signal.cc

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/*
 * Dillo Widget
 *
 * Copyright 2005-2007 Sebastian Geerken <sgeerken@dillo.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 
 
#include "signal.hh"
 
namespace lout {
namespace signal {
 
using namespace container::typed;
 
// ------------
//    Emitter
// ------------
 
Emitter::Emitter ()
{
   receivers = new List <Receiver> (false);
}
 
Emitter::~Emitter ()
{
   for (Iterator<Receiver> it = receivers->iterator (); it.hasNext (); ) {
      Receiver *receiver = it.getNext ();
      receiver->unconnectFrom (this);
   }
   delete receivers;
}
 
void Emitter::intoStringBuffer(misc::StringBuffer *sb)
{
   sb->append ("<emitter: ");
   receivers->intoStringBuffer (sb);
   sb->append (">");
}
 
void Emitter::unconnect (Receiver *receiver)
{
   receivers->removeRef (receiver);
}
 
void Emitter::connect (Receiver *receiver)
{
   receivers->append (receiver);
   receiver->connectTo (this);
}
 
void Emitter::emitVoid (int signalNo, int argc, Object **argv)
{
   for (Iterator <Receiver> it = receivers->iterator (); it.hasNext (); ) {
      Receiver *receiver = it.getNext();
      emitToReceiver (receiver, signalNo, argc, argv);
   }
}
 
bool Emitter::emitBool (int signalNo, int argc, Object **argv)
{
   bool b = false, bt;
 
   for (Iterator <Receiver> it = receivers->iterator (); it.hasNext (); ) {
      Receiver *receiver = it.getNext();
      // Note: All receivers are called, even if one returns true.
      // Therefore, something like
      //    b = b || emitToReceiver (receiver, signalNo, argc, argv);
      // does not work.
      bt = emitToReceiver (receiver, signalNo, argc, argv);
      b = b || bt;
   }
 
   return b;
}
 
 
// --------------
//    Receiver
// --------------
 
Receiver::Receiver()
{
   emitters = new List <Emitter> (false);
}
 
Receiver::~Receiver()
{
   for (Iterator<Emitter> it = emitters->iterator(); it.hasNext(); ) {
      Emitter *emitter = it.getNext();
      emitter->unconnect (this);
   }
   delete emitters;
}
 
void Receiver::intoStringBuffer(misc::StringBuffer *sb)
{
   // emitters are not listed, to prevent recursion
   sb->append ("<receiver>");
}
 
void Receiver::connectTo(Emitter *emitter)
{
   emitters->append (emitter);
}
 
void Receiver::unconnectFrom(Emitter *emitter)
{
   emitters->removeRef (emitter);
}
 
// ------------------------
//    ObservedObject
// ------------------------
 
bool ObservedObject::DeletionEmitter::emitToReceiver (Receiver *receiver,
                                                      int signalNo,
                                                      int argc, Object **argv)
{
   object::TypedPointer <ObservedObject> *p =
      (object::TypedPointer<ObservedObject>*)argv[0];
   ((DeletionReceiver*)receiver)->deleted (p->getTypedValue ());
   return false;
}
 
void ObservedObject::DeletionEmitter::emitDeletion (ObservedObject *obj)
{
   object::TypedPointer <ObservedObject> p(obj);
   object::Object *argv[1] = { &p };
   emitVoid (0, 1, argv);
}
 
ObservedObject::~ObservedObject()
{
   deletionEmitter.emitDeletion (this);
}
 
} // namespace signal
} // namespace lout