Settings

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

Reads and writes can be considered to be non-blocking. Reading settings with gio.settings.Settings is typically extremely fast: on approximately the same order of magnitude (but slower than) a glib.hash_table.HashTable 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 gio.settings.Settings 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 gio.settings.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 gio.settings.Settings 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 a 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 glib.variant.VariantG, and allows any glib.variant_type.VariantType 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 glib.variant.VariantGs (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 glib.variant.VariantG types, keys can have types that have enumerated types. These can be described by a <choice>, <enum> or <flags> element, as seen in the second example below. The underlying type of such a key is string, but you can use gio.settings.Settings.getEnum, gio.settings.Settings.setEnum, gio.settings.Settings.getFlags, gio.settings.Settings.setFlags 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>

    <key name="empty-string" type="s">
      <default>""</default>
      <summary>Empty strings have to be provided in GVariant form</summary>
    </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` 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 glib.variant.VariantG 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.object.ObjectG properties directly to settings, using gio.settings.Settings.bind. Once a gobject.object.ObjectG 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.object.ObjectG and glib.variant.VariantG 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 gio.types.SettingsBindFlags.NoSensitivity flag.

Relocatable schemas

A relocatable schema is one with no path attribute specified on its <schema> element. By using gio.settings.Settings.newWithPath, a gio.settings.Settings object can be instantiated for a relocatable schema, assigning a path to the instance. Paths passed to gio.settings.Settings.newWithPath 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 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.

class Settings : ObjectG {

this(string schemaId);

static gio.settings.Settings newFull(gio.settings_schema.SettingsSchema schema, gio.settings_backend.SettingsBackend backend, string path);

static gio.settings.Settings newWithBackend(string schemaId, gio.settings_backend.SettingsBackend backend);

static gio.settings.Settings newWithBackendAndPath(string schemaId, gio.settings_backend.SettingsBackend backend, string path);

static gio.settings.Settings newWithPath(string schemaId, string path);

static string[] listRelocatableSchemas();

static string[] listSchemas();

static void sync();

static void unbind(gobject.object.ObjectG object, string property);

void apply();

void bind(string key, gobject.object.ObjectG object, string property, gio.types.SettingsBindFlags flags);

void bindWritable(string key, gobject.object.ObjectG object, string property, bool inverted);

gio.action.Action createAction(string key);

void delay();

bool getBoolean(string key);

gio.settings.Settings getChild(string name);

glib.variant.VariantG getDefaultValue(string key);

double getDouble(string key);

int getEnum(string key);

uint getFlags(string key);

bool getHasUnapplied();

int getInt(string key);

long getInt64(string key);

void* getMapped(string key, gio.types.SettingsGetMapping mapping);

glib.variant.VariantG getRange(string key);

string getString(string key);

string[] getStrv(string key);

uint getUint(string key);

ulong getUint64(string key);

glib.variant.VariantG getUserValue(string key);

glib.variant.VariantG getValue(string key);

bool isWritable(string name);

string[] listChildren();

string[] listKeys();

bool rangeCheck(string key, glib.variant.VariantG value);

void reset(string key);

void revert();

bool setBoolean(string key, bool value);

bool setDouble(string key, double value);

bool setEnum(string key, int value);

bool setFlags(string key, uint value);

bool setInt(string key, int value);

bool setInt64(string key, long value);

bool setString(string key, string value);

bool setStrv(string key, string[] value);

bool setUint(string key, uint value);

bool setUint64(string key, ulong value);

bool setValue(string key, glib.variant.VariantG value);

ulong connectChangeEvent(T callback, Flag!"After" after);

ulong connectChanged(string detail, T callback, Flag!"After" after);

ulong connectWritableChangeEvent(T callback, Flag!"After" after);

ulong connectWritableChanged(string detail, T callback, Flag!"After" after);

}

Constructors

this this(string schemaId): Creates a new #GSettings object with the schema specified by schema_id.

Members

Functions

apply void apply(): Applies any changes that have been made to the settings. This function does nothing unless settings is in 'delay-apply' mode; see gio.settings.Settings.delay. In the normal case settings are always applied immediately.
bind void bind(string key, gobject.object.ObjectG object, string property, gio.types.SettingsBindFlags flags): Create a binding between the key in the settings object and the property property of object.
bindWritable void bindWritable(string key, gobject.object.ObjectG object, string property, bool 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.
connectChangeEvent ulong connectChangeEvent(T callback, Flag!"After" after): Connect to ChangeEvent signal.
connectChanged ulong connectChanged(string detail, T callback, Flag!"After" after): Connect to Changed signal.
connectWritableChangeEvent ulong connectWritableChangeEvent(T callback, Flag!"After" after): Connect to WritableChangeEvent signal.
connectWritableChanged ulong connectWritableChanged(string detail, T callback, Flag!"After" after): Connect to WritableChanged signal.
createAction gio.action.Action createAction(string key): Creates a #GAction corresponding to a given #GSettings key.
delay void delay(): 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 gio.settings.Settings.apply is called.
getBoolean bool getBoolean(string key): Gets the value that is stored at key in settings.
getChild gio.settings.Settings getChild(string name): Creates a child settings object which has a base path of base-path/name, where base-path is the base path of settings.
getDefaultValue glib.variant.VariantG getDefaultValue(string key): Gets the "default value" of a key.
getDouble double getDouble(string key): Gets the value that is stored at key in settings.
getEnum int getEnum(string key): Gets the value that is stored in settings for key and converts it to the enum value that it represents.
getFlags uint getFlags(string key): Gets the value that is stored in settings for key and converts it to the flags value that it represents.
getHasUnapplied bool getHasUnapplied(): Returns whether the #GSettings object has any unapplied changes. This can only be the case if it is in 'delayed-apply' mode.
getInt int getInt(string key): Gets the value that is stored at key in settings.
getInt64 long getInt64(string key): Gets the value that is stored at key in settings.
getMapped void* getMapped(string key, gio.types.SettingsGetMapping mapping): Gets the value that is stored at key in settings, subject to application-level validation/mapping.
getRange glib.variant.VariantG getRange(string key): Queries the range of a key.
getString string getString(string key): Gets the value that is stored at key in settings.
getStrv string[] getStrv(string key): A convenience variant of gio.settings.Settings.get for string arrays.
getUint uint getUint(string key): Gets the value that is stored at key in settings.
getUint64 ulong getUint64(string key): Gets the value that is stored at key in settings.
getUserValue glib.variant.VariantG getUserValue(string key): Checks the "user value" of a key, if there is one.
getValue glib.variant.VariantG getValue(string key): Gets the value that is stored in settings for key.
isWritable bool isWritable(string name): Finds out if a key can be written or not
listChildren string[] listChildren(): Gets the list of children on settings.
listKeys string[] listKeys(): Introspects the list of keys on settings.
rangeCheck bool rangeCheck(string key, glib.variant.VariantG value): Checks if the given value is of the correct type and within the permitted range for key.
reset void reset(string key): Resets key to its default value.
revert void revert(): Reverts all non-applied changes to the settings. This function does nothing unless settings is in 'delay-apply' mode; see gio.settings.Settings.delay. In the normal case settings are always applied immediately.
setBoolean bool setBoolean(string key, bool value): Sets key in settings to value.
setDouble bool setDouble(string key, double value): Sets key in settings to value.
setEnum bool setEnum(string key, int value): Looks up the enumerated type nick for value and writes it to key, within settings.
setFlags bool setFlags(string key, uint 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.
setInt bool setInt(string key, int value): Sets key in settings to value.
setInt64 bool setInt64(string key, long value): Sets key in settings to value.
setString bool setString(string key, string value): Sets key in settings to value.
setStrv bool setStrv(string key, string[] value): Sets key in settings to value.
setUint bool setUint(string key, uint value): Sets key in settings to value.
setUint64 bool setUint64(string key, ulong value): Sets key in settings to value.
setValue bool setValue(string key, glib.variant.VariantG value): Sets key in settings to value.

Static functions

listRelocatableSchemas string[] listRelocatableSchemas(): Deprecated.
listSchemas string[] listSchemas(): Deprecated.
newFull gio.settings.Settings newFull(gio.settings_schema.SettingsSchema schema, gio.settings_backend.SettingsBackend backend, string path): Creates a new #GSettings object with a given schema, backend and path.
newWithBackend gio.settings.Settings newWithBackend(string schemaId, gio.settings_backend.SettingsBackend backend): Creates a new #GSettings object with the schema specified by schema_id and a given #GSettingsBackend.
newWithBackendAndPath gio.settings.Settings newWithBackendAndPath(string schemaId, gio.settings_backend.SettingsBackend backend, string path): Creates a new #GSettings object with the schema specified by schema_id and a given #GSettingsBackend and path.
newWithPath gio.settings.Settings newWithPath(string schemaId, string path): Creates a new #GSettings object with the relocatable schema specified by schema_id and a given path.
sync void sync(): Ensures that all pending operations are complete for the default backend.
unbind void unbind(gobject.object.ObjectG object, string property): Removes an existing binding for property on object.

Inherited Members

From ObjectG

setGObject void setGObject(void* cObj, Flag!"Take" take): Set the GObject of a D ObjectG wrapper.
cPtr void* cPtr(Flag!"Dup" dup): Get a pointer to the underlying C object.
ref_ void* ref_(void* gObj): Calls g_object_ref() on a GObject.
unref unref(void* gObj): Calls g_object_unref() on a GObject.
getType GType getType(): Get the GType of an object.
gType GType gType [@property getter]: GObject GType property.
self ObjectG self(): Convenience method to return this cast to a type. For use in D with statements.
getDObject T getDObject(void* cptr, Flag!"Take" take): Template to get the D object from a C GObject and cast it to the given D object type.
connectSignalClosure ulong connectSignalClosure(string signalDetail, DClosure closure, Flag!"After" after): Connect a D closure to an object signal.
setProperty void setProperty(string propertyName, T val): Template for setting a GObject property.
getProperty T getProperty(string propertyName): Template for getting a GObject property.
compatControl size_t compatControl(size_t what, void* data)
bindProperty gobject.binding.Binding bindProperty(string sourceProperty, gobject.object.ObjectG target, string targetProperty, gobject.types.BindingFlags flags): Creates a binding between source_property on source and target_property on target.
bindPropertyFull gobject.binding.Binding bindPropertyFull(string sourceProperty, gobject.object.ObjectG target, string targetProperty, gobject.types.BindingFlags flags, gobject.closure.Closure transformTo, gobject.closure.Closure transformFrom): 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.
forceFloating void forceFloating(): 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 gobject.object.ObjectG.refSink.
freezeNotify void freezeNotify(): 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.
getData void* getData(string key): Gets a named field from the objects table of associations (see gobject.object.ObjectG.setData).
getProperty void getProperty(string propertyName, gobject.value.Value value): Gets a property of an object.
getQdata void* getQdata(glib.types.Quark quark): This function gets back user data pointers stored via gobject.object.ObjectG.setQdata.
getv void getv(string[] names, gobject.value.Value[] values): 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.
isFloating bool isFloating(): Checks whether object has a floating[floating-ref] reference.
notify void notify(string propertyName): Emits a "notify" signal for the property property_name on object.
notifyByPspec void notifyByPspec(gobject.param_spec.ParamSpec pspec): Emits a "notify" signal for the property specified by pspec on object.
refSink gobject.object.ObjectG refSink(): Increase the reference count of object, and possibly remove the floating[floating-ref] reference, if object has a floating reference.
runDispose void runDispose(): Releases all references to other objects. This can be used to break reference cycles.
setData void setData(string key, void* data): Each object carries around a table of associations from strings to pointers. This function lets you set an association.
setProperty void setProperty(string propertyName, gobject.value.Value value): Sets a property on an object.
stealData void* stealData(string key): Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
stealQdata void* stealQdata(glib.types.Quark quark): This function gets back user data pointers stored via gobject.object.ObjectG.setQdata 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:
thawNotify void thawNotify(): Reverts the effect of a previous call to gobject.object.ObjectG.freezeNotify. The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.
watchClosure void watchClosure(gobject.closure.Closure closure): 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 gobject.closure.Closure.invalidate on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, gobject.object.ObjectG.ref_ and gobject.object.ObjectG.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.
connectNotify ulong connectNotify(string detail, T callback, Flag!"After" after): Connect to Notify signal.

gio settings classes

Settings