixmap_x11_new() api was recently changed
to take an explicit context argument and return a GError on failures.
This updates Clutter's use of the api accordingly.
We were only exposing clutter_backend_get_cogl_context() if
COGL_ENABLE_EXPERIMENTAL_2_0_API had been defined but the CoglContext
api is also available if COGL_ENABLE_EXPERIMENTAL_API has been defined.
As it was it meant that code opting into the experimental Cogl api
but not limiting to the 2.0 only api would have to #define
COGL_ENABLE_EXPERIMENTAL_2_0_API before including clutter.h but make
sure it wasn't defined when including cogl.h which was particularly
awkward.
Recently the cogl_framebuffer_swap_* apis were moved into the
cogl_onscreen_* namespace since only CoglOnscreen framebuffers can be
double buffered. This renames all uses of the cogl_framebuffer_swap_*
apis in Clutter.
The experimental cogl_pipeline_new() api was recently changed so it
explicitly takes a CoglContext. This updates all calls to
cogl_pipeline_new() in clutter accordingly.
ATK_ROLE_CANVAS is not a suitable role, as the user (in general) can't
draw on the Stage. CallyStage implements AtkWindow, so the proper role
is ATK_ROLE_WINDOW
Removing atkcomponent, focus_tracker, etc. Emitting focus state change
from the stage. Now things are more simple, and stop to use some
of the soon-to-be-deprecated signals on ATK.
It should be possible to do:
clutter_stage_set_fullscreen (stage, TRUE);
clutter_actor_show (stage);
and have the stage be full screen as soon as it is shown.
Currently, we need to call clutter_actor_realize() prior to calling
set_fullscreen(), otherwise the backing X window will not be set,
and ClutterStageX11 will silently discard the change.
If set_fullscreen() was called prior to realization, ClutterStageX11
should delay setting the fullscreen hint until the realize() chain
has been successfully executed.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2515
If you execute the following sequence :
stage = clutter_stage_new ();
clutter_actor_set_size (stage, 1280, 800);
clutter_actor_realize (stage);
Then you end up creating an onscreen buffer of size 1280x800 but
ClutterStageX11 storing the stage size at 640x480.
This patch resync the 2 implementation by using the ClutterStage's
size in both classes when realizing.
Signed-off-by: Lionel Landwerlin <llandwerlin@gmail.com>
https://bugzilla.gnome.org/show_bug.cgi?id=667540
Unconditionally creating CoglPipeline and CoglSnippets inside the class
initialization functions does not seem to be enough when dealing with
headless builds.
Our last resort is to lazily create the base pipeline the first time we
try to copy it, during the instance initialization.
The class initialization function may be called when Clutter hasn't been
fully initialized — for instance, when scanning the source with gtk-doc
or with the introspection scanner.
The allocation code for BoxLayout contains a sequence of brain farts
that make it barely working since the synchronization of the layout
algorithm to the one in GtkBox.
The origin of the layout is inverted, and it doesn't take into
consideration a modified allocation origin (for actors the provide
padding or margin).
The pack-start property is broken, and it only works because we walk the
children list backwards; this horribly breaks when a child changes
visibility. Plus, we count invisible children, which leads to
allocations getting insane origins (either close to -MAX_FLOAT or
MAX_FLOAT).
Finally, the allocation is applied twice even for non-animated cases.
https://bugzilla.gnome.org/show_bug.cgi?id=669291
* clutter_wayland_input_device_get_wl_input_device for the input device
* clutter_wayland_stage_get_wl_surface for the Wayland surface
* clutter_wayland_stage_get_wl_shell_surface for the shell surface
This converts the blur, colorize and desaturate effects to use
snippets instead of CoglPrograms. Cogl can handle the snippets much
more efficiently than programs so this should be a performance win. It
also fixes the problem that Cogl would end up recompiling the program
for every instance of the effects because Clutter was not reusing the
same program.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
The blur effect needs to pass a uniform to the GLSL shader so that it
can know the texture coordinate offset from one texel to another. To
calculate this the blur effect was previously using the allocation
size of the actor rounded up to the next power of two. Presumably the
assumption was that Cogl would round up the size of the texture to the
next power of two when allocating the texture. However this is not be
true if the driver supports NPOT textures. Also it doesn't take into
account the paint volume of the actor which may cause the texture to
be a completely different size. This patch just changes to directly
use the size of the texture.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Sometimes a subclass of ClutterOffscreenEffect wants to paint with a
completely custom material. In that case it is awkward to modify the
material returned owned by ClutterOffscreenEffect so it makes more
sense to just get the texture and manage its own material.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
All of the pipelines used for ClutterTexture actors share a common
pipeline ancestor created with cogl_pipeline_copy. Previously this
ancestor had a dummy 1x1 texture attached to it so that it would end
up with the same state as the child pipelines that will render with a
texture. Cogl now has a mechanism to specify that a texture will be
used with a pipeline layer without having to create an actual texture.
This patch makes it use that to avoid having an unused texture.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
If we have N children and the user passes N (or a number beyond N) to
clutter_actor_insert_child_at_index, we should respond by adding the
child at the end, not silently doing nothing.
This should avoid trying to fix the origin of a paint volume set from
the allocation's origin, and thus breaking everything.
A PaintVolume for an actor is defined to be relative to the actor's
modelview unless specifically modified by internal functions; the origin
of an actor's allocation is, on the other hand, parent-relative.
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.
ClutterActor has a background-color property, now; we should use it for
the Stage, re-implement the color property in terms of background-color.
and deprecate the Stage property.
Being able to easily set the number of repeats has been a request for
the animation framework for some time now. The usual way to implement
this is: connect to the ::completed signal, use a static counter, and
stop the timeline when the counter hits a specific spot.
In the same light as the :auto-reverse property, we can make it easier
to implement this common functionality by adding a :repeat-count
property that, when set, limits the amount of loops that a Timeline can
perform before stopping itself.
In fact, we can implement the :loop property in terms of the
:repeat-count property just by using a sentinel value mapping to
"infinity", and map loop=FALSE to repeat-count=0, and loop=TRUE to
repeat-count=-1.
The clutter_timeline_clone() method was a pretty dumb idea when it was
introduced, back when we still had the ClutterEffectTemplate and the
clutter_effect_* animation API. It has since become an API wart: we
cannot change or add new properties to be cloned without the risk of
breaking existing code. All in all, cloning a GObject is just a matter
of calling g_object_new() with the wanted properties.
Let's deprecate this throwback of the Olden Days™, so that we can remove
it for good once we break for 2.0.
When the ClutterTextBuffer support inside ClutterText was merged, it
introduced a regression that was identified and fixed in bug 659116.
The optimization to not paint empty ClutterText actors is only valid
is the actor is not editable, or if the cursor is not visible.
Courtesy of GLib and GTK+. The abicheck.sh is a simple, Linux-only,
script to check that we're not leaking private symbols, or that the
clutter.symbols file hasn't been updated.
In theory, it should go inside the distcheck phase.
A bunch of private symbols have escaped into the SO; let's rectify this
situation by using the '_' private prefix, or making them static as they
should have been.
Cogl now requires that all applications integrate their main loop with
Cogl so that it can listen for events from winsys. This patch just
adds Cogl's GSource to the main loop.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Some of Cogl's experimental apis have changed so that the buffer apis
now need to be passed a context argument and some drawing apis have been
replaced with cogl_framebuffer_ drawing apis that take explicit
framebuffer and pipeline arguments.
These changes were made as part of Cogl moving towards a more stateless
api that doesn't rely on a global context.
This patch updates Clutter to work with the latest Cogl api and bumps
the required Cogl version to 1.9.5.
Reviewed-by: Emmanuele Bassi <ebassi@linux.intel.com>
Reviewed-by: Neil Roberts <neil@linux.intel.com>
Similar to the clutter_actor_iter_remove(), but it'll call destroy()
instead of remove_child().
We can also reimplement the ::destroy default handler using it, and make
it more compact.
There is a typo in the check for a negative index: the index variable
should be index_, not index - unfortunately, the latter can still be
resolved to index(3), so compiler and linker are perfectly happy.
https://bugzilla.gnome.org/show_bug.cgi?id=669730
An editable ClutterText will reset the selection and cursor whenever the
contents are changed — even if those contents are the same. As this may
confuse the user, we should check if we're setting the exact same string,
and bail out if necessary.
The reverse of position_to_coords().
While providing documentation on how to implement it using the
PangoLayout API, I realized that the verbosity of it all, plus the usage
of the Pango API, was not worth it, and decided to expose the method we
are using internally.
GValueArray is on its way to deprecation in GLib; as far as the
ListModel class is concerned, a plain C array of GValue is a perfectly
suitable replacement for the GValueArray usage. It actually is an
improvement, given that it's going to take less memory.
ClutterActor stopped requiring to override the map and unmap virtual
functions some time ago.
Now that ClutterActor implements the Container interface, overriding map
and unmap to control the MAPPED state of the children is pretty much
going to be a source of bugs and misunderstandings.
Plus, the ordering of the unmap, destroy, dispose, and finalize calls
should be be documented properly.
The documentation should clarify all that.
When calling clutter_actor_destroy(), ClutterActor calls
update_map_state() on itself to unset the REALIZED and MAPPED states,
prior to running the dispose() implementation.
The default dispose() will call remove_child() (either directly or
through the Container implementation), which will check for the MAPPED
state and then run update_map_state() again. We use the previously set
MAPPED state to decide whether or not the parent should queue for a
relayout/redraw when removing a visible children.
If the MAPPED flag was cleared prior to remove_child(), though, it'll
always be unset by the time we get to remove_child(), and this will
cause missing redraws/relayouts; we were ignoring this prior the
post-First Apocalypse changes because we were doing:
if (was_mapped)
clutter_actor_queue_relayout (parent);
clutter_actor_queue_redraw (parent);
which is obviously wrong. Once I removed that glaring brain damage from
the remove_child() implementation, bugs started appearing — bugs that
were probably the reason why we introduced that brain damage in the
first place, instead of checking the source of those bugs.
The obvious fix is to avoid clearing up the actor's state on destroy()
until we remove the actor from its parent. This also reduces the amount
of work we do, and the code paths that can potentially go wrong.
Since the code dealing with ClutterShader is pretty self-contained, now,
we can safely move it outside of the main ClutterActor source file and
into its own. This will allow us to just drop a bunch of files when
branching for 2.0.
The YUV support depends on the driver support, and not only not many
drivers support YUV natively: the supported colorspaces are pretty much
useless.
The proper way to do YUV to RGB colorspace conversion on the GPU is to
use a fragment shader; for that, ClutterTexture and Cogl provide enough
API to achieve a good result - see the Clutter-GStreamer implementation,
for instance.
ClutterFixedLayout is the default layout manager for ClutterActor.
Existing subclasses of ClutterActor will get a fixed layout manager
regardless of whether they are going to use it, but since it sets the
CLUTTER_ACTOR_NO_LAYOUT flag, it will introduce regressions on actors
that perform their own layout management.
The CLUTTER_ACTOR_NO_LAYOUT flag was a bit of a mistake in the first
place, as it was introduced as a last minute workaround in the 1.0
process to deal with broken stuff in Moblin. It's going to be a target
for deprecation towards a removal when we start the 2.0 process.
Iterating over children and ancestors of an actor is a relatively common
operation. Currently, you only have one option: start a for() loop, get
the first child of the actor, and advance to the next sibling for the
list of children; or start a for() loop and advance to the parent of the
actor.
These operations can be easily done through the ClutterActor API, but
they all require going through the public API, and performing multiple
type checks on the arguments.
Along with the DOM API, it would be nice to have an ancillary, utility
API that uses an iterator structure to hold the state, and can be
advanced in a loop.
https://bugzilla.gnome.org/show_bug.cgi?id=668669
During the gutting of ClutterBox, the destroy and dispose implementation
were removed. The former, especially, destroyed all children - which
usually meant that the redraw queues for the childre was cleared as
well. The removal introduced crashes when a Box was destroyed while its
children were still queueing redraws.
Symbolic names are better than magic numbers, even if they are
well-established and won't likely change.
This maps to a commit in GTK+ that introduced the same names; it
was decided to go for PRIMARY, MIDDLE, and SECONDARY because of
the confusion that may arise when the button order gets flipped
in left-handed configurations - the "left" button (i.e. 1) becomes
the right-most button, and the "right" button (i.e. 3) becomes
the left-most button.
https://bugzilla.gnome.org/show_bug.cgi?id=668692
Also update the code to set the size of the stage to set it to the size of the
output. In future versions of the Wayland protocol we'll get a configure
message advising of us of the size we can be to achieve fullscreen.
* stage-state:
docs: Update ClutterStageState flags
wayland: Use the Stage state tracking
gdk: Use the Stage state tracking
win32: Use the Stage state tracking
x11: Use the Stage state tracking
osx: Use the Stage state tracking
stage: Add state tracking
State changes on the Stage are currently deferred to the windowing
system backends, but the code is generally the same, and it should
be abstracted neatly inside the Stage class itself.
There's also the extra caveat for backends that state changes on a
Stage must also emit a ClutterEvent of type CLUTTER_STAGE_STATE, a
requirement that needlessly complicates the backend code.
GLib has gained support for compiling ancillary data files into the same
binary blob as a library or as an executable.
We should add this feature to ClutterScript, so that it's possible to
bundle UI definitions with an application.
The only actor that results in a mix of the old Container API and the
new Actor API is ClutterStage. By inheritance, a Stage is a Group, but
we don't want it to behave like a Group - as it already overrides most
of the Actor API, and the reason why it was made as a Group in the
first place was convenience for adding/removing children.
Given that touching Group to make it aware of the new Actor API has
rapidly devolved into a struggle between a Demiurge that tries to
avoid breakage and a Chaos that finds new and interesting ways to
break ClutterGroup, let's declare API bankruptcy here and now.
ClutterStage should override ClutterContainer methods, and use the
layout management of ClutterFixedLayout as the proper class that it
was meant to be ages ago. Let ClutterGroup rot in pieces.
Now that we reinstated Group to its "former glory", we need to ensure
that applications using the deprecated containers with the new DOM API
in ClutterActor can actually work - or, at least, not break horribly.
This actually means making sure that ClutterStage and ClutterGroup can
cope with the DOM, while retaining their old implementations, as well as
their bizarre idiosyncrasies and their utter, utter brokenness.
Making Group just a proxy to Actor broke some behaviour that application
and toolkit code was relying on. Let's keep Group around to fight
another day.
This commit fixes gnome-shell as far as I can test it.
A Group is a just a ClutterActor with the layout-manager property set at
instance initialization time. It doesn't need anything else from
ClutterActor's vtable, except the slightly custom show_all/hide_all
implementation, and a simplified get_paint_volume.
Instead of chaining up, given that we want to bypass chaining up and
just set the allocation. This also allows us to bail out of the
overridden allocate vfunc check, given that we want the default Actor
behaviour to apply - including eventual layout manager delegates.
The usual way to implement a container actor is to override the
allocate() virtual function, chain up, and then allocate the actor's
children.
Clutter now has the ability to delegate layout management to
ClutterLayoutManager directly; in the allocation, this is done by
checking whether the actor has children, and then call
clutter_layout_manager_allocate() from within the default implementation
of the ClutterActor::allocate() vfunc. The same vfunc that everyone, has
been chaining up to.
Whoopsie.
Well, we can check if there's a layout manager, and if it's NULL, we
bail out. Except that there's a default layout manager, and it's the
fixed layout manager, so that classes like Group and Stage work by
default.
Double whoopsie.
The fix for this scenario is a bit nasty; we have to check if the actor
class has overridden the allocate() vfunc or not, before actually
looking at the layout manager. This means that classes that override the
allocate() vfunc are expected to do everything that ClutterActor's
default implementation does - which I think it's a fair requirement to
have.
For newly written code, though, it would probably be best if we just
provided a function that does the right thing by default, and that
you're supposed to be calling from within the allocate() vfunc
implementation, if you ever chose to override it. This new function,
clutter_actor_set_allocation(), should come with a warning the size of
Texas, to avoid people thinking it's a way to override the whole "call
allocate() on each child" mechanism. Plus, it should check if we're
inside an allocation sequence, and bail out if not.
If we want to set a default layout manager, we need to do so inside
init(), as it's not guaranteed that people subclassing Actor and
overriding ::constructed will actually chain up as they should.
The default pick() behaviour does not take into consideration the
children of a ClutterActor because the existing containter actors
usually override pick(), chain up, and then paint their children.
With ClutterActor now a concrete class, though, we need a way to pick
its children without requiring a sub-class; we could simply iterate over
the children inside the default pick() implementation, but this would
lead to double painting, which is not acceptable.
A moderately gross hack is to check if the Actor instance did override
the pick() implementation, and if it is not the case, paint the children
in pick mode.
The hide_all() method is pretty much pointless, as hiding an actor will
automatically prevent its children from being painted. The show_all()
method would only be marginally useful, if actors weren't set to be
visible by default when added to another actor - which was the case when
we introduced show_all() and hide_all().
* Abstracts the buffer for text in ClutterText
* Allows implementation of undo/redo.
* Allows use of non-pageable memory for text
in the case of sensitive passwords.
* Implement a test with two ClutterText using the same
buffer.
https://bugzilla.gnome.org/show_bug.cgi?id=652653
When dereferencing GArray.data to a C structure you need a double cast
from guint8* to void*, and then from void* to the actual type. This
avoids compiler warnings, especially when using clang on OSX.
The concept of "internal child" only meant anything when we had a
separate API for containers and actors. Now that we plugged that
particular hole, we can drop all the hacks we used to have in place
to work around its design limitations.
It can be convenient to be able to set, or get, all the components of an
actor's margin at the same time; since we already have a boxed type for
storing a margin, an accessors pair based on it is not a complicated
addition to the API.
Inside the set_child_[above|below]_sibling() and set_child_at_index() we
should be using the internal API for mutating the children list, instead
of the delegate functions. This ensures that we go through a single,
well-defined code path for all operations on the list of children of
an actor.
We have a replacement in ClutterActor, now.
The old ClutterContainer API needs to be deprecated, and the raise() and
lower() virtual functions need a default implementation, so we can check
for implementations overriding them, by using the diagnostic mode like
we do for add(), remove(), and foreach().
The sort_depth_order() virtual function just doesn't do anything, as it
should have been made ages ago.
The Actor wrappers for the Container methods also need to be deprecated.
ClutterActor provides four methods for changing the paint sequence order
of its children:
raise_top()
raise()
lower()
lower_bottom()
The first and last one being just wrappers around raise() and lower(),
respectively. These methods have various issues: they omit the parent,
preferring to retrieve it from the actor passed as the first argument;
this does not match the new style of API introduced to operate on the
list of children of an actor.
Additionally, the raise() and lower() methods of ClutterActor call into
the Container interface, and are not really aptly named (raise() in
particular collides with the completely unrelated 'raise' keyword in
Python, and usually needs to be wrapped in order to be used at all).
Furthermore, we need public methods that Container can call from its
default implementation, as well as methods to port current Container
implementations.
Finally, since we have insert_child_at_index(), we should also have an
equivalent set_child_at_index() as well.
The internal versions of add_child() and remove_child() currently use
boolean arguments to control things like the ChildMeta instances and
the emissions of signals; using more than one boolean argument is an
indication that you need flags to avoid readability issues, as well as
providing a way to add new behaviours without a combinatorial explosion
of arguments, later on.
I don't feel comfortable with this feature, and its implementation
still has too many rough edges. We can safely punt it for now, and
introduce it at a later point, as it doesn't block existing features
or API.
This virtual function will let layout managers with legacy expansion
flags be able to influence the lazy computation of the expansion flags
on ClutterActor.
We need to paint the background color in the default class handler for
two reasons: it's logically appropriate, and we don't want actor
subclasses overriding the ::paint class handler to change behaviour only
because somebody decided to set the background color.
The old add(), remove(), and foreach() virtual functions are deprecated;
ClutterContainer should warn if the public API detects that the vfuncs
have been overridden.
Strictly speaking, it's still legal to override those vfuncs: you can
chain up to the default vtable, or you could just provide an equivalent
implementation. The goal is to avoid having to override the Container
interface, until we can safely deprecate it and remove it in Clutter
2.0.
Instead of making ClutterActor implement the basic add/remove/foreach
virtual functions of ClutterContainer, we can simply do that from
within the ClutterContainer implementation.
The get_children(), foreach(), and foreach_with_internals() methods and
virtual functions are superceded by the Actor API, and should not be
used in newly written code.
Given the size and scope of the changes in ClutterActor, we ought to
rewrite the overall description of what an actor is, what it does, and
how are you supposed to use it and subclass it.
This will make things interesting.
We have better replacements in ClutterActor, that do The Right Thing™
instead of deferring control and requiring reimplementation in every
single container actor.
The correct sequence of actions should be remove(old) → insert(new), not
insert(new) → remove(old). We can implement a simple delegate insertion
functions to insert the new child between the previous and next siblings
of the old child.
While we're at it, let's also add a unit test for replace_child().
Providing a default get_paint_volume() that takes into account the
children of an actor was a goal of the whole First Apocalypse; if we
make all the containers rely on it, and yet we return a FALSE value
(meaning: we don't have a valid paint volume) even when we do have it,
then we are going to break the whole machinery, though.
Cally is doing a bunch of list traversals through the list returned by
ClutterContainer.get_children(); this means a traversal already, plus
a bunch of allocations. We can do better than that, now that we have
a proper graph iteration API inside ClutterActor.
The insert_child_at_index, insert_below and insert_above messed up the
first and last child pointers in various cases. This commit fixes all
the instances of first and last child pointers being stale or set to
NULL.
Instead of getting the list of children to iterate over it, let's use
the newly added child iteration API; this should save us a bunch of
allocations, as well as indirections.
Ported: ClutterBinLayout and ClutterBoxLayout.
Instead of requiring every consumer of the ClutterActor API that wishes
to iterate over the children of an actor to use the get_children()
method, we should provide an iteration API directly inside ClutterActor
itself.
Instead of storing the list of children, let's turn Actor inside a
proper node of a tree.
This change adds the following members to the Actor private data
structure:
first_child
last_child
prev_sibling
next_sibling
and removes the "children" GList from it; iteration is performed through
the direct pointers to the siblings and children.
This change makes removal, insertion before a sibling, and insertion
after a sibling constant time operations, but it still retains the
feature of ClutterActor.add_child() to build the list of children while
taking into account the depth set on the newly added child, to allow the
default painter's algorithm we employ inside the paint() implementation
to at least try and cope with the :depth property (albeit in a fairly
naïve way). Changes in the :depth property will not change the paint
sequence any more: this functionality will be restored later.
ClutterTransformInfo is a (private) ancillary data structure that
contains all the decomposed transformation data, i.e. rotation angles
and centers, scale factors and centers, and anchor point. This data
structure is stored in the GData of the actor instance instead of the
actor's private data. This change gives us:
• a smaller, cleaner private data structure;
• no size penalty for untransformed actors;
• static constant storage for the defaults, shared across all
instances;
• cache locality for all the decomposed transformation data,
given that the structure size is smaller.
At the end of the day, the only authoritative piece of information for
actor transformation is the CoglMatrix that we initialize in
apply_transform() from all the decomposed parameters, and that can stay
inside the private data structure of ClutterActor.
There are only two kinds of actors that allow underallocations,
according to the API contract:
• ClutterStage, as it is a viewport and it doesn't have an implicit
minimum size;
• Actors using the CLUTTER_ACTOR_NO_LAYOUT escape hatch, which allows
them to bail out from our layout management policies.
The warning about underallocations should take these two exceptions
under consideration.
The Group functionality is now provided by ClutterActor.
Sadly, we need to keep the ClutterGroup structure definition in the
non-deprecated header because ClutterStage inherits from Group - an API
wart that was never fixed during the 0.x cycles, and that we'll have to
keep around until we can break API.
