Data.GI.Base.GParamSpec

Management of GParamSpecs.

Memory management

wrapGParamSpecPtr :: Ptr GParamSpec -> IO GParamSpec

Take ownership of a ParamSpec passed in Ptr.

newGParamSpecFromPtr :: Ptr GParamSpec -> IO GParamSpec

Construct a Haskell wrapper for the given GParamSpec, without assuming ownership.

unrefGParamSpec :: GParamSpec -> IO ()

Remove a reference to the given GParamSpec.

disownGParamSpec :: GParamSpec -> IO (Ptr GParamSpec)

Disown a GParamSpec, i.e. do not longer unref the associated foreign GParamSpec when the Haskell GParamSpec gets garbage collected.

GParamSpec building

data PropertyInfo o a

Information on a property encoding a Haskell value. Note that from the C side this property will appear as an opaque pointer. Use the specialized constructors below for creating properties meaningful from the C side.

A property name consists of segments consisting of ASCII letters and digits, separated by either the '-' or '_' character. The first character of a property name must be a letter. Names which violate these rules lead to undefined behaviour.

When creating and looking up a property, either separator can be used, but they cannot be mixed. Using '-' is considerably more efficient and in fact required when using property names as detail strings for signals.

Beyond the name, properties have two more descriptive strings associated with them, the nick, which should be suitable for use as a label for the property in a property editor, and the blurb, which should be a somewhat longer description, suitable for e.g. a tooltip. The nick and blurb should ideally be localized.

Constructors

PropertyInfo

Fields

• name :: Text

  Identifier for the property.

• nick :: Text

  Identifier for display to the user.

• blurb :: Text

  Description of the property.

• setter :: o -> a -> IO ()

  Handler invoked when the property is being set.

• getter :: o -> IO a

  Handler that returns the current value of the property.

• flags :: Maybe [GParamFlag]

  Set of flags, or Nothing for the default set of flags.

gParamSpecValue :: forall o a. GObject o => PropertyInfo o a -> IO GParamSpec

Create a GParamSpec for a Haskell value.

data CStringPropertyInfo o

Information on a property of type Text to be registered. A property name consists of segments consisting of ASCII letters and digits, separated by either the '-' or '_' character. The first character of a property name must be a letter. Names which violate these rules lead to undefined behaviour.

When creating and looking up a property, either separator can be used, but they cannot be mixed. Using '-' is considerably more efficient and in fact required when using property names as detail strings for signals.

Beyond the name, properties have two more descriptive strings associated with them, the nick, which should be suitable for use as a label for the property in a property editor, and the blurb, which should be a somewhat longer description, suitable for e.g. a tooltip. The nick and blurb should ideally be localized.

Constructors

CStringPropertyInfo

Fields

• name :: Text
• nick :: Text
• blurb :: Text
• defaultValue :: Maybe Text
• flags :: Maybe [GParamFlag]
• setter :: o -> Maybe Text -> IO ()
• getter :: o -> IO (Maybe Text)

gParamSpecCString :: GObject o => CStringPropertyInfo o -> IO GParamSpec

Create a GParamSpec for a string param.

data CIntPropertyInfo o

Information on a property of type CInt to be registered. A property name consists of segments consisting of ASCII letters and digits, separated by either the '-' or '_' character. The first character of a property name must be a letter. Names which violate these rules lead to undefined behaviour.

When creating and looking up a property, either separator can be used, but they cannot be mixed. Using '-' is considerably more efficient and in fact required when using property names as detail strings for signals.

Beyond the name, properties have two more descriptive strings associated with them, the nick, which should be suitable for use as a label for the property in a property editor, and the blurb, which should be a somewhat longer description, suitable for e.g. a tooltip. The nick and blurb should ideally be localized.

Constructors

CIntPropertyInfo

Fields

• name :: Text

  Identifier for the property.

• nick :: Text

  Identifier for display to the user.

• blurb :: Text

  Description of the property.

• defaultValue :: CInt

  Default value.

• setter :: o -> CInt -> IO ()

  Handler invoked when the property is being set.

• getter :: o -> IO CInt

  Handler that returns the current value of the property.

• flags :: Maybe [GParamFlag]

  Set of flags, or Nothing for the default set of flags.

• minValue :: Maybe CInt

  Minimum value, or Nothing, which would be replaced by MININT.

• maxValue :: Maybe CInt

  Maximum value, or Nothing, which would be replaced by MAXINT.

gParamSpecCInt :: GObject o => CIntPropertyInfo o -> IO GParamSpec

Create a GParamSpec for an integer param.

Get/Set

data PropGetSetter o

Low-level getter and setter for the property.

Constructors

PropGetSetter

Fields

• propGetter :: Ptr o -> Ptr GValue -> IO ()
• propSetter :: Ptr o -> Ptr GValue -> IO ()

getGParamSpecGetterSetter :: forall o. Ptr GParamSpec -> IO (Maybe (PropGetSetter o))

Attempt to get the Haskell setter and getter for the given GParamSpec. This will only be possible if the GParamSpec was created with one of the functions above, if this is not the case the function will return Nothing.