Emmanuele Bassi [Fri, 27 Jan 2012 11:42:33 +0000 (11:42 +0000)]
conform: Avoid a deadlock
Something is causing a deadlock when using clutter_threads_* API inside
the offscreen redirect conformance test. The conformance tests are
pretty insane anyway, so for the time being, let's put g_timeout_add()
back in while we figure out the issue.
Emmanuele Bassi [Fri, 27 Jan 2012 09:47:25 +0000 (09:47 +0000)]
tests: Update to use the symbolic button names
https://bugzilla.gnome.org/show_bug.cgi?id=668692
Emmanuele Bassi [Fri, 27 Jan 2012 09:46:51 +0000 (09:46 +0000)]
docs: Update to show the symbolic button names
https://bugzilla.gnome.org/show_bug.cgi?id=668692
Emmanuele Bassi [Fri, 27 Jan 2012 09:46:10 +0000 (09:46 +0000)]
drag-action: Use the symbolic constants for the button
https://bugzilla.gnome.org/show_bug.cgi?id=668692
Emmanuele Bassi [Fri, 27 Jan 2012 09:43:06 +0000 (09:43 +0000)]
event: Add symbolic names for left, middle, and right buttons
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
Emmanuele Bassi [Fri, 27 Jan 2012 07:30:02 +0000 (07:30 +0000)]
doc/cookbook: Remove dead link
Emmanuele Bassi [Thu, 26 Jan 2012 17:11:27 +0000 (17:11 +0000)]
Remove unused variable
Rob Bradford [Thu, 26 Jan 2012 15:39:16 +0000 (15:39 +0000)]
wayland: Correctly support fullscreening before the stage is realized
Rather than just call into wl_shell_surface_set_fullscreen we must repeat all
the steps to correctly fullscreen the surface.
Rob Bradford [Thu, 26 Jan 2012 14:23:57 +0000 (14:23 +0000)]
wayland: Force a redraw of the stage to get the new sized buffer attached
Rob Bradford [Thu, 26 Jan 2012 14:23:16 +0000 (14:23 +0000)]
wayland: Use new stage state manipulation functions
Rob Bradford [Mon, 23 Jan 2012 13:07:13 +0000 (13:07 +0000)]
wayland: Refine fullscreen/unfullscreen to emit the state change events
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.
Rob Bradford [Fri, 20 Jan 2012 15:49:16 +0000 (15:49 +0000)]
wayland: Support programmatically resizing the stage
This will call into Cogl and ask it to resize the framebuffer which will then
update the underlying EGL surface.
Rob Bradford [Thu, 12 Jan 2012 15:25:02 +0000 (15:25 +0000)]
wayland: Support setting fullscreen before the stage is realized
Rob Bradford [Fri, 9 Dec 2011 16:54:52 +0000 (16:54 +0000)]
wayland: Implement set_fullscreen vfunc in ClutterStageWayland
Rob Bradford [Fri, 9 Dec 2011 16:52:29 +0000 (16:52 +0000)]
wayland: Include the Wayland surface and shell surface in ClutterStageWayland
Rob Bradford [Fri, 20 Jan 2012 18:22:50 +0000 (18:22 +0000)]
wayland: Save the output mode so that it can be used to fullscreen windows
Emmanuele Bassi [Thu, 26 Jan 2012 10:29:50 +0000 (10:29 +0000)]
x11: Unbreak the build
The stage wrapper is on the ClutterStageCogl instance.
Emmanuele Bassi [Thu, 26 Jan 2012 08:42:00 +0000 (08:42 +0000)]
Merge branch 'stage-state'
* 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
Emmanuele Bassi [Thu, 26 Jan 2012 08:33:45 +0000 (08:33 +0000)]
docs: Update ClutterStageState flags
Emmanuele Bassi [Thu, 26 Jan 2012 08:27:39 +0000 (08:27 +0000)]
wayland: Use the Stage state tracking
Emmanuele Bassi [Thu, 26 Jan 2012 08:27:25 +0000 (08:27 +0000)]
gdk: Use the Stage state tracking
Emmanuele Bassi [Thu, 26 Jan 2012 08:27:08 +0000 (08:27 +0000)]
win32: Use the Stage state tracking
Emmanuele Bassi [Wed, 25 Jan 2012 21:36:55 +0000 (21:36 +0000)]
x11: Use the Stage state tracking
Emmanuele Bassi [Wed, 25 Jan 2012 21:25:59 +0000 (21:25 +0000)]
osx: Use the Stage state tracking
Emmanuele Bassi [Wed, 25 Jan 2012 21:24:47 +0000 (21:24 +0000)]
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.
Emmanuele Bassi [Wed, 25 Jan 2012 23:09:38 +0000 (23:09 +0000)]
tests/*: Use symbolic constants for sources and events
And make sure to use clutter_threads_add_* instead of the bare
g_*_add().
Emmanuele Bassi [Wed, 25 Jan 2012 23:09:03 +0000 (23:09 +0000)]
docs: Use symbolic constants for sources and events
Emmanuele Bassi [Wed, 25 Jan 2012 23:17:42 +0000 (23:17 +0000)]
x11/stage: Use symbolic constants for source function
And make sure to use the clutter_threads_add_timeout(), so that the
function is called under the Clutter lock.
Emmanuele Bassi [Tue, 24 Jan 2012 15:42:20 +0000 (15:42 +0000)]
Post-release version bump to 1.9.9
Emmanuele Bassi [Tue, 24 Jan 2012 15:20:35 +0000 (15:20 +0000)]
Release Clutter 1.9.8 (snapshot)
Emmanuele Bassi [Tue, 24 Jan 2012 15:12:41 +0000 (15:12 +0000)]
cookbook: Start migrating to the new API
Drop mentions of deprecated classes and API, and update the inline
example code.
Still some way to go, and the cookbook would probably benefit from
having a recipe on how to use ClutterActor to build a scene.
Emmanuele Bassi [Tue, 24 Jan 2012 15:01:00 +0000 (15:01 +0000)]
cookbook: Begin porting examples to the new API
Start dropping the usage of deprecated classes and API.
Emmanuele Bassi [Tue, 24 Jan 2012 14:52:33 +0000 (14:52 +0000)]
actor: use paint opacity to paint the background color
Emmanuele Bassi [Tue, 24 Jan 2012 14:20:07 +0000 (14:20 +0000)]
docs: Add missing function
Emmanuele Bassi [Tue, 24 Jan 2012 14:13:53 +0000 (14:13 +0000)]
docs: Inlined examples break enums gtk-doc
Emmanuele Bassi [Mon, 16 Jan 2012 11:27:08 +0000 (11:27 +0000)]
script: Add loading from a resource
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.
Emmanuele Bassi [Tue, 24 Jan 2012 09:36:31 +0000 (09:36 +0000)]
actor: Remove unused function
Emmanuele Bassi [Mon, 23 Jan 2012 18:00:01 +0000 (18:00 +0000)]
Override Container inside ClutterStage
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.
Emmanuele Bassi [Sat, 21 Jan 2012 23:06:49 +0000 (23:06 +0000)]
Allow mixing old and new API without falling apart
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.
Emmanuele Bassi [Fri, 20 Jan 2012 18:05:53 +0000 (18:05 +0000)]
interactive/actors: Update the venerable test-actors
Fran Diéguez [Sun, 22 Jan 2012 23:34:20 +0000 (00:34 +0100)]
Updated Galician translations
Emmanuele Bassi [Fri, 20 Jan 2012 17:15:20 +0000 (17:15 +0000)]
actor: NULL-ify sibling fields when removing
Let's try and avoid leaving around stale pointers.
Rob Bradford [Mon, 16 Jan 2012 11:55:32 +0000 (11:55 +0000)]
wayland: Update to changes in the SHM api
The enum value for the SHM formats has changed to be more explicit about the
format of the data.
Emmanuele Bassi [Fri, 20 Jan 2012 16:00:19 +0000 (16:00 +0000)]
group: Restore previous implementation
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.
Emmanuele Bassi [Fri, 20 Jan 2012 14:55:57 +0000 (14:55 +0000)]
stage: Restore the chain up inside allocate()
Group does not have a custom allocate() any more, so it would end up
calling the default allocate() implementation provided by ClutterActor
anyway.
Emmanuele Bassi [Fri, 20 Jan 2012 14:55:13 +0000 (14:55 +0000)]
actor: Remove default layout-manager
It's creating more issues than what it's trying to solve. At least for
the time being, let's not set one.
Emmanuele Bassi [Fri, 20 Jan 2012 14:53:41 +0000 (14:53 +0000)]
group: Gut the implementation
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.
Emmanuele Bassi [Fri, 20 Jan 2012 12:04:48 +0000 (12:04 +0000)]
actor: Move underallocation warning to diagnostic mode
This should keep down the warning messages — at least for the time
being.
Emmanuele Bassi [Fri, 20 Jan 2012 12:02:49 +0000 (12:02 +0000)]
actor: Use internal add/remove child in reparent()
Do not use the public API; reparent() used to use unparent() and
set_parent(), so we need to maintain the old behaviour.
Emmanuele Bassi [Thu, 19 Jan 2012 14:01:20 +0000 (14:01 +0000)]
Post-release version bump to 1.9.7
Emmanuele Bassi [Thu, 19 Jan 2012 13:42:37 +0000 (13:42 +0000)]
Release Clutter 1.9.6 (snapshot)
Emmanuele Bassi [Thu, 19 Jan 2012 13:41:45 +0000 (13:41 +0000)]
build: Bump up the Cogl requirement
Clutter requires a new version of Cogl's API, but we never bumped the
requirement inside configure.ac.
Emmanuele Bassi [Thu, 19 Jan 2012 13:40:02 +0000 (13:40 +0000)]
stage: Use clutter_actor_set_allocation()
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.
Emmanuele Bassi [Thu, 19 Jan 2012 13:39:14 +0000 (13:39 +0000)]
actor: Fix the has_overridden_allocate check
Emmanuele Bassi [Thu, 19 Jan 2012 13:14:47 +0000 (13:14 +0000)]
docs: Add clutter_actor_set_allocation()
Emmanuele Bassi [Thu, 19 Jan 2012 13:14:33 +0000 (13:14 +0000)]
symbols: Add clutter_actor_set_allocation()
Emmanuele Bassi [Thu, 19 Jan 2012 12:40:32 +0000 (12:40 +0000)]
actor: Maintain behaviour of old allocate() implementations
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.
Emmanuele Bassi [Wed, 18 Jan 2012 16:05:12 +0000 (16:05 +0000)]
actor: Be more conservative with the default paint volume
Check the allocation, when one is being used to initialize the paint
volume.
Daniel Mustieles [Wed, 18 Jan 2012 11:39:55 +0000 (12:39 +0100)]
Updated Spanish translation
Emmanuele Bassi [Tue, 17 Jan 2012 22:54:44 +0000 (22:54 +0000)]
build: Fix up the test rules for private deps
Thanks to diegoe for the help with testing.
Piotr Drąg [Tue, 17 Jan 2012 22:24:14 +0000 (23:24 +0100)]
Updated POTFILES.in
Emmanuele Bassi [Tue, 17 Jan 2012 21:59:37 +0000 (21:59 +0000)]
build: Add private deps to cflags and libs
If we go through the whole exercise of having private dependencies, we
should at least use the compiler flags and linker flags that those
dependencies give us when building Clutter.
https://bugzilla.gnome.org/show_bug.cgi?id=668137
Emmanuele Bassi [Tue, 17 Jan 2012 18:46:41 +0000 (18:46 +0000)]
actor: Add :first-child and :last-child properties
Toolkits tracking first and last children of a ClutterActor can use
these properties to get notification of hierarchy changes.
Emmanuele Bassi [Tue, 17 Jan 2012 18:13:42 +0000 (18:13 +0000)]
actor: Do not use ::constructed
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.
Emmanuele Bassi [Tue, 17 Jan 2012 16:54:30 +0000 (16:54 +0000)]
interactive: Drop more deprecated classes
Emmanuele Bassi [Tue, 17 Jan 2012 16:20:41 +0000 (16:20 +0000)]
interactive: Use ClutterActor instead of deprecated classes
Emmanuele Bassi [Tue, 17 Jan 2012 16:20:19 +0000 (16:20 +0000)]
conform/actor-size: Do not use Rectangle
Use ClutterActor directly, instead.
Emmanuele Bassi [Tue, 17 Jan 2012 16:13:55 +0000 (16:13 +0000)]
actor: Provide a better default pick() behaviour
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.
Emmanuele Bassi [Tue, 17 Jan 2012 16:11:29 +0000 (16:11 +0000)]
actor: Deprecate show_all()/hide_all()
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().
Daniel Mustieles [Tue, 17 Jan 2012 16:12:52 +0000 (17:12 +0100)]
Updated Spanish translation
Emmanuele Bassi [Tue, 17 Jan 2012 14:44:28 +0000 (14:44 +0000)]
Post-release version bump to 1.9.5
Emmanuele Bassi [Tue, 17 Jan 2012 14:32:19 +0000 (14:32 +0000)]
Release Clutter 1.9.4 (snapshot)
Emmanuele Bassi [Tue, 17 Jan 2012 14:21:02 +0000 (14:21 +0000)]
text: Fix the buffer length check on paint
Emmanuele Bassi [Tue, 17 Jan 2012 14:17:20 +0000 (14:17 +0000)]
script: Fix a segfault
Accessing a variable before it is being set is not a great plan.
Emmanuele Bassi [Tue, 17 Jan 2012 12:23:28 +0000 (12:23 +0000)]
text-buffer: Fix the Since annotations
Emmanuele Bassi [Tue, 17 Jan 2012 12:19:35 +0000 (12:19 +0000)]
Update the NEWS file
Emmanuele Bassi [Tue, 17 Jan 2012 12:00:54 +0000 (12:00 +0000)]
Add ClutterTextBuffer to the API reference
Emmanuele Bassi [Tue, 17 Jan 2012 11:56:23 +0000 (11:56 +0000)]
Update clutter.symbols for TextBuffer
Emmanuele Bassi [Tue, 17 Jan 2012 11:52:37 +0000 (11:52 +0000)]
interactive/text: Remove spurious g_object_unref()
Stef Walter [Wed, 15 Jun 2011 09:06:31 +0000 (10:06 +0100)]
text: Implement ClutterTextBuffer
* 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
Daniel Mustieles [Tue, 17 Jan 2012 11:52:01 +0000 (12:52 +0100)]
Updated Spanish translation
Emmanuele Bassi [Tue, 17 Jan 2012 11:49:05 +0000 (11:49 +0000)]
Update clutter.symbols
Fran Diéguez [Tue, 17 Jan 2012 00:44:53 +0000 (01:44 +0100)]
Updated Galician translations
Piotr Drąg [Tue, 17 Jan 2012 00:29:26 +0000 (01:29 +0100)]
Updated POTFILES.in
Emmanuele Bassi [Mon, 16 Jan 2012 23:49:49 +0000 (23:49 +0000)]
Fix compiler warnings
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.
Emmanuele Bassi [Tue, 3 Jan 2012 14:51:37 +0000 (14:51 +0000)]
docs: Move deprecated sections to the proper location
Emmanuele Bassi [Tue, 3 Jan 2012 14:36:32 +0000 (14:36 +0000)]
actor: Deprecated push/pop internal methods
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.
Emmanuele Bassi [Tue, 3 Jan 2012 14:31:06 +0000 (14:31 +0000)]
docs: Fixes for the API reference
Emmanuele Bassi [Tue, 3 Jan 2012 14:29:39 +0000 (14:29 +0000)]
actor: Add boxed margin accessors
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.
Emmanuele Bassi [Wed, 28 Dec 2011 18:37:16 +0000 (18:37 +0000)]
docs: Update the release notes
Emmanuele Bassi [Wed, 28 Dec 2011 18:32:00 +0000 (18:32 +0000)]
build: Add inclusion guards and license notices
Emmanuele Bassi [Tue, 27 Dec 2011 19:28:47 +0000 (19:28 +0000)]
actor: Use proper internal 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.
Emmanuele Bassi [Tue, 27 Dec 2011 18:57:32 +0000 (18:57 +0000)]
Deprecate the old raise/lower API
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.
Emmanuele Bassi [Tue, 27 Dec 2011 18:22:05 +0000 (18:22 +0000)]
actor: Add new methods for changing the paint sequence
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.
Emmanuele Bassi [Tue, 27 Dec 2011 11:28:36 +0000 (11:28 +0000)]
actor: Use flags to control add/remove child
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.
Emmanuele Bassi [Wed, 21 Dec 2011 17:07:25 +0000 (17:07 +0000)]
actor: Remove automagic "expand" flag
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.
Emmanuele Bassi [Tue, 20 Dec 2011 18:42:53 +0000 (18:42 +0000)]
table-layout: Override compute_expand()
The TableLayout has two expansion flags that need to be taken into
consideration when computing the Actor expansion flags.
Emmanuele Bassi [Tue, 20 Dec 2011 18:41:51 +0000 (18:41 +0000)]
box-layout: Override compute_expand()
ClutterBoxLayout has an expansion flag, and we need to take that into
consideration when computing the Actor expansion flags.
Emmanuele Bassi [Tue, 20 Dec 2011 18:40:11 +0000 (18:40 +0000)]
actor: Ask the LayoutManager to compute the expansion flags
If an actor has a layout manager, we want to involve the delegate object
into the lazy computation of the expansion flags state.
Emmanuele Bassi [Tue, 20 Dec 2011 18:38:47 +0000 (18:38 +0000)]
layout-manager: Add compute_expand() vfunc
This virtual function will let layout managers with legacy expansion
flags be able to influence the lazy computation of the expansion flags
on ClutterActor.