param_value_types.sgml

This GLib version 2.16.1. GLib is the low-level core library that forms the basis for projects such

<!-- ##### FUNCTION g_value_get_boxed ##### -->
<para>
Get the contents of a %G_TYPE_BOXED derived #GValue.
</para>

@value:   a valid #GValue of %G_TYPE_BOXED derived type
@Returns: boxed contents of @value


<!-- ##### FUNCTION g_value_dup_boxed ##### -->
<para>
Get the contents of a %G_TYPE_BOXED derived #GValue.
Upon getting, the boxed value is duplicated and needs to be
later freed with g_boxed_free(), e.g. like: g_boxed_free (G_VALUE_TYPE (@value), return_value);
</para>

@value:   a valid #GValue of %G_TYPE_BOXED derived type
@Returns: boxed contents of @value


<!-- ##### MACRO G_IS_PARAM_SPEC_POINTER ##### -->
<para>
Returns whether the given #GParamSpec is of type %G_TYPE_PARAM_POINTER.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_PARAM_SPEC_POINTER ##### -->
<para>
Casts a #GParamSpec instance into a #GParamSpecPointer.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_VALUE_HOLDS_POINTER ##### -->
<para>
Return whether the given #GValue can hold values of type %G_TYPE_POINTER.
</para>

@value: a valid #GValue structure


<!-- ##### MACRO G_TYPE_PARAM_POINTER ##### -->
<para>
The #GType of #GParamSpecPointer.
</para>



<!-- ##### STRUCT GParamSpecPointer ##### -->
<para>
A #GParamSpec derived structure that contains the meta data for pointer properties.
</para>

@parent_instance: private #GParamSpec portion

<!-- ##### FUNCTION g_param_spec_pointer ##### -->
<para>
Creates a new #GParamSpecPoiner instance specifying a pointer property.
</para>
<para> 
See g_param_spec_internal() for details on property names.
</para>

@name:          canonical name of the property specified
@nick:          nick name for the property specified
@blurb:         description of the property specified
@flags:         flags for the property specified
@Returns: a newly created parameter specification


<!-- ##### FUNCTION g_value_set_pointer ##### -->
<para>
Set the contents of a pointer #GValue to @v_pointer.
</para>

@value:   a valid #GValue of %G_TYPE_POINTER
@v_pointer: pointer value to be set


<!-- ##### FUNCTION g_value_get_pointer ##### -->
<para>
Get the contents of a pointer #GValue.
</para>

@value:   a valid #GValue of %G_TYPE_POINTER
@Returns: pointer contents of @value


<!-- ##### MACRO G_IS_PARAM_SPEC_OBJECT ##### -->
<para>
Returns whether the given #GParamSpec is of type %G_TYPE_PARAM_OBJECT.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_PARAM_SPEC_OBJECT ##### -->
<para>
Casts a #GParamSpec instance into a #GParamSpecObject.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_VALUE_HOLDS_OBJECT ##### -->
<para>
Return whether the given #GValue can hold values derived from type %G_TYPE_OBJECT.
</para>

@value: a valid #GValue structure


<!-- ##### MACRO G_TYPE_PARAM_OBJECT ##### -->
<para>
The #GType of #GParamSpecObject.
</para>



<!-- ##### STRUCT GParamSpecObject ##### -->
<para>
A #GParamSpec derived structure that contains the meta data for object properties.
</para>

@parent_instance: private #GParamSpec portion

<!-- ##### FUNCTION g_param_spec_object ##### -->
<para>
Creates a new #GParamSpecBoxed instance specifying a %G_TYPE_OBJECT 
derived property.
</para>
<para> 
See g_param_spec_internal() for details on property names.
</para>

@name:          canonical name of the property specified
@nick:          nick name for the property specified
@blurb:         description of the property specified
@object_type:   %G_TYPE_OBJECT derived type of this property
@flags:         flags for the property specified
@Returns: a newly created parameter specification


<!-- ##### FUNCTION g_value_set_object ##### -->
<para>
Set the contents of a %G_TYPE_OBJECT derived #GValue to @v_object.
</para>
<para>
g_value_set_object() increases the reference count of @v_object
(the #GValue holds a reference to @v_object).
If you do not wish to increase the reference count of the object
(i.e. you wish to pass your current reference to the #GValue because you no
longer need it),
use g_value_take_object() instead.
</para>
<para>
It is important that your #GValue holds a reference to @v_object (either its
own, or one it has taken) to ensure that the object won't be destroyed while
the #GValue still exists).
</para>

@value:   a valid #GValue of %G_TYPE_OBJECT derived type
@v_object: object value to be set


<!-- ##### FUNCTION g_value_take_object ##### -->
<para>
Sets the contents of a %G_TYPE_OBJECT derived #GValue to @v_object 
and takes over the ownership of the callers reference to @v_object; 
the caller doesn't have to unref it any more (i.e. the reference
count of the object is not increased).
</para>
<para>
If you want the #GValue to hold its own reference to @v_object, use
g_value_set_object() instead.
</para>

@value:  a valid #GValue of %G_TYPE_OBJECT derived type
@v_object: object value to be set
@Since: 2.4


<!-- ##### FUNCTION g_value_set_object_take_ownership ##### -->
<para>
This is an internal function introduced mainly for C marshallers.
</para>

@value:  a valid #GValue of %G_TYPE_OBJECT derived type
@v_object: object value to be set
@Deprecated: 2.4: Use g_value_take_object() instead.


<!-- ##### FUNCTION g_value_get_object ##### -->
<para>
Get the contents of a %G_TYPE_OBJECT derived #GValue.
</para>

@value:   a valid #GValue of %G_TYPE_OBJECT derived type
@Returns: object contents of @value


<!-- ##### FUNCTION g_value_dup_object ##### -->
<para>
Get the contents of a %G_TYPE_OBJECT derived #GValue, increasing its reference count.
</para>

@value: a valid #GValue whose type is derived from %G_TYPE_OBJECT
@Returns: object content of @value, should be unreferenced when no longer needed.


<!-- ##### MACRO G_IS_PARAM_SPEC_UNICHAR ##### -->
<para>
Return whether the given #GParamSpec is of type %G_TYPE_PARAM_UNICHAR.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_PARAM_SPEC_UNICHAR ##### -->
<para>
Cast a #GParamSpec instance into a #GParamSpecUnichar.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_TYPE_PARAM_UNICHAR ##### -->
<para>
The #GType of #GParamSpecUnichar.
</para>



<!-- ##### STRUCT GParamSpecUnichar ##### -->
<para>
A #GParamSpec derived structure that contains the meta data for unichar (unsigned integer) properties.
</para>

@parent_instance: private #GParamSpec portion
@default_value:   default value for the property specified

<!-- ##### FUNCTION g_param_spec_unichar ##### -->
<para>
Creates a new #GParamSpecUnichar instance specifying a %G_TYPE_UINT 
property. #GValue structures for this property can be accessed with 
g_value_set_uint() and g_value_get_uint().
</para>
<para>
See g_param_spec_internal() for details on property names.
</para>

@name:          canonical name of the property specified
@nick:          nick name for the property specified
@blurb:         description of the property specified
@default_value: default value for the property specified
@flags:         flags for the property specified
@Returns: a newly created parameter specification


<!-- ##### MACRO G_IS_PARAM_SPEC_VALUE_ARRAY ##### -->
<para>
Return whether the given #GParamSpec is of type %G_TYPE_PARAM_VALUE_ARRAY.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_PARAM_SPEC_VALUE_ARRAY ##### -->
<para>
Cast a #GParamSpec instance into a #GParamSpecValueArray.
</para>

@pspec: a valid #GParamSpec instance


<!-- ##### MACRO G_TYPE_PARAM_VALUE_ARRAY ##### -->
<para>
The #GType of #GParamSpecValueArray.
</para>



<!-- ##### STRUCT GParamSpecValueArray ##### -->
<para>
A #GParamSpec derived structure that contains the meta data for #GValueArray properties.
</para>

@parent_instance:  private #GParamSpec portion
@element_spec:     a #GParamSpec describing the elements contained in arrays of this property, may be %NULL
@fixed_n_elements: if greater than 0, arrays of this property will always have this many elements

<!-- ##### FUNCTION g_param_spec_value_array ##### -->
<para>
Creates a new #GParamSpecValueArray instance specifying a 
%G_TYPE_VALUE_ARRAY property. %G_TYPE_VALUE_ARRAY is a %G_TYPE_BOXED 
type, as such, #GValue structures for this property can be accessed 
with g_value_set_boxed() and g_value_get_boxed().
</para>
<para>
See g_param_spec_internal() for details on property names.
</para>

@name:          canonical name of the property specified
@nick:          nick name for the property specified
@blurb:         description of the property specified
@element_spec:  a #GParamSpec describing the elements contained in 
                arrays of this property, may be %NULL
@flags:         flags for the property specified
@Returns: a newly created parameter specification


<!-- ##### MACRO G_IS_PARAM_SPEC_OVERRIDE ##### -->
<para>
Returns whether the given #GParamSpec is of type %G_TYPE_PARAM_OVERRIDE.
</para>

@pspec: a #GParamSpec
@Since: 2.4


<!-- ##### MACRO G_PARAM_SPEC_OVERRIDE ##### -->
<para>
Casts a #GParamSpec into a #GParamSpecOverride.
</para>

@pspec:  a #GParamSpec
@Since: 2.4


<!-- ##### MACRO G_TYPE_PARAM_OVERRIDE ##### -->
<para>
The #GType of #GParamSpecOverride.
</para>

@Since: 2.4


<!-- ##### STRUCT GParamSpecOverride ##### -->
<para>
This is a type of #GParamSpec type that simply redirects operations to
another paramspec.  All operations other than getting or
setting the value are redirected, including accessing the nick and
blurb, validating a value, and so forth. See
g_param_spec_get_redirect_target() for retrieving the overidden
property. #GParamSpecOverride is used in implementing
g_object_class_override_property(), and will not be directly useful
unless you are implementing a new base type similar to GObject.
</para>

@Since: 2.4

<!-- ##### FUNCTION g_param_spec_override ##### -->
<para>
Creates a new property of type #GParamSpecOverride. This is used
to direct operations to another paramspec, and will not be directly
useful unless you are implementing a new base type similar to GObject.
</para>

@name: the name of the property.
@overridden: The property that is being overridden
@Returns: the newly created #GParamSpec
@Since: 2.4


<!-- ##### MACRO G_IS_PARAM_SPEC_GTYPE ##### -->
<para>
Returns whether the given #GParamSpec is of type %G_TYPE_PARAM_GTYPE.
</para>

@pspec: a #GParamSpec
@Since: 2.10


<!-- ##### MACRO G_PARAM_SPEC_GTYPE ##### -->
<para>
Casts a #GParamSpec into a #GParamSpecGType.
</para>

@pspec:  a #GParamSpec
@Since: 2.10


<!-- ##### MACRO G_VALUE_HOLDS_GTYPE ##### -->
<para>
Returns whether the given #GValue can hold values of type %G_TYPE_GTYPE.
</para>

@value:  a valid #GValue structure
@Since: 2.12


<!-- ##### MACRO G_TYPE_PARAM_GTYPE ##### -->
<para>
The #GType of #GParamSpecGType.
</para>

@Since: 2.10


<!-- ##### STRUCT GParamSpecGType ##### -->
<para>
A #GParamSpec derived structure that contains the meta data for #GType properties.
</para>

@parent_instance:  private #GParamSpec portion
@is_a_type:        a #GType whose subtypes can occur as values
@Since: 2.10

<!-- ##### FUNCTION g_param_spec_gtype ##### -->
<para>
Creates a new #GParamSpecGType instance specifying a 
%G_TYPE_GTYPE property. 
</para>
<para>
See g_param_spec_internal() for details on property names.
</para>

@name:          canonical name of the property specified
@nick:          nick name for the property specified
@blurb:         description of the property specified
@is_a_type:     a #GType whose subtypes are allowed as values
                of the property (use %G_TYPE_NONE for any type)
@flags:         flags for the property specified
@Returns: a newly created parameter specification
@Since: 2.10


<!-- ##### FUNCTION g_value_get_gtype ##### -->
<para>
Get the contents of a %G_TYPE_GTYPE #GValue.
</para>

@value: a valid #GValue of type %G_TYPE_GTYPE
@Returns: the #GType stored in @value
@Since: 2.12


<!-- ##### FUNCTION g_value_set_gtype ##### -->
<para>
Set the contents of a %G_TYPE_GTYPE #GValue to @v_gtype.
</para>

@value: a valid #GValue of type %G_TYPE_GTYPE
@v_gtype: #GType to be set
@Since: 2.12