Failable object initialization interface. More...

#include <giomm/initable.h>

Inheritance diagram for Gio::Initable:

[legend]

Public Member Functions
	Initable (Initable && src) noexcept

Initable &	operator= (Initable && src) noexcept

	~Initable () noexcept override

GInitable *	gobj ()
	Provides access to the underlying C GObject. More...

const GInitable *	gobj () const
	Provides access to the underlying C GObject. More...

Public Member Functions inherited from Glib::Interface
	Interface ()
	A Default constructor. More...

	Interface (Interface && src) noexcept

Interface &	operator= (Interface && src) noexcept

	Interface (const Glib::Interface_Class & interface_class)
	Called by constructors of derived classes. More...

	Interface (GObject * castitem)
	Called by constructors of derived classes. More...

	~Interface () noexcept override

	Interface (const Interface &)=delete

Interface &	operator= (const Interface &)=delete

GObject *	gobj ()

const GObject *	gobj () const

Public Member Functions inherited from Glib::ObjectBase
	ObjectBase (const ObjectBase &)=delete

ObjectBase &	operator= (const ObjectBase &)=delete

void	set_property_value (const Glib::ustring & property_name, const Glib::ValueBase & value)
	You probably want to use a specific property_*() accessor method instead. More...

void	get_property_value (const Glib::ustring & property_name, Glib::ValueBase & value) const
	You probably want to use a specific property_*() accessor method instead. More...

template<class PropertyType >
void	set_property (const Glib::ustring & property_name, const PropertyType & value)
	You probably want to use a specific property_*() accessor method instead. More...

template<class PropertyType >
void	get_property (const Glib::ustring & property_name, PropertyType & value) const
	You probably want to use a specific property_*() accessor method instead. More...

void	connect_property_changed (const Glib::ustring & property_name, const sigc::slot< void > & slot)
	You can use the signal_changed() signal of the property proxy instead. More...

void	connect_property_changed (const Glib::ustring & property_name, sigc::slot< void > && slot)
	You can use the signal_changed() signal of the property proxy instead. More...

sigc::connection	connect_property_changed_with_return (const Glib::ustring & property_name, const sigc::slot< void > & slot)
	You can use the signal_changed() signal of the property proxy instead. More...

sigc::connection	connect_property_changed_with_return (const Glib::ustring & property_name, sigc::slot< void > && slot)
	You can use the signal_changed() signal of the property proxy instead. More...

void	freeze_notify ()
	Increases the freeze count on object. More...

void	thaw_notify ()
	Reverts the effect of a previous call to freeze_notify(). More...

virtual void	reference () const
	Increment the reference count for this object. More...

virtual void	unreference () const
	Decrement the reference count for this object. More...

GObject *	gobj ()
	Provides access to the underlying C GObject. More...

const GObject *	gobj () const
	Provides access to the underlying C GObject. More...

GObject *	gobj_copy () const
	Give a ref-ed copy to someone. Use for direct struct access. More...

Static Public Member Functions
static void	add_interface (GType gtype_implementer)

static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system. More...

Protected Member Functions
	Initable ()
	You should derive from this class to use it. More...

void	init (const Glib::RefPtr< Cancellable > & cancellable)
	Initializes the object implementing the interface. More...

void	init ()
	A init() convenience overload. More...

virtual bool	init_vfunc (const Glib::RefPtr< Cancellable > & cancellable, GError ** error)

Protected Member Functions inherited from Glib::ObjectBase
	ObjectBase ()
	This default constructor is called implicitly from the constructor of user-derived classes, even if, for instance, Gtk::Button calls a different ObjectBase constructor. More...

	ObjectBase (const char * custom_type_name)
	A derived constructor always overrides this choice. More...

	ObjectBase (const std::type_info & custom_type_info)
	This constructor is a special feature to allow creation of derived types on the fly, without having to use g_object_new() manually. More...

	ObjectBase (ObjectBase && src) noexcept

ObjectBase &	operator= (ObjectBase && src) noexcept

virtual	~ObjectBase () noexcept=0

void	initialize (GObject * castitem)

void	initialize_move (GObject * castitem, Glib::ObjectBase * previous_wrapper)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gio::Initable >	wrap (GInitable * object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Detailed Description

Failable object initialization interface.

Initable is implemented by objects that can fail during initialization. If an object implements this interface the init() function must be called as the first thing after construction. If init() is not called, or if it returns an error, all further operations on the object should fail, generally with a G_IO_ERROR_NOT_INITIALIZED error.

Users of objects implementing this are not intended to use the interface method directly, instead it will be used automatically in various ways. For C applications you generally just call g_initable_new() directly, or indirectly via a foo_thing_new() wrapper. This will call g_initable_init() under the cover, returning nullptr and setting a GError on failure.

For bindings in languages where the native constructor supports exceptions the binding could check for objects implemention GInitable during normal construction and automatically initialize them, throwing an exception on failure.

Since glibmm 2.24:

Constructor & Destructor Documentation

◆ Initable() [1/2]

Gio::Initable::Initable ( )

protected

You should derive from this class to use it.

◆ Initable() [2/2]

Gio::Initable::Initable ( Initable && src )

noexcept

◆ ~Initable()

Gio::Initable::~Initable ( )

overridenoexcept

Member Function Documentation

◆ add_interface()

static void Gio::Initable::add_interface ( GType gtype_implementer )

static

◆ get_type()

static GType Gio::Initable::get_type ( )

static

Get the GType for this class, for use with the underlying GObject type system.

◆ gobj() [1/2]

GInitable * Gio::Initable::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GInitable * Gio::Initable::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ init() [1/2]

void Gio::Initable::init ( )

protected

A init() convenience overload.

◆ init() [2/2]

void Gio::Initable::init ( const Glib::RefPtr< Cancellable > & cancellable )

protected

Initializes the object implementing the interface.

This method is intended for language bindings. If writing in C, g_initable_new() should typically be used instead.

The object must be initialized before any real use after initial construction, either with this function or g_async_initable_init_async().

Implementations may also support cancellation. If cancellable is not nullptr, then initialization can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error IO_ERROR_CANCELLED will be returned. If cancellable is not nullptr and the object doesn't support cancellable initialization the error IO_ERROR_NOT_SUPPORTED will be returned.

If the object is not initialized, or initialization returns with an error, then all operations on the object except Glib::object_ref() and Glib::object_unref() are considered to be invalid, and have undefined behaviour. See the [introduction][ginitable] for more details.

Callers should not assume that a class which implements Initable can be initialized multiple times, unless the class explicitly documents itself as supporting this. Generally, a class’ implementation of init() can assume (and assert) that it will only be called once. Previously, this documentation recommended all Initable implementations should be idempotent; that recommendation was relaxed in GLib 2.54.

If a class explicitly supports being initialized multiple times, it is recommended that the method is idempotent: multiple calls with the same arguments should return the same results. Only the first call initializes the object; further calls return the result of the first call.

One reason why a class might need to support idempotent initialization is if it is designed to be used via the singleton pattern, with a ObjectClass.constructor that sometimes returns an existing instance. In this pattern, a caller would expect to be able to call g_initable_init() on the result of Glib::object_new(), regardless of whether it is in fact a new instance.

Since glibmm 2.22:

Parameters

cancellable Optional Cancellable object, nullptr to ignore.

Exceptions

Glib::Error

◆ init_vfunc()

virtual bool Gio::Initable::init_vfunc	(	const Glib::RefPtr< Cancellable > &	cancellable,
		GError **	error
	)

protectedvirtual

◆ operator=()

Initable & Gio::Initable::operator= ( Initable && src )

noexcept

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gio::Initable > wrap	(	GInitable *	object,
		bool	take_copy = `false`
	)

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns: A C++ instance that wraps this C instance.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Related Functions

Detailed Description

Constructor & Destructor Documentation

◆ Initable() [1/2]

◆ Initable() [2/2]

◆ ~Initable()

Member Function Documentation

◆ add_interface()

◆ get_type()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ init() [1/2]

◆ init() [2/2]

◆ init_vfunc()

◆ operator=()

Friends And Related Function Documentation

◆ wrap()