Revert of Remove webrtc/libjingle/{xmllite,xmpp}

webrtc/libjingle/xmpp/moduleimpl.h

+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_LIBJINGLE_XMPP_MODULEIMPL_H_
+#define WEBRTC_LIBJINGLE_XMPP_MODULEIMPL_H_
+
+#include "webrtc/libjingle/xmpp/module.h"
+#include "webrtc/libjingle/xmpp/xmppengine.h"
+
+namespace buzz {
+
+//! This is the base implementation class for extension modules.
+//! An engine is registered with the module and the module then hooks the
+//! appropriate parts of the engine to implement that set of features.  It is
+//! important to unregister modules before destructing the engine.
+class XmppModuleImpl {
+protected:
+  XmppModuleImpl();
+  virtual ~XmppModuleImpl();
+
+  //! Register the engine with the module.  Only one engine can be associated
+  //! with a module at a time.  This method will return an error if there is
+  //! already an engine registered.
+  XmppReturnStatus RegisterEngine(XmppEngine* engine);
+
+  //! Gets the engine that this module is attached to.
+  XmppEngine* engine();
+
+  //! Process the given stanza.
+  //! The module must return true if it has handled the stanza.
+  //! A false return value causes the stanza to be passed on to
+  //! the next registered handler.
+  virtual bool HandleStanza(const XmlElement *) { return false; };
+
+private:
+
+  //! The ModuleSessionHelper nested class allows the Module
+  //! to hook into and get stanzas and events from the engine.
+  class ModuleStanzaHandler : public XmppStanzaHandler {
+    friend class XmppModuleImpl;
+
+    ModuleStanzaHandler(XmppModuleImpl* module) :
+      module_(module) {
+    }
+
+    bool HandleStanza(const XmlElement* stanza) {
+      return module_->HandleStanza(stanza);
+    }
+
+    XmppModuleImpl* module_;
+  };
+
+  friend class ModuleStanzaHandler;
+
+  XmppEngine* engine_;
+  ModuleStanzaHandler stanza_handler_;
+};
+
+
+// This macro will implement the XmppModule interface for a class
+// that derives from both XmppModuleImpl and XmppModule
+#define IMPLEMENT_XMPPMODULE \
+  XmppReturnStatus RegisterEngine(XmppEngine* engine) { \
+    return XmppModuleImpl::RegisterEngine(engine); \
+  }
+
+}
+
+#endif  // WEBRTC_LIBJINGLE_XMPP_MODULEIMPL_H_