gi-gio-2.0.19: Gio bindings

Copyright | Will Thompson Iñaki García Etxebarria and Jonas Platte
License | LGPL-2.1
Maintainer | Iñaki García Etxebarria (garetxe@gmail.com)
Safe Haskell | None
Language | Haskell2010

GI.Gio.Objects.Settings

Contents

- Exported types
- Methods
  - apply
  - bind
  - bindWritable
  - createAction
  - delay
  - getBoolean
  - getChild
  - getDefaultValue
  - getDouble
  - getEnum
  - getFlags
  - getHasUnapplied
  - getInt
  - getInt64
  - getMapped
  - getRange
  - getString
  - getStrv
  - getUint
  - getUint64
  - getUserValue
  - getValue
  - isWritable
  - listChildren
  - listKeys
  - listRelocatableSchemas
  - listSchemas
  - new
  - newFull
  - newWithBackend
  - newWithBackendAndPath
  - newWithPath
  - rangeCheck
  - reset
  - revert
  - setBoolean
  - setDouble
  - setEnum
  - setFlags
  - setInt
  - setInt64
  - setString
  - setStrv
  - setUint
  - setUint64
  - setValue
  - sync
  - unbind
- Properties
  - backend
  - delayApply
  - hasUnapplied
  - path
  - schema
  - schemaId
  - settingsSchema
- Signals
  - changeEvent
  - changed
  - writableChangeEvent
  - writableChanged

Description

The `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 `Settings` is typically extremely fast: on approximately the same order of magnitude (but slower than) a `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 `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 `settingsBind` 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 a 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 `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 <https://www.gnu.org/software/gettext/manual/html_node/Aspects.html#index-locale-categories-1 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: > > <!-- 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 --> > 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 `settingsGetEnum`, `settingsSetEnum`, `settingsGetFlags`, `settingsSetFlags` access the numeric values corresponding to the string value of enum and flags keys.

An example for default value: > >schemalist > id="org.gtk.Test" path="/org/gtk/Test/" gettext-domain="test" > > name="greeting" type="s" > l10n="messages""Hello, earthlings"/default > summaryA greeting/summary > description > Greeting of the invading martians > /description > /key > > name="box" type="(ii)" > default(20,30)/default > /key > > name="empty-string" type="s" > default""/default > summaryEmpty strings have to be provided in GVariant form/summary > /key > > /schema >/schemalist

An example for ranges, choices and enumerated types: > >schemalist > > id="org.gtk.Test.myenum" > nick="first" value="1"/ > nick="second" value="2"/ > /enum > > id="org.gtk.Test.myflags" > nick="flag1" value="1"/ > nick="flag2" value="2"/ > nick="flag3" value="4"/ > /flags > > id="org.gtk.Test" > > name="key-with-range" type="i" > min="1" max="100"/ > default10/default > /key > > name="key-with-choices" type="s" > choices > value='Elisabeth'/ > value='Annabeth'/ > value='Joe'/ > /choices > aliases > value='Anna' target='Annabeth'/ > value='Beth' target='Elisabeth'/ > /aliases > default `Joe`/default > /key > > name='enumerated-key' enum='org.gtk.Test.myenum' > default `first`/default > /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 `Object` properties directly to settings, using `settingsBind`. 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.

# {`gsettings`-relocatable}

A relocatable schema is one with no `path` attribute specified on its <schema> element. By using `settingsNewWithPath`, a `Settings` object can be instantiated for a relocatable schema, assigning a path to the instance. Paths passed to `settingsNewWithPath` 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.: > >id="org.foo.MyApp" path="/org/foo/MyApp/" > name="main" schema="org.foo.MyApp.Window"/ >/schema

# {`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: gettextgsettings]dataorg.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`.

Synopsis

- newtype Settings = Settings (ManagedPtr Settings)
- class GObject o => IsSettings o
- toSettings :: (MonadIO m, IsSettings o) => o -> m Settings
- noSettings :: Maybe Settings
- settingsApply :: (HasCallStack, MonadIO m, IsSettings a) => a -> m ()
- settingsBind :: (HasCallStack, MonadIO m, IsSettings a, IsObject b) => a -> Text -> b -> Text -> [SettingsBindFlags] -> m ()
- settingsBindWritable :: (HasCallStack, MonadIO m, IsSettings a, IsObject b) => a -> Text -> b -> Text -> Bool -> m ()
- settingsCreateAction :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Action
- settingsDelay :: (HasCallStack, MonadIO m, IsSettings a) => a -> m ()
- settingsGetBoolean :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Bool
- settingsGetChild :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Settings
- settingsGetDefaultValue :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m (Maybe GVariant)
- settingsGetDouble :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Double
- settingsGetEnum :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Int32
- settingsGetFlags :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Word32
- settingsGetHasUnapplied :: (HasCallStack, MonadIO m, IsSettings a) => a -> m Bool
- settingsGetInt :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Int32
- settingsGetInt64 :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Int64
- settingsGetMapped :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> SettingsGetMapping -> m (Ptr ())
- settingsGetRange :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m GVariant
- settingsGetString :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Text
- settingsGetStrv :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m [Text]
- settingsGetUint :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Word32
- settingsGetUint64 :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Word64
- settingsGetUserValue :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m (Maybe GVariant)
- settingsGetValue :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m GVariant
- settingsIsWritable :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m Bool
- settingsListChildren :: (HasCallStack, MonadIO m, IsSettings a) => a -> m [Text]
- settingsListKeys :: (HasCallStack, MonadIO m, IsSettings a) => a -> m [Text]
- settingsListRelocatableSchemas :: (HasCallStack, MonadIO m) => m [Text]
- settingsListSchemas :: (HasCallStack, MonadIO m) => m [Text]
- settingsNew :: (HasCallStack, MonadIO m) => Text -> m Settings
- settingsNewFull :: (HasCallStack, MonadIO m, IsSettingsBackend a) => SettingsSchema -> Maybe a -> Maybe Text -> m Settings
- settingsNewWithBackend :: (HasCallStack, MonadIO m, IsSettingsBackend a) => Text -> a -> m Settings
- settingsNewWithBackendAndPath :: (HasCallStack, MonadIO m, IsSettingsBackend a) => Text -> a -> Text -> m Settings
- settingsNewWithPath :: (HasCallStack, MonadIO m) => Text -> Text -> m Settings
- settingsRangeCheck :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> GVariant -> m Bool
- settingsReset :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> m ()
- settingsRevert :: (HasCallStack, MonadIO m, IsSettings a) => a -> m ()
- settingsSetBoolean :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Bool -> m Bool
- settingsSetDouble :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Double -> m Bool
- settingsSetEnum :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Int32 -> m Bool
- settingsSetFlags :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Word32 -> m Bool
- settingsSetInt :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Int32 -> m Bool
- settingsSetInt64 :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Int64 -> m Bool
- settingsSetString :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Text -> m Bool
- settingsSetStrv :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Maybe [Text] -> m Bool
- settingsSetUint :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Word32 -> m Bool
- settingsSetUint64 :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> Word64 -> m Bool
- settingsSetValue :: (HasCallStack, MonadIO m, IsSettings a) => a -> Text -> GVariant -> m Bool
- settingsSync :: (HasCallStack, MonadIO m) => m ()
- settingsUnbind :: (HasCallStack, MonadIO m, IsObject a) => a -> Text -> m ()
- constructSettingsBackend :: (IsSettings o, IsSettingsBackend a) => a -> IO (GValueConstruct o)
- getSettingsBackend :: (MonadIO m, IsSettings o) => o -> m (Maybe SettingsBackend)
- getSettingsDelayApply :: (MonadIO m, IsSettings o) => o -> m Bool
- getSettingsHasUnapplied :: (MonadIO m, IsSettings o) => o -> m Bool
- constructSettingsPath :: IsSettings o => Text -> IO (GValueConstruct o)
- getSettingsPath :: (MonadIO m, IsSettings o) => o -> m (Maybe Text)
- constructSettingsSchema :: IsSettings o => Text -> IO (GValueConstruct o)
- getSettingsSchema :: (MonadIO m, IsSettings o) => o -> m (Maybe Text)
- constructSettingsSchemaId :: IsSettings o => Text -> IO (GValueConstruct o)
- getSettingsSchemaId :: (MonadIO m, IsSettings o) => o -> m (Maybe Text)
- constructSettingsSettingsSchema :: IsSettings o => SettingsSchema -> IO (GValueConstruct o)
- getSettingsSettingsSchema :: (MonadIO m, IsSettings o) => o -> m (Maybe SettingsSchema)
- type C_SettingsChangeEventCallback = Ptr () -> Ptr Word32 -> Int32 -> Ptr () -> IO CInt
- type SettingsChangeEventCallback = Maybe [Word32] -> IO Bool
- afterSettingsChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsChangeEventCallback -> m SignalHandlerId
- genClosure_SettingsChangeEvent :: SettingsChangeEventCallback -> IO Closure
- mk_SettingsChangeEventCallback :: C_SettingsChangeEventCallback -> IO (FunPtr C_SettingsChangeEventCallback)
- noSettingsChangeEventCallback :: Maybe SettingsChangeEventCallback
- onSettingsChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsChangeEventCallback -> m SignalHandlerId
- wrap_SettingsChangeEventCallback :: SettingsChangeEventCallback -> C_SettingsChangeEventCallback
- type C_SettingsChangedCallback = Ptr () -> CString -> Ptr () -> IO ()
- type SettingsChangedCallback = Text -> IO ()
- afterSettingsChanged :: (IsSettings a, MonadIO m) => a -> SettingsChangedCallback -> m SignalHandlerId
- genClosure_SettingsChanged :: SettingsChangedCallback -> IO Closure
- mk_SettingsChangedCallback :: C_SettingsChangedCallback -> IO (FunPtr C_SettingsChangedCallback)
- noSettingsChangedCallback :: Maybe SettingsChangedCallback
- onSettingsChanged :: (IsSettings a, MonadIO m) => a -> SettingsChangedCallback -> m SignalHandlerId
- wrap_SettingsChangedCallback :: SettingsChangedCallback -> C_SettingsChangedCallback
- type C_SettingsWritableChangeEventCallback = Ptr () -> Word32 -> Ptr () -> IO CInt
- type SettingsWritableChangeEventCallback = Word32 -> IO Bool
- afterSettingsWritableChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangeEventCallback -> m SignalHandlerId
- genClosure_SettingsWritableChangeEvent :: SettingsWritableChangeEventCallback -> IO Closure
- mk_SettingsWritableChangeEventCallback :: C_SettingsWritableChangeEventCallback -> IO (FunPtr C_SettingsWritableChangeEventCallback)
- noSettingsWritableChangeEventCallback :: Maybe SettingsWritableChangeEventCallback
- onSettingsWritableChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangeEventCallback -> m SignalHandlerId
- wrap_SettingsWritableChangeEventCallback :: SettingsWritableChangeEventCallback -> C_SettingsWritableChangeEventCallback
- type C_SettingsWritableChangedCallback = Ptr () -> CString -> Ptr () -> IO ()
- type SettingsWritableChangedCallback = Text -> IO ()
- afterSettingsWritableChanged :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangedCallback -> m SignalHandlerId
- genClosure_SettingsWritableChanged :: SettingsWritableChangedCallback -> IO Closure
- mk_SettingsWritableChangedCallback :: C_SettingsWritableChangedCallback -> IO (FunPtr C_SettingsWritableChangedCallback)
- noSettingsWritableChangedCallback :: Maybe SettingsWritableChangedCallback
- onSettingsWritableChanged :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangedCallback -> m SignalHandlerId
- wrap_SettingsWritableChangedCallback :: SettingsWritableChangedCallback -> C_SettingsWritableChangedCallback

# Exported types

newtype Settings Source #

Memory-managed wrapper type.

Constructors

Settings (ManagedPtr Settings) |

Instances

GObject Settings Source # |
Instance details Defined in GI.Gio.Objects.Settings Methods gobjectType :: Settings -> IO GType Source #
IsObject Settings Source # |
Instance details Defined in GI.Gio.Objects.Settings
IsSettings Settings Source # |
Instance details Defined in GI.Gio.Objects.Settings

class GObject o => IsSettings o Source #

Type class for types which can be safely cast to `Settings`, for instance with `toSettings`.

Instances

(GObject a, (UnknownAncestorError Settings a :: Constraint)) => IsSettings a Source # |
Instance details Defined in GI.Gio.Objects.Settings
IsSettings Settings Source # |
Instance details Defined in GI.Gio.Objects.Settings

toSettings :: (MonadIO m, IsSettings o) => o -> m Settings Source #

Cast to `Settings`, for types for which this is known to be safe. For general casts, use `castTo`.

noSettings :: Maybe Settings Source #

A convenience alias for `Nothing` :: `Maybe` `Settings`.

# Methods

## apply

settingsApply Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` instance
-> m () |

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

## bind

settingsBind Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a, IsObject b) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to bind
-> b | `object`: a `Object`
-> Text | `property`: the name of the property to bind
-> [SettingsBindFlags] | `flags`: flags for the binding
-> m () |

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 `SettingsBindFlagsNoSensitivity`, 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 `settingsBindWritable` for more details about writable bindings.

Note that the lifecycle of the binding is tied to `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.

Since: 2.26

## bindWritable

settingsBindWritable Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a, IsObject b) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to bind
-> b | `object`: a `Object`
-> Text | `property`: the name of a boolean property to bind
-> Bool | `inverted`: whether to 'invert' the value
-> m () |

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 `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.

Since: 2.26

## createAction

settingsCreateAction Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings`
-> Text | `key`: the name of a key in `settings`
-> m Action | Returns: a new `Action`

Creates a `Action` corresponding to a given `Settings` 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).

Since: 2.32

## delay

settingsDelay Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> m () |

Changes the `Settings` object into 'delay-apply' mode. In this mode, changes to `settings` are not immediately propagated to the backend, but kept locally until `settingsApply` is called.

Since: 2.26

## getBoolean

settingsGetBoolean Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Bool | Returns: a boolean

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`.

Since: 2.26

## getChild

settingsGetChild Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `name`: the name of the child schema
-> m Settings | Returns: a 'child' settings object

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.

Since: 2.26

## getDefaultValue

settingsGetDefaultValue Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the default value for
-> m (Maybe GVariant) | Returns: the default value

Gets the "default value" of a key.

This is the value that would be read if `settingsReset` were to be called on the key.

Note that this may be a different value than returned by `settingsSchemaKeyGetDefaultValue` if the system administrator has provided a default value.

Comparing the return values of `settingsGetDefaultValue` and `settingsGetValue` 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`.

Since: 2.40

## getDouble

settingsGetDouble Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Double | Returns: a double

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`.

Since: 2.26

## getEnum

settingsGetEnum Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Int32 | Returns: the enum value

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.

Since: 2.26

## getFlags

settingsGetFlags Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Word32 | Returns: the flags value

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.

Since: 2.26

## getHasUnapplied

settingsGetHasUnapplied Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> m Bool | Returns: `True` if `settings` has unapplied changes

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

Since: 2.26

## getInt

settingsGetInt Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Int32 | Returns: an integer

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`.

Since: 2.26

## getInt64

settingsGetInt64 Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Int64 | Returns: a 64-bit integer

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`.

Since: 2.50

## getMapped

settingsGetMapped Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> SettingsGetMapping | `mapping`: the function to map the value in the settings database to the value used by the application
-> m (Ptr ()) | Returns: the result, which may be `Nothing`

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 `Nothing` 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 `Nothing`. The same pointer is given to each invocation of `mapping`. The final value of that `gpointer` is what is returned by this function. `Nothing` is valid; it is returned just as any other value would be.

## getRange

settingsGetRange Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings`
-> Text | `key`: the key to query the range of
-> m GVariant |

Deprecated: (Since version 2.40)Use `settingsSchemaKeyGetRange` instead.

Queries the range of a key.

Since: 2.28

## getString

settingsGetString Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Text | Returns: a newly-allocated string

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`.

Since: 2.26

## getStrv

settingsGetStrv Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m [Text] | Returns: a newly-allocated, `Nothing`-terminated array of strings, the value that is stored at `key` in `settings`.

A convenience variant of `g_settings_get()` for string arrays.

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

Since: 2.26

## getUint

settingsGetUint Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Word32 | Returns: an unsigned integer

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`.

Since: 2.30

## getUint64

settingsGetUint64 Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m Word64 | Returns: a 64-bit unsigned integer

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`.

Since: 2.50

## getUserValue

settingsGetUserValue Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the user value for
-> m (Maybe GVariant) | Returns: the user's value, if set

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 `settingsReset` this function should always return `Nothing` (assuming something is not wrong with the system configuration).

It is possible that `settingsGetValue` 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`.

Since: 2.40

## getValue

settingsGetValue Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the key to get the value for
-> m GVariant | Returns: a new `GVariant`

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`.

Since: 2.26

## isWritable

settingsIsWritable Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `name`: the name of a key
-> m Bool | Returns: `True` if the key `name` is writable

Finds out if a key can be written or not

Since: 2.26

## listChildren

settingsListChildren Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> m [Text] | Returns: a list of the children on `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 `settingsGetChild`.

There is little reason to call 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 `strfreev` when you are done with it.

## listKeys

settingsListKeys Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> m [Text] | Returns: a list of the keys on `settings`

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 `strfreev` when you are done with it.

## listRelocatableSchemas

settingsListRelocatableSchemas Source #

Arguments

:: (HasCallStack, MonadIO m) |
=> m [Text] | Returns: a list of relocatable `Settings` schemas that are available. The list must not be modified or freed.

Deprecated: (Since version 2.40)Use `settingsSchemaSourceListSchemas` instead

Deprecated.

Since: 2.28

## listSchemas

settingsListSchemas Source #

Arguments

:: (HasCallStack, MonadIO m) |
=> m [Text] | Returns: a list of `Settings` schemas that are available. The list must not be modified or freed.

Deprecated: (Since version 2.40)Use `settingsSchemaSourceListSchemas` instead.If you used `settingsListSchemas` to check for the presence ofa particular schema, use `settingsSchemaSourceLookup` insteadof your whole loop.

Deprecated.

Since: 2.26

## new

settingsNew Source #

Arguments

:: (HasCallStack, MonadIO m) |
=> Text | `schemaId`: the id of the schema
-> m Settings | Returns: a new `Settings` object

Creates a new `Settings` object with the schema specified by `schemaId`.

Signals on the newly created `Settings` object will be dispatched via the thread-default `MainContext` in effect at the time of the call to `settingsNew`. The new `Settings` will hold a reference on the context. See `mainContextPushThreadDefault`.

Since: 2.26

## newFull

settingsNewFull Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettingsBackend a) |
=> SettingsSchema | `schema`: a `SettingsSchema`
-> Maybe a | `backend`: a `SettingsBackend`
-> Maybe Text | `path`: the path to use
-> m Settings | Returns: a new `Settings` object

Creates a new `Settings` 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 `Settings` object is a pure composition of 4 things: a `SettingsSchema`, a `SettingsBackend`, a path within that backend, and a `MainContext` to which signals are dispatched.

This constructor therefore gives you full control over constructing `Settings` 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 `settingsNew`).

If `backend` is `Nothing` then the default backend is used.

If `path` is `Nothing` then the path from the schema is used. It is an error if `path` is `Nothing` and the schema has no path of its own or if `path` is non-`Nothing` and not equal to the path that the schema does have.

Since: 2.32

## newWithBackend

settingsNewWithBackend Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettingsBackend a) |
=> Text | `schemaId`: the id of the schema
-> a | `backend`: the `SettingsBackend` to use
-> m Settings | Returns: a new `Settings` object

Creates a new `Settings` object with the schema specified by `schemaId` and a given `SettingsBackend`.

Creating a `Settings` 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.

Since: 2.26

## newWithBackendAndPath

settingsNewWithBackendAndPath Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettingsBackend a) |
=> Text | `schemaId`: the id of the schema
-> a | `backend`: the `SettingsBackend` to use
-> Text | `path`: the path to use
-> m Settings | Returns: a new `Settings` object

Creates a new `Settings` object with the schema specified by `schemaId` and a given `SettingsBackend` and path.

This is a mix of `settingsNewWithBackend` and `settingsNewWithPath`.

Since: 2.26

## newWithPath

settingsNewWithPath Source #

Arguments

:: (HasCallStack, MonadIO m) |
=> Text | `schemaId`: the id of the schema
-> Text | `path`: the path to use
-> m Settings | Returns: a new `Settings` object

Creates a new `Settings` object with the relocatable schema specified by `schemaId` 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.

Since: 2.26

## rangeCheck

settingsRangeCheck Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings`
-> Text | `key`: the key to check
-> GVariant | `value`: the value to check
-> m Bool | Returns: `True` if `value` is valid for `key`

Deprecated: (Since version 2.40)Use `settingsSchemaKeyRangeCheck` instead.

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

Since: 2.28

## reset

settingsReset Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of a key
-> m () |

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.

## revert

settingsRevert Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` instance
-> m () |

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

Change notifications will be emitted for affected keys.

## setBoolean

settingsSetBoolean Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Bool | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.26

## setDouble

settingsSetDouble Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Double | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.26

## setEnum

settingsSetEnum Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: a key, within `settings`
-> Int32 | `value`: an enumerated value
-> m Bool | Returns: `True`, if the set succeeds

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 `settingsGetString` will return the 'nick' associated with `value`.

## setFlags

settingsSetFlags Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: a key, within `settings`
-> Word32 | `value`: a flags value
-> m Bool | Returns: `True`, if the set succeeds

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 `settingsGetStrv` will return an array of 'nicks'; one for each bit in `value`.

## setInt

settingsSetInt Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Int32 | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.26

## setInt64

settingsSetInt64 Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Int64 | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.50

## setString

settingsSetString Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Text | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.26

## setStrv

settingsSetStrv Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Maybe [Text] | `value`: the value to set it to, or `Nothing`
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

Sets `key` in `settings` to `value`.

A convenience variant of `g_settings_set()` for string arrays. If `value` is `Nothing`, 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`.

Since: 2.26

## setUint

settingsSetUint Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Word32 | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.30

## setUint64

settingsSetUint64 Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> Word64 | `value`: the value to set it to
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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`.

Since: 2.50

## setValue

settingsSetValue Source #

Arguments

:: (HasCallStack, MonadIO m, IsSettings a) |
=> a | `settings`: a `Settings` object
-> Text | `key`: the name of the key to set
-> GVariant | `value`: a `GVariant` of the correct type
-> m Bool | Returns: `True` if setting the key succeeded, `False` if the key was not writable

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.

Since: 2.26

## sync

settingsSync :: (HasCallStack, MonadIO m) => m () Source #

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

Writes made to a `Settings` 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).

## unbind

settingsUnbind Source #

Arguments

:: (HasCallStack, MonadIO m, IsObject a) |
=> a | `object`: the object
-> Text | `property`: the property whose binding is removed
-> m () |

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.

Since: 2.26

# Properties

## backend

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

constructSettingsBackend :: (IsSettings o, IsSettingsBackend a) => a -> IO (GValueConstruct o) Source #

Construct a `GValueConstruct` with valid value for the “`backend`” property. This is rarely needed directly, but it is used by `new`.

getSettingsBackend :: (MonadIO m, IsSettings o) => o -> m (Maybe SettingsBackend) Source #

Get the value of the “`backend`” property. When overloading is enabled, this is equivalent to

    get settings #backend

## delayApply

Whether the `Settings` object is in 'delay-apply' mode. See `settingsDelay` for details.

Since: 2.28

getSettingsDelayApply :: (MonadIO m, IsSettings o) => o -> m Bool Source #

Get the value of the “`delay-apply`” property. When overloading is enabled, this is equivalent to

    get settings #delayApply

## hasUnapplied

If this property is `True`, the `Settings` object has outstanding changes that will be applied when `settingsApply` is called.

getSettingsHasUnapplied :: (MonadIO m, IsSettings o) => o -> m Bool Source #

Get the value of the “`has-unapplied`” property. When overloading is enabled, this is equivalent to

    get settings #hasUnapplied

## path

The path within the backend where the settings are stored.

constructSettingsPath :: IsSettings o => Text -> IO (GValueConstruct o) Source #

Construct a `GValueConstruct` with valid value for the “`path`” property. This is rarely needed directly, but it is used by `new`.

getSettingsPath :: (MonadIO m, IsSettings o) => o -> m (Maybe Text) Source #

Get the value of the “`path`” property. When overloading is enabled, this is equivalent to

    get settings #path

## schema

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

The type of this property is *not* `SettingsSchema`. `SettingsSchema` 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 `SettingsSchema`.

constructSettingsSchema :: IsSettings o => Text -> IO (GValueConstruct o) Source #

Construct a `GValueConstruct` with valid value for the “`schema`” property. This is rarely needed directly, but it is used by `new`.

getSettingsSchema :: (MonadIO m, IsSettings o) => o -> m (Maybe Text) Source #

Get the value of the “`schema`” property. When overloading is enabled, this is equivalent to

    get settings #schema

## schemaId

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

constructSettingsSchemaId :: IsSettings o => Text -> IO (GValueConstruct o) Source #

Construct a `GValueConstruct` with valid value for the “`schema-id`” property. This is rarely needed directly, but it is used by `new`.

getSettingsSchemaId :: (MonadIO m, IsSettings o) => o -> m (Maybe Text) Source #

Get the value of the “`schema-id`” property. When overloading is enabled, this is equivalent to

    get settings #schemaId

## settingsSchema

The `SettingsSchema` describing the types of keys for this `Settings` object.

Ideally, this property would be called 'schema'. `SettingsSchema` 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.

constructSettingsSettingsSchema :: IsSettings o => SettingsSchema -> IO (GValueConstruct o) Source #

Construct a `GValueConstruct` with valid value for the “`settings-schema`” property. This is rarely needed directly, but it is used by `new`.

getSettingsSettingsSchema :: (MonadIO m, IsSettings o) => o -> m (Maybe SettingsSchema) Source #

Get the value of the “`settings-schema`” property. When overloading is enabled, this is equivalent to

    get settings #settingsSchema

# Signals

## changeEvent

type C_SettingsChangeEventCallback = Ptr () -> Ptr Word32 -> Int32 -> Ptr () -> IO CInt Source #

Type for the callback on the (unwrapped) C side.

type SettingsChangeEventCallback Source #

Arguments

= Maybe [Word32] | `keys`: an array of `GQuarks` for the changed keys, or `Nothing`
-> IO Bool | Returns: `True` to stop other handlers from being invoked for the event. FALSE to propagate the event further.

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 `nKeys`. In the event that the change event applies to the `Settings` object as a whole (ie: potentially every key has been changed) then `keys` will be `Nothing` and `nKeys` 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.

afterSettingsChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsChangeEventCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`change-event`” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

    after settings #changeEvent callback

genClosure_SettingsChangeEvent :: SettingsChangeEventCallback -> IO Closure Source #

Wrap the callback into a `Closure`.

mk_SettingsChangeEventCallback :: C_SettingsChangeEventCallback -> IO (FunPtr C_SettingsChangeEventCallback) Source #

Generate a function pointer callable from C code, from a `C_SettingsChangeEventCallback`.

noSettingsChangeEventCallback :: Maybe SettingsChangeEventCallback Source #

A convenience synonym for ``Nothing` :: `Maybe` `SettingsChangeEventCallback``.

onSettingsChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsChangeEventCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`change-event`” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

    on settings #changeEvent callback

wrap_SettingsChangeEventCallback :: SettingsChangeEventCallback -> C_SettingsChangeEventCallback Source #

Wrap a `SettingsChangeEventCallback` into a `C_SettingsChangeEventCallback`.

## changed

type C_SettingsChangedCallback = Ptr () -> CString -> Ptr () -> IO () Source #

Type for the callback on the (unwrapped) C side.

type SettingsChangedCallback Source #

Arguments

= Text | `key`: the name of the key that changed
-> IO () |

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`.

afterSettingsChanged :: (IsSettings a, MonadIO m) => a -> SettingsChangedCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`changed`” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

    after settings #changed callback

genClosure_SettingsChanged :: SettingsChangedCallback -> IO Closure Source #

Wrap the callback into a `Closure`.

mk_SettingsChangedCallback :: C_SettingsChangedCallback -> IO (FunPtr C_SettingsChangedCallback) Source #

Generate a function pointer callable from C code, from a `C_SettingsChangedCallback`.

noSettingsChangedCallback :: Maybe SettingsChangedCallback Source #

A convenience synonym for ``Nothing` :: `Maybe` `SettingsChangedCallback``.

onSettingsChanged :: (IsSettings a, MonadIO m) => a -> SettingsChangedCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`changed`” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

    on settings #changed callback

wrap_SettingsChangedCallback :: SettingsChangedCallback -> C_SettingsChangedCallback Source #

Wrap a `SettingsChangedCallback` into a `C_SettingsChangedCallback`.

## writableChangeEvent

type C_SettingsWritableChangeEventCallback = Ptr () -> Word32 -> Ptr () -> IO CInt Source #

Type for the callback on the (unwrapped) C side.

type SettingsWritableChangeEventCallback Source #

Arguments

= Word32 | `key`: the quark of the key, or 0
-> IO Bool | Returns: `True` to stop other handlers from being invoked for the event. FALSE to propagate the event further.

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.

afterSettingsWritableChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangeEventCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`writable-change-event`” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

    after settings #writableChangeEvent callback

genClosure_SettingsWritableChangeEvent :: SettingsWritableChangeEventCallback -> IO Closure Source #

Wrap the callback into a `Closure`.

mk_SettingsWritableChangeEventCallback :: C_SettingsWritableChangeEventCallback -> IO (FunPtr C_SettingsWritableChangeEventCallback) Source #

Generate a function pointer callable from C code, from a `C_SettingsWritableChangeEventCallback`.

noSettingsWritableChangeEventCallback :: Maybe SettingsWritableChangeEventCallback Source #

A convenience synonym for ``Nothing` :: `Maybe` `SettingsWritableChangeEventCallback``.

onSettingsWritableChangeEvent :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangeEventCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`writable-change-event`” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

    on settings #writableChangeEvent callback

wrap_SettingsWritableChangeEventCallback :: SettingsWritableChangeEventCallback -> C_SettingsWritableChangeEventCallback Source #

Wrap a `SettingsWritableChangeEventCallback` into a `C_SettingsWritableChangeEventCallback`.

## writableChanged

type C_SettingsWritableChangedCallback = Ptr () -> CString -> Ptr () -> IO () Source #

Type for the callback on the (unwrapped) C side.

type SettingsWritableChangedCallback Source #

Arguments

= Text | `key`: the key
-> IO () |

The "writable-changed" signal is emitted when the writability of a key has potentially changed. You should call `settingsIsWritable` 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.

afterSettingsWritableChanged :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangedCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`writable-changed`” signal, to be run after the default handler. When overloading is enabled, this is equivalent to

    after settings #writableChanged callback

genClosure_SettingsWritableChanged :: SettingsWritableChangedCallback -> IO Closure Source #

Wrap the callback into a `Closure`.

mk_SettingsWritableChangedCallback :: C_SettingsWritableChangedCallback -> IO (FunPtr C_SettingsWritableChangedCallback) Source #

Generate a function pointer callable from C code, from a `C_SettingsWritableChangedCallback`.

noSettingsWritableChangedCallback :: Maybe SettingsWritableChangedCallback Source #

A convenience synonym for ``Nothing` :: `Maybe` `SettingsWritableChangedCallback``.

onSettingsWritableChanged :: (IsSettings a, MonadIO m) => a -> SettingsWritableChangedCallback -> m SignalHandlerId Source #

Connect a signal handler for the “`writable-changed`” signal, to be run before the default handler. When overloading is enabled, this is equivalent to

    on settings #writableChanged callback

wrap_SettingsWritableChangedCallback :: SettingsWritableChangedCallback -> C_SettingsWritableChangedCallback Source #

Wrap a `SettingsWritableChangedCallback` into a `C_SettingsWritableChangedCallback`.