c++-gtk-utils
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Cgu::EmitterArg< FreeArgs > Class Template Reference

A class to execute callbacks connected to it, with provision for automatic disconnection. More...

#include <c++-gtk-utils/emitter.h>

Public Member Functions

void operator() (typename Cgu::Param< FreeArgs >::ParamType...args) const
 
void emit (typename Cgu::Param< FreeArgs >::ParamType...args) const
 
bool test_emit (typename Cgu::Param< FreeArgs >::ParamType...args) const
 
Callback::FunctorArg< FreeArgs...> connect (const Callback::FunctorArg< FreeArgs...> &f)
 
Callback::FunctorArg< FreeArgs...> connect (const Callback::FunctorArg< FreeArgs...> &f, Releaser &r)
 
template<class F , class = typename std::enable_if<!std::is_convertible<typename std::remove_reference<F>::type, const Callback::FunctorArg<FreeArgs...>>::value>::type>
Callback::FunctorArg< FreeArgs...> connect (F &&f)
 
template<class F , class = typename std::enable_if<!std::is_convertible<typename std::remove_reference<F>::type, const Callback::FunctorArg<FreeArgs...>>::value>::type>
Callback::FunctorArg< FreeArgs...> connect (F &&f, Releaser &r)
 
void disconnect (const Callback::FunctorArg< FreeArgs...> &f)
 
void block (const Callback::FunctorArg< FreeArgs...> &f)
 
void unblock (const Callback::FunctorArg< FreeArgs...> &f)
 
 EmitterArg ()=default
 
 EmitterArg (const EmitterArg &)=delete
 
EmitterArgoperator= (const EmitterArg &)=delete
 
 ~EmitterArg ()
 

Friends

class Releaser
 

Detailed Description

template<class... FreeArgs>
class Cgu::EmitterArg< FreeArgs >

A class to execute callbacks connected to it, with provision for automatic disconnection.

See also
SafeEmitterArg Releaser
emitter.h
Callback namespace

Callable objects (such as lambda expressions or the return value of std::bind) or Callback::FunctorArg objects may be connected to Emitter classes, and will be executed when EmitterArg::emit() or EmitterArg::operator()() are called.

One version of the connect() method takes a Releaser object as an argument. Such a Releaser object should be a public member of any target class which wants functors representing (or calling into) any of its methods to be disconnected automatically from the EmitterArg object when the target class object is destroyed.

A connection may be explicitly disconnected by calling the disconnect() method, and may also be temporarily blocked and subsequently unblocked with the block() and unblock() methods.

The template types are the types of the unbound arguments, if any. EmitterArg<> is typedef'ed to Emitter.

Usage

These are examples:

using namespace Cgu;
e1.connect([] () {std::cout << "Hello world\n";});
e1();
int res;
e2.connect([] (int i, int& j) {j = 10 * i;});
e2(2, res);
std::cout << "10 times 2 is " << res << '\n';

Callback::FunctorArg objects may be connected to an emitter, and the connect() method may be directly initialized with the result of Callback::make(), Callback::make_ref() or Callback::lambda() and implicit conversion will take place. Here is an example using Callback::make_ref(), with a class object my_obj of type MyClass, with a method void MyClass::my_method(const Something&, int):

using namespace Cgu;
Something arg;
e.connect(Callback::make_ref(my_obj, &MyClass::my_method, arg));
e(5);

For further background, including about thread-safety and exception safety and other matters, read this: emitter.h, or for more information about bound and unbound arguments, read this: Cgu::Callback.

Constructor & Destructor Documentation

template<class... FreeArgs>
Cgu::EmitterArg< FreeArgs >::EmitterArg ( )
default
Exceptions
std::bad_allocThe constructor might throw std::bad_alloc if memory is exhausted and the system throws in that case.
template<class... FreeArgs>
Cgu::EmitterArg< FreeArgs >::EmitterArg ( const EmitterArg< FreeArgs > &  )
delete

This class cannot be copied. The copy constructor is deleted.

template<class... FreeArgs>
Cgu::EmitterArg< FreeArgs >::~EmitterArg ( )

The destructor does not throw provided that the destructors of any bound arguments do not throw (as they should not do), and assuming that merely iterating through a list does not throw (as it would not on any sane implementation).

Member Function Documentation

template<class... FreeArgs>
void Cgu::EmitterArg< FreeArgs >::block ( const Callback::FunctorArg< FreeArgs...> &  f)

Blocks a connected functor from executing when emit() or operator()() is called until unblock() is called. This method does not throw (assuming that merely iterating through a list does not throw, as it would not on any sane implementation).

Parameters
fThe functor to block.
Note
If the same functor has been connected more than once to the same EmitterArg object, this call will block all of them.
template<class... FreeArgs>
Callback::FunctorArg< FreeArgs...> Cgu::EmitterArg< FreeArgs >::connect ( const Callback::FunctorArg< FreeArgs...> &  f)

Connects a Callback::FunctorArg object.

Parameters
fThe Callback::FunctorArg object to connect.
Returns
The Callback::FunctorArg object connected.
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case.
template<class... FreeArgs>
Callback::FunctorArg< FreeArgs...> Cgu::EmitterArg< FreeArgs >::connect ( const Callback::FunctorArg< FreeArgs...> &  f,
Releaser r 
)

Connects a Callback::FunctorArg object.

Parameters
fThe Callback::FunctorArg object to connect.
rA Releaser object for automatic disconnection of the Callback::FunctorArg object if the object whose method it represents is destroyed.
Returns
The Callback::FunctorArg object connected.
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case.
template<class... FreeArgs>
template<class F , class = typename std::enable_if<!std::is_convertible<typename std::remove_reference<F>::type, const Callback::FunctorArg<FreeArgs...>>::value>::type>
Callback::FunctorArg<FreeArgs...> Cgu::EmitterArg< FreeArgs >::connect ( F &&  f)
inline

Connects a callable object, such as formed by a lambda expression or the result of std::bind.

Parameters
fThe callable object to connect. If must have the same unbound argument types as the EmitterArg object concerned.
Returns
A Callback::FunctorArg object which can be passed to disconnect(), block() or unblock().
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case. If might also throw if the copy or move constructor of the callable object throws.

Since 2.1.0

template<class... FreeArgs>
template<class F , class = typename std::enable_if<!std::is_convertible<typename std::remove_reference<F>::type, const Callback::FunctorArg<FreeArgs...>>::value>::type>
Callback::FunctorArg<FreeArgs...> Cgu::EmitterArg< FreeArgs >::connect ( F &&  f,
Releaser r 
)
inline

Connects a callable object, such as formed by a lambda expression or the result of std::bind.

Parameters
fThe callable object to connect. If must have the same unbound argument types as the EmitterArg object concerned.
rA Releaser object for automatic disconnection of the callable object if an object whose method it represents or calls into is destroyed.
Returns
A Callback::FunctorArg object which can be passed to disconnect(), block() or unblock().
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case. If might also throw if the copy or move constructor of the callable object throws.

Since 2.1.0

template<class... FreeArgs>
void Cgu::EmitterArg< FreeArgs >::disconnect ( const Callback::FunctorArg< FreeArgs...> &  f)

Disconnects a functor previously connected. This does not throw provided that the destructors of any bound arguments do not throw (as they should not do), and assuming that merely iterating through a list does not throw (as it would not on any sane implementation).

Parameters
fThe functor to disconnect.
Note
If the same functor has been connected more than once to the same EmitterArg object, this call will disconnect all of them.
template<class... FreeArgs>
void Cgu::EmitterArg< FreeArgs >::emit ( typename Cgu::Param< FreeArgs >::ParamType...  args) const

This will execute the connected functors.

Parameters
argsThe unbound arguments to be passed to the referenced function or class method, if any.
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case. In addition, it will throw if the functions or class methods referenced by the functors throw (or if the copy constructor of a free or bound argument throws and it is not a reference argument).
template<class... FreeArgs>
void Cgu::EmitterArg< FreeArgs >::operator() ( typename Cgu::Param< FreeArgs >::ParamType...  args) const
inline

This will execute the connected functors.

Parameters
argsThe unbound arguments to be passed to the referenced function or class method, if any.
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case. In addition, it will throw if the functions or class methods referenced by the functors throw (or if the copy constructor of a free or bound argument throws and it is not a reference argument).
template<class... FreeArgs>
EmitterArg& Cgu::EmitterArg< FreeArgs >::operator= ( const EmitterArg< FreeArgs > &  )
delete

This class cannot be copied. The assignment operator is deleted.

template<class... FreeArgs>
bool Cgu::EmitterArg< FreeArgs >::test_emit ( typename Cgu::Param< FreeArgs >::ParamType...  args) const

This will execute the connected functors, but it also reports whether in fact there were any connected functors to execute. (It is not necessary to use this function just because it is not known whether a functor is connected - if the standard emit() function is called when no functor is connected, nothing will happen. The feature of this method is that it will report the outcome.)

Parameters
argsThe unbound arguments to be passed to the connected functions or class methods, if any.
Returns
Returns false if there were no functors to execute, or true if functors have been executed.
Exceptions
std::bad_allocThe method might throw std::bad_alloc if memory is exhausted and the system throws in that case. In addition, it will throw if the functions or class methods referenced by the functors throw (or if the copy constructor of a free or bound argument throws and it is not a reference argument).
template<class... FreeArgs>
void Cgu::EmitterArg< FreeArgs >::unblock ( const Callback::FunctorArg< FreeArgs...> &  f)

Unblocks a previously blocked functor. This method does not throw (assuming that merely iterating through a list does not throw, as it would not on any sane implementation).

Parameters
fThe functor to unblock.
Note
If the same functor has been connected more than once to the same EmitterArg object, this call will unblock all of them.

Friends And Related Function Documentation

template<class... FreeArgs>
friend class Releaser
friend

The documentation for this class was generated from the following file: