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GObject Reference Manual | ![]() |
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#include <glib-object.h> GEnumClass; GFlagsClass; #define G_ENUM_CLASS_TYPE (class) #define G_ENUM_CLASS_TYPE_NAME (class) #define G_TYPE_IS_ENUM (type) #define G_ENUM_CLASS (class) #define G_IS_ENUM_CLASS (class) #define G_TYPE_IS_FLAGS (type) #define G_FLAGS_CLASS (class) #define G_IS_FLAGS_CLASS (class) #define G_FLAGS_CLASS_TYPE (class) #define G_FLAGS_CLASS_TYPE_NAME (class) GEnumValue; GFlagsValue; GEnumValue* g_enum_get_value (GEnumClass *enum_class, gint value); GEnumValue* g_enum_get_value_by_name (GEnumClass *enum_class, const gchar *name); GEnumValue* g_enum_get_value_by_nick (GEnumClass *enum_class, const gchar *nick); GFlagsValue* g_flags_get_first_value (GFlagsClass *flags_class, guint value); GFlagsValue* g_flags_get_value_by_name (GFlagsClass *flags_class, const gchar *name); GFlagsValue* g_flags_get_value_by_nick (GFlagsClass *flags_class, const gchar *nick); GType g_enum_register_static (const gchar *name, const GEnumValue *const_static_values); GType g_flags_register_static (const gchar *name, const GFlagsValue *const_static_values); void g_enum_complete_type_info (GType g_enum_type, GTypeInfo *info, const GEnumValue *const_values); void g_flags_complete_type_info (GType g_flags_type, GTypeInfo *info, const GFlagsValue *const_values);
glib-mkenums
title
: Enumeration and Flag Types
The GLib type system provides fundamental types for enumeration and
flags types. (Flags types are like enumerations, but allow their
values to be combined by bitwise or). A registered enumeration or
flags type associates a name and a nickname with each allowed
value, and the methods g_enum_get_value_by_name()
,
g_enum_get_value_by_nick()
, g_flags_get_value_by_name()
and
g_flags_get_value_by_nick()
can look up values by their name or
nickname. When an enumeration or flags type is registered with the
GLib type system, it can be used as value type for object
properties, using g_param_spec_enum()
or g_param_spec_flags()
.
GObject ships with a utility called glib-mkenums that can construct suitable type registration functions from C enumeration definitions.
typedef struct { GTypeClass g_type_class; gint minimum; gint maximum; guint n_values; GEnumValue *values; } GEnumClass;
The class of an enumeration type holds information about its possible values.
GTypeClass |
the parent class |
gint |
the smallest possible value. |
gint |
the largest possible value. |
guint |
the number of possible values. |
GEnumValue * |
an array of GEnumValue structs describing the individual values. |
typedef struct { GTypeClass g_type_class; guint mask; guint n_values; GFlagsValue *values; } GFlagsClass;
The class of a flags type holds information about its possible values.
GTypeClass |
the parent class |
guint |
a mask covering all possible values. |
guint |
the number of possible values. |
GFlagsValue * |
an array of GFlagsValue structs describing the individual values. |
#define G_ENUM_CLASS_TYPE(class) (G_TYPE_FROM_CLASS (class))
Get the type identifier from a given GEnumClass structure.
|
a GEnumClass |
#define G_ENUM_CLASS_TYPE_NAME(class) (g_type_name (G_ENUM_CLASS_TYPE (class)))
Get the static type name from a given GEnumClass structure.
|
a GEnumClass |
#define G_TYPE_IS_ENUM(type) (G_TYPE_FUNDAMENTAL (type) == G_TYPE_ENUM)
Checks whether type
"is a" G_TYPE_ENUM
.
|
a GType ID. |
#define G_ENUM_CLASS(class) (G_TYPE_CHECK_CLASS_CAST ((class), G_TYPE_ENUM, GEnumClass))
Casts a derived GEnumClass structure into a GEnumClass structure.
|
a valid GEnumClass |
#define G_IS_ENUM_CLASS(class) (G_TYPE_CHECK_CLASS_TYPE ((class), G_TYPE_ENUM))
Checks whether class
"is a" valid GEnumClass structure of type G_TYPE_ENUM
or derived.
|
a GEnumClass |
#define G_TYPE_IS_FLAGS(type) (G_TYPE_FUNDAMENTAL (type) == G_TYPE_FLAGS)
Checks whether type
"is a" G_TYPE_FLAGS
.
|
a GType ID. |
#define G_FLAGS_CLASS(class) (G_TYPE_CHECK_CLASS_CAST ((class), G_TYPE_FLAGS, GFlagsClass))
Casts a derived GFlagsClass structure into a GFlagsClass structure.
|
a valid GFlagsClass |
#define G_IS_FLAGS_CLASS(class) (G_TYPE_CHECK_CLASS_TYPE ((class), G_TYPE_FLAGS))
Checks whether class
"is a" valid GFlagsClass structure of type G_TYPE_FLAGS
or derived.
|
a GFlagsClass |
#define G_FLAGS_CLASS_TYPE(class) (G_TYPE_FROM_CLASS (class))
Get the type identifier from a given GFlagsClass structure.
|
a GFlagsClass |
#define G_FLAGS_CLASS_TYPE_NAME(class) (g_type_name (G_FLAGS_CLASS_TYPE (class)))
Get the static type name from a given GFlagsClass structure.
|
a GFlagsClass |
typedef struct { gint value; const gchar *value_name; const gchar *value_nick; } GEnumValue;
A structure which contains a single enum value, its name, and its nickname.
typedef struct { guint value; const gchar *value_name; const gchar *value_nick; } GFlagsValue;
A structure which contains a single flags value, its name, and its nickname.
GEnumValue* g_enum_get_value (GEnumClass *enum_class, gint value);
Returns the GEnumValue for a value.
|
a GEnumClass |
|
the value to look up |
Returns : |
the GEnumValue for value , or NULL if value is not a
member of the enumeration
|
GEnumValue* g_enum_get_value_by_name (GEnumClass *enum_class, const gchar *name);
Looks up a GEnumValue by name.
|
a GEnumClass |
|
the name to look up |
Returns : |
the GEnumValue with name name , or NULL if the
enumeration doesn't have a member with that name
|
GEnumValue* g_enum_get_value_by_nick (GEnumClass *enum_class, const gchar *nick);
Looks up a GEnumValue by nickname.
|
a GEnumClass |
|
the nickname to look up |
Returns : |
the GEnumValue with nickname nick , or NULL if the
enumeration doesn't have a member with that nickname
|
GFlagsValue* g_flags_get_first_value (GFlagsClass *flags_class, guint value);
Returns the first GFlagsValue which is set in value
.
|
a GFlagsClass |
|
the value |
Returns : |
the first GFlagsValue which is set in value , or NULL if
none is set
|
GFlagsValue* g_flags_get_value_by_name (GFlagsClass *flags_class, const gchar *name);
Looks up a GFlagsValue by name.
|
a GFlagsClass |
|
the name to look up |
Returns : |
the GFlagsValue with name name , or NULL if there is no
flag with that name
|
GFlagsValue* g_flags_get_value_by_nick (GFlagsClass *flags_class, const gchar *nick);
Looks up a GFlagsValue by nickname.
|
a GFlagsClass |
|
the nickname to look up |
Returns : |
the GFlagsValue with nickname nick , or NULL if there is
no flag with that nickname
|
GType g_enum_register_static (const gchar *name, const GEnumValue *const_static_values);
Registers a new static enumeration type with the name name
.
It is normally more convenient to let glib-mkenums generate a
my_enum_get_type()
function from a usual C enumeration definition
than to write one yourself using g_enum_register_static()
.
|
A nul-terminated string used as the name of the new type. |
|
An array of GEnumValue structs for the possible enumeration values. The array is terminated by a struct with all members being 0. GObject keeps a reference to the data, so it cannot be stack-allocated. |
Returns : |
The new type identifier. |
GType g_flags_register_static (const gchar *name, const GFlagsValue *const_static_values);
Registers a new static flags type with the name name
.
It is normally more convenient to let glib-mkenums generate a
my_flags_get_type()
function from a usual C enumeration definition
than to write one yourself using g_flags_register_static()
.
|
A nul-terminated string used as the name of the new type. |
|
An array of GFlagsValue structs for the possible flags values. The array is terminated by a struct with all members being 0. GObject keeps a reference to the data, so it cannot be stack-allocated. |
Returns : |
The new type identifier. |
void g_enum_complete_type_info (GType g_enum_type, GTypeInfo *info, const GEnumValue *const_values);
This function is meant to be called from the complete_type_info()
function of a GTypePlugin implementation, as in the following
example:
static void my_enum_complete_type_info (GTypePlugin *plugin, GType g_type, GTypeInfo *info, GTypeValueTable *value_table) { static const GEnumValue values[] = { { MY_ENUM_FOO, "MY_ENUM_FOO", "foo" }, { MY_ENUM_BAR, "MY_ENUM_BAR", "bar" }, { 0, NULL, NULL } }; g_enum_complete_type_info (type, info, values); }
|
the type identifier of the type being completed |
|
the GTypeInfo struct to be filled in |
|
An array of GEnumValue structs for the possible enumeration values. The array is terminated by a struct with all members being 0. |
void g_flags_complete_type_info (GType g_flags_type, GTypeInfo *info, const GFlagsValue *const_values);
This function is meant to be called from the complete_type_info()
function of a GTypePlugin implementation, see the example for
g_enum_complete_type_info()
above.
|
the type identifier of the type being completed |
|
the GTypeInfo struct to be filled in |
|
An array of GFlagsValue structs for the possible enumeration values. The array is terminated by a struct with all members being 0. |