toolkit/xre/nsAppStartupNotifier.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsCOMPtr.h"
   7 #include "nsString.h"
   8 #include "nsIServiceManager.h"
   9 #include "nsICategoryManager.h"
  10 #include "nsXPCOM.h"
  11 #include "nsISupportsPrimitives.h"
  12 #include "nsAppStartupNotifier.h"
  13 #include "nsISimpleEnumerator.h"
  14
  15 /* static */ nsresult
  16 nsAppStartupNotifier::NotifyObservers(const char* aTopic)
  17 {
  18     NS_ENSURE_ARG(aTopic);
  19     nsresult rv;
  20
  21     // now initialize all startup listeners
  22     nsCOMPtr<nsICategoryManager> categoryManager =
  23                     do_GetService(NS_CATEGORYMANAGER_CONTRACTID, &rv);
  24     NS_ENSURE_SUCCESS(rv, rv);
  25
  26     nsDependentCString topic(aTopic);
  27
  28     nsCOMPtr<nsISimpleEnumerator> enumerator;
  29     rv = categoryManager->EnumerateCategory(topic,
  30                                getter_AddRefs(enumerator));
  31     if (NS_FAILED(rv)) return rv;
  32
  33     nsCOMPtr<nsISupports> entry;
  34     while (NS_SUCCEEDED(enumerator->GetNext(getter_AddRefs(entry)))) {
  35         nsCOMPtr<nsISupportsCString> category = do_QueryInterface(entry, &rv);
  36
  37         if (NS_SUCCEEDED(rv)) {
  38             nsAutoCString categoryEntry;
  39             rv = category->GetData(categoryEntry);
  40
  41             nsCString contractId;
  42             categoryManager->GetCategoryEntry(topic, categoryEntry,
  43                                               contractId);
  44
  45             if (NS_SUCCEEDED(rv)) {
  46
  47                 // If we see the word "service," in the beginning
  48                 // of the contractId then we create it as a service
  49                 // if not we do a createInstance
  50
  51                 nsCOMPtr<nsISupports> startupInstance;
  52                 if (Substring(contractId, 0, 8).EqualsLiteral("service,"))
  53                     startupInstance = do_GetService(contractId.get() + 8, &rv);
  54                 else
  55                     startupInstance = do_CreateInstance(contractId.get(), &rv);
  56
  57                 if (NS_SUCCEEDED(rv)) {
  58                     // Try to QI to nsIObserver
  59                     nsCOMPtr<nsIObserver> startupObserver =
  60                         do_QueryInterface(startupInstance, &rv);
  61                     if (NS_SUCCEEDED(rv)) {
  62                         rv = startupObserver->Observe(nullptr, aTopic, nullptr);
  63
  64                         // mainly for debugging if you want to know if your observer worked.
  65                         NS_ASSERTION(NS_SUCCEEDED(rv), "Startup Observer failed!\n");
  66                     }
  67                 }
  68                 else {
  69                   #ifdef DEBUG
  70                     nsAutoCString warnStr("Cannot create startup observer : ");
  71                     warnStr += contractId.get();
  72                     NS_WARNING(warnStr.get());
  73                   #endif
  74                 }
  75
  76             }
  77         }
  78     }
  79
  80     return NS_OK;
  81 }