GObject.TypePlugin

Implementations:  GObject.TypeModule

Methods

	complete_interface_info (instance_type, interface_type, info)
	complete_type_info (g_type, info, value_table)
	unuse ()
	use ()

Virtual Methods

None

Properties

None

Signals

None

Fields

None

Class Details

class GObject.TypePlugin

Bases:GObject.GInterface

The GObject.Object type system supports dynamic loading of types. The GObject.TypePlugin interface is used to handle the lifecycle of dynamically loaded types. It goes as follows:

The type is initially introduced (usually upon loading the module the first time, or by your main application that knows what modules introduces what types), like this:

new_type_id = g_type_register_dynamic (parent_type_id,
"TypeName",
new_type_plugin,
type_flags);

where new_type_plugin is an implementation of the GObject.TypePlugin interface.

The type’s implementation is referenced, e.g. through GObject.TypeClass.ref() or through g_type_create_instance() (this is being called by g_object_new()) or through one of the above done on a type derived from new_type_id.

This causes the type system to load the type’s implementation by calling GObject.TypePlugin.use() and GObject.TypePlugin.complete_type_info() on new_type_plugin.

At some point the type’s implementation isn’t required anymore, e.g. after GObject.TypeClass.unref() or GObject.type_free_instance() (called when the reference count of an instance drops to zero).

This causes the type system to throw away the information retrieved from GObject.TypePlugin.complete_type_info() and then it calls GObject.TypePlugin.unuse() on new_type_plugin.

Things may repeat from the second step.

So basically, you need to implement a GObject.TypePlugin type that carries a use_count, once use_count goes from zero to one, you need to load the implementation to successfully handle the upcoming GObject.TypePlugin.complete_type_info() call. Later, maybe after succeeding use/unuse calls, once use_count drops to zero, you can unload the implementation again. The type system makes sure to call GObject.TypePlugin.use() and GObject.TypePlugin.complete_type_info() again when the type is needed again.

GObject.TypeModule is an implementation of GObject.TypePlugin that already implements most of this except for the actual module loading and unloading. It even handles multiple registered types per module.

complete_interface_info(instance_type, interface_type, info)

Parameters:

• instance_type (GObject.GType) – the GObject.GType of an instantiable type to which the interface is added
• interface_type (GObject.GType) – the GObject.GType of the interface whose info is completed
• info (GObject.InterfaceInfo) – the GObject.InterfaceInfo to fill in

Calls the complete_interface_info function from the GObject.TypePluginClass of self. There should be no need to use this function outside of the GObject.Object type system itself.

complete_type_info(g_type, info, value_table)

Parameters:

• g_type (GObject.GType) – the GObject.GType whose info is completed
• info (GObject.TypeInfo) – the GObject.TypeInfo struct to fill in
• value_table (GObject.TypeValueTable) – the GObject.TypeValueTable to fill in

Calls the complete_type_info function from the GObject.TypePluginClass of self. There should be no need to use this function outside of the GObject.Object type system itself.

unuse()

Calls the unuse_plugin function from the GObject.TypePluginClass of self. There should be no need to use this function outside of the GObject.Object type system itself.

use()

Calls the use_plugin function from the GObject.TypePluginClass of self. There should be no need to use this function outside of the GObject.Object type system itself.