1 /* 2 * libjingle 3 * Copyright 2004--2005, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef _moduleimpl_h_ 29 #define _moduleimpl_h_ 30 31 #include "talk/xmpp/xmppengine.h" 32 #include "talk/xmpp/module.h" 33 34 namespace buzz { 35 36 //! This is the base implementation class for extension modules. 37 //! An engine is registered with the module and the module then hooks the 38 //! appropriate parts of the engine to implement that set of features. It is 39 //! important to unregister modules before destructing the engine. 40 class XmppModuleImpl { 41 protected: 42 XmppModuleImpl(); 43 virtual ~XmppModuleImpl(); 44 45 //! Register the engine with the module. Only one engine can be associated 46 //! with a module at a time. This method will return an error if there is 47 //! already an engine registered. 48 XmppReturnStatus RegisterEngine(XmppEngine* engine); 49 50 //! Gets the engine that this module is attached to. 51 XmppEngine* engine(); 52 53 //! Process the given stanza. 54 //! The module must return true if it has handled the stanza. 55 //! A false return value causes the stanza to be passed on to 56 //! the next registered handler. HandleStanza(const XmlElement *)57 virtual bool HandleStanza(const XmlElement *) { return false; }; 58 59 private: 60 61 //! The ModuleSessionHelper nested class allows the Module 62 //! to hook into and get stanzas and events from the engine. 63 class ModuleStanzaHandler : public XmppStanzaHandler { 64 friend class XmppModuleImpl; 65 ModuleStanzaHandler(XmppModuleImpl * module)66 ModuleStanzaHandler(XmppModuleImpl* module) : 67 module_(module) { 68 } 69 HandleStanza(const XmlElement * stanza)70 bool HandleStanza(const XmlElement* stanza) { 71 return module_->HandleStanza(stanza); 72 } 73 74 XmppModuleImpl* module_; 75 }; 76 77 friend class ModuleStanzaHandler; 78 79 XmppEngine* engine_; 80 ModuleStanzaHandler stanza_handler_; 81 }; 82 83 84 // This macro will implement the XmppModule interface for a class 85 // that derives from both XmppModuleImpl and XmppModule 86 #define IMPLEMENT_XMPPMODULE \ 87 XmppReturnStatus RegisterEngine(XmppEngine* engine) { \ 88 return XmppModuleImpl::RegisterEngine(engine); \ 89 } 90 91 } 92 93 #endif 94