One of the uses of a ClutterState state machine along with ClutterScript
is to provide a quick way to transition from state to state in response
to signal emitted on specific instances.
Connecting a real function, in code, to a specific signal does not
improve the ease of use of ClutterScript to define scenes.
By adding a new signal definition to the current one we can have both a
simple way to define application logic in code and in the UI definition
file.
The new syntax is trivial:
{
"name" : <signal name>,
"state" : <state machine script id>,
"target-state" : <target state>
}
The ClutterState instance is identified by its script id, and the target
state is resolved at run-time, so it can be defined both in
ClutterScript or in code. Ideally, we should find a way to associate a
default ClutterState instance to the ClutterScript one that parses the
definition; this way we would be able to remove the "state" member, or
even "style" the behaviour of an object by replacing the ClutterState
instance.
The implementation uses a signal emission hook, to avoid knowing the
signal signature; we check the emitter of the signal against the object
that defined the signal, to avoid erroneous state changes.
Currently, the memory management in ClutterScript is overly complicated.
The basic design tenet should be:
- ClutterScript owns a reference on every object it creates
This allows the Script instance to reliably handle the lifetime of the
instances from creation to disposal.
In case of unmerge, the Script instance should destroy any Actor
instance, except for the Stage, and release the reference it owns. The
Stage is special because it's really owned by Clutter itself, and it
should be destroyed explicitly.
When disposing the Script itself, it should just release the reference;
any parented actor, or any InitiallyUnowned instance, will then be
managed by the parent object, as they should, while every GObject
instance will go away, as documented.
This commit is based on a patch by:
Henrik Hedberg <hhedberg@innologies.fi>
http://bugzilla.clutter-project.org/show_bug.cgi?id=2316
The internal copy of JSON-GLib was meant to go away right after the 1.0
release, given that JSON-GLib was still young and relatively unknown.
Nowadays, many projects started depending on this little library, and
distributions ship it and keep it up to date.
Keeping a copy of JSON-GLib means keeping it up to date; unfortunately,
this would also imply updating the code not just for the API but for the
internal implementations.
Starting with the 1.2 release, Clutter preferably dependend on the
system copy; with the 1.4 release we stopped falling back automatically.
The 1.6 cycle finally removes the internal copy and requires a copy of
JSON-GLib installed on the target system in order to compile Clutter.
Up until now, the "behaviours" member of an actor definition was parsed
by the ClutterScript parser itself - even though it's not strictly
necessary.
In an effort to minimize the ad hoc code in the Script parser, we should
let ClutterActor handle all the special cases that involve
actor-specific members.
The get_id_from_node() internal function should be exposed inside
Clutter (as a private function) because it can be useful to other
custom parsing code. The code is pretty trivial, but it would be
pointless to re-implement it.
Layout properties work similarly to child properties, with the added
headache that they require the 3-tuple:
( layout manager, container, actor )
to be valid in order to be inspected, parsed and applied. This means
using the newly added back-pointer from the container to the layout
manager and then rejigging a bit how the ScriptParser handles the
unresolved properties.
Similarly to the child properties, which use the "child::" prefix, the
layout manager properties use the "layout::" prefix and are defined with
the child of a container holding a layout manager.
Since using addresses that might change is something that finally
the FSF acknowledge as a plausible scenario (after changing address
twice), the license blurb in the source files should use the URI
for getting the license in case the library did not come with it.
Not that URIs cannot possibly change, but at least it's easier to
set up a redirection at the same place.
As a side note: this commit closes the oldes bug in Clutter's bug
report tool.
http://bugzilla.openedhand.com/show_bug.cgi?id=521
Instead of taking a string and duplicating the "is it a string or an
integer" check in both Alpha and Animation, the function in
ClutterScript that resolves the animation mode values should take a
JsonNode and do all the checks it needs.
ClutterBehaviour should implement the Scriptable interface
and parse ClutterAlpha when implicitly defined, instead of
having this ad hoc code inside ClutterScriptParser itself.
After all, only ClutterBehaviour supports Alpha defined
implicitly.
The ClutterScript parser needs to be extended to parse child properties
and apply them after an actor has been added to a container. In order to
distinguish child properties from regular GObject properties we can use
the "child::" prefix, e.g.:
{
"type" : "ClutterRectangle",
"id" : "child-01",
"child::has-focus" : true,
...
}
Parsing child properties can be deferred to the ClutterScriptable
interface, just like regular properties.
Currently, ClutterScriptParser will construct the object (using the
construct-only and construct parameters), apply the properties from
the ClutterScript definition, and eventuall will add children and
behaviours.
The construction phase should be more compartimentalized: the objects
should be constructed first and eventual children and behaviours
added. Then, once an object is requested or when the parsing process
has terminated, all the properties should be applied.
This change allows us to set up the actors before setting their
non-construct properties.
ClutterScript is currently a mix of parser-related code and
the ClutterScript object. All the parser-related code should
be moved inside a private class, ClutterScriptParser, inheriting
from JsonParser.
The json-types.h header is found by the mere fact of it being
in the project; if we are compiling against the system JSON-GLib
this could be horribly out of date.
We need to use clutter-json.h, which will include the right
header for us.
* clutter/clutter-script-parser.c:
* clutter/clutter-script-private.h: Clean up the code; add a
conversion function for reading a ClutterColor out of a
JSON object or array definition.
* clutter/clutter-script.c: Clean up the code; document properly
how we translate from type name to type function.
* clutter/clutter-script-private.h: Add a flag for the
default stage.
* clutter/clutter-script.c:
(json_object_end): If the "type" member is "ClutterStage"
and we have a "is-default" member set to true then this
is the default stage.
(clutter_script_construct_object): Special case the default
stage instead of each ClutterStage.
(object_info_free): Ditto as above.
* tests/test-script.json: Test the creation of a non-default
stage and the ::destroy handler to quit.
Remove the layout containers: they will be moved to a
high-level library.
* clutter/clutter.h:
* clutter/Makefile.am: Remove layout and boxes from the
build.
* clutter/clutter-layout.[ch]: Remove the ClutterLayout
interface.
* clutter/clutter-box.[ch]:
* clutter/clutter-hbox.[ch]:
* clutter/clutter-vbox.[ch]: Remove ClutterBox and its
subclasses.
* clutter/clutter-label.c: Remove ClutterLayout implementation
* clutter/clutter-script-private.h:
* clutter/clutter-script-parser.c:
* clutter/clutter-script.c:
(clutter_script_parse_node): Remove special parsing for
ClutterMargin and ClutterPadding.
* clutter/clutter-types.h: Remove ClutterPadding and ClutterMargin.
* tests/Makefile.am:
* tests/test-boxes.c: Remove the boxes test case.
* clutter.symbols: Update with the new public symbols
* clutter/clutter-script.h:
* clutter/clutter-script-private.h:
* clutter/clutter-script.c:
(parse_signals), (json_object_end),
(signal_info_free), (object_info_free): Parse the "signals"
member for GObjects.
(clutter_script_connect_signals),
(clutter_script_connect_signals_full): Add new API for autoconnecting
signal handlers using the UI definition files.
* tests/test-script.c:
* tests/test-script.json: Test signal autoconnection.
* clutter/Makefile.am:
* clutter/clutter.h:
* clutter/clutter-scriptable.[ch]: Add the ClutterScriptable
interface; by implementing this interface, a class can
override the UI definition parsing and transform complex data
types into GObject properties, or allow custom properties.
* clutter/clutter-script.c:
* clutter/clutter-script-parser.c:
* clutter/clutter-script-private.h: Rearrange the code and
use the ClutterScriptable interface to parse and build the
custom properties. This cleans up the code and also it makes
it more reliable (the complex type parsing is now done using
the target type and not just the name of the property).
* clutter/clutter-script-private.h:
* clutter/clutter-script.h:
* clutter/clutter-script.c: Allow id-less objects: as long
as they have a "type" member, a unique id will be provided.
(json_object_end): Add merge id to the object information
structure.
(apply_behaviours), (add_children): Keep the unresolved
objects around.
(construct_stage), (clutter_script_construct_object): If an
object has unresolved children or behaviours try resolving
them when we ask for it.
(json_parse_end), (clutter_script_ensure_objects): Ensure
that the objects are fully constructed as best as we can when
finished parsing.
(object_info_free), (remove_by_merge_id):
(clutter_script_unmerge_objects): Remove objects under the
same merge id returned by the loading functions. (Fixes
bug #558)
* clutter/json/json-parser.c: Use the commodity JsonNode API
and accept bare values as root nodes.
* clutter/clutter-script-private.h:
* clutter/clutter-script.c: Unreference the created objects
only if they are top-levels, like ClutterBehaviour and
ClutterTimelines. Actors have floating references, so we
just transfer ownership to their containers, and the stage
is owned by the backend. Add the "type_func" key to the
object definition, so the user can supply its own GType
function if the class name doesn't follow the GObject rules.
Document the ClutterScript public API.
* clutter/clutter-script-private.h:
* clutter/clutter-script.h:
* clutter/clutter-script.c: Add licensing information to
the newly added files.
* clutter/clutter-script.c: Support creating behaviours with
ClutterScript. ClutterAlpha objects are implicit, but
timelines can be both explicit objects using their id or
implicit objects. Make the property resolution and translation
more robust. Support the pixbuf property.
* tests/test-script.c: Test the newly added features.
* docs/reference/clutter-docs.sgml:
* docs/reference/clutter-sections.txt: Add ClutterScript.
Initial implementation of the UI definition files. (#424)
* clutter/json/Makefile.am:
* clutter/json/*.[ch]: In-tree copy of JSON-GLib, a GLib-based
JSON parser/generator library. We use it in-tree because we might
need to change the API. Ideally, we'd depend on it.
* clutter/clutter.h:
* clutter/clutter-script-private.h:
* clutter/clutter-script.[ch]: ClutterScript, the scenegraph
generator class. It parses JSON streams in form of buffers and
files and builds the scene.
* clutter/clutter-debug.h:
* clutter/clutter-main.c: Add a "script" debug flag
* clutter/Makefile.am: Build glue.
* tests/Makefile.am:
* tests/test-script.c: Add a test case for the ClutterScript.
* configure.ac: Depend on GLib 2.14, so we can use the
g_hash_table_get_key() and g_hash_table_get_values() functions
for the time being; we can probably reimplement those, but we
are going to need 2.14 anyway if we are going to implement a
list model using GSequence.
