xpcom/proxy/public/nsProxiedService.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
   7  * the License. You may obtain a copy of the License at
   8  * http://www.mozilla.org/MPL/
   9  *
  10  * Software distributed under the License is distributed on an "AS IS" basis,
  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  12  * for the specific language governing rights and limitations under the
  13  * License.
  14  *
  15  * The Original Code is mozilla.org code.
  16  *
  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Pierre Phaneuf <pp@ludusdesign.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either of the GNU General Public License Version 2 or later (the "GPL"),
  27  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 #ifndef nsProxiedService_h__
  40 #define nsProxiedService_h__
  41
  42 #include "nsServiceManagerUtils.h"
  43 #include "nsIProxyObjectManager.h"
  44 #include "nsXPCOMCIDInternal.h"
  45
  46 ////////////////////////////////////////////////////////////////////////////////
  47 // NS_WITH_PROXIED_SERVICE: macro to make using services that need to be proxied
  48 //                                   before using them easier.
  49 // Now you can replace this:
  50 // {
  51 //      nsresult rv;
  52 //      nsCOMPtr<nsIMyService> pIMyService =
  53 //               do_GetService(kMyServiceCID, &rv);
  54 //      if(NS_FAILED(rv))
  55 //          return;
  56 //      nsCOMPtr<nsIProxyObjectManager> pIProxyObjectManager =
  57 //               do_GetService(kProxyObjectManagerCID, &rv);
  58 //      if(NS_FAILED(rv))
  59 //          return;
  60 //      nsIMyService pIProxiedObject = NULL;
  61 //      rv = pIProxyObjectManager->GetProxyForObject(pIDispatchTarget,
  62 //                                                   NS_GET_IID(nsIMyService),
  63 //                                                   pIMyService, NS_PROXY_SYNC,
  64 //                                                   (void**)&pIProxiedObject);
  65 //      pIProxiedObject->DoIt(...);  // Executed on same thread as pIProxyQueue
  66 //      ...
  67 //      pIProxiedObject->Release();  // Must be done as not managed for you.
  68 //      }
  69 //  with this:
  70 //      {
  71 //      nsresult rv;
  72 //      NS_WITH_PROXIED_SERVICE(nsIMyService, pIMyService, kMyServiceCID,
  73 //                              pIDispatchTarget, &rv);
  74 //      if(NS_FAILED(rv))
  75 //          return;
  76 //      pIMyService->DoIt(...);  // Executed on the same thread as pIProxyQueue
  77 //      }
  78 // and the automatic destructor will take care of releasing the service and
  79 // the proxied object for you.
  80 //
  81 // Note that this macro requires you to link with the xpcom DLL to pick up the
  82 // static member functions from nsServiceManager.
  83
  84 #define NS_WITH_PROXIED_SERVICE(T, var, cid, Q, rvAddr)     \
  85     nsProxiedService _serv##var(cid, NS_GET_IID(T), Q, PR_FALSE, rvAddr);     \
  86     T* var = (T*)(nsISupports*)_serv##var;
  87
  88 #define NS_WITH_ALWAYS_PROXIED_SERVICE(T, var, cid, Q, rvAddr)     \
  89     nsProxiedService _serv##var(cid, NS_GET_IID(T), Q, PR_TRUE, rvAddr);       \
  90     T* var = (T*)(nsISupports*)_serv##var;
  91
  92 ////////////////////////////////////////////////////////////////////////////////
  93 // nsProxiedService
  94 ////////////////////////////////////////////////////////////////////////////////
  95
  96 class NS_STACK_CLASS nsProxiedService
  97 {
  98 public:
  99     nsProxiedService(const nsCID &aClass, const nsIID &aIID,
 100                      nsIEventTarget* aTarget, PRBool always, nsresult* rv)
 101     {
 102         nsCOMPtr<nsISupports> svc = do_GetService(aClass, rv);
 103         if (NS_SUCCEEDED(*rv))
 104             InitProxy(svc, aIID, aTarget, always, rv);
 105     }
 106
 107     nsProxiedService(const char* aContractID, const nsIID &aIID,
 108                      nsIEventTarget* aTarget, PRBool always, nsresult* rv)
 109     {
 110         nsCOMPtr<nsISupports> svc = do_GetService(aContractID, rv);
 111         if (NS_SUCCEEDED(*rv))
 112             InitProxy(svc, aIID, aTarget, always, rv);
 113     }
 114
 115     operator nsISupports*() const
 116     {
 117         return mProxiedService;
 118     }
 119
 120 private:
 121
 122     void InitProxy(nsISupports *aObj, const nsIID &aIID,
 123                    nsIEventTarget* aTarget, PRBool always, nsresult*rv)
 124     {
 125         PRInt32 proxyType = NS_PROXY_SYNC;
 126         if (always)
 127             proxyType |= NS_PROXY_ALWAYS;
 128
 129         nsCOMPtr<nsIProxyObjectManager> proxyObjMgr = do_GetService(NS_XPCOMPROXY_CONTRACTID, rv);
 130         if (NS_FAILED(*rv))
 131           return;
 132
 133         *rv = proxyObjMgr->GetProxyForObject(aTarget,
 134                                              aIID,
 135                                              aObj,
 136                                              proxyType,
 137                                              getter_AddRefs(mProxiedService));
 138     }
 139
 140     nsCOMPtr<nsISupports> mProxiedService;
 141 };
 142
 143 #endif // nsProxiedService_h__