Event.cpp

/************************************************************************
 *
 *  This example shows how to use the Event class
 *
 ************************************************************************/


#include <jem/base/System.h>
#include <jem/util/Event.h>


using namespace jem;
using namespace jem::io;
using namespace jem::util;


//-----------------------------------------------------------------------
//   printValue
//-----------------------------------------------------------------------


void printValue ( int i )
{
  print ( System::out(), i, '\n' );
}


//-----------------------------------------------------------------------
//   class Listener
//-----------------------------------------------------------------------


class Listener : public Object
{
 public:

                      Listener    ();

  void                printValue

    ( double            f );

  void                printHello  ();


 protected:

  virtual            ~Listener    ();

};


Listener::Listener ()
{}


Listener::~Listener ()
{}


void Listener::printValue ( double f )
{
  print ( System::out(), f, endl );
}


void Listener::printHello ()
{
  print ( System::out(), "Hello\n" );
}


//-----------------------------------------------------------------------
//   class Signaller
//-----------------------------------------------------------------------


class Signaller : public Object
{
 public:

  Event<>             zeroReached;
  Event<int,int>      newValue;

                      Signaller ();

  void                setAndDecr

    ( int               i );

  void                destroy   ();


  static
    Ref<Signaller>    instance;


 protected:

  virtual            ~Signaller ();


 private:

  int                 value_;

};


Ref<Signaller> Signaller::instance;


Signaller::Signaller () : value_ ( 0 )
{}


Signaller::~Signaller ()
{
  print ( System::out(), "Bye Bye ...\n" );
}


void Signaller::setAndDecr ( int i )
{
  int oldValue = value_;

  value_ = (--i);

  if ( value_ <= 0 )
  {
    zeroReached.emit ();
  }
  else
  {
    newValue.emit ( value_, oldValue );
  }
}


void Signaller::destroy ()
{
  instance = NIL;
}


//-----------------------------------------------------------------------
//   run
//-----------------------------------------------------------------------


int run()
{
  Ref<Listener>  listener = newInstance<Listener>  ();

  Signaller::instance     = newInstance<Signaller> ();

  {
    Ref<Signaller>  s = Signaller::instance;

    connect ( s->zeroReached, listener, & Listener::printHello  );
    connect ( s->zeroReached, s,        & Signaller::destroy    );
    connect ( s->newValue,    s,        & Signaller::setAndDecr );
    connect ( s->newValue,    listener, & Listener::printValue  );
    connect ( s->newValue,              & printValue            );
  }

  Signaller::instance->setAndDecr ( 10 );

  return 0;
}


//-----------------------------------------------------------------------
//   main
//-----------------------------------------------------------------------


int main ()
{
  return System::exec ( & run );
}