sigc::slot_base Class Reference

Base type for slots. More...

#include <sigc++/functors/slot_base.h>

Inheritance diagram for sigc::slot_base:

Public Types
using	func_destroy_notify = notifiable::func_destroy_notify

Public Member Functions
	slot_base () noexcept
	Constructs an empty slot. More...
	slot_base (const slot_base & src)
	Constructs a slot, copying an existing one. More...
	slot_base (rep_type * rep) noexcept
	Constructs a slot from an existing slot_rep object. More...
	slot_base (slot_base && src)
	Constructs a slot, moving an existing one. More...
	~slot_base ()
void	add_destroy_notify_callback (notifiable *data, notifiable::func_destroy_notify func) const
	Add a callback that is executed (notified) when the slot is destroyed. More...
bool	block (bool should_block=true) noexcept
	Sets the blocking state. More...
bool	blocked () const noexcept
	Returns whether the slot is blocked. More...
void	disconnect ()
	Disconnects the slot. More...
bool	empty () const noexcept
	Returns whether the slot is invalid. More...
	operator bool () const noexcept
	Tests whether a slot is null, because the default constructor was used. More...
slot_base &	operator= (const slot_base & src)
	Overrides this slot, making a copy from another slot. More...
slot_base &	operator= (slot_base && src)
	Overrides this slot, making a move from another slot. More...
void	remove_destroy_notify_callback (notifiable *data) const
	Remove a callback previously installed with add_destroy_notify_callback(). More...
void	set_parent (notifiable * parent, notifiable::func_destroy_notify cleanup) const noexcept
	Sets the parent of this slot. More...
bool	unblock () noexcept
	Unsets the blocking state. More...

Public Attributes
bool	blocked_
	Indicates whether the slot is blocked. More...
rep_type *	rep_
	Typed slot_rep object that contains a functor. More...

Detailed Description

Base type for slots.

slot_base integrates most of the interface of the derived sigc::slot template. Slots can be connected to signals, be disconnected at some later point (disconnect()) and temporarily be blocked (block(), unblock()). The validity of a slot can be tested with empty().

The internal representation of a sigc::internal::slot_rep derived type is built from slot_base's derivations. set_parent() is used to register a notification callback that is executed when the slot gets invalid. add_destroy_notify_callback() is used by connection objects to add a notification callback that is executed on destruction.

Member Typedef Documentation

func_destroy_notify

using sigc::slot_base::func_destroy_notify = notifiable::func_destroy_notify

Constructor & Destructor Documentation

slot_base() [1/4]

sigc::slot_base::slot_base ( )

noexcept

Constructs an empty slot.

slot_base() [2/4]

sigc::slot_base::slot_base ( rep_type *  rep )

explicitnoexcept

Constructs a slot from an existing slot_rep object.

Parameters

rep	The slot_rep object this slot should contain.

slot_base() [3/4]

sigc::slot_base::slot_base

(

const slot_base &

src

)

Constructs a slot, copying an existing one.

Parameters

src	The existing slot to copy.

slot_base() [4/4]

sigc::slot_base::slot_base

(

slot_base &&

src

)

Constructs a slot, moving an existing one.

If src is connected to a parent (e.g. a signal), it is copied, not moved.

Parameters

src	The existing slot to move or copy.

~slot_base()

sigc::slot_base::~slot_base

(

)

Member Function Documentation

add_destroy_notify_callback()

void sigc::slot_base::add_destroy_notify_callback	(	notifiable *	data,
		notifiable::func_destroy_notify	func
	)		const

Add a callback that is executed (notified) when the slot is destroyed.

This function is used internally by connection objects.

Parameters

data	Passed into func upon notification.
func	Callback executed upon destruction of the object.

block()

bool sigc::slot_base::block ( bool  should_block = true )

noexcept

Sets the blocking state.

If should_block is true then the blocking state is set. Subsequent calls to slot::operator()() don't invoke the functor contained by this slot until unblock() or block() with should_block = false is called.

Parameters

should_block

Indicates whether the blocking state should be set or unset.

Returns

true if the slot was in blocking state before.

blocked()

bool sigc::slot_base::blocked ( ) const

inlinenoexcept

Returns whether the slot is blocked.

Returns

true if the slot is blocked.

disconnect()

void sigc::slot_base::disconnect

(

)

Disconnects the slot.

Invalidates the slot and notifies the parent.

empty()

bool sigc::slot_base::empty ( ) const

inlinenoexcept

Returns whether the slot is invalid.

Returns

true if the slot is invalid (empty).

operator bool()

sigc::slot_base::operator bool ( ) const

explicitnoexcept

Tests whether a slot is null, because the default constructor was used.

Test a slot for null like so:

if(slot)
 do_something()

operator=() [1/2]

slot_base& sigc::slot_base::operator=

(

const slot_base &

src

)

Overrides this slot, making a copy from another slot.

Parameters

src	The slot from which to make a copy.

Returns

this.

operator=() [2/2]

slot_base& sigc::slot_base::operator=

(

slot_base &&

src

)

Overrides this slot, making a move from another slot.

If src is connected to a parent (e.g. a signal), it is copied, not moved.

Parameters

src	The slot from which to move or copy.

Returns

this.

remove_destroy_notify_callback()

void sigc::slot_base::remove_destroy_notify_callback

(

notifiable *

data

)

const

Remove a callback previously installed with add_destroy_notify_callback().

The callback is not executed.

Parameters

data	Parameter passed into previous call to add_destroy_notify_callback().

set_parent()

void sigc::slot_base::set_parent ( notifiable *  parent, notifiable::func_destroy_notify  cleanup  ) const

noexcept

Sets the parent of this slot.

This function is used by signals to register a notification callback. This notification callback is executed when the slot becomes invalid because of some referred object dying.

Parameters

parent	The new parent.
cleanup	The notification callback.

unblock()

bool sigc::slot_base::unblock ( )

noexcept

Unsets the blocking state.

Returns

true if the slot was in blocking state before.

Member Data Documentation

blocked_

bool sigc::slot_base::blocked_

Indicates whether the slot is blocked.

rep_

rep_type* sigc::slot_base::rep_

mutable

Typed slot_rep object that contains a functor.