GObject.ParamSpec

g GObject.ParamSpec GObject.ParamSpec

Subclasses

GObject.ParamSpecBoolean, GObject.ParamSpecBoxed, GObject.ParamSpecChar, GObject.ParamSpecDouble, GObject.ParamSpecEnum, GObject.ParamSpecFlags, GObject.ParamSpecFloat, GObject.ParamSpecGType, GObject.ParamSpecInt, GObject.ParamSpecInt64, GObject.ParamSpecLong, GObject.ParamSpecObject, GObject.ParamSpecOverride, GObject.ParamSpecParam, GObject.ParamSpecPointer, GObject.ParamSpecString, GObject.ParamSpecUChar, GObject.ParamSpecUInt, GObject.ParamSpecUInt64, GObject.ParamSpecULong, GObject.ParamSpecUnichar, GObject.ParamSpecValueArray, GObject.ParamSpecVariant

Methods

class

is_valid_name (name)

get_blurb ()

get_default_value ()

get_name ()

get_name_quark ()

get_nick ()

get_qdata (quark)

get_redirect_target ()

set_qdata (quark, data)

sink ()

steal_qdata (quark)

Virtual Methods

do_finalize ()

do_value_is_valid (value)

do_value_set_default (value)

do_value_validate (value)

do_values_cmp (value1, value2)

Fields

Name

Type

Access

Description

flags

GObject.ParamFlags

r

GObject.ParamFlags flags for this parameter

g_type_instance

GObject.TypeInstance

r

private GObject.TypeInstance portion

name

str

r

name of this parameter: always an interned string

owner_type

GObject.GType

r

GObject.GType type that uses (introduces) this parameter

param_id

int

r

qdata

GLib.Data

r

ref_count

int

r

value_type

GObject.GType

r

the GObject.Value type for this parameter

Class Details

class GObject.ParamSpec
Abstract

Yes

Structure

GObject.ParamSpecClass

GObject.ParamSpec is an object structure that encapsulates the metadata required to specify parameters, such as e.g. GObject.Object properties.

Parameter names

A property name consists of one or more segments consisting of ASCII letters and digits, separated by either the - or _ character. The first character of a property name must be a letter. These are the same rules as for signal naming (see GObject.signal_new()).

When creating and looking up a GObject.ParamSpec, either separator can be used, but they cannot be mixed. Using - is considerably more efficient, and is the ‘canonical form’. Using _ is discouraged.

classmethod is_valid_name(name)
Parameters

name (str) – the canonical name of the property

Returns

True if name is a valid property name, False otherwise.

Return type

bool

Validate a property name for a GObject.ParamSpec. This can be useful for dynamically-generated properties which need to be validated at run-time before actually trying to create them.

See canonical parameter names for details of the rules for valid names.

New in version 2.66.

get_blurb()
Returns

the short description of self.

Return type

str or None

Get the short description of a GObject.ParamSpec.

get_default_value()
Returns

a pointer to a GObject.Value which must not be modified

Return type

GObject.Value

Gets the default value of self as a pointer to a GObject.Value.

The GObject.Value will remain valid for the life of self.

New in version 2.38.

get_name()
Returns

the name of self.

Return type

str

Get the name of a GObject.ParamSpec.

The name is always an “interned” string (as per GLib.intern_string()). This allows for pointer-value comparisons.

get_name_quark()
Returns

the GQuark for self->name.

Return type

int

Gets the GQuark for the name.

New in version 2.46.

get_nick()
Returns

the nickname of self.

Return type

str

Get the nickname of a GObject.ParamSpec.

get_qdata(quark)
Parameters

quark (int) – a #GQuark, naming the user data pointer

Returns

the user data pointer set, or None

Return type

object or None

Gets back user data pointers stored via GObject.ParamSpec.set_qdata().

get_redirect_target()
Returns

paramspec to which requests on this paramspec should be redirected, or None if none.

Return type

GObject.ParamSpec or None

If the paramspec redirects operations to another paramspec, returns that paramspec. Redirect is used typically for providing a new implementation of a property in a derived type while preserving all the properties from the parent type. Redirection is established by creating a property of type GObject.ParamSpecOverride. See GObject.ObjectClass.override_property() for an example of the use of this capability.

New in version 2.4.

set_qdata(quark, data)
Parameters
  • quark (int) – a #GQuark, naming the user data pointer

  • data (object or None) – an opaque user data pointer

Sets an opaque, named pointer on a GObject.ParamSpec. The name is specified through a #GQuark (retrieved e.g. via GLib.quark_from_static_string()), and the pointer can be gotten back from the self with GObject.ParamSpec.get_qdata(). Setting a previously set user data pointer, overrides (frees) the old pointer set, using None as pointer essentially removes the data stored.

sink()

The initial reference count of a newly created GObject.ParamSpec is 1, even though no one has explicitly called g_param_spec_ref() on it yet. So the initial reference count is flagged as “floating”, until someone calls g_param_spec_ref (pspec); g_param_spec_sink (pspec); in sequence on it, taking over the initial reference count (thus ending up with a self that has a reference count of 1 still, but is not flagged “floating” anymore).

steal_qdata(quark)
Parameters

quark (int) – a #GQuark, naming the user data pointer

Returns

the user data pointer set, or None

Return type

object or None

Gets back user data pointers stored via GObject.ParamSpec.set_qdata() and removes the data from self without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier.

do_finalize() virtual
do_value_is_valid(value) virtual
Parameters

value (GObject.Value) –

Return type

bool

do_value_set_default(value) virtual
Parameters

value (GObject.Value) –

do_value_validate(value) virtual
Parameters

value (GObject.Value) –

Return type

bool

do_values_cmp(value1, value2) virtual
Parameters
Return type

int