Holds a set of objects and can invoke a member function callback on each object in the set with a single call. More...

Classes
class	DummyBailOutChecker
	A dummy bail-out checker that always returns false. More...

class	Iterator
	Iterates the listeners in a ListenerList. More...

Public Types
typedef ListenerList< ListenerClass, ArrayType >	ThisType

typedef ListenerClass	ListenerType

Public Member Functions
	ListenerList ()
	Creates an empty list. More...

	~ListenerList ()
	Destructor. More...

void	add (ListenerClass *const listenerToAdd)
	Adds a listener to the list. More...

void	remove (ListenerClass *const listenerToRemove)
	Removes a listener from the list. More...

int	size () const noexcept
	Returns the number of registered listeners. More...

bool	isEmpty () const noexcept
	Returns true if any listeners are registered. More...

void	clear ()
	Clears the list. More...

bool	contains (ListenerClass *const listener) const noexcept
	Returns true if the specified listener has been added to the list. More...

void	call (void(ListenerClass::*callbackFunction)())
	Calls a member function on each listener in the list, with no parameters. More...

template<class BailOutCheckerType >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)())
	Calls a member function on each listener in the list, with no parameters and a bail-out-checker. More...

template<LL_TEMPLATE(1) >
void	call (void(ListenerClass::*callbackFunction)(P1), LL_PARAM(1))
	Calls a member function on each listener in the list, with 1 parameter. More...

template<class BailOutCheckerType , LL_TEMPLATE(1) >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)(P1), LL_PARAM(1))
	Calls a member function on each listener in the list, with one parameter and a bail-out-checker. More...

template<LL_TEMPLATE(1) , LL_TEMPLATE(2) >
void	call (void(ListenerClass::*callbackFunction)(P1, P2), LL_PARAM(1), LL_PARAM(2))
	Calls a member function on each listener in the list, with 2 parameters. More...

template<class BailOutCheckerType , LL_TEMPLATE(1) , LL_TEMPLATE(2) >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)(P1, P2), LL_PARAM(1), LL_PARAM(2))
	Calls a member function on each listener in the list, with 2 parameters and a bail-out-checker. More...

template<LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) >
void	call (void(ListenerClass::*callbackFunction)(P1, P2, P3), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3))
	Calls a member function on each listener in the list, with 3 parameters. More...

template<class BailOutCheckerType , LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)(P1, P2, P3), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3))
	Calls a member function on each listener in the list, with 3 parameters and a bail-out-checker. More...

template<LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) , LL_TEMPLATE(4) >
void	call (void(ListenerClass::*callbackFunction)(P1, P2, P3, P4), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4))
	Calls a member function on each listener in the list, with 4 parameters. More...

template<class BailOutCheckerType , LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) , LL_TEMPLATE(4) >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)(P1, P2, P3, P4), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4))
	Calls a member function on each listener in the list, with 4 parameters and a bail-out-checker. More...

template<LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) , LL_TEMPLATE(4) , LL_TEMPLATE(5) >
void	call (void(ListenerClass::*callbackFunction)(P1, P2, P3, P4, P5), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5))
	Calls a member function on each listener in the list, with 5 parameters. More...

template<class BailOutCheckerType , LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) , LL_TEMPLATE(4) , LL_TEMPLATE(5) >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)(P1, P2, P3, P4, P5), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5))
	Calls a member function on each listener in the list, with 5 parameters and a bail-out-checker. More...

template<LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) , LL_TEMPLATE(4) , LL_TEMPLATE(5) , LL_TEMPLATE(6) >
void	call (void(ListenerClass::*callbackFunction)(P1, P2, P3, P4, P5, P6), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5), LL_PARAM(6))
	Calls a member function on each listener in the list, with 5 parameters. More...

template<class BailOutCheckerType , LL_TEMPLATE(1) , LL_TEMPLATE(2) , LL_TEMPLATE(3) , LL_TEMPLATE(4) , LL_TEMPLATE(5) , LL_TEMPLATE(6) >
void	callChecked (const BailOutCheckerType &bailOutChecker, void(ListenerClass::*callbackFunction)(P1, P2, P3, P4, P5, P6), LL_PARAM(1), LL_PARAM(2), LL_PARAM(3), LL_PARAM(4), LL_PARAM(5), LL_PARAM(6))
	Calls a member function on each listener in the list, with 5 parameters and a bail-out-checker. More...

const ArrayType &	getListeners () const noexcept

Detailed Description

template<class ListenerClass, class ArrayType = Array<ListenerClass*>>
class ListenerList< ListenerClass, ArrayType >

Holds a set of objects and can invoke a member function callback on each object in the set with a single call.

Use a ListenerList to manage a set of objects which need a callback, and you can invoke a member function by simply calling call() or callChecked().

E.g.

class MyListenerType
{
public:
    void myCallbackMethod (int foo, bool bar);
};
ListenerList <MyListenerType> listeners;
listeners.add (someCallbackObjects...);
// This will invoke myCallbackMethod (1234, true) on each of the objects
// in the list...
listeners.call (&MyListenerType::myCallbackMethod, 1234, true);

If you add or remove listeners from the list during one of the callbacks - i.e. while it's in the middle of iterating the listeners, then it's guaranteed that no listeners will be mistakenly called after they've been removed, but it may mean that some of the listeners could be called more than once, or not at all, depending on the list's order.

Sometimes, there's a chance that invoking one of the callbacks might result in the list itself being deleted while it's still iterating - to survive this situation, you can use callChecked() instead of call(), passing it a local object to act as a "BailOutChecker". The BailOutChecker must implement a method of the form "bool shouldBailOut()", and the list will check this after each callback to determine whether it should abort the operation. For an example of a bail-out checker, see the Component::BailOutChecker class, which can be used to check when a Component has been deleted. See also ListenerList::DummyBailOutChecker, which is a dummy checker that always returns false.