Sets our main struct and passes it to the parent class.
Creates a new #GSettings object with the schema specified by @schema_id.
Creates a new #GSettings object with a given schema, backend and path.
Creates a new #GSettings object with the schema specified by @schema_id and a given #GSettingsBackend.
Creates a new #GSettings object with the schema specified by @schema_id and a given #GSettingsBackend and path.
Creates a new #GSettings object with the relocatable schema specified by @schema_id and a given path.
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.
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.
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.
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.
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.
Create a binding between the @key in the @settings object and the property @property of @object.
Create a binding between the @key in the @settings object and the property @property of @object.
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.
Creates a #GAction corresponding to a given #GSettings key.
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.
Gets the value that is stored at @key in @settings.
Creates a child settings object which has a base path of base-path/@name, where base-path is the base path of @settings.
Gets the "default value" of a key.
Gets the value that is stored at @key in @settings.
Gets the value that is stored in @settings for @key and converts it to the enum value that it represents.
Gets the value that is stored in @settings for @key and converts it to the flags value that it represents.
Returns whether the #GSettings object has any unapplied changes. This can only be the case if it is in 'delayed-apply' mode.
Gets the value that is stored at @key in @settings.
Gets the value that is stored at @key in @settings.
Gets the value that is stored at @key in @settings, subject to application-level validation/mapping.
Queries the range of a key.
Get the main Gtk struct
Gets the value that is stored at @key in @settings.
the main Gtk struct as a void*
A convenience variant of g_settings_get() for string arrays.
Gets the value that is stored at @key in @settings.
Gets the value that is stored at @key in @settings.
Checks the "user value" of a key, if there is one.
Gets the value that is stored in @settings for @key.
Finds out if a key can be written or not
Gets the list of children on @settings.
Introspects the list of keys on @settings.
Checks if the given @value is of the correct type and within the permitted range for @key.
Resets @key to its default value.
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.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
Looks up the enumerated type nick for @value and writes it to @key, within @settings.
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.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
Sets @key in @settings to @value.
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Ensures that all pending operations are complete for the default backend.
Removes an existing binding for @property on @object.
the main Gtk struct
the main Gtk struct
Get the main Gtk struct
the main Gtk struct as a void*
Gets a D Object from the objects table of associations.
The notify signal is emitted on an object when one of its properties has been changed. Note that getting this signal doesn't guarantee that the value of the property has actually changed, it may also be emitted when the setter for the property is called to reinstate the previous value.
Find the #GParamSpec with the given name for an interface. Generally, the interface vtable passed in as @g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().
Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.
Lists the properties of an interface.Generally, the interface vtable passed in as @g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().
Increases the reference count of the object by one and sets a callback to be called when all other references to the object are dropped, or when this is already the last reference to the object and another reference is established.
Adds a weak reference from weak_pointer to @object to indicate that the pointer located at @weak_pointer_location is only valid during the lifetime of @object. When the @object is finalized, @weak_pointer will be set to %NULL.
Creates a binding between @source_property on @source and @target_property on @target. Whenever the @source_property is changed the @target_property is updated using the same value. For instance:
Complete version of g_object_bind_property().
Creates a binding between @source_property on @source and @target_property on @target, allowing you to set the transformation functions to be used by the binding.
This is a variant of g_object_get_data() which returns a 'duplicate' of the value. @dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.
This is a variant of g_object_get_qdata() which returns a 'duplicate' of the value. @dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.
This function is intended for #GObject implementations to re-enforce a floating[floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().
Increases the freeze count on @object. If the freeze count is non-zero, the emission of "notify" signals on @object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one #GObject::notify signal is emitted for each property modified while the object is frozen.
Gets a named field from the objects table of associations (see g_object_set_data()).
Gets a property of an object. @value must have been initialized to the expected type of the property (or a type to which the expected type can be transformed) using g_value_init().
This function gets back user data pointers stored via g_object_set_qdata().
Gets properties of an object.
Gets @n_properties properties for an @object. Obtained properties will be set to @values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.
Checks whether @object has a floating[floating-ref] reference.
Emits a "notify" signal for the property @property_name on @object.
Emits a "notify" signal for the property specified by @pspec on @object.
Increases the reference count of @object.
Increase the reference count of @object, and possibly remove the floating[floating-ref] reference, if @object has a floating reference.
Removes a reference added with g_object_add_toggle_ref(). The reference count of the object is decreased by one.
Removes a weak reference from @object that was previously added using g_object_add_weak_pointer(). The @weak_pointer_location has to match the one used with g_object_add_weak_pointer().
Compares the user data for the key @key on @object with @oldval, and if they are the same, replaces @oldval with @newval.
Compares the user data for the key @quark on @object with @oldval, and if they are the same, replaces @oldval with @newval.
Releases all references to other objects. This can be used to break reference cycles.
Each object carries around a table of associations from strings to pointers. This function lets you set an association.
Like g_object_set_data() except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed.
Sets a property on an object.
This sets an opaque, named pointer on an object. The name is specified through a #GQuark (retrived e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the @object with g_object_get_qdata() until the @object is finalized. Setting a previously set user data pointer, overrides (frees) the old pointer set, using #NULL as pointer essentially removes the data stored.
This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with @data as argument when the @object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same @quark.
Sets properties on an object.
Sets @n_properties properties for an @object. Properties to be set will be taken from @values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
This function gets back user data pointers stored via g_object_set_qdata() and removes the @data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example: |[<!-- language="C" --> void object_add_to_user_list (GObject *object, const gchar *new_string) { // the quark, naming the object data GQuark quark_string_list = g_quark_from_static_string ("my-string-list"); // retrive the old string list GList *list = g_object_steal_qdata (object, quark_string_list);
Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on @object and when it reaches zero, queued "notify" signals are emitted.
Decreases the reference count of @object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).
This function essentially limits the life time of the @closure to the life time of the object. That is, when the object is finalized, the @closure is invalidated by calling g_closure_invalidate() on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the @closure, to ensure that an extra reference count is held on @object during invocation of the @closure. Usually, this function will be called on closures that use this @object as closure data.
Adds a weak reference callback to an object. Weak references are used for notification when an object is finalized. They are called "weak references" because they allow you to safely hold a pointer to an object without calling g_object_ref() (g_object_ref() adds a strong reference, that is, forces the object to stay alive).
Removes a weak reference callback to an object.
Clears a reference to a #GObject.
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[gsettings-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](https://www.gnu.org/software/gettext/manual/html_node/Aspects.html#index-locale-categories-1). 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: |[ <!-- 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][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][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[schema-enumerated]. 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: |[ <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: |[ <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][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: |[ 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 # {#gsettings-relocatable}
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.: |[ <schema id="org.foo.MyApp" path="/org/foo/MyApp/"> <child name="main" schema="org.foo.MyApp.Window"/> </schema> ]|
Build system integration # {#gsettings-build-system}
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: |[ GLIB_GSETTINGS ]|
In the appropriate Makefile.am, use the following snippet to compile and install the named schema: |[ 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): |[ data/org.foo.MyApp.gschema.xml ]|
Alternatively, if intltool 0.50.1 is in use: |[ [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: |[ 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.