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::property-name. The whole naming scheme is recursive. Thus child1::child2::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

HasParentTypes ChildProxy

Defined in GI.Gst.Interfaces.ChildProxy

IsGValue (Maybe ChildProxy)

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

Defined in GI.Gst.Interfaces.ChildProxy

Methods

gvalueGType_ :: IO GType

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

gvalueGet_ :: Ptr GValue -> IO (Maybe 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

Click to display all available methods, including inherited ones

Methods

bindProperty, bindPropertyFull, childAdded, childRemoved, forceFloating, freezeNotify, getv, isFloating, lookup, notify, notifyByPspec, ref, refSink, runDispose, stealData, stealQdata, thawNotify, unref, watchClosure.

Getters

getChildByIndex, getChildByName, getChildrenCount, getData, getProperty, getQdata.

Setters

setData, setDataFull, setProperty.

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 childAdded 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 childRemoved 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).

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.

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

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 Object target is the same as object.

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

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 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 -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onChildProxyChildAdded :: (IsChildProxy a, MonadIO m) => a -> ((?self :: 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

childRemoved

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 -> ((?self :: 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

By default the object invoking the signal is not passed to the callback. If you need to access it, you can use the implit ?self parameter. Note that this requires activating the ImplicitParams GHC extension.

onChildProxyChildRemoved :: (IsChildProxy a, MonadIO m) => a -> ((?self :: 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