GI.GObject.Objects.TypeModule

TypeModule provides a simple implementation of the TypePlugin interface. The model of TypeModule is a dynamically loaded module which implements some number of types and interface implementations. When the module is loaded, it registers its types and interfaces using typeModuleRegisterType and typeModuleAddInterface. As long as any instances of these types and interface implementations are in use, the module is kept loaded. When the types and interfaces are gone, the module may be unloaded. If the types and interfaces become used again, the module will be reloaded. Note that the last unref cannot happen in module code, since that would lead to the caller's code being unloaded before objectUnref returns to it.

Keeping track of whether the module should be loaded or not is done by using a use count - it starts at zero, and whenever it is greater than zero, the module is loaded. The use count is maintained internally by the type system, but also can be explicitly controlled by typeModuleUse and typeModuleUnuse. Typically, when loading a module for the first type, typeModuleUse will be used to load it so that it can initialize its types. At some later point, when the module no longer needs to be loaded except for the type implementations it contains, typeModuleUnuse is called.

TypeModule does not actually provide any implementation of module loading and unloading. To create a particular module type you must derive from TypeModule and implement the load and unload functions in TypeModuleClass.

Exported types

newtype TypeModule

Memory-managed wrapper type.

Constructors

TypeModule (ManagedPtr TypeModule)

Instances

Eq TypeModule

Defined in GI.GObject.Objects.TypeModule

Methods

(==) :: TypeModule -> TypeModule -> Bool

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

GObject TypeModule

Defined in GI.GObject.Objects.TypeModule

Methods

gobjectType :: IO GType

IsGValue TypeModule

Convert TypeModule to and from GValue with toGValue and fromGValue.

Defined in GI.GObject.Objects.TypeModule

Methods

toGValue :: TypeModule -> IO GValue

fromGValue :: GValue -> IO TypeModule

HasParentTypes TypeModule

Defined in GI.GObject.Objects.TypeModule

type ParentTypes TypeModule

Defined in GI.GObject.Objects.TypeModule

type ParentTypes TypeModule = '[Object, TypePlugin]

class (GObject o, IsDescendantOf TypeModule o) => IsTypeModule o

Type class for types which can be safely cast to TypeModule, for instance with toTypeModule.

Instances

(GObject o, IsDescendantOf TypeModule o) => IsTypeModule o

Defined in GI.GObject.Objects.TypeModule

toTypeModule :: (MonadIO m, IsTypeModule o) => o -> m TypeModule

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

noTypeModule :: Maybe TypeModule

A convenience alias for Nothing :: Maybe TypeModule.

Methods

Overloaded methods

addInterface

typeModuleAddInterface

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule

-> GType

instanceType: type to which to add the interface.

-> GType

interfaceType: interface type to add

-> InterfaceInfo

interfaceInfo: type information structure

-> m ()

Registers an additional interface for a type, whose interface lives in the given type plugin. If the interface was already registered for the type in this plugin, nothing will be done.

As long as any instances of the type exist, the type plugin will not be unloaded.

Since 2.56 if module is Nothing this will call typeAddInterfaceStatic instead. This can be used when making a static build of the module.

registerEnum

typeModuleRegisterEnum

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule

-> Text

name: name for the type

-> EnumValue

constStaticValues: an array of EnumValue structs for the possible enumeration values. The array is terminated by a struct with all members being 0.

-> m GType

Returns: the new or existing type ID

Looks up or registers an enumeration that is implemented with a particular type plugin. If a type with name typeName was previously registered, the GType identifier for the type is returned, otherwise the type is newly registered, and the resulting GType identifier returned.

As long as any instances of the type exist, the type plugin will not be unloaded.

Since 2.56 if module is Nothing this will call typeRegisterStatic instead. This can be used when making a static build of the module.

Since: 2.6

registerFlags

typeModuleRegisterFlags

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule

-> Text

name: name for the type

-> FlagsValue

constStaticValues: an array of FlagsValue structs for the possible flags values. The array is terminated by a struct with all members being 0.

-> m GType

Returns: the new or existing type ID

Looks up or registers a flags type that is implemented with a particular type plugin. If a type with name typeName was previously registered, the GType identifier for the type is returned, otherwise the type is newly registered, and the resulting GType identifier returned.

As long as any instances of the type exist, the type plugin will not be unloaded.

Since 2.56 if module is Nothing this will call typeRegisterStatic instead. This can be used when making a static build of the module.

Since: 2.6

registerType

typeModuleRegisterType

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule

-> GType

parentType: the type for the parent class

-> Text

typeName: name for the type

-> TypeInfo

typeInfo: type information structure

-> [TypeFlags]

flags: flags field providing details about the type

-> m GType

Returns: the new or existing type ID

Looks up or registers a type that is implemented with a particular type plugin. If a type with name typeName was previously registered, the GType identifier for the type is returned, otherwise the type is newly registered, and the resulting GType identifier returned.

When reregistering a type (typically because a module is unloaded then reloaded, and reinitialized), module and parentType must be the same as they were previously.

As long as any instances of the type exist, the type plugin will not be unloaded.

Since 2.56 if module is Nothing this will call typeRegisterStatic instead. This can be used when making a static build of the module.

setName

typeModuleSetName

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule.

-> Text

name: a human-readable name to use in error messages.

-> m ()

Sets the name for a TypeModule

unuse

typeModuleUnuse

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule

-> m ()

Decreases the use count of a TypeModule by one. If the result is zero, the module will be unloaded. (However, the TypeModule will not be freed, and types associated with the TypeModule are not unregistered. Once a TypeModule is initialized, it must exist forever.)

use

typeModuleUse

Arguments

:: (HasCallStack, MonadIO m, IsTypeModule a)

=> a

module: a TypeModule

-> m Bool

Returns: False if the plugin needed to be loaded and loading the plugin failed.

Increases the use count of a TypeModule by one. If the use count was zero before, the plugin will be loaded. If loading the plugin fails, the use count is reset to its prior value.