SettingsBackend

Object Hierarchy:

Description:

[ CCode ( type_id = "g_settings_backend_get_type ()" ) ]
public abstract class SettingsBackend : Object

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 [class@Gio.Settings], 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 [struct@GLib.Tree]. These trees always have strings as keys and [ struct@GLib.Variant] as values.

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`.

Namespace: GLib

Package: gio-2.0

Content:

Static methods:

public static void flatten_tree (Tree<string,Variant> tree, out string path, out (unowned string)[] keys, out (unowned Variant)[] values)
Calculate the longest common prefix of all keys in a tree and write out an array of the key names relative to that prefix and, optionally, the value to store at each of those keys.
public static SettingsBackend get_default ()
Returns the default SettingsBackend.
public static SettingsBackend keyfile_settings_backend_new (string filename, string root_path, string? root_group)
Creates a keyfile-backed SettingsBackend .
public static SettingsBackend memory_settings_backend_new ()
Creates a memory-backed SettingsBackend.
public static SettingsBackend null_settings_backend_new ()
Creates a readonly SettingsBackend.

Creation methods:

protected SettingsBackend ()

Methods:

public void changed (string key, void* origin_tag)
Signals that a single key has possibly changed.
public void changed_tree (Tree<string,Variant> tree, void* origin_tag)
This call is a convenience wrapper.
public virtual Permission get_permission (string path)
virtual method to get permission of a key
public virtual bool get_writable (string key)
virtual method to get if a key is writable
public void keys_changed (string path, string[] items, void* origin_tag)
Signals that a list of keys have possibly changed.
public void path_changed (string path, void* origin_tag)
Signals that all keys below a given path may have possibly changed.
public void path_writable_changed (string path)
Signals that the writability of all keys below a given path may have changed.
public virtual Variant read (string key, VariantType expected_type, bool default_value)
virtual method to read a key's value
public virtual Variant read_user_value (string key, VariantType expected_type)
virtual method to read user's key value
public virtual void reset (string key, void* origin_tag)
virtual method to reset state
public virtual void subscribe (string name)
virtual method to subscribe to key changes
public virtual void sync ()
virtual method to sync state
public virtual void unsubscribe (string name)
virtual method to unsubscribe to key changes
public void writable_changed (string key)
Signals that the writability of a single key has possibly changed.
public virtual bool write (string key, Variant value, void* origin_tag)
virtual method to change key's value
public virtual bool write_tree (Tree<string,Variant> tree, void* origin_tag)
virtual method to change a tree of keys

Inherited Members:

All known members inherited from class GLib.Object