GSettings

GSettings — a high-level API for application settings

Synopsis

                    GSettings;
GSettings *         g_settings_new                      (const gchar *schema);
GSettings *         g_settings_new_with_path            (const gchar *schema,
                                                         const gchar *path);
GSettings *         g_settings_new_with_context         (const gchar *schema,
                                                         const gchar *context);
GSettings *         g_settings_new_with_context_and_path
                                                        (const gchar *schema,
                                                         const gchar *context,
                                                         const gchar *path);
gboolean            g_settings_supports_context         (const gchar *context);
GVariant *          g_settings_get_value                (GSettings *settings,
                                                         const gchar *key);
gboolean            g_settings_set_value                (GSettings *settings,
                                                         const gchar *key,
                                                         GVariant *value);
gboolean            g_settings_is_writable              (GSettings *settings,
                                                         const gchar *name);
void                g_settings_delay                    (GSettings *settings);
void                g_settings_apply                    (GSettings *settings);
void                g_settings_revert                   (GSettings *settings);
gboolean            g_settings_get_has_unapplied        (GSettings *settings);
GSettings *         g_settings_get_child                (GSettings *settings,
                                                         const gchar *name);

void                g_settings_get                      (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *format,
                                                         ...);
gboolean            g_settings_set                      (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *format,
                                                         ...);
gboolean            g_settings_get_boolean              (GSettings *settings,
                                                         const gchar *key);
gboolean            g_settings_set_boolean              (GSettings *settings,
                                                         const gchar *key,
                                                         gboolean value);
gint                g_settings_get_int                  (GSettings *settings,
                                                         const gchar *key);
gboolean            g_settings_set_int                  (GSettings *settings,
                                                         const gchar *key,
                                                         gint value);
gdouble             g_settings_get_double               (GSettings *settings,
                                                         const gchar *key);
gboolean            g_settings_set_double               (GSettings *settings,
                                                         const gchar *key,
                                                         gdouble value);
gchar *             g_settings_get_string               (GSettings *settings,
                                                         const gchar *key);
gboolean            g_settings_set_string               (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *value);
gchar **            g_settings_get_strv                 (GSettings *settings,
                                                         const gchar *key,
                                                         gsize *length);
gboolean            g_settings_set_strv                 (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *const *value,
                                                         gssize length);

enum                GSettingsBindFlags;
void                g_settings_bind                     (GSettings *settings,
                                                         const gchar *key,
                                                         gpointer object,
                                                         const gchar *property,
                                                         GSettingsBindFlags flags);
void                g_settings_bind_with_mapping        (GSettings *settings,
                                                         const gchar *key,
                                                         gpointer object,
                                                         const gchar *property,
                                                         GSettingsBindFlags flags,
                                                         GSettingsBindGetMapping get_mapping,
                                                         GSettingsBindSetMapping set_mapping,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy);
void                g_settings_bind_writable            (GSettings *settings,
                                                         const gchar *key,
                                                         gpointer object,
                                                         const gchar *property,
                                                         gboolean inverted);
void                g_settings_unbind                   (gpointer object,
                                                         const gchar *property);
GVariant *          (*GSettingsBindSetMapping)          (const GValue *value,
                                                         const GVariantType *expected_type,
                                                         gpointer user_data);
gboolean            (*GSettingsBindGetMapping)          (GValue *value,
                                                         GVariant *variant,
                                                         gpointer user_data);

Object Hierarchy

  GObject
   +----GSettings

Properties

  "context"                  gchar*                : Read / Write / Construct Only
  "has-unapplied"            gboolean              : Read
  "path"                     gchar*                : Read / Write / Construct Only
  "schema"                   gchar*                : Read / Write / Construct Only

Signals

  "change-event"                                   : Run Last
  "changed"                                        : Run Last / Has Details
  "writable-change-event"                          : Run Last
  "writable-changed"                               : Run Last / Has Details

Description

The GSettings class provides a convenient API for storing and retrieving application settings.

When creating a GSettings instance, you have to specify a schema that describes the keys in your settings and their types and default values, as well as some other information.

Normally, a schema has as fixed path that determines where the settings are stored in the conceptual global tree of settings. However, schemas can also be 'relocatable', i.e. not equipped with a fixed path. This is useful e.g. when the schema describes an 'account', and you want to be able to store a arbitrary number of accounts.

Unlike other configuration systems (like GConf), GSettings does not restrict keys to basic types like strings and numbers. GSettings stores values as GVariant, and allows any GVariantType for keys. Key names are restricted to lowercase characters, numbers and '-'. Furthermore, the names must begin with a lowercase character, must not end with a '-', and must not contain consecutive dashes. Key names can be up to 32 characters long.

Similar to GConf, the default values in GSettings schemas can be localized, but the localized values are stored in gettext catalogs and looked up with the domain that is specified in the gettext-domain attribute of the <schemalist> or <schema> elements and the category that is specified in the l10n attribute of the <key> element.

GSettings uses schemas in a compact binary form that is created by the glib-compile-schemas utility. The input is a schema description in an XML format that can be described by the following DTD:

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<!ELEMENT schemalist (schema*) >
<!ATTLIST schemalist gettext-domain #IMPLIED >

<!ELEMENT schema (key|child)* >
<!ATTLIST schema id             CDATA #REQUIRED
                 path           CDATA #IMPLIED
                 gettext-domain CDATA #IMPLIED >

<!ELEMENT key (default|summary?|description?|range?|choices?) >
<!-- name can only contain lowercase letters, numbers and '-' -->
<!-- type must be a GVariant type string -->
<!ATTLIST key name CDATA #REQUIRED
              type CDATA #REQUIRED >

<!-- the default value is specified a a serialized GVariant,
     i.e. you have to include the quotes when specifying a string -->
<!ELEMENT default (#PCDATA) >
<!-- the presence of the l10n attribute marks a default value for
     translation, its value is the gettext category to use -->
<!-- if context is present, it specifies msgctxt to use -->
<!ATTLIST default l10n (messages|time) #IMPLIED
                  context CDATA #IMPLIED >

<!ELEMENT summary (#PCDATA) >
<!ELEMENT description (#PCDATA) >

<!ELEMENT range EMPTY >
<!ATTLIST range min CDATA #REQUIRED
                max CDATA #REQUIRED >

<!ELEMENT choices (choice+) >
<!ELEMENT choice (alias?) >
<!ATTLIST choice value CDATA #REQUIRED >
<!ELEMENT choice (alias?) >
<!ELEMENT alias EMPTY >
<!ATTLIST alias value CDATA #REQUIRED >

<!ELEMENT child EMPTY >
<!ATTLIST child name  CDATA #REQUIRED
                schema CDATA #REQUIRED >

At runtime, schemas are identified by their id (as specified in the id attribute of the <schema> element). The convention for schema ids is to use a dotted name, similar in style to a DBus bus name, e.g. "org.gnome.font-rendering".

Binding

A very convenient feature of GSettings lets you bind GObject properties directly to settings, using g_settings_bind(). Once a GObject property has been bound to a setting, changes on either side are automatically propagated to the other side. GSettings handles details like mapping between GObject and GVariant types, and preventing infinite cycles.

This makes it very easy to hook up a preferences dialog to the underlying settings. To make this even more convenient, GSettings looks for a boolean property with the name "sensitivity" and automatically binds it to the writability of the bound setting. If this 'magic' gets in the way, it can be suppressed with the G_SETTINGS_BIND_NO_SENSITIVITY flag.

Details

GSettings

typedef struct _GSettings GSettings;


g_settings_new ()

GSettings *         g_settings_new                      (const gchar *schema);

Creates a new GSettings object with a given schema.

schema :

the name of the schema

Returns :

a new GSettings object

Since 2.26


g_settings_new_with_path ()

GSettings *         g_settings_new_with_path            (const gchar *schema,
                                                         const gchar *path);

Creates a new GSettings object with a given schema and path.

You only need to do this if you want to directly create a settings object with a schema that doesn't have a specified path of its own. That's quite rare.

It is a programmer error to call this function for a schema that has an explicitly specified path.

schema :

the name of the schema

path :

the path to use

Returns :

a new GSettings object

Since 2.26


g_settings_new_with_context ()

GSettings *         g_settings_new_with_context         (const gchar *schema,
                                                         const gchar *context);

Creates a new GSettings object with a given schema and context.

Creating settings objects with a context allow accessing settings from a database other than the usual one. For example, it may make sense to specify "defaults" in order to get a settings object that modifies the system default settings instead of the settings for this user.

It is a programmer error to call this function for an unsupported context. Use g_settings_supports_context() to determine if a context is supported if you are unsure.

schema :

the name of the schema

context :

the context to use

Returns :

a new GSettings object

Since 2.26


g_settings_new_with_context_and_path ()

GSettings *         g_settings_new_with_context_and_path
                                                        (const gchar *schema,
                                                         const gchar *context,
                                                         const gchar *path);

Creates a new GSettings object with a given schema, context and path.

This is a mix of g_settings_new_with_context() and g_settings_new_with_path().

schema :

the name of the schema

context :

path :

the path to use

Returns :

a new GSettings object

Since 2.26


g_settings_supports_context ()

gboolean            g_settings_supports_context         (const gchar *context);

context :

Returns :


g_settings_get_value ()

GVariant *          g_settings_get_value                (GSettings *settings,
                                                         const gchar *key);

Gets the value that is stored in settings for key.

It is a programmer error to give a key that isn't valid for settings.

settings :

a GSettings object

key :

the key to get the value for

Returns :

a new GVariant

Since 2.26


g_settings_set_value ()

gboolean            g_settings_set_value                (GSettings *settings,
                                                         const gchar *key,
                                                         GVariant *value);

Sets key in settings to value.

It is a programmer error to give a key that isn't valid for settings. It is a programmer error to give a value of the incorrect type.

If value is floating then this function consumes the reference.

settings :

a GSettings object

key :

the name of the key to set

value :

a GVariant of the correct type

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


g_settings_is_writable ()

gboolean            g_settings_is_writable              (GSettings *settings,
                                                         const gchar *name);

Finds out if a key can be written or not

settings :

a GSettings object

name :

the name of a key

Returns :

TRUE if the key name is writable

Since 2.26


g_settings_delay ()

void                g_settings_delay                    (GSettings *settings);

Changes the GSettings object into 'delay-apply' mode. In this mode, changes to settings are not immediately propagated to the backend, but kept locally until g_settings_apply() is called.

settings :

a GSettings object

Since 2.26


g_settings_apply ()

void                g_settings_apply                    (GSettings *settings);

Applies any changes that have been made to the settings. This function does nothing unless settings is in 'delay-apply' mode; see g_settings_set_delay_apply(). In the normal case settings are always applied immediately.

settings :

a GSettings instance

g_settings_revert ()

void                g_settings_revert                   (GSettings *settings);

Reverts all non-applied changes to the settings. This function does nothing unless settings is in 'delay-apply' mode; see g_settings_set_delay_apply(). In the normal case settings are always applied immediately.

Change notifications will be emitted for affected keys.

settings :

a GSettings instance

g_settings_get_has_unapplied ()

gboolean            g_settings_get_has_unapplied        (GSettings *settings);

Returns whether the GSettings object has any unapplied changes. This can only be the case if it is in 'delayed-apply' mode.

settings :

a GSettings object

Returns :

TRUE if settings has unapplied changes

Since 2.26


g_settings_get_child ()

GSettings *         g_settings_get_child                (GSettings *settings,
                                                         const gchar *name);

Creates a 'child' settings object which has a base path of base-path/name", where base-path is the base path of settings.

The schema for the child settings object must have been declared in the schema of settings using a <child> element.

settings :

a GSettings object

name :

the name of the 'child' schema

Returns :

a 'child' settings object

Since 2.26


g_settings_get ()

void                g_settings_get                      (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *format,
                                                         ...);

Gets the value that is stored at key in settings.

A convenience function that combines g_settings_get_value() with g_variant_get().

It is a programmer error to pass a key that isn't valid for settings or a format_string that doesn't match the type of key according to the schema of settings.

settings :

a GSettings object

key :

the key to get the value for

format :

a GVariant format string

... :

arguments as per format

Since 2.26


g_settings_set ()

gboolean            g_settings_set                      (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *format,
                                                         ...);

Sets key in settings to value.

A convenience function that combines g_settings_set_value() with g_variant_new().

It is a programmer error to pass a key that isn't valid for settings or a format that doesn't match the type of key according to the schema of settings.

settings :

a GSettings object

key :

the name of the key to set

format :

a GVariant format string

... :

arguments as per format

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


g_settings_get_boolean ()

gboolean            g_settings_get_boolean              (GSettings *settings,
                                                         const gchar *key);

Gets the value that is stored at key in settings.

A convenience variant of g_settings_get() for booleans.

It is a programmer error to pass a key that isn't valid for settings or is not of type boolean.

settings :

a GSettings object

key :

the key to get the value for

Returns :

a boolean

Since 2.26


g_settings_set_boolean ()

gboolean            g_settings_set_boolean              (GSettings *settings,
                                                         const gchar *key,
                                                         gboolean value);

Sets key in settings to value.

A convenience variant of g_settings_set() for booleans.

It is a programmer error to pass a key that isn't valid for settings or is not of type boolean.

settings :

a GSettings object

key :

the name of the key to set

value :

the value to set it to

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


g_settings_get_int ()

gint                g_settings_get_int                  (GSettings *settings,
                                                         const gchar *key);

Gets the value that is stored at key in settings.

A convenience variant of g_settings_get() for 32-bit integers.

It is a programmer error to pass a key that isn't valid for settings or is not of type int32.

settings :

a GSettings object

key :

the key to get the value for

Returns :

an integer

Since 2.26


g_settings_set_int ()

gboolean            g_settings_set_int                  (GSettings *settings,
                                                         const gchar *key,
                                                         gint value);

Sets key in settings to value.

A convenience variant of g_settings_set() for 32-bit integers.

It is a programmer error to pass a key that isn't valid for settings or is not of type int32.

settings :

a GSettings object

key :

the name of the key to set

value :

the value to set it to

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


g_settings_get_double ()

gdouble             g_settings_get_double               (GSettings *settings,
                                                         const gchar *key);

Gets the value that is stored at key in settings.

A convenience variant of g_settings_get() for doubles.

It is a programmer error to pass a key that isn't valid for settings or is not of type double.

settings :

a GSettings object

key :

the key to get the value for

Returns :

a double

Since 2.26


g_settings_set_double ()

gboolean            g_settings_set_double               (GSettings *settings,
                                                         const gchar *key,
                                                         gdouble value);

Sets key in settings to value.

A convenience variant of g_settings_set() for doubles.

It is a programmer error to pass a key that isn't valid for settings or is not of type double.

settings :

a GSettings object

key :

the name of the key to set

value :

the value to set it to

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


g_settings_get_string ()

gchar *             g_settings_get_string               (GSettings *settings,
                                                         const gchar *key);

Gets the value that is stored at key in settings.

A convenience variant of g_settings_get() for strings.

It is a programmer error to pass a key that isn't valid for settings or is not of type string.

settings :

a GSettings object

key :

the key to get the value for

Returns :

a newly-allocated string

Since 2.26


g_settings_set_string ()

gboolean            g_settings_set_string               (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *value);

Sets key in settings to value.

A convenience variant of g_settings_set() for strings.

It is a programmer error to pass a key that isn't valid for settings or is not of type string.

settings :

a GSettings object

key :

the name of the key to set

value :

the value to set it to

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


g_settings_get_strv ()

gchar **            g_settings_get_strv                 (GSettings *settings,
                                                         const gchar *key,
                                                         gsize *length);

Gets the value that is stored at key in settings.

A convenience variant of g_settings_get() for string arrays.

It is a programmer error to pass a key that isn't valid for settings or is not of type 'string array'.

settings :

a GSettings object

key :

the key to get the value for

length :

return location for the length of the result, or NULL

Returns :

a newly-allocated, NULL-terminated array of strings

Since 2.26


g_settings_set_strv ()

gboolean            g_settings_set_strv                 (GSettings *settings,
                                                         const gchar *key,
                                                         const gchar *const *value,
                                                         gssize length);

Sets key in settings to value.

A convenience variant of g_settings_set() for string arrays.

It is a programmer error to pass a key that isn't valid for settings or is not of type 'string array'.

settings :

a GSettings object

key :

the name of the key to set

value :

the value to set it to

length :

the length of the value array, or -1

Returns :

TRUE if setting the key succeeded, FALSE if the key was not writable

Since 2.26


enum GSettingsBindFlags

typedef enum
{
  G_SETTINGS_BIND_DEFAULT,
  G_SETTINGS_BIND_GET            = (1<<0),
  G_SETTINGS_BIND_SET            = (1<<1),
  G_SETTINGS_BIND_NO_SENSITIVITY = (1<<2),
  G_SETTINGS_BIND_GET_NO_CHANGES = (1<<3)
} GSettingsBindFlags;

Flags used when creating a binding. These flags determine in which direction the binding works. The default is to synchronize in both directions.

G_SETTINGS_BIND_DEFAULT

Equivalent to G_SETTINGS_BIND_GET|G_SETTINGS_BIND_SET

G_SETTINGS_BIND_GET

Update the GObject property when the setting changes. It is an error to use this flag if the property is not writable.

G_SETTINGS_BIND_SET

Update the setting when the GObject property changes. It is an error to use this flag if the property is not readable.

G_SETTINGS_BIND_NO_SENSITIVITY

Do not try to bind a "sensitivity" property to the writability of the setting

G_SETTINGS_BIND_GET_NO_CHANGES

When set in addition to G_SETTINGS_BIND_GET, set the GObject property value initially from the setting, but do not listen for changes of the setting

g_settings_bind ()

void                g_settings_bind                     (GSettings *settings,
                                                         const gchar *key,
                                                         gpointer object,
                                                         const gchar *property,
                                                         GSettingsBindFlags flags);

Create a binding between the key in the settings object and the property property of object.

The binding uses the default GIO mapping functions to map between the settings and property values. These functions handle booleans, numeric types and string types in a straightforward way. Use g_settings_bind_with_mapping() if you need a custom mapping, or map between types that are not supported by the default mapping functions.

Unless the flags include G_SETTINGS_BIND_NO_SENSITIVITY, this function also establishes a binding between the writability of key and the "sensitive" property of object (if object has a boolean property by that name). See g_settings_bind_writable() for more details about writable bindings.

Note that the lifecycle of the binding is tied to the object, and that you can have only one binding per object property. If you bind the same property twice on the same object, the second binding overrides the first one.

settings :

a GSettings object

key :

the key to bind

object :

a GObject

property :

the name of the property to bind

flags :

flags for the binding

Since 2.26


g_settings_bind_with_mapping ()

void                g_settings_bind_with_mapping        (GSettings *settings,
                                                         const gchar *key,
                                                         gpointer object,
                                                         const gchar *property,
                                                         GSettingsBindFlags flags,
                                                         GSettingsBindGetMapping get_mapping,
                                                         GSettingsBindSetMapping set_mapping,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy);

Create a binding between the key in the settings object and the property property of object.

The binding uses the provided mapping functions to map between settings and property values.

Note that the lifecycle of the binding is tied to the object, and that you can have only one binding per object property. If you bind the same property twice on the same object, the second binding overrides the first one.

settings :

a GSettings object

key :

the key to bind

object :

a GObject

property :

the name of the property to bind

flags :

flags for the binding

get_mapping :

a function that gets called to convert values from settings to object, or NULL to use the default GIO mapping

set_mapping :

a function that gets called to convert values from object to settings, or NULL to use the default GIO mapping

user_data :

data that gets passed to get_mapping and set_mapping

destroy :

GDestroyNotify function for user_data

Since 2.26


g_settings_bind_writable ()

void                g_settings_bind_writable            (GSettings *settings,
                                                         const gchar *key,
                                                         gpointer object,
                                                         const gchar *property,
                                                         gboolean inverted);

Create a binding between the writability of key in the settings object and the property property of object. The property must be boolean; "sensitive" or "visible" properties of widgets are the most likely candidates.

Writable bindings are always uni-directional; changes of the writability of the setting will be propagated to the object property, not the other way.

When the inverted argument is TRUE, the binding inverts the value as it passes from the setting to the object, i.e. property will be set to TRUE if the key is not writable.

Note that the lifecycle of the binding is tied to the object, and that you can have only one binding per object property. If you bind the same property twice on the same object, the second binding overrides the first one.

settings :

a GSettings object

key :

the key to bind

object :

a GObject

property :

the name of a boolean property to bind

inverted :

whether to 'invert' the value

Since 2.26


g_settings_unbind ()

void                g_settings_unbind                   (gpointer object,
                                                         const gchar *property);

Removes an existing binding for property on object.

Note that bindings are automatically removed when the object is finalized, so it is rarely necessary to call this function.

object :

the object

property :

the property whose binding is removed

Since 2.26


GSettingsBindSetMapping ()

GVariant *          (*GSettingsBindSetMapping)          (const GValue *value,
                                                         const GVariantType *expected_type,
                                                         gpointer user_data);

The type for the function that is used to convert an object property value to a GVariant for storing it in GSettings.

value :

a GValue containing the property value to map

expected_type :

the GVariantType to create

user_data :

user data that was specified when the binding was created

Returns :

a new GVariant holding the data from value, or NULL in case of an error

GSettingsBindGetMapping ()

gboolean            (*GSettingsBindGetMapping)          (GValue *value,
                                                         GVariant *variant,
                                                         gpointer user_data);

The type for the function that is used to convert from GSettings to an object property. The value is already initialized to hold values of the appropriate type.

value :

return location for the property value

variant :

the GVariant

user_data :

user data that was specified when the binding was created

Returns :

TRUE if the conversion succeeded, FALSE in case of an error

Property Details

The "context" property

  "context"                  gchar*                : Read / Write / Construct Only

The name of the context that the settings are stored in.

Default value: ""


The "has-unapplied" property

  "has-unapplied"            gboolean              : Read

If this property is TRUE, the GSettings object has outstanding changes that will be applied when g_settings_apply() is called.

Default value: FALSE


The "path" property

  "path"                     gchar*                : Read / Write / Construct Only

The path within the backend where the settings are stored.

Default value: NULL


The "schema" property

  "schema"                   gchar*                : Read / Write / Construct Only

The name of the schema that describes the types of keys for this GSettings object.

Default value: NULL

Signal Details

The "change-event" signal

gboolean            user_function                      (GSettings *settings,
                                                        gpointer   keys,
                                                        gint       n_keys,
                                                        gpointer   user_data)      : Run Last

The "change-event" signal is emitted once per change event that affects this settings object. You should connect to this signal only if you are interested in viewing groups of changes before they are split out into multiple emissions of the "changed" signal. For most use cases it is more appropriate to use the "changed" signal.

In the event that the change event applies to one or more specified keys, keys will be an array of GQuark of length n_keys. In the event that the change event applies to the GSettings object as a whole (ie: potentially every key has been changed) then keys will be NULL and n_keys will be 0.

The default handler for this signal invokes the "changed" signal for each affected key. If any other connected handler returns TRUE then this default functionality will be supressed.

settings :

the object on which the signal was emitted

keys :

an array of GQuarks for the changed keys, or NULL

n_keys :

the length of the keys array, or 0

returns :

TRUE to stop other handlers from being invoked for the event. FALSE to propagate the event further.

user_data :

user data set when the signal handler was connected.

The "changed" signal

void                user_function                      (GSettings *settings,
                                                        gchar     *key,
                                                        gpointer   user_data)      : Run Last / Has Details

The "changed" signal is emitted when a key has potentially changed. You should call one of the g_settings_get() calls to check the new value.

This signal supports detailed connections. You can connect to the detailed signal "changed::x" in order to only receive callbacks when key "x" changes.

settings :

the object on which the signal was emitted

key :

the name of the key that changed

user_data :

user data set when the signal handler was connected.

The "writable-change-event" signal

gboolean            user_function                      (GSettings *settings,
                                                        guint      key,
                                                        gpointer   user_data)      : Run Last

The "writable-change-event" signal is emitted once per writability change event that affects this settings object. You should connect to this signal if you are interested in viewing groups of changes before they are split out into multiple emissions of the "writable-changed" signal. For most use cases it is more appropriate to use the "writable-changed" signal.

In the event that the writability change applies only to a single key, key will be set to the GQuark for that key. In the event that the writability change affects the entire settings object, key will be 0.

The default handler for this signal invokes the "writable-changed" and "changed" signals for each affected key. This is done because changes in writability might also imply changes in value (if for example, a new mandatory setting is introduced). If any other connected handler returns TRUE then this default functionality will be supressed.

settings :

the object on which the signal was emitted

key :

the quark of the key, or 0

returns :

TRUE to stop other handlers from being invoked for the event. FALSE to propagate the event further.

user_data :

user data set when the signal handler was connected.

The "writable-changed" signal

void                user_function                      (GSettings *settings,
                                                        gchar     *key,
                                                        gpointer   user_data)      : Run Last / Has Details

The "writable-changed" signal is emitted when the writability of a key has potentially changed. You should call g_settings_is_writable() in order to determine the new status.

This signal supports detailed connections. You can connect to the detailed signal "writable-changed::x" in order to only receive callbacks when the writability of "x" changes.

settings :

the object on which the signal was emitted

key :

the key

user_data :

user data set when the signal handler was connected.