GSettings

GSettings — High-level API for application settings

Functions

GSettings * g_settings_new ()
GSettings * g_settings_new_with_path ()
GSettings * g_settings_new_with_backend ()
GSettings * g_settings_new_with_backend_and_path ()
GSettings * g_settings_new_full ()
void g_settings_sync ()
GVariant * g_settings_get_value ()
gboolean g_settings_set_value ()
gboolean g_settings_is_writable ()
void g_settings_delay ()
void g_settings_apply ()
void g_settings_revert ()
gboolean g_settings_get_has_unapplied ()
GSettings * g_settings_get_child ()
void g_settings_reset ()
GVariant * g_settings_get_user_value ()
GVariant * g_settings_get_default_value ()
const gchar * const * g_settings_list_schemas ()
const gchar * const * g_settings_list_relocatable_schemas ()
gchar ** g_settings_list_keys ()
gchar ** g_settings_list_children ()
GVariant * g_settings_get_range ()
gboolean g_settings_range_check ()
void g_settings_get ()
gboolean g_settings_set ()
gboolean g_settings_get_boolean ()
gboolean g_settings_set_boolean ()
gint g_settings_get_int ()
gboolean g_settings_set_int ()
gint64 g_settings_get_int64 ()
gboolean g_settings_set_int64 ()
guint g_settings_get_uint ()
gboolean g_settings_set_uint ()
guint64 g_settings_get_uint64 ()
gboolean g_settings_set_uint64 ()
gdouble g_settings_get_double ()
gboolean g_settings_set_double ()
gchar * g_settings_get_string ()
gboolean g_settings_set_string ()
gchar ** g_settings_get_strv ()
gboolean g_settings_set_strv ()
gint g_settings_get_enum ()
gboolean g_settings_set_enum ()
guint g_settings_get_flags ()
gboolean g_settings_set_flags ()
gboolean (*GSettingsGetMapping) ()
gpointer g_settings_get_mapped ()
void g_settings_bind ()
void g_settings_bind_with_mapping ()
void g_settings_bind_writable ()
void g_settings_unbind ()
GVariant * (*GSettingsBindSetMapping) ()
gboolean (*GSettingsBindGetMapping) ()
GAction * g_settings_create_action ()

Properties

GSettingsBackend * backend Read / Write / Construct Only
gboolean delay-apply Read
gboolean has-unapplied Read
gchar * path Read / Write / Construct Only
gchar * schema Read / Write / Construct Only
gchar * schema-id Read / Write / Construct Only
GSettingsSchema * settings-schema Read / Write / Construct Only

Types and Values

Object Hierarchy

    GObject
    ╰── GSettings

Includes

#include <gio/gio.h>

Description

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

Reads and writes can be considered to be non-blocking. Reading settings with GSettings is typically extremely fast: on approximately the same order of magnitude (but slower than) a GHashTable lookup. Writing settings is also extremely fast in terms of time to return to your application, but can be extremely expensive for other threads and other processes. Many settings backends (including dconf) have lazy initialisation which means in the common case of the user using their computer without modifying any settings a lot of work can be avoided. For dconf, the D-Bus service doesn't even need to be started in this case. For this reason, you should only ever modify GSettings keys in response to explicit user action. Particular care should be paid to ensure that modifications are not made during startup -- for example, when setting the initial value of preferences widgets. The built-in g_settings_bind() functionality is careful not to write settings in response to notify signals as a result of modifications that it makes to widgets.

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.

Paths must start with and end with a forward slash character ('/') and must not contain two sequential slash characters. Paths should be chosen based on a domain name associated with the program or library to which the settings belong. Examples of paths are "/org/gtk/settings/file-chooser/" and "/ca/desrt/dconf-editor/". Paths should not start with "/apps/", "/desktop/" or "/system/" as they often did in GConf.

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.

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 <default> element. The string which is translated includes all text in the <default> element, including any surrounding quotation marks.

The l10n attribute must be set to messages or time, and sets the locale category for translation. The messages category should be used by default; use time for translatable date or time formats. A translation comment can be added as an XML comment immediately above the <default> element — it is recommended to add these comments to aid translators understand the meaning and implications of the default value. An optional translation context attribute can be set on the <default> element to disambiguate multiple defaults which use the same string.

For example:

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<!-- Translators: A list of words which are not allowed to be typed, in
     GVariant serialization syntax.
     See: https://developer.gnome.org/glib/stable/gvariant-text.html -->
<default l10n='messages' context='Banned words'>['bad', 'words']</default>

Translations of default values must remain syntactically valid serialized GVariants (e.g. retaining any surrounding quotation marks) or runtime errors will occur.

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.

A DTD for the gschema XML format can be found here: gschema.dtd

The glib-compile-schemas tool expects schema files to have the extension .gschema.xml.

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 D-Bus bus name, e.g. "org.gnome.SessionManager". In particular, if the settings are for a specific service that owns a D-Bus bus name, the D-Bus bus name and schema id should match. For schemas which deal with settings not associated with one named application, the id should not use StudlyCaps, e.g. "org.gnome.font-rendering".

In addition to GVariant types, keys can have types that have enumerated types. These can be described by a <choice>, <enum> or <flags> element, as seen in the example. The underlying type of such a key is string, but you can use g_settings_get_enum(), g_settings_set_enum(), g_settings_get_flags(), g_settings_set_flags() access the numeric values corresponding to the string value of enum and flags keys.

An example for default value:

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<schemalist>
  <schema id="org.gtk.Test" path="/org/gtk/Test/" gettext-domain="test">

    <key name="greeting" type="s">
      <default l10n="messages">"Hello, earthlings"</default>
      <summary>A greeting</summary>
      <description>
        Greeting of the invading martians
      </description>
    </key>

    <key name="box" type="(ii)">
      <default>(20,30)</default>
    </key>

  </schema>
</schemalist>

An example for ranges, choices and enumerated types:

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<schemalist>

  <enum id="org.gtk.Test.myenum">
    <value nick="first" value="1"/>
    <value nick="second" value="2"/>
  </enum>

  <flags id="org.gtk.Test.myflags">
    <value nick="flag1" value="1"/>
    <value nick="flag2" value="2"/>
    <value nick="flag3" value="4"/>
  </flags>

  <schema id="org.gtk.Test">

    <key name="key-with-range" type="i">
      <range min="1" max="100"/>
      <default>10</default>
    </key>

    <key name="key-with-choices" type="s">
      <choices>
        <choice value='Elisabeth'/>
        <choice value='Annabeth'/>
        <choice value='Joe'/>
      </choices>
      <aliases>
        <alias value='Anna' target='Annabeth'/>
        <alias value='Beth' target='Elisabeth'/>
      </aliases>
      <default>'Joe'</default>
    </key>

    <key name='enumerated-key' enum='org.gtk.Test.myenum'>
      <default>'first'</default>
    </key>

    <key name='flags-key' flags='org.gtk.Test.myflags'>
      <default>["flag1","flag2"]</default>
    </key>
  </schema>
</schemalist>

Vendor overrides

Default values are defined in the schemas that get installed by an application. Sometimes, it is necessary for a vendor or distributor to adjust these defaults. Since patching the XML source for the schema is inconvenient and error-prone, glib-compile-schemas reads so-called vendor override' files. These are keyfiles in the same directory as the XML schema sources which can override default values. The schema id serves as the group name in the key file, and the values are expected in serialized GVariant form, as in the following example:

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[org.gtk.Example]
key1='string'
key2=1.5

glib-compile-schemas expects schema files to have the extension .gschema.override.

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.

Relocatable schemas

A relocatable schema is one with no path attribute specified on its <schema> element. By using g_settings_new_with_path(), a GSettings object can be instantiated for a relocatable schema, assigning a path to the instance. Paths passed to g_settings_new_with_path() will typically be constructed dynamically from a constant prefix plus some form of instance identifier; but they must still be valid GSettings paths. Paths could also be constant and used with a globally installed schema originating from a dependency library.

For example, a relocatable schema could be used to store geometry information for different windows in an application. If the schema ID was org.foo.MyApp.Window, it could be instantiated for paths /org/foo/MyApp/main/, /org/foo/MyApp/document-1/, /org/foo/MyApp/document-2/, etc. If any of the paths are well-known they can be specified as <child> elements in the parent schema, e.g.:

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<schema id="org.foo.MyApp" path="/org/foo/MyApp/">
  <child name="main" schema="org.foo.MyApp.Window"/>
</schema>

Build system integration

GSettings comes with autotools integration to simplify compiling and installing schemas. To add GSettings support to an application, add the following to your configure.ac:

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GLIB_GSETTINGS

In the appropriate Makefile.am, use the following snippet to compile and install the named schema:

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gsettings_SCHEMAS = org.foo.MyApp.gschema.xml
EXTRA_DIST = $(gsettings_SCHEMAS)

@GSETTINGS_RULES@

No changes are needed to the build system to mark a schema XML file for translation. Assuming it sets the gettext-domain attribute, a schema may be marked for translation by adding it to POTFILES.in, assuming gettext 0.19 is in use (the preferred method for translation):

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data/org.foo.MyApp.gschema.xml

Alternatively, if intltool 0.50.1 is in use:

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[type: gettext/gsettings]data/org.foo.MyApp.gschema.xml

GSettings will use gettext to look up translations for the <summary> and <description> elements, and also any <default> elements which have a l10n attribute set. Translations must not be included in the .gschema.xml file by the build system, for example by using intltool XML rules with a .gschema.xml.in template.

If an enumerated type defined in a C header file is to be used in a GSettings schema, it can either be defined manually using an <enum> element in the schema XML, or it can be extracted automatically from the C header. This approach is preferred, as it ensures the two representations are always synchronised. To do so, add the following to the relevant Makefile.am:

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gsettings_ENUM_NAMESPACE = org.foo.MyApp
gsettings_ENUM_FILES = my-app-enums.h my-app-misc.h

gsettings_ENUM_NAMESPACE specifies the schema namespace for the enum files, which are specified in gsettings_ENUM_FILES. This will generate a org.foo.MyApp.enums.xml file containing the extracted enums, which will be automatically included in the schema compilation, install and uninstall rules. It should not be committed to version control or included in EXTRA_DIST.

Functions

g_settings_new ()

GSettings *
g_settings_new (const gchar *schema_id);

Creates a new GSettings object with the schema specified by schema_id .

Signals on the newly created GSettings object will be dispatched via the thread-default GMainContext in effect at the time of the call to g_settings_new(). The new GSettings will hold a reference on the context. See g_main_context_push_thread_default().

Parameters

schema_id

the id 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_id,
                          const gchar *path);

Creates a new GSettings object with the relocatable schema specified by schema_id and a given 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.

It is a programmer error if path is not a valid path. A valid path begins and ends with '/' and does not contain two consecutive '/' characters.

Parameters

schema_id

the id of the schema

 

path

the path to use

 

Returns

a new GSettings object

Since: 2.26


g_settings_new_with_backend ()

GSettings *
g_settings_new_with_backend (const gchar *schema_id,
                             GSettingsBackend *backend);

Creates a new GSettings object with the schema specified by schema_id and a given GSettingsBackend.

Creating a GSettings object with a different backend allows accessing settings from a database other than the usual one. For example, it may make sense to pass a backend corresponding to the "defaults" settings database on the system to get a settings object that modifies the system default settings instead of the settings for this user.

Parameters

schema_id

the id of the schema

 

backend

the GSettingsBackend to use

 

Returns

a new GSettings object

Since: 2.26


g_settings_new_with_backend_and_path ()

GSettings *
g_settings_new_with_backend_and_path (const gchar *schema_id,
                                      GSettingsBackend *backend,
                                      const gchar *path);

Creates a new GSettings object with the schema specified by schema_id and a given GSettingsBackend and path.

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

Parameters

schema_id

the id of the schema

 

backend

the GSettingsBackend to use

 

path

the path to use

 

Returns

a new GSettings object

Since: 2.26


g_settings_new_full ()

GSettings *
g_settings_new_full (GSettingsSchema *schema,
                     GSettingsBackend *backend,
                     const gchar *path);

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

It should be extremely rare that you ever want to use this function. It is made available for advanced use-cases (such as plugin systems that want to provide access to schemas loaded from custom locations, etc).

At the most basic level, a GSettings object is a pure composition of 4 things: a GSettingsSchema, a GSettingsBackend, a path within that backend, and a GMainContext to which signals are dispatched.

This constructor therefore gives you full control over constructing GSettings instances. The first 3 parameters are given directly as schema , backend and path , and the main context is taken from the thread-default (as per g_settings_new()).

If backend is NULL then the default backend is used.

If path is NULL then the path from the schema is used. It is an error if path is NULL and the schema has no path of its own or if path is non-NULL and not equal to the path that the schema does have.

Parameters

schema

a GSettingsSchema

 

backend

a GSettingsBackend.

[allow-none]

path

the path to use.

[allow-none]

Returns

a new GSettings object

Since: 2.32


g_settings_sync ()

void
g_settings_sync (void);

Ensures that all pending operations for the given are complete for the default backend.

Writes made to a GSettings are handled asynchronously. For this reason, it is very unlikely that the changes have it to disk by the time g_settings_set() returns.

This call will block until all of the writes have made it to the backend. Since the mainloop is not running, no change notifications will be dispatched during this call (but some may be queued by the time the call is done).


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 contained in the schema for settings .

Parameters

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 contained in the schema for settings or for value to have the incorrect type, per the schema.

If value is floating then this function consumes the reference.

Parameters

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

Parameters

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.

Parameters

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_delay(). In the normal case settings are always applied immediately.

Parameters

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_delay(). In the normal case settings are always applied immediately.

Change notifications will be emitted for affected keys.

Parameters

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.

Parameters

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.

Parameters

settings

a GSettings object

 

name

the name of the child schema

 

Returns

a 'child' settings object.

[transfer full]

Since: 2.26


g_settings_reset ()

void
g_settings_reset (GSettings *settings,
                  const gchar *key);

Resets key to its default value.

This call resets the key, as much as possible, to its default value. That might the value specified in the schema or the one set by the administrator.

Parameters

settings

a GSettings object

 

key

the name of a key

 

g_settings_get_user_value ()

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

Checks the "user value" of a key, if there is one.

The user value of a key is the last value that was set by the user.

After calling g_settings_reset() this function should always return NULL (assuming something is not wrong with the system configuration).

It is possible that g_settings_get_value() will return a different value than this function. This can happen in the case that the user set a value for a key that was subsequently locked down by the system administrator -- this function will return the user's old value.

This function may be useful for adding a "reset" option to a UI or for providing indication that a particular value has been changed.

It is a programmer error to give a key that isn't contained in the schema for settings .

Parameters

settings

a GSettings object

 

key

the key to get the user value for

 

Returns

the user's value, if set.

[allow-none][transfer full]

Since: 2.40


g_settings_get_default_value ()

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

Gets the "default value" of a key.

This is the value that would be read if g_settings_reset() were to be called on the key.

Note that this may be a different value than returned by g_settings_schema_key_get_default_value() if the system administrator has provided a default value.

Comparing the return values of g_settings_get_default_value() and g_settings_get_value() is not sufficient for determining if a value has been set because the user may have explicitly set the value to something that happens to be equal to the default. The difference here is that if the default changes in the future, the user's key will still be set.

This function may be useful for adding an indication to a UI of what the default value was before the user set it.

It is a programmer error to give a key that isn't contained in the schema for settings .

Parameters

settings

a GSettings object

 

key

the key to get the default value for

 

Returns

the default value.

[allow-none][transfer full]

Since: 2.40


g_settings_list_schemas ()

const gchar * const *
g_settings_list_schemas (void);

g_settings_list_schemas has been deprecated since version 2.40 and should not be used in newly-written code.

Use g_settings_schema_source_list_schemas() instead. If you used g_settings_list_schemas() to check for the presence of a particular schema, use g_settings_schema_source_lookup() instead of your whole loop.

<!-- -->

Returns

a list of GSettings schemas that are available. The list must not be modified or freed.

[element-type utf8][transfer none]

Since: 2.26


g_settings_list_relocatable_schemas ()

const gchar * const *
g_settings_list_relocatable_schemas (void);

g_settings_list_relocatable_schemas has been deprecated since version 2.40 and should not be used in newly-written code.

Use g_settings_schema_source_list_schemas() instead

<!-- -->

Returns

a list of relocatable GSettings schemas that are available. The list must not be modified or freed.

[element-type utf8][transfer none]

Since: 2.28


g_settings_list_keys ()

gchar **
g_settings_list_keys (GSettings *settings);

g_settings_list_keys is deprecated and should not be used in newly-written code.

Introspects the list of keys on settings .

You should probably not be calling this function from "normal" code (since you should already know what keys are in your schema). This function is intended for introspection reasons.

You should free the return value with g_strfreev() when you are done with it.

Parameters

settings

a GSettings object

 

Returns

a list of the keys on settings .

[transfer full][element-type utf8]


g_settings_list_children ()

gchar **
g_settings_list_children (GSettings *settings);

Gets the list of children on settings .

The list is exactly the list of strings for which it is not an error to call g_settings_get_child().

For GSettings objects that are lists, this value can change at any time and you should connect to the "children-changed" signal to watch for those changes. Note that there is a race condition here: you may request a child after listing it only for it to have been destroyed in the meantime. For this reason, g_settings_get_child() may return NULL even for a child that was listed by this function.

For GSettings objects that are not lists, you should probably not be calling this function from "normal" code (since you should already know what children are in your schema). This function may still be useful there for introspection reasons, however.

You should free the return value with g_strfreev() when you are done with it.

Parameters

settings

a GSettings object

 

Returns

a list of the children on settings .

[transfer full][element-type utf8]


g_settings_get_range ()

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

g_settings_get_range has been deprecated since version 2.40 and should not be used in newly-written code.

Use g_settings_schema_key_get_range() instead.

Queries the range of a key.

Parameters

settings

a GSettings

 

key

the key to query the range of

 

Since: 2.28


g_settings_range_check ()

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

g_settings_range_check has been deprecated since version 2.40 and should not be used in newly-written code.

Use g_settings_schema_key_range_check() instead.

Checks if the given value is of the correct type and within the permitted range for key .

Parameters

settings

a GSettings

 

key

the key to check

 

value

the value to check

 

Returns

TRUE if value is valid for key

Since: 2.28


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 give a key that isn't contained in the schema for settings or for the GVariantType of format to mismatch the type given in the schema.

Parameters

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 give a key that isn't contained in the schema for settings or for the GVariantType of format to mismatch the type given in the schema.

Parameters

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 give a key that isn't specified as having a boolean type in the schema for settings .

Parameters

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 give a key that isn't specified as having a boolean type in the schema for settings .

Parameters

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 give a key that isn't specified as having a int32 type in the schema for settings .

Parameters

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 give a key that isn't specified as having a int32 type in the schema for settings .

Parameters

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_int64 ()

gint64
g_settings_get_int64 (GSettings *settings,
                      const gchar *key);

Gets the value that is stored at key in settings .

A convenience variant of g_settings_get() for 64-bit integers.

It is a programmer error to give a key that isn't specified as having a int64 type in the schema for settings .

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

Returns

a 64-bit integer

Since: 2.50


g_settings_set_int64 ()

gboolean
g_settings_set_int64 (GSettings *settings,
                      const gchar *key,
                      gint64 value);

Sets key in settings to value .

A convenience variant of g_settings_set() for 64-bit integers.

It is a programmer error to give a key that isn't specified as having a int64 type in the schema for settings .

Parameters

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: 2.50


g_settings_get_uint ()

guint
g_settings_get_uint (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 unsigned integers.

It is a programmer error to give a key that isn't specified as having a uint32 type in the schema for settings .

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

Returns

an unsigned integer

Since: 2.30


g_settings_set_uint ()

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

Sets key in settings to value .

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

It is a programmer error to give a key that isn't specified as having a uint32 type in the schema for settings .

Parameters

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: 2.30


g_settings_get_uint64 ()

guint64
g_settings_get_uint64 (GSettings *settings,
                       const gchar *key);

Gets the value that is stored at key in settings .

A convenience variant of g_settings_get() for 64-bit unsigned integers.

It is a programmer error to give a key that isn't specified as having a uint64 type in the schema for settings .

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

Returns

a 64-bit unsigned integer

Since: 2.50


g_settings_set_uint64 ()

gboolean
g_settings_set_uint64 (GSettings *settings,
                       const gchar *key,
                       guint64 value);

Sets key in settings to value .

A convenience variant of g_settings_set() for 64-bit unsigned integers.

It is a programmer error to give a key that isn't specified as having a uint64 type in the schema for settings .

Parameters

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: 2.50


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 give a key that isn't specified as having a 'double' type in the schema for settings .

Parameters

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 give a key that isn't specified as having a 'double' type in the schema for settings .

Parameters

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 give a key that isn't specified as having a string type in the schema for settings .

Parameters

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 give a key that isn't specified as having a string type in the schema for settings .

Parameters

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);

A convenience variant of g_settings_get() for string arrays.

It is a programmer error to give a key that isn't specified as having an array of strings type in the schema for settings .

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

Returns

a newly-allocated, NULL-terminated array of strings, the value that is stored at key in settings .

[array zero-terminated=1][transfer full]

Since: 2.26


g_settings_set_strv ()

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

Sets key in settings to value .

A convenience variant of g_settings_set() for string arrays. If value is NULL, then key is set to be the empty array.

It is a programmer error to give a key that isn't specified as having an array of strings type in the schema for settings .

Parameters

settings

a GSettings object

 

key

the name of the key to set

 

value

the value to set it to, or NULL.

[allow-none][array zero-terminated=1]

Returns

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

Since: 2.26


g_settings_get_enum ()

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

Gets the value that is stored in settings for key and converts it to the enum value that it represents.

In order to use this function the type of the value must be a string and it must be marked in the schema file as an enumerated type.

It is a programmer error to give a key that isn't contained in the schema for settings or is not marked as an enumerated type.

If the value stored in the configuration database is not a valid value for the enumerated type then this function will return the default value.

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

Returns

the enum value

Since: 2.26


g_settings_set_enum ()

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

Looks up the enumerated type nick for value and writes it to key , within settings .

It is a programmer error to give a key that isn't contained in the schema for settings or is not marked as an enumerated type, or for value not to be a valid value for the named type.

After performing the write, accessing key directly with g_settings_get_string() will return the 'nick' associated with value .

Parameters

settings

a GSettings object

 

key

a key, within settings

 

value

an enumerated value

 

Returns

TRUE, if the set succeeds


g_settings_get_flags ()

guint
g_settings_get_flags (GSettings *settings,
                      const gchar *key);

Gets the value that is stored in settings for key and converts it to the flags value that it represents.

In order to use this function the type of the value must be an array of strings and it must be marked in the schema file as an flags type.

It is a programmer error to give a key that isn't contained in the schema for settings or is not marked as a flags type.

If the value stored in the configuration database is not a valid value for the flags type then this function will return the default value.

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

Returns

the flags value

Since: 2.26


g_settings_set_flags ()

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

Looks up the flags type nicks for the bits specified by value , puts them in an array of strings and writes the array to key , within settings .

It is a programmer error to give a key that isn't contained in the schema for settings or is not marked as a flags type, or for value to contain any bits that are not value for the named type.

After performing the write, accessing key directly with g_settings_get_strv() will return an array of 'nicks'; one for each bit in value .

Parameters

settings

a GSettings object

 

key

a key, within settings

 

value

a flags value

 

Returns

TRUE, if the set succeeds


GSettingsGetMapping ()

gboolean
(*GSettingsGetMapping) (GVariant *value,
                        gpointer *result,
                        gpointer user_data);

The type of the function that is used to convert from a value stored in a GSettings to a value that is useful to the application.

If the value is successfully mapped, the result should be stored at result and TRUE returned. If mapping fails (for example, if value is not in the right format) then FALSE should be returned.

If value is NULL then it means that the mapping function is being given a "last chance" to successfully return a valid value. TRUE must be returned in this case.

Parameters

value

the GVariant to map, or NULL

 

result

the result of the mapping.

[out]

user_data

the user data that was passed to g_settings_get_mapped().

[closure]

Returns

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


g_settings_get_mapped ()

gpointer
g_settings_get_mapped (GSettings *settings,
                       const gchar *key,
                       GSettingsGetMapping mapping,
                       gpointer user_data);

Gets the value that is stored at key in settings , subject to application-level validation/mapping.

You should use this function when the application needs to perform some processing on the value of the key (for example, parsing). The mapping function performs that processing. If the function indicates that the processing was unsuccessful (due to a parse error, for example) then the mapping is tried again with another value.

This allows a robust 'fall back to defaults' behaviour to be implemented somewhat automatically.

The first value that is tried is the user's setting for the key. If the mapping function fails to map this value, other values may be tried in an unspecified order (system or site defaults, translated schema default values, untranslated schema default values, etc).

If the mapping function fails for all possible values, one additional attempt is made: the mapping function is called with a NULL value. If the mapping function still indicates failure at this point then the application will be aborted.

The result parameter for the mapping function is pointed to a gpointer which is initially set to NULL. The same pointer is given to each invocation of mapping . The final value of that gpointer is what is returned by this function. NULL is valid; it is returned just as any other value would be.

Parameters

settings

a GSettings object

 

key

the key to get the value for

 

mapping

the function to map the value in the settings database to the value used by the application.

[scope call]

user_data

user data for mapping

 

Returns

the result, which may be NULL.

[transfer full]


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.

Parameters

settings

a GSettings object

 

key

the key to bind

 

object

a GObject.

[type GObject.Object]

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.

[skip]

Parameters

settings

a GSettings object

 

key

the key to bind

 

object

a GObject.

[type GObject.Object]

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.

Parameters

settings

a GSettings object

 

key

the key to bind

 

object

a GObject.

[type GObject.Object]

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.

Parameters

object

the object.

[type GObject.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.

Parameters

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.

Parameters

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


g_settings_create_action ()

GAction *
g_settings_create_action (GSettings *settings,
                          const gchar *key);

Creates a GAction corresponding to a given GSettings key.

The action has the same name as the key.

The value of the key becomes the state of the action and the action is enabled when the key is writable. Changing the state of the action results in the key being written to. Changes to the value or writability of the key cause appropriate change notifications to be emitted for the action.

For boolean-valued keys, action activations take no parameter and result in the toggling of the value. For all other types, activations take the new value for the key (which must have the correct type).

Parameters

settings

a GSettings

 

key

the name of a key in settings

 

Returns

a new GAction.

[transfer full]

Since: 2.32

Types and Values

GSettings

typedef struct _GSettings GSettings;

GSettings is an opaque data structure and can only be accessed using the following functions.


enum GSettingsBindFlags

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

Members

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_INVERT_BOOLEAN

When passed to g_settings_bind(), uses a pair of mapping functions that invert the boolean value when mapping between the setting and the property. The setting and property must both be booleans. You cannot pass this flag to g_settings_bind_with_mapping().

 

Property Details

The “backend” property

  “backend”                  GSettingsBackend *

The GSettingsBackend for this settings object.

Flags: Read / Write / Construct Only


The “delay-apply” property

  “delay-apply”              gboolean

Whether the GSettings object is in 'delay-apply' mode. See g_settings_delay() for details.

Flags: Read

Default value: FALSE

Since: 2.28


The “has-unapplied” property

  “has-unapplied”            gboolean

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

Flags: Read

Default value: FALSE


The “path” property

  “path”                     gchar *

The path within the backend where the settings are stored.

Flags: Read / Write / Construct Only

Default value: NULL


The “schema” property

  “schema”                   gchar *

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

The type of this property is *not* GSettingsSchema. GSettingsSchema has only existed since version 2.32 and unfortunately this name was used in previous versions to refer to the schema ID rather than the schema itself. Take care to use the 'settings-schema' property if you wish to pass in a GSettingsSchema.

GSettings:schema has been deprecated since version 2.32 and should not be used in newly-written code.

Use the 'schema-id' property instead. In a future version, this property may instead refer to a GSettingsSchema.

Flags: Read / Write / Construct Only

Default value: NULL


The “schema-id” property

  “schema-id”                gchar *

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

Flags: Read / Write / Construct Only

Default value: NULL


The “settings-schema” property

  “settings-schema”          GSettingsSchema *

The GSettingsSchema describing the types of keys for this GSettings object.

Ideally, this property would be called 'schema'. GSettingsSchema has only existed since version 2.32, however, and before then the 'schema' property was used to refer to the ID of the schema rather than the schema itself. Take care.

Flags: Read / Write / Construct Only

Signal Details

The “change-event” signal

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

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 suppressed.

Parameters

settings

the object on which the signal was emitted

 

keys

an array of GQuarks for the changed keys, or NULL.

[array length=n_keys][element-type GQuark][allow-none]

n_keys

the length of the keys array, or 0

 

user_data

user data set when the signal handler was connected.

 

Returns

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

Flags: Run Last


The “changed” signal

void
user_function (GSettings *settings,
               gchar     *key,
               gpointer   user_data)

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.

Note that settings only emits this signal if you have read key at least once while a signal handler was already connected for key .

Parameters

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.

 

Flags: Has Details


The “writable-change-event” signal

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

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 suppressed.

Parameters

settings

the object on which the signal was emitted

 

key

the quark of the key, or 0

 

user_data

user data set when the signal handler was connected.

 

Returns

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

Flags: Run Last


The “writable-changed” signal

void
user_function (GSettings *settings,
               gchar     *key,
               gpointer   user_data)

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.

Parameters

settings

the object on which the signal was emitted

 

key

the key

 

user_data

user data set when the signal handler was connected.

 

Flags: Has Details