3 files changed, 78 insertions, 0 deletions
diff --git a/src/common/interface/EngineInterface.h b/src/common/interface/EngineInterface.h
index 8a10c840..1701a78e 100644
--- a/src/common/interface/EngineInterface.h
+++ b/src/common/interface/EngineInterface.h
@@ -29,6 +29,7 @@ namespace Ingen {
 namespace Shared {
 
 class ClientKey;
+class Responder;
 
 
 /** The (only) interface clients use to communicate with the engine.
@@ -41,6 +42,7 @@ public:
 	virtual ~EngineInterface() {}
 	
 	// Responses
+	virtual void set_responder(SharedPtr<Responder> responder) = 0;
 	virtual void set_next_response_id(int32_t id) = 0;
 	virtual void disable_responses() = 0;
 	
diff --git a/src/common/interface/Makefile.am b/src/common/interface/Makefile.am
index 8719cccd..347e8186 100644
--- a/src/common/interface/Makefile.am
+++ b/src/common/interface/Makefile.am
@@ -2,4 +2,5 @@ EXTRA_DIST = \
 	README \
 	ClientInterface.h \
 	ClientKey.h \
+	Responder.h \
 	EngineInterface.h
diff --git a/src/common/interface/Responder.h b/src/common/interface/Responder.h
new file mode 100644
index 00000000..6e809e1a
--- /dev/null
+++ b/src/common/interface/Responder.h
@@ -0,0 +1,75 @@
+/* This file is part of Ingen.
+ * Copyright (C) 2007 Dave Robillard <http://drobilla.net>
+ * 
+ * Ingen 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 2 of the License, or (at your option) any later
+ * version.
+ * 
+ * Ingen 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 details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef RESPONDER_H
+#define RESPONDER_H
+
+#include <inttypes.h>
+#include <string>
+#include <raul/SharedPtr.h>
+#include "interface/ClientKey.h"
+#include "interface/ClientInterface.h"
+using std::string;
+
+namespace Ingen {
+namespace Shared {
+
+using Shared::ClientKey;
+using Shared::ClientInterface;
+
+
+/** Class to handle responding to clients.
+ *
+ * This is an abstract base class to fully abstract the details of client
+ * communication from the internals of the engine.
+ *
+ * Note that this class only handles sending responses to commands from
+ * clients, (ie OK or an error), <b>not</b> notifications (ie new node,
+ * disconnection) - that's what ClientInterface is for.  If a command is
+ * a request, the ClientKey of the Responder can be used to find the
+ * ClientInterface which should receive the response.
+ *
+ * ClientInterface and Responder are seperate because responding might not
+ * actually get exposed to the client interface (eg in simulated blocking
+ * interfaces that wait for responses before returning).
+ *
+ * Note for messages that have a "response" and some broadcasted effect
+ * (eg setting a port value) the "response" MUST be sent first since Responder
+ * is responsible for controlling whether the client wishes to receive the
+ * notification.
+ */
+class Responder
+{
+public:
+	Responder() {}
+	virtual ~Responder() {}
+
+	virtual ClientKey                  client_key() { return ClientKey(); }
+	virtual SharedPtr<ClientInterface> client()     { return SharedPtr<ClientInterface>(); }
+
+	virtual void set_id(int32_t id) {}
+
+	virtual void respond_ok() {}
+	virtual void respond_error(const string& msg) {}
+};
+
+
+} // namespace Shared
+} // namespace Ingen
+
+#endif // RESPONDER_H
+