The base class for signal emitters. More...

#include <signal.hh>

Public Member Functions
	Emitter ()

	~Emitter ()

void	intoStringBuffer (misc::StringBuffer *sb)
	Store a textual representation of the object in a misc::StringBuffer. More...

Public Member Functions inherited from lout::object::Object
virtual	~Object ()
	The destructor is defined as virtual (but not abstract), so that destruction of Object's works properly. More...

virtual bool	equals (Object *other)
	Returns, whether two objects are equal. More...

virtual int	hashValue ()
	Return a hash value for the object. More...

virtual Object *	clone ()
	Return an exact copy of the object. More...

const char *	toString ()
	Use object::Object::intoStringBuffer to return a textual representation of the object. More...

virtual size_t	sizeOf ()
	Return the number of bytes, this object totally uses. More...

Protected Member Functions
void	emitVoid (int signalNo, int argc, Object **argv)
	Emit a void signal. More...

bool	emitBool (int signalNo, int argc, Object **argv)
	Emit a boolean signal. More...

void	connect (Receiver *receiver)
	Connect a receiver to the emitter. More...

virtual bool	emitToReceiver (Receiver receiver, int signalNo, int argc, Object *argv)=0
	A sub class must implement this for a call to a single receiver. More...

Private Member Functions
void	unconnect (Receiver *receiver)

Private Attributes
container::typed::List < Receiver > *	receivers

Friends
class	Receiver

Detailed Description

The base class for signal emitters.

If defining a signal group, a sub class of this class must be defined, with

a definition of the different signals (as enumeration),
an implementation of signal::Emitter::emitToReceiver,
wrappers for signal::Emitter::emitVoid and signal::Emitter::emitBool, respectively (one for each signal), and
a wrapper for signal::Emitter::connect.

There are two representations of signals:

In the unfolded representation, the signal itself is represented by the method itself (in the emitter or the receiver), and the arguments are represented as normal C++ types.
Folding signals means to represent the signal itself by an integer number (enumeration), and translate the arguments in an object::Object* array. (If a given argument is not an instance of object::Object*, the wrappers in object can be used.)

See also: signal

Constructor & Destructor Documentation

lout::signal::Emitter::Emitter ( )

lout::signal::Emitter::~Emitter ( )

References lout::container::typed::Iterator< T >::hasNext(), and lout::signal::Receiver::unconnectFrom().

Member Function Documentation

void lout::signal::Emitter::connect ( Receiver * receiver )

protected

Connect a receiver to the emitter.

This is protected, a sub class should define a wrapper, with the respective receiver as an argument, to gain type safety.

References lout::signal::Receiver::connectTo().

Referenced by dw::core::ui::Resource::ActivateEmitter::connectActivate(), dw::core::ui::Resource::ClickedEmitter::connectClicked(), lout::signal::ObservedObject::DeletionEmitter::connectDeletion(), dw::core::Layout::Emitter::connectLayout(), and dw::core::Layout::LinkEmitter::connectLink().

bool lout::signal::Emitter::emitBool	(	int	signalNo,
		int	argc,
		Object **	argv
	)

protected

Emit a boolean signal.

This method should be called by a wrapper, which folds the signal, delegates the emission to here, and returns the same boolean value.

References lout::container::typed::Iterator< T >::hasNext().

virtual bool lout::signal::Emitter::emitToReceiver	(	Receiver *	receiver,
		int	signalNo,
		int	argc,
		Object **	argv
	)

protectedpure virtual

A sub class must implement this for a call to a single receiver.

This methods gets the signal in a folded representation, it has to unfold it, and pass it to a single receiver. For boolean signals, the return value of the receiver must be returned, for void signals, the return value is discarded.

Implemented in dw::core::ui::Resource::ClickedEmitter, dw::core::ui::Resource::ActivateEmitter, lout::signal::ObservedObject::DeletionEmitter, dw::core::Layout::Emitter, and dw::core::Layout::LinkEmitter.