sigc::connection Struct Reference

Convenience class for safe disconnection. More...

#include <sigc++/connection.h>

Public Member Functions
	connection () noexcept
	Constructs an empty connection object. More...
	connection (const connection & c)
	Constructs a connection object copying an existing one. More...
	connection (slot_base & slot)
	Constructs a connection object from a slot object. More...
	~connection ()
bool	block (bool should_block=true) noexcept
	Sets or unsets the blocking state of this connection. More...
bool	blocked () const noexcept
	Returns whether the connection is blocked. More...
bool	connected () const noexcept
	Returns whether the connection is still active. More...
void	disconnect ()
	Disconnects the referred slot. More...
bool	empty () const noexcept
	Returns whether the connection is still active. More...
	operator bool () const noexcept
	Returns whether the connection is still active. More...
connection &	operator= (const connection & src)
	Overrides this connection object copying another one. More...
bool	unblock () noexcept
	Unsets the blocking state of this connection. More...

Detailed Description

Convenience class for safe disconnection.

This may be used to disconnect the referred slot at any time (disconnect()). sigc::signal::connect() and sigc::signal::connect_first() return a sigc::connection.

sigc::connection conn = sig.connect(sigc::mem_fun(a, &A::foo));

If the slot has already been destroyed, disconnect() does nothing. empty() or operator bool() can be used to test whether the connection is still active. The connection can be blocked (block(), unblock()).

sigc::connection doesnʼt disconnect the slot automatically upon destruction. You do not need to keep the sigc::connection object to retain the connection of the slot to the signal. See also sigc::scoped_connection, which does disconnect automatically when the connection object is destroyed or replaced.

Constructor & Destructor Documentation

connection() [1/3]

sigc::connection::connection ( )

noexcept

Constructs an empty connection object.

connection() [2/3]

sigc::connection::connection

(

const connection &

c

)

Constructs a connection object copying an existing one.

Parameters

c	The connection object to make a copy from.

connection() [3/3]

sigc::connection::connection ( slot_base &  slot )

explicit

Constructs a connection object from a slot object.

Parameters

slot	The slot to operate on.

~connection()

sigc::connection::~connection

(

)

Member Function Documentation

block()

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

noexcept

Sets or unsets the blocking state of this connection.

See slot_base::block() for details.

Parameters

should_block

Indicates whether the blocking state should be set or unset.

Returns

true if the connection has been in blocking state before.

blocked()

bool sigc::connection::blocked ( ) const

noexcept

Returns whether the connection is blocked.

Returns

true if the connection is blocked.

connected()

bool sigc::connection::connected ( ) const

noexcept

Returns whether the connection is still active.

Returns

true if the connection is still active.

disconnect()

void sigc::connection::disconnect

(

)

Disconnects the referred slot.

empty()

bool sigc::connection::empty ( ) const

noexcept

Returns whether the connection is still active.

Returns

false if the connection is still active.

operator bool()

sigc::connection::operator bool ( ) const

explicitnoexcept

Returns whether the connection is still active.

Returns

true if the connection is still active.

operator=()

connection& sigc::connection::operator=

(

const connection &

src

)

Overrides this connection object copying another one.

Parameters

src	The connection object to make a copy from.

unblock()

bool sigc::connection::unblock ( )

noexcept

Unsets the blocking state of this connection.

Returns

true if the connection has been in blocking state before.