GI.Gst.Interfaces.ChildProxy

This interface abstracts handling of property sets for elements with children. Imagine elements such as mixers or polyphonic generators. They all have multiple Pad or some kind of voice objects. Another use case are container elements like Bin. The element implementing the interface acts as a parent for those child objects.

By implementing this interface the child properties can be accessed from the parent element by using gst_child_proxy_get() and gst_child_proxy_set().

Property names are written as "child-name[propertyName](#g:signal:propertyName)". The whole naming scheme is recursive. Thus "child1[child2](g:signal:property)" is valid too, if "child1" and "child2" implement the ChildProxy interface.

Exported types

newtype ChildProxy

Memory-managed wrapper type.

Constructors

ChildProxy (ManagedPtr ChildProxy)

Instances

Eq ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

Methods

(==) :: ChildProxy -> ChildProxy -> Bool

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

GObject ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

ManagedPtrNewtype ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

Methods

toManagedPtr :: ChildProxy -> ManagedPtr ChildProxy

TypedObject ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

Methods

glibType :: IO GType

IsGValue ChildProxy

Convert ChildProxy to and from GValue with toGValue and fromGValue.

Defined in GI.Gst.Interfaces.ChildProxy

Methods

toGValue :: ChildProxy -> IO GValue

fromGValue :: GValue -> IO ChildProxy

HasParentTypes ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

type ParentTypes ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

type ParentTypes ChildProxy = '[Object]

class (GObject o, IsDescendantOf ChildProxy o) => IsChildProxy o

Type class for types which can be safely cast to ChildProxy, for instance with toChildProxy.

Instances

(GObject o, IsDescendantOf ChildProxy o) => IsChildProxy o

Defined in GI.Gst.Interfaces.ChildProxy

toChildProxy :: (MonadIO m, IsChildProxy o) => o -> m ChildProxy

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

Methods

Overloaded methods

childAdded

childProxyChildAdded

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a, IsObject b)

=> a

parent: the parent object

-> b

child: the newly added child

-> Text

name: the name of the new child

-> m ()

Emits the "child-added" signal.

childRemoved

childProxyChildRemoved

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a, IsObject b)

=> a

parent: the parent object

-> b

child: the removed child

-> Text

name: the name of the old child

-> m ()

Emits the "child-removed" signal.

getChildByIndex

childProxyGetChildByIndex

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a)

=> a

parent: the parent object to get the child from

-> Word32

index: the child's position in the child list

-> m (Maybe Object)

Returns: the child object or Nothing if not found (index too high). Unref after usage.

MT safe.

Fetches a child by its number.

getChildByName

childProxyGetChildByName

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a)

=> a

parent: the parent object to get the child from

-> Text

name: the child's name

-> m (Maybe Object)

Returns: the child object or Nothing if not found. Unref after usage.

MT safe.

Looks up a child element by the given name.

This virtual method has a default implementation that uses Object together with objectGetName. If the interface is to be used with GObjects, this methods needs to be overridden.

getChildrenCount

childProxyGetChildrenCount

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a)

=> a

parent: the parent object

-> m Word32

Returns: the number of child objects

MT safe.

Gets the number of child objects this parent contains.

getProperty

childProxyGetProperty

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a)

=> a

object: object to query

-> Text

name: name of the property

-> m GValue

Gets a single property using the GstChildProxy mechanism. You are responsible for freeing it by calling valueUnset

lookup

childProxyLookup

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a)

=> a

object: child proxy object to lookup the property in

-> Text

name: name of the property to look up

-> m (Bool, Object, GParamSpec)

Returns: True if target and pspec could be found. False otherwise. In that case the values for pspec and target are not modified. Unref target after usage. For plain GObjects target is the same as object.

Looks up which object and ParamSpec would be effected by the given name.

MT safe.

setProperty

childProxySetProperty

Arguments

:: (HasCallStack, MonadIO m, IsChildProxy a)

=> a

object: the parent object

-> Text

name: name of the property to set

-> GValue

value: new Value for the property

-> m ()

Sets a single property using the GstChildProxy mechanism.

Signals

childAdded

type C_ChildProxyChildAddedCallback = Ptr () -> Ptr Object -> CString -> Ptr () -> IO ()

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

type ChildProxyChildAddedCallback

Arguments

 = Object

object: the Object that was added

-> Text

name: the name of the new child

-> IO ()

Will be emitted after the object was added to the childProxy.

afterChildProxyChildAdded :: (IsChildProxy a, MonadIO m) => a -> ChildProxyChildAddedCallback -> m SignalHandlerId

Connect a signal handler for the childAdded signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after childProxy #childAdded callback

genClosure_ChildProxyChildAdded :: MonadIO m => ChildProxyChildAddedCallback -> m (GClosure C_ChildProxyChildAddedCallback)

Wrap the callback into a GClosure.

mk_ChildProxyChildAddedCallback :: C_ChildProxyChildAddedCallback -> IO (FunPtr C_ChildProxyChildAddedCallback)

Generate a function pointer callable from C code, from a C_ChildProxyChildAddedCallback.

noChildProxyChildAddedCallback :: Maybe ChildProxyChildAddedCallback

A convenience synonym for Nothing :: Maybe ChildProxyChildAddedCallback.

onChildProxyChildAdded :: (IsChildProxy a, MonadIO m) => a -> ChildProxyChildAddedCallback -> m SignalHandlerId

Connect a signal handler for the childAdded signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on childProxy #childAdded callback

wrap_ChildProxyChildAddedCallback :: ChildProxyChildAddedCallback -> C_ChildProxyChildAddedCallback

Wrap a ChildProxyChildAddedCallback into a C_ChildProxyChildAddedCallback.

childRemoved

type C_ChildProxyChildRemovedCallback = Ptr () -> Ptr Object -> CString -> Ptr () -> IO ()

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

type ChildProxyChildRemovedCallback

Arguments

 = Object

object: the Object that was removed

-> Text

name: the name of the old child

-> IO ()

Will be emitted after the object was removed from the childProxy.

afterChildProxyChildRemoved :: (IsChildProxy a, MonadIO m) => a -> ChildProxyChildRemovedCallback -> m SignalHandlerId

Connect a signal handler for the childRemoved signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after childProxy #childRemoved callback

genClosure_ChildProxyChildRemoved :: MonadIO m => ChildProxyChildRemovedCallback -> m (GClosure C_ChildProxyChildRemovedCallback)

Wrap the callback into a GClosure.

mk_ChildProxyChildRemovedCallback :: C_ChildProxyChildRemovedCallback -> IO (FunPtr C_ChildProxyChildRemovedCallback)

Generate a function pointer callable from C code, from a C_ChildProxyChildRemovedCallback.

noChildProxyChildRemovedCallback :: Maybe ChildProxyChildRemovedCallback

A convenience synonym for Nothing :: Maybe ChildProxyChildRemovedCallback.

onChildProxyChildRemoved :: (IsChildProxy a, MonadIO m) => a -> ChildProxyChildRemovedCallback -> m SignalHandlerId

Connect a signal handler for the childRemoved signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on childProxy #childRemoved callback

wrap_ChildProxyChildRemovedCallback :: ChildProxyChildRemovedCallback -> C_ChildProxyChildRemovedCallback

Wrap a ChildProxyChildRemovedCallback into a C_ChildProxyChildRemovedCallback.