ClutterScript

ClutterScript — Loads a scene from UI definition data

Properties

gchar * filename Read
gboolean filename-set Read
gchar * translation-domain Read / Write

Types and Values

Object Hierarchy

    GObject
    ╰── ClutterScript

Description

ClutterScript is an object used for loading and building parts or a complete scenegraph from external definition data in forms of string buffers or files.

The UI definition format is JSON, the JavaScript Object Notation as described by RFC 4627. ClutterScript can load a JSON data stream, parse it and build all the objects defined into it. Each object must have an "id" and a "type" properties defining the name to be used to retrieve it from ClutterScript with clutter_script_get_object(), and the class type to be instanciated. Every other attribute will be mapped to the class properties.

A ClutterScript holds a reference on every object it creates from the definition data, except for the stage. Every non-actor object will be finalized when the ClutterScript instance holding it will be finalized, so they need to be referenced using g_object_ref() in order for them to survive.

A simple object might be defined as:

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{
  "id"     : "red-button",
  "type"   : "ClutterRectangle",
  "width"  : 100,
  "height" : 100,
  "color"  : "#ff0000ff"
}

This will produce a red ClutterRectangle, 100x100 pixels wide, and with a ClutterScript id of "red-button"; it can be retrieved by calling:

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ClutterActor *red_button;

red_button = CLUTTER_ACTOR (clutter_script_get_object (script, "red-button"));

and then manipulated with the Clutter API. For every object created using ClutterScript it is possible to check the id by calling clutter_get_script_id().

Packing can be represented using the "children" member, and passing an array of objects or ids of objects already defined (but not packed: the packing rules of Clutter still apply, and an actor cannot be packed in multiple containers without unparenting it in between).

Behaviours and timelines can also be defined inside a UI definition buffer:

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{
  "id"          : "rotate-behaviour",
  "type"        : "ClutterBehaviourRotate",
  "angle-start" : 0.0,
  "angle-end"   : 360.0,
  "axis"        : "z-axis",
  "alpha"       : {
    "timeline" : { "duration" : 4000, "loop" : true },
    "mode"     : "easeInSine"
  }
}

And then to apply a defined behaviour to an actor defined inside the definition of an actor, the "behaviour" member can be used:

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{
  "id" : "my-rotating-actor",
  "type" : "ClutterTexture",
  ...
  "behaviours" : [ "rotate-behaviour" ]
}

A ClutterAlpha belonging to a ClutterBehaviour can only be defined implicitly like in the example above, or explicitly by setting the "alpha" property to point to a previously defined ClutterAlpha, e.g.:

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{
  "id"          : "rotate-behaviour",
  "type"        : "ClutterBehaviourRotate",
  "angle-start" : 0.0,
  "angle-end"   : 360.0,
  "axis"        : "z-axis",
  "alpha"       : {
    "id"       : "rotate-alpha",
    "type"     : "ClutterAlpha",
    "timeline" : {
      "id"       : "rotate-timeline",
      "type      : "ClutterTimeline",
      "duration" : 4000,
      "loop"     : true
    },
    "function" : "custom_sine_alpha"
  }
}

Implicitely defined ClutterAlphas and ClutterTimelines can omit the id, as well as the type members, but will not be available using clutter_script_get_object() (they can, however, be extracted using the ClutterBehaviour and ClutterAlpha API respectively).

Signal handlers can be defined inside a Clutter UI definition file and then autoconnected to their respective signals using the clutter_script_connect_signals() function:

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...
"signals" : [
  { "name" : "button-press-event", "handler" : "on_button_press" },
  {
    "name" : "foo-signal",
    "handler" : "after_foo",
    "after" : true
  },
],
...

Signal handler definitions must have a "name" and a "handler" members; they can also have the "after" and "swapped" boolean members (for the signal connection flags G_CONNECT_AFTER and G_CONNECT_SWAPPED respectively) and the "object" string member for calling g_signal_connect_object() instead of g_signal_connect().

Signals can also be directly attached to a specific state defined inside a ClutterState instance, for instance:

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...
"signals" : [
  {
    "name" : "enter-event",
    "states" : "button-states",
    "target-state" : "hover"
  },
  {
    "name" : "leave-event",
    "states" : "button-states",
    "target-state" : "base"
  },
  {
    "name" : "button-press-event",
    "states" : "button-states",
    "target-state" : "active",
  },
  {
    "name" : "key-press-event",
    "states" : "button-states",
    "target-state" : "key-focus",
    "warp" : true
  }
],
...

The "states" key defines the ClutterState instance to be used to resolve the "target-state" key; it can be either a script id for a ClutterState built by the same ClutterScript instance, or to a ClutterState built in code and associated to the ClutterScript instance through the clutter_script_add_states() function. If no "states" key is present, then the default ClutterState associated to the ClutterScript instance will be used; the default ClutterState can be set using clutter_script_add_states() using a NULL name. The "warp" key can be used to warp to a specific state instead of animating to it. State changes on signal emission will not affect the signal emission chain.

Clutter reserves the following names, so classes defining properties through the usual GObject registration process should avoid using these names to avoid collisions:

  "id"         := the unique name of a ClutterScript object
  "type"       := the class literal name, also used to infer the type
                  function
  "type_func"  := the GType function name, for non-standard classes
  "children"   := an array of names or objects to add as children
  "behaviours" := an array of names or objects to apply to an actor
  "signals"    := an array of signal definitions to connect to an object
  "is-default" := a boolean flag used when defining the #ClutterStage;
                  if set to "true" the default stage will be used instead
                  of creating a new #ClutterStage instance

ClutterScript is available since Clutter 0.6

Functions

clutter_script_new ()

ClutterScript *
clutter_script_new (void);

Creates a new ClutterScript instance. ClutterScript can be used to load objects definitions for scenegraph elements, like actors, or behavioural elements, like behaviours and timelines. The definitions must be encoded using the JavaScript Object Notation (JSON) language.

Returns

the newly created ClutterScript instance. Use g_object_unref() when done.

Since: 0.6


clutter_script_load_from_data ()

guint
clutter_script_load_from_data (ClutterScript *script,
                               const gchar *data,
                               gssize length,
                               GError **error);

Loads the definitions from data into script and merges with the currently loaded ones, if any.

Parameters

script

a ClutterScript

 

data

a buffer containing the definitions

 

length

the length of the buffer, or -1 if data is a NUL-terminated buffer

 

error

return location for a GError, or NULL

 

Returns

on error, zero is returned and error is set accordingly. On success, the merge id for the UI definitions is returned. You can use the merge id with clutter_script_unmerge_objects().

Since: 0.6


clutter_script_load_from_file ()

guint
clutter_script_load_from_file (ClutterScript *script,
                               const gchar *filename,
                               GError **error);

Loads the definitions from filename into script and merges with the currently loaded ones, if any.

Parameters

script

a ClutterScript

 

filename

the full path to the definition file

 

error

return location for a GError, or NULL

 

Returns

on error, zero is returned and error is set accordingly. On success, the merge id for the UI definitions is returned. You can use the merge id with clutter_script_unmerge_objects().

Since: 0.6


clutter_script_load_from_resource ()

guint
clutter_script_load_from_resource (ClutterScript *script,
                                   const gchar *resource_path,
                                   GError **error);

Loads the definitions from a resource file into script and merges with the currently loaded ones, if any.

Parameters

script

a ClutterScript

 

resource_path

the resource path of the file to parse

 

error

return location for a GError, or NULL

 

Returns

on error, zero is returned and error is set accordingly. On success, the merge id for the UI definitions is returned. You can use the merge id with clutter_script_unmerge_objects().

Since: 1.10


clutter_script_add_search_paths ()

void
clutter_script_add_search_paths (ClutterScript *script,
                                 const gchar * const paths[],
                                 gsize n_paths);

Adds paths to the list of search paths held by script .

The search paths are used by clutter_script_lookup_filename(), which can be used to define search paths for the textures source file name or other custom, file-based properties.

Parameters

script

a ClutterScript

 

paths

an array of strings containing different search paths.

[array length=n_paths]

n_paths

the length of the passed array

 

Since: 0.8


clutter_script_lookup_filename ()

gchar *
clutter_script_lookup_filename (ClutterScript *script,
                                const gchar *filename);

Looks up filename inside the search paths of script . If filename is found, its full path will be returned .

Parameters

script

a ClutterScript

 

filename

the name of the file to lookup

 

Returns

the full path of filename or NULL if no path was found.

Since: 0.8


clutter_script_get_object ()

GObject *
clutter_script_get_object (ClutterScript *script,
                           const gchar *name);

Retrieves the object bound to name . This function does not increment the reference count of the returned object.

Parameters

script

a ClutterScript

 

name

the name of the object to retrieve

 

Returns

the named object, or NULL if no object with the given name was available.

[transfer none]

Since: 0.6


clutter_script_get_objects ()

gint
clutter_script_get_objects (ClutterScript *script,
                            const gchar *first_name,
                            ...);

Retrieves a list of objects for the given names. After script , object names/return location pairs should be listed, with a NULL pointer ending the list, like:

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GObject *my_label, *a_button, *main_timeline;

clutter_script_get_objects (script,
                            "my-label", &my_label,
                            "a-button", &a_button,
                            "main-timeline", &main_timeline,
                            NULL);

Note: This function does not increment the reference count of the returned objects.

Parameters

script

a ClutterScript

 

first_name

the name of the first object to retrieve

 

...

return location for a GObject, then additional names, ending with NULL

 

Returns

the number of objects returned.

Since: 0.6


clutter_script_unmerge_objects ()

void
clutter_script_unmerge_objects (ClutterScript *script,
                                guint merge_id);

Unmerges the objects identified by merge_id .

Parameters

script

a ClutterScript

 

merge_id

merge id returned when loading a UI definition

 

Since: 0.6


clutter_script_ensure_objects ()

void
clutter_script_ensure_objects (ClutterScript *script);

Ensure that every object defined inside script is correctly constructed. You should rarely need to use this function.

Parameters

script

a ClutterScript

 

Since: 0.6


clutter_script_list_objects ()

GList *
clutter_script_list_objects (ClutterScript *script);

Retrieves all the objects created by script .

Note: this function does not increment the reference count of the objects it returns.

Parameters

script

a ClutterScript

 

Returns

a list of GObjects, or NULL. The objects are owned by the ClutterScript instance. Use g_list_free() on the returned list when done.

[transfer container][element-type GObject.Object]

Since: 0.8


ClutterScriptConnectFunc ()

void
(*ClutterScriptConnectFunc) (ClutterScript *script,
                             GObject *object,
                             const gchar *signal_name,
                             const gchar *handler_name,
                             GObject *connect_object,
                             GConnectFlags flags,
                             gpointer user_data);

This is the signature of a function used to connect signals. It is used by the clutter_script_connect_signals_full() function. It is mainly intended for interpreted language bindings, but could be useful where the programmer wants more control over the signal connection process.

Parameters

script

a ClutterScript

 

object

the object to connect

 

signal_name

the name of the signal

 

handler_name

the name of the signal handler

 

connect_object

the object to connect the signal to, or NULL

 

flags

signal connection flags

 

user_data

user data to pass to the signal handler

 

Since: 0.6


clutter_script_connect_signals ()

void
clutter_script_connect_signals (ClutterScript *script,
                                gpointer user_data);

Connects all the signals defined into a UI definition file to their handlers.

This method invokes clutter_script_connect_signals_full() internally and uses GModule's introspective features (by opening the current module's scope) to look at the application's symbol table.

Note that this function will not work if GModule is not supported by the platform Clutter is running on.

Parameters

script

a ClutterScript

 

user_data

data to be passed to the signal handlers, or NULL

 

Since: 0.6


clutter_script_connect_signals_full ()

void
clutter_script_connect_signals_full (ClutterScript *script,
                                     ClutterScriptConnectFunc func,
                                     gpointer user_data);

Connects all the signals defined into a UI definition file to their handlers.

This function allows to control how the signal handlers are going to be connected to their respective signals. It is meant primarily for language bindings to allow resolving the function names using the native API, but it can also be used on platforms that do not support GModule.

Applications should use clutter_script_connect_signals().

Parameters

script

a ClutterScript

 

func

signal connection function.

[scope call]

user_data

data to be passed to the signal handlers, or NULL

 

Since: 0.6


clutter_script_add_states ()

void
clutter_script_add_states (ClutterScript *script,
                           const gchar *name,
                           ClutterState *state);

clutter_script_add_states has been deprecated since version 1.12 and should not be used in newly-written code.

Associates a ClutterState to the ClutterScript instance using the given name.

The ClutterScript instance will use state to resolve target states when connecting signal handlers.

The ClutterScript instance will take a reference on the ClutterState passed to this function.

Parameters

script

a ClutterScript

 

name

a name for the state , or NULL to set the default ClutterState.

[allow-none]

state

a ClutterState

 

Since: 1.8


clutter_script_get_states ()

ClutterState *
clutter_script_get_states (ClutterScript *script,
                           const gchar *name);

clutter_script_get_states has been deprecated since version 1.12 and should not be used in newly-written code.

Retrieves the ClutterState for the given state_name .

If name is NULL, this function will return the default ClutterState instance.

Parameters

script

a ClutterScript

 

name

the name of the ClutterState, or NULL.

[allow-none]

Returns

a pointer to the ClutterState for the given name. The ClutterState is owned by the ClutterScript instance and it should not be unreferenced.

[transfer none]

Since: 1.8


clutter_script_get_type_from_name ()

GType
clutter_script_get_type_from_name (ClutterScript *script,
                                   const gchar *type_name);

Looks up a type by name, using the virtual function that ClutterScript has for that purpose. This function should rarely be used.

Parameters

script

a ClutterScript

 

type_name

name of the type to look up

 

Returns

the type for the requested type name, or G_TYPE_INVALID if not corresponding type was found.

Since: 0.6


clutter_get_script_id ()

const gchar *
clutter_get_script_id (GObject *gobject);

Retrieves the Clutter script id, if any.

Parameters

gobject

a GObject

 

Returns

the script id, or NULL if object was not defined inside a UI definition file. The returned string is owned by the object and should never be modified or freed.

Since: 0.6


clutter_script_get_translation_domain ()

const gchar *
clutter_script_get_translation_domain (ClutterScript *script);

Retrieves the translation domain set using clutter_script_set_translation_domain().

Parameters

script

a ClutterScript

 

Returns

the translation domain, if any is set, or NULL.

[transfer none]

Since: 1.10


clutter_script_set_translation_domain ()

void
clutter_script_set_translation_domain (ClutterScript *script,
                                       const gchar *domain);

Sets the translation domain for script .

Parameters

script

a ClutterScript

 

domain

the translation domain, or NULL.

[allow-none]

Since: 1.10

Types and Values

struct ClutterScript

struct ClutterScript;

The ClutterScript structure contains only private data and should be accessed using the provided API

Since: 0.6


struct ClutterScriptClass

struct ClutterScriptClass {
  GType (* get_type_from_name) (ClutterScript *script,
                                const gchar   *type_name);
};

The ClutterScriptClass structure contains only private data

Members

get_type_from_name ()

virtual function used to map a type name to a GType. This function should only be overridden by language bindings in order to map native types to GType. The default implementation is equivalent to g_type_from_name()

 

Since: 0.6


enum ClutterScriptError

ClutterScript error enumeration.

Members

CLUTTER_SCRIPT_ERROR_INVALID_TYPE_FUNCTION

Type function not found or invalid

 

CLUTTER_SCRIPT_ERROR_INVALID_PROPERTY

Property not found or invalid

 

CLUTTER_SCRIPT_ERROR_INVALID_VALUE

Invalid value

 

Since: 0.6

Property Details

The “filename” property

  “filename”                 gchar *

The path of the currently parsed file. If “filename-set” is FALSE then the value of this property is undefined.

Flags: Read

Default value: NULL

Since: 0.6


The “filename-set” property

  “filename-set”             gboolean

Whether the “filename” property is set. If this property is TRUE then the currently parsed data comes from a file, and the file name is stored inside the “filename” property.

Flags: Read

Default value: FALSE

Since: 0.6


The “translation-domain” property

  “translation-domain”       gchar *

The translation domain, used to localize strings marked as translatable inside a UI definition.

If “translation-domain” is set to NULL, ClutterScript will use gettext(), otherwise g_dgettext() will be used.

Flags: Read / Write

Default value: NULL

Since: 1.10