class GObject::ParamSpec

Overview

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

Parameter names # {#canonical-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 g_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.

Defined in:

lib/gi-crystal/src/auto/g_object-2.0/param_spec.cr
lib/gi-crystal/src/bindings/g_object/param_spec.cr

Class Method Summary

Instance Method Summary

Class Method Detail

def self.g_type : UInt64 #

Returns the type id (GType) registered in GLib type system.


[View source]
def self.is_valid_name(name : String) : Bool #

Validate a property name for a #GParamSpec. 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][canonical-parameter-names] for details of the rules for valid names.


[View source]

Instance Method Detail

def ==(other : self) #
Description copied from class Reference

Returns true if this reference is the same as other. Invokes same?.


def blurb : String | Nil #

Get the short description of a #GParamSpec.


[View source]
def default_value : GObject::Value #

Gets the default value of pspec as a pointer to a #GValue.

The #GValue will remain valid for the life of pspec.


[View source]
def finalize #

Called by the garbage collector. Decreases the reference count of object. (i.e. its memory is freed).


[View source]
def hash(hasher) #
Description copied from class Reference

See Object#hash(hasher)


def name : String #

Get the name of a #GParamSpec.

The name is always an "interned" string (as per g_intern_string()). This allows for pointer-value comparisons.


[View source]
def name_quark : UInt32 #

Gets the GQuark for the name.


[View source]
def nick : String #

Get the nickname of a #GParamSpec.


[View source]
def qdata(quark : UInt32) : Pointer(Void) | Nil #

Gets back user data pointers stored via g_param_spec_set_qdata().


[View source]
def redirect_target : GObject::ParamSpec | Nil #

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 g_object_class_override_property() for an example of the use of this capability.


[View source]
def ref_count : UInt32 #

Returns ParamSpec reference counter.


[View source]
def set_qdata(quark : UInt32, data : Pointer(Void) | Nil) : Nil #

Sets an opaque, named pointer on a #GParamSpec. The name is specified through a #GQuark (retrieved e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the pspec with g_param_spec_get_qdata(). Setting a previously set user data pointer, overrides (frees) the old pointer set, using nil as pointer essentially removes the data stored.


[View source]
def sink : Nil #

The initial reference count of a newly created #GParamSpec 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 pspec that has a reference count of 1 still, but is not flagged "floating" anymore).


[View source]
def steal_qdata(quark : UInt32) : Pointer(Void) | Nil #

Gets back user data pointers stored via g_param_spec_set_qdata() and removes the data from pspec 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.


[View source]
def to_unsafe : Pointer(Void) #

Returns a pointer to the C object.


[View source]