GI.GObject.Objects.ParamSpec

GParamSpec encapsulates the metadata required to specify parameters, such as GObject properties.

Parameter names

A property name consists of one or more segments consisting of ASCII letters and digits, separated by either the - or _ character. The first character of a property name must be a letter. These are the same rules as for signal naming (see GObject.signal_new).

When creating and looking up a GParamSpec, either separator can be used, but they cannot be mixed. Using - is considerably more efficient, and is the ‘canonical form’. Using _ is discouraged.

Exported types

newtype ParamSpec

Memory-managed wrapper type.

Constructors

ParamSpec (ManagedPtr ParamSpec)

Instances

Eq ParamSpec

Defined in GI.GObject.Objects.ParamSpec

Methods

(==) :: ParamSpec -> ParamSpec -> Bool

(/=) :: ParamSpec -> ParamSpec -> Bool

BoxedPtr ParamSpec

Defined in GI.GObject.Objects.ParamSpec

Methods

boxedPtrCopy :: ParamSpec -> IO ParamSpec

boxedPtrFree :: ParamSpec -> IO ()

ManagedPtrNewtype ParamSpec

Defined in GI.GObject.Objects.ParamSpec

Methods

toManagedPtr :: ParamSpec -> ManagedPtr ParamSpec

TypedObject ParamSpec

Defined in GI.GObject.Objects.ParamSpec

Methods

glibType :: IO GType

HasParentTypes ParamSpec

Defined in GI.GObject.Objects.ParamSpec

IsGValue (Maybe ParamSpec)

Convert ParamSpec to and from GValue. See toGValue and fromGValue.

Defined in GI.GObject.Objects.ParamSpec

Methods

gvalueGType_ :: IO GType

gvalueSet_ :: Ptr GValue -> Maybe ParamSpec -> IO ()

gvalueGet_ :: Ptr GValue -> IO (Maybe ParamSpec)

type ParentTypes ParamSpec

Defined in GI.GObject.Objects.ParamSpec

type ParentTypes ParamSpec = '[] :: [Type]

class (BoxedPtr o, TypedObject o, IsDescendantOf ParamSpec o) => IsParamSpec o

Type class for types which can be safely cast to ParamSpec, for instance with toParamSpec.

Instances

(BoxedPtr o, TypedObject o, IsDescendantOf ParamSpec o) => IsParamSpec o

Defined in GI.GObject.Objects.ParamSpec

toParamSpec :: (MonadIO m, IsParamSpec o) => o -> m ParamSpec

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

Methods

Click to display all available methods, including inherited ones

Methods

sink, stealQdata.

Getters

getBlurb, getDefaultValue, getName, getNameQuark, getNick, getQdata, getRedirectTarget.

Setters

setQdata.

getBlurb

paramSpecGetBlurb

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a valid ParamSpec

-> m (Maybe Text)

Returns: the short description of pspec.

Get the short description of a ParamSpec.

getDefaultValue

paramSpecGetDefaultValue

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a ParamSpec

-> m GValue

Returns: a pointer to a Value which must not be modified

Gets the default value of pspec as a pointer to a Value.

The Value will remain valid for the life of pspec.

Since: 2.38

getName

paramSpecGetName

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a valid ParamSpec

-> m Text

Returns: the name of pspec.

Get the name of a ParamSpec.

The name is always an "interned" string (as per internString). This allows for pointer-value comparisons.

getNameQuark

paramSpecGetNameQuark

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a ParamSpec

-> m Word32

Returns: the GQuark for pspec->name.

Gets the GQuark for the name.

Since: 2.46

getNick

paramSpecGetNick

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a valid ParamSpec

-> m Text

Returns: the nickname of pspec.

Get the nickname of a ParamSpec.

getQdata

paramSpecGetQdata

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a valid ParamSpec

-> Word32

quark: a GQuark, naming the user data pointer

-> m (Ptr ())

Returns: the user data pointer set, or Nothing

Gets back user data pointers stored via paramSpecSetQdata.

getRedirectTarget

paramSpecGetRedirectTarget

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a ParamSpec

-> m (Maybe GParamSpec)

Returns: paramspec to which requests on this paramspec should be redirected, or Nothing if none.

If the paramspec redirects operations to another paramspec, returns that paramspec. Redirect is used typically for providing a new implementation of a property in a derived type while preserving all the properties from the parent type. Redirection is established by creating a property of type ParamSpecOverride. See objectClassOverrideProperty for an example of the use of this capability.

Since: 2.4

isValidName

paramSpecIsValidName

Arguments

:: (HasCallStack, MonadIO m)

=> Text

name: the canonical name of the property

-> m Bool

Returns: True if name is a valid property name, False otherwise.

Validate a property name for a ParamSpec. This can be useful for dynamically-generated properties which need to be validated at run-time before actually trying to create them.

See [canonical parameter names][canonical-parameter-names] for details of the rules for valid names.

Since: 2.66

setQdata

paramSpecSetQdata

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: the ParamSpec to set store a user data pointer

-> Word32

quark: a GQuark, naming the user data pointer

-> Ptr ()

data: an opaque user data pointer

-> m ()

Sets an opaque, named pointer on a ParamSpec. The name is specified through a GQuark (retrieved e.g. via quarkFromStaticString), and the pointer can be gotten back from the pspec with paramSpecGetQdata. Setting a previously set user data pointer, overrides (frees) the old pointer set, using Nothing as pointer essentially removes the data stored.

sink

paramSpecSink

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: a valid ParamSpec

-> m ()

The initial reference count of a newly created ParamSpec is 1, even though no one has explicitly called g_param_spec_ref() on it yet. So the initial reference count is flagged as "floating", until someone calls g_param_spec_ref (pspec); g_param_spec_sink (pspec); in sequence on it, taking over the initial reference count (thus ending up with a pspec that has a reference count of 1 still, but is not flagged "floating" anymore).

stealQdata

paramSpecStealQdata

Arguments

:: (HasCallStack, MonadIO m)

=> GParamSpec

pspec: the ParamSpec to get a stored user data pointer from

-> Word32

quark: a GQuark, naming the user data pointer

-> m (Ptr ())

Returns: the user data pointer set, or Nothing

Gets back user data pointers stored via paramSpecSetQdata and removes the data from pspec 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.