ParamSpec

class ParamSpec(*args, **kwargs)

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

GParamSpec encapsulates the metadata required to specify parameters, such as GObject 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 signal_new).

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

Methods

class ParamSpec

get_blurb() → str | None

Get the short description of a ParamSpec.

get_default_value() → Any

Gets the default value of pspec as a pointer to a Value.

The Value will remain valid for the life of pspec.

Added in version 2.38.

get_name() → str

Get the name of a ParamSpec.

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

get_name_quark() → int

Gets the GQuark for the name.

Added in version 2.46.

get_nick() → str

Get the nickname of a ParamSpec.

get_qdata(quark: int) → None

Gets back user data pointers stored via set_qdata().

Parameters:

quark – a Quark, naming the user data pointer

get_redirect_target() → ParamSpec | 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 GParamSpecOverride. See override_property() for an example of the use of this capability.

Added in version 2.4.

is_valid_name(name: str) → bool

Validate a property name for a 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]:obj:ParamSpec#parameter-names for details of the rules for valid names.

Added in version 2.66.

Parameters:

name – the canonical name of the property

set_qdata(quark: int, data: None) → None

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

Parameters:

• quark – a Quark, naming the user data pointer

• data – an opaque user data pointer

sink() → None

The initial reference count of a newly created ParamSpec is 1, even though no one has explicitly called 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 pspec that has a reference count of 1 still, but is not flagged “floating” anymore).

Virtual Methods

class ParamSpec

do_finalize() → None

The type of the None singleton.

do_value_is_valid(value: Any) → bool

The type of the None singleton.

Parameters:

value

do_value_set_default(value: Any) → None

The type of the None singleton.

Parameters:

value

do_value_validate(value: Any) → bool

The type of the None singleton.

Parameters:

value

do_values_cmp(value1: Any, value2: Any) → int

The type of the None singleton.

Parameters:

• value1

• value2

Fields

class ParamSpec

flags

GParamFlags flags for this parameter

g_type_instance

Private GTypeInstance portion

name

Name of this parameter: always an interned string

owner_type

GType type that uses (introduces) this parameter

param_id

qdata

ref_count

value_type

The GValue type for this parameter