{- | Copyright : Will Thompson, Iñaki García Etxebarria and Jonas Platte License : LGPL-2.1 Maintainer : Iñaki García Etxebarria (garetxe@gmail.com) The #GSettingsBackend interface defines a generic interface for non-strictly-typed data that is stored in a hierarchy. To implement an alternative storage backend for #GSettings, you need to implement the #GSettingsBackend interface and then make it implement the extension point #G_SETTINGS_BACKEND_EXTENSION_POINT_NAME. The interface defines methods for reading and writing values, a method for determining if writing of certain values will fail (lockdown) and a change notification mechanism. The semantics of the interface are very precisely defined and implementations must carefully adhere to the expectations of callers that are documented on each of the interface methods. Some of the GSettingsBackend functions accept or return a #GTree. These trees always have strings as keys and #GVariant as values. g_settings_backend_create_tree() is a convenience function to create suitable trees. The GSettingsBackend API is exported to allow third-party implementations, but does not carry the same stability guarantees as the public GIO API. For this reason, you have to define the C preprocessor symbol %G_SETTINGS_ENABLE_BACKEND before including `gio/gsettingsbackend.h`. -} module GI.Gio.Structs.SettingsBackend ( -- * Exported types SettingsBackend(..) , noSettingsBackend , ) where import Prelude () import Data.GI.Base.ShortPrelude import qualified Data.Text as T import qualified Data.ByteString.Char8 as B import qualified Data.Map as Map import GI.Gio.Types import GI.Gio.Callbacks newtype SettingsBackend = SettingsBackend (ForeignPtr SettingsBackend) noSettingsBackend :: Maybe SettingsBackend noSettingsBackend = Nothing type family ResolveSettingsBackendMethod (t :: Symbol) (o :: *) :: * where ResolveSettingsBackendMethod l o = MethodResolutionFailed l o instance (info ~ ResolveSettingsBackendMethod t SettingsBackend, MethodInfo info SettingsBackend p) => IsLabelProxy t (SettingsBackend -> p) where fromLabelProxy _ = overloadedMethod (MethodProxy :: MethodProxy info) #if MIN_VERSION_base(4,9,0) instance (info ~ ResolveSettingsBackendMethod t SettingsBackend, MethodInfo info SettingsBackend p) => IsLabel t (SettingsBackend -> p) where fromLabel _ = overloadedMethod (MethodProxy :: MethodProxy info) #endif