+ trains[t.get_address()] = &t;
+ signal_train_added.emit(t);
+}
+
+Train &Layout::get_train(unsigned addr) const
+{
+ map<unsigned, Train *>::const_iterator i = trains.find(addr);
+ if(i==trains.end())
+ throw KeyError("Unknown train", lexical_cast(addr));
+ return *i->second;
+}
+
+void Layout::remove_train(Train &t)
+{
+ if(trains.erase(t.get_address()))
+ signal_train_removed.emit(t);
+}
+
+void Layout::add_vehicle(Vehicle &v)
+{
+ if(vehicles.insert(&v).second)
+ signal_vehicle_added.emit(v);
+}
+
+void Layout::remove_vehicle(Vehicle &v)
+{
+ if(vehicles.erase(&v))
+ signal_vehicle_removed.emit(v);
+}
+
+void Layout::tick()
+{
+ if(driver)
+ driver->tick();
+
+ Time::TimeStamp t = Time::now();
+ Time::TimeDelta dt;
+ if(last_tick)
+ dt = t-last_tick;
+ last_tick = t;
+
+ for(map<unsigned, Train *>::iterator i=trains.begin(); i!=trains.end(); ++i)
+ i->second->tick(t, dt);
+}
+
+void Layout::emergency(const string &msg)
+{
+ if(driver)
+ driver->halt(true);
+ IO::print("Emergency: %s\n", msg);
+ signal_emergency.emit(msg);
+}
+
+void Layout::save(const string &fn)
+{
+ IO::BufferedFile out(fn, IO::M_WRITE);
+ DataFile::Writer writer(out);