Signals

A callback function used by the type system to finalize those portions of a derived types class structure that were setup from the corresponding GBaseInitFunc() function. Class finalization basically works the inverse way in which class initialization is performed. See GClassInitFunc() for a discussion of the class initialization process.

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

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe BaseFinalizeFunc.

Wrap a BaseFinalizeFunc into a C_BaseFinalizeFunc.

A callback function used by the type system to do base initialization of the class structures of derived types. It is called as part of the initialization process of all derived classes and should reallocate or reset all dynamic class members copied over from the parent class. For example, class members (such as strings) that are not sufficiently handled by a plain memory copy of the parent class into the derived class have to be altered. See GClassInitFunc() for a discussion of the class initialization process.

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

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe BaseInitFunc.

Wrap a BaseInitFunc into a C_BaseInitFunc.

A function to be called to transform fromValue to toValue. If this is the transformTo function of a binding, then fromValue is the sourceProperty on the source object, and toValue is the targetProperty on the target object. If this is the transformFrom function of a BindingFlagsBidirectional binding, then those roles are reversed.

Since: 2.26

A function to be called to transform fromValue to toValue. If this is the transformTo function of a binding, then fromValue is the sourceProperty on the source object, and toValue is the targetProperty on the target object. If this is the transformFrom function of a BindingFlagsBidirectional binding, then those roles are reversed.

Since: 2.26

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

A simple wrapper that ignores the closure arguments.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe BindingTransformFunc.

A convenience synonym for Nothing :: Maybe BindingTransformFunc_WithClosures.

Wrap a BindingTransformFunc into a C_BindingTransformFunc.

This function is provided by the user and should produce a copy of the passed in boxed structure.

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

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe BoxedCopyFunc.

Wrap a BoxedCopyFunc into a C_BoxedCopyFunc.

This function is provided by the user and should free the boxed structure passed.

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

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe BoxedFreeFunc.

Wrap a BoxedFreeFunc into a C_BoxedFreeFunc.

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

The type used for callback functions in structure definitions and function signatures. This doesn't mean that all callback functions must take no parameters and return void. The required signature of a callback function is determined by the context in which is used (e.g. the signal to which it is connected). Use G_CALLBACK() to cast the callback function to a Callback.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe Callback.

Wrap a Callback into a C_Callback.

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

A callback function used by the type system to finalize a class. This function is rarely needed, as dynamically allocated class resources should be handled by GBaseInitFunc() and GBaseFinalizeFunc(). Also, specification of a GClassFinalizeFunc() in the TypeInfo structure of a static type is invalid, because classes of static types will never be finalized (they are artificially kept alive when their reference count drops to zero).

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ClassFinalizeFunc.

Wrap a ClassFinalizeFunc into a C_ClassFinalizeFunc.

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

A callback function used by the type system to initialize the class of a specific type. This function should initialize all static class members.

The initialization process of a class involves:

• Copying common members from the parent class over to the derived class structure.
• Zero initialization of the remaining members not copied over from the parent class.
• Invocation of the GBaseInitFunc() initializers of all parent types and the class' type.
• Invocation of the class' GClassInitFunc() initializer.

Since derived classes are partially initialized through a memory copy of the parent class, the general rule is that GBaseInitFunc() and GBaseFinalizeFunc() should take care of necessary reinitialization and release of those class members that were introduced by the type that specified these GBaseInitFunc()/GBaseFinalizeFunc(). GClassInitFunc() should only care about initializing static class members, while dynamic class members (such as allocated strings or reference counted resources) are better handled by a GBaseInitFunc() for this type, so proper initialization of the dynamic class members is performed for class initialization of derived types as well.

An example may help to correspond the intend of the different class initializers:

C code

typedef struct {
  GObjectClass parent_class;
  gint         static_integer;
  gchar       *dynamic_string;
} TypeAClass;
static void
type_a_base_class_init (TypeAClass *class)
{
  class->dynamic_string = g_strdup ("some string");
}
static void
type_a_base_class_finalize (TypeAClass *class)
{
  g_free (class->dynamic_string);
}
static void
type_a_class_init (TypeAClass *class)
{
  class->static_integer = 42;
}

typedef struct {
  TypeAClass   parent_class;
  gfloat       static_float;
  GString     *dynamic_gstring;
} TypeBClass;
static void
type_b_base_class_init (TypeBClass *class)
{
  class->dynamic_gstring = g_string_new ("some other string");
}
static void
type_b_base_class_finalize (TypeBClass *class)
{
  g_string_free (class->dynamic_gstring);
}
static void
type_b_class_init (TypeBClass *class)
{
  class->static_float = 3.14159265358979323846;
}

Initialization of TypeBClass will first cause initialization of TypeAClass (derived classes reference their parent classes, see typeClassRef on this).

Initialization of TypeAClass roughly involves zero-initializing its fields, then calling its GBaseInitFunc() type_a_base_class_init() to allocate its dynamic members (dynamic_string), and finally calling its GClassInitFunc() type_a_class_init() to initialize its static members (static_integer). The first step in the initialization process of TypeBClass is then a plain memory copy of the contents of TypeAClass into TypeBClass and zero-initialization of the remaining fields in TypeBClass. The dynamic members of TypeAClass within TypeBClass now need reinitialization which is performed by calling type_a_base_class_init() with an argument of TypeBClass.

After that, the GBaseInitFunc() of TypeBClass, type_b_base_class_init() is called to allocate the dynamic members of TypeBClass (dynamic_gstring), and finally the GClassInitFunc() of TypeBClass, type_b_class_init(), is called to complete the initialization process with the static members (static_float).

Corresponding finalization counter parts to the GBaseInitFunc() functions have to be provided to release allocated resources at class finalization time.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ClassInitFunc.

Wrap a ClassInitFunc into a C_ClassInitFunc.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ClosureMarshalFieldCallback.

Wrap a ClosureMarshalFieldCallback into a C_ClosureMarshalFieldCallback.

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

The type used for the various notification callbacks which can be registered on closures.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ClosureNotify.

Wrap a ClosureNotify into a C_ClosureNotify.

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

A callback function used by the type system to initialize a new instance of a type. This function initializes all instance members and allocates any resources required by it.

Initialization of a derived instance involves calling all its parent types instance initializers, so the class member of the instance is altered during its initialization to always point to the class that belongs to the type the current initializer was introduced for.

The extended members of instance are guaranteed to have been filled with zeros before this function is called.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe InstanceInitFunc.

Wrap a InstanceInitFunc into a C_InstanceInitFunc.

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

A callback function used by the type system to finalize an interface. This function should destroy any internal data and release any resources allocated by the corresponding GInterfaceInitFunc() function.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe InterfaceFinalizeFunc.

Wrap a InterfaceFinalizeFunc into a C_InterfaceFinalizeFunc.

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

A callback function used by the type system to initialize a new interface. This function should initialize all internal data and allocate any resources required by the interface.

The members of ifaceData are guaranteed to have been filled with zeros before this function is called.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe InterfaceInitFunc.

Wrap a InterfaceInitFunc into a C_InterfaceInitFunc.

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

The type of the finalize function of ObjectClass.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ObjectFinalizeFunc.

Wrap a ObjectFinalizeFunc into a C_ObjectFinalizeFunc.

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

The type of the getProperty function of ObjectClass.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ObjectGetPropertyFunc.

Wrap a ObjectGetPropertyFunc into a C_ObjectGetPropertyFunc.

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

The type of the setProperty function of ObjectClass.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ObjectSetPropertyFunc.

Wrap a ObjectSetPropertyFunc into a C_ObjectSetPropertyFunc.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ParamSpecTypeInfoFinalizeFieldCallback.

Wrap a ParamSpecTypeInfoFinalizeFieldCallback into a C_ParamSpecTypeInfoFinalizeFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ParamSpecTypeInfoInstanceInitFieldCallback.

Wrap a ParamSpecTypeInfoInstanceInitFieldCallback into a C_ParamSpecTypeInfoInstanceInitFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ParamSpecTypeInfoValueSetDefaultFieldCallback.

Wrap a ParamSpecTypeInfoValueSetDefaultFieldCallback into a C_ParamSpecTypeInfoValueSetDefaultFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ParamSpecTypeInfoValueValidateFieldCallback.

Wrap a ParamSpecTypeInfoValueValidateFieldCallback into a C_ParamSpecTypeInfoValueValidateFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ParamSpecTypeInfoValuesCmpFieldCallback.

Wrap a ParamSpecTypeInfoValuesCmpFieldCallback into a C_ParamSpecTypeInfoValuesCmpFieldCallback.

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

The signal accumulator is a special callback function that can be used to collect return values of the various callbacks that are called during a signal emission. The signal accumulator is specified at signal creation time, if it is left Nothing, no accumulation of callback return values is performed. The return value of signal emissions is then the value returned by the last callback.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe SignalAccumulator.

Wrap a SignalAccumulator into a C_SignalAccumulator.

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

A simple function pointer to get invoked when the signal is emitted. This allows you to tie a hook to the signal type, so that it will trap all emissions of that signal, from any object.

You may not attach these to signals created with the G_SIGNAL_NO_HOOKS flag.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe SignalEmissionHook.

Wrap a SignalEmissionHook into a C_SignalEmissionHook.

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

A callback function used for notification when the state of a toggle reference changes. See g_object_add_toggle_ref().

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ToggleNotify.

Wrap a ToggleNotify into a C_ToggleNotify.

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

A callback function which is called when the reference count of a class drops to zero. It may use typeClassRef to prevent the class from being freed. You should not call typeClassUnref from a TypeClassCacheFunc function to prevent infinite recursion, use g_type_class_unref_uncached() instead.

The functions have to check the class id passed in to figure whether they actually want to cache the class of this type, since all classes are routed through the same TypeClassCacheFunc chain.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeClassCacheFunc.

Wrap a TypeClassCacheFunc into a C_TypeClassCacheFunc.

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

A callback called after an interface vtable is initialized. See g_type_add_interface_check().

Since: 2.4

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeInterfaceCheckFunc.

Wrap a TypeInterfaceCheckFunc into a C_TypeInterfaceCheckFunc.

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

The type of the completeInterfaceInfo function of GTypePluginClass.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypePluginCompleteInterfaceInfo.

Wrap a TypePluginCompleteInterfaceInfo into a C_TypePluginCompleteInterfaceInfo.

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

The type of the completeTypeInfo function of GTypePluginClass.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypePluginCompleteTypeInfo.

Wrap a TypePluginCompleteTypeInfo into a C_TypePluginCompleteTypeInfo.

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

The type of the unusePlugin function of GTypePluginClass.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypePluginUnuse.

Wrap a TypePluginUnuse into a C_TypePluginUnuse.

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

The type of the usePlugin function of GTypePluginClass, which gets called to increase the use count of plugin.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypePluginUse.

Wrap a TypePluginUse into a C_TypePluginUse.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeValueTableCollectValueFieldCallback.

Wrap a TypeValueTableCollectValueFieldCallback into a C_TypeValueTableCollectValueFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeValueTableLcopyValueFieldCallback.

Wrap a TypeValueTableLcopyValueFieldCallback into a C_TypeValueTableLcopyValueFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeValueTableValueCopyFieldCallback.

Wrap a TypeValueTableValueCopyFieldCallback into a C_TypeValueTableValueCopyFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeValueTableValueFreeFieldCallback.

Wrap a TypeValueTableValueFreeFieldCallback into a C_TypeValueTableValueFreeFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeValueTableValueInitFieldCallback.

Wrap a TypeValueTableValueInitFieldCallback into a C_TypeValueTableValueInitFieldCallback.

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

No description available in the introspection data.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe TypeValueTableValuePeekPointerFieldCallback.

Wrap a TypeValueTableValuePeekPointerFieldCallback into a C_TypeValueTableValuePeekPointerFieldCallback.

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

The type of value transformation functions which can be registered with g_value_register_transform_func().

destValue will be initialized to the correct destination type.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe ValueTransform.

Wrap a ValueTransform into a C_ValueTransform.

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

A WeakNotify function can be added to an object as a callback that gets triggered when the object is finalized. Since the object is already being finalized when the WeakNotify is called, there's not much you could do with the object, apart from e.g. using its address as hash-index or the like.

Given a pointer to a foreign C function, wrap it into a function callable from Haskell.

Wrap the callback into a Closure.

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

A convenience synonym for Nothing :: Maybe WeakNotify.

Wrap a WeakNotify into a C_WeakNotify.