layout/base/nsStyleSheetService.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   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.
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  17  * The Initial Developer of the Original Code is
  18  * IBM Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 2005
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *  Brian Ryner <bryner@brianryner.com>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
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  34  * the provisions above, a recipient may use your version of this file under
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  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38
  39 /* implementation of interface for managing user and user-agent style sheets */
  40
  41 #include "prlog.h"
  42 #include "nsStyleSheetService.h"
  43 #include "nsIStyleSheet.h"
  44 #include "mozilla/css/Loader.h"
  45 #include "nsCSSStyleSheet.h"
  46 #include "nsIURI.h"
  47 #include "nsContentCID.h"
  48 #include "nsCOMPtr.h"
  49 #include "nsIServiceManager.h"
  50 #include "nsICategoryManager.h"
  51 #include "nsISupportsPrimitives.h"
  52 #include "nsNetUtil.h"
  53 #include "nsIObserverService.h"
  54 #include "nsLayoutStatics.h"
  55
  56 nsStyleSheetService *nsStyleSheetService::gInstance = nsnull;
  57
  58 nsStyleSheetService::nsStyleSheetService()
  59 {
  60   PR_STATIC_ASSERT(0 == AGENT_SHEET && 1 == USER_SHEET);
  61   NS_ASSERTION(!gInstance, "Someone is using CreateInstance instead of GetService");
  62   gInstance = this;
  63   nsLayoutStatics::AddRef();
  64 }
  65
  66 nsStyleSheetService::~nsStyleSheetService()
  67 {
  68   gInstance = nsnull;
  69   nsLayoutStatics::Release();
  70 }
  71
  72 NS_IMPL_ISUPPORTS1(nsStyleSheetService, nsIStyleSheetService)
  73
  74 void
  75 nsStyleSheetService::RegisterFromEnumerator(nsICategoryManager  *aManager,
  76                                             const char          *aCategory,
  77                                             nsISimpleEnumerator *aEnumerator,
  78                                             PRUint32             aSheetType)
  79 {
  80   if (!aEnumerator)
  81     return;
  82
  83   PRBool hasMore;
  84   while (NS_SUCCEEDED(aEnumerator->HasMoreElements(&hasMore)) && hasMore) {
  85     nsCOMPtr<nsISupports> element;
  86     if (NS_FAILED(aEnumerator->GetNext(getter_AddRefs(element))))
  87       break;
  88
  89     nsCOMPtr<nsISupportsCString> icStr = do_QueryInterface(element);
  90     NS_ASSERTION(icStr,
  91                  "category manager entries must be nsISupportsCStrings");
  92
  93     nsCAutoString name;
  94     icStr->GetData(name);
  95
  96     nsXPIDLCString spec;
  97     aManager->GetCategoryEntry(aCategory, name.get(), getter_Copies(spec));
  98
  99     nsCOMPtr<nsIURI> uri;
 100     NS_NewURI(getter_AddRefs(uri), spec);
 101     if (uri)
 102       LoadAndRegisterSheetInternal(uri, aSheetType);
 103   }
 104 }
 105
 106 PRInt32
 107 nsStyleSheetService::FindSheetByURI(const nsCOMArray<nsIStyleSheet> &sheets,
 108                                     nsIURI *sheetURI)
 109 {
 110   for (PRInt32 i = sheets.Count() - 1; i >= 0; i-- ) {
 111     PRBool bEqual;
 112     nsIURI* uri = sheets[i]->GetSheetURI();
 113     if (uri
 114         && NS_SUCCEEDED(uri->Equals(sheetURI, &bEqual))
 115         && bEqual) {
 116       return i;
 117     }
 118   }
 119
 120   return -1;
 121 }
 122
 123 nsresult
 124 nsStyleSheetService::Init()
 125 {
 126   // Enumerate all of the style sheet URIs registered in the category
 127   // manager and load them.
 128
 129   nsCOMPtr<nsICategoryManager> catMan =
 130     do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
 131
 132   NS_ENSURE_TRUE(catMan, NS_ERROR_OUT_OF_MEMORY);
 133
 134   nsCOMPtr<nsISimpleEnumerator> sheets;
 135   catMan->EnumerateCategory("agent-style-sheets", getter_AddRefs(sheets));
 136   RegisterFromEnumerator(catMan, "agent-style-sheets", sheets, AGENT_SHEET);
 137
 138   catMan->EnumerateCategory("user-style-sheets", getter_AddRefs(sheets));
 139   RegisterFromEnumerator(catMan, "user-style-sheets", sheets, USER_SHEET);
 140
 141   return NS_OK;
 142 }
 143
 144 NS_IMETHODIMP
 145 nsStyleSheetService::LoadAndRegisterSheet(nsIURI *aSheetURI,
 146                                           PRUint32 aSheetType)
 147 {
 148   nsresult rv = LoadAndRegisterSheetInternal(aSheetURI, aSheetType);
 149   if (NS_SUCCEEDED(rv)) {
 150     const char* message = (aSheetType == AGENT_SHEET) ?
 151       "agent-sheet-added" : "user-sheet-added";
 152     nsCOMPtr<nsIObserverService> serv =
 153       mozilla::services::GetObserverService();
 154     if (serv) {
 155       // We're guaranteed that the new sheet is the last sheet in
 156       // mSheets[aSheetType]
 157       const nsCOMArray<nsIStyleSheet> & sheets = mSheets[aSheetType];
 158       serv->NotifyObservers(sheets[sheets.Count() - 1], message, nsnull);
 159     }
 160   }
 161   return rv;
 162 }
 163
 164 nsresult
 165 nsStyleSheetService::LoadAndRegisterSheetInternal(nsIURI *aSheetURI,
 166                                                   PRUint32 aSheetType)
 167 {
 168   NS_ENSURE_ARG(aSheetType == AGENT_SHEET || aSheetType == USER_SHEET);
 169   NS_ENSURE_ARG_POINTER(aSheetURI);
 170
 171   nsRefPtr<mozilla::css::Loader> loader = new mozilla::css::Loader();
 172   NS_ENSURE_TRUE(loader, NS_ERROR_OUT_OF_MEMORY);
 173
 174   nsRefPtr<nsCSSStyleSheet> sheet;
 175   // Allow UA sheets, but not user sheets, to use unsafe rules
 176   nsresult rv = loader->LoadSheetSync(aSheetURI, aSheetType == AGENT_SHEET,
 177                                       PR_TRUE, getter_AddRefs(sheet));
 178   NS_ENSURE_SUCCESS(rv, rv);
 179
 180   if (!mSheets[aSheetType].AppendObject(sheet)) {
 181     rv = NS_ERROR_OUT_OF_MEMORY;
 182   }
 183
 184   return rv;
 185 }
 186
 187 NS_IMETHODIMP
 188 nsStyleSheetService::SheetRegistered(nsIURI *sheetURI,
 189                                      PRUint32 aSheetType, PRBool *_retval)
 190 {
 191   NS_ENSURE_ARG(aSheetType == AGENT_SHEET || aSheetType == USER_SHEET);
 192   NS_ENSURE_ARG_POINTER(sheetURI);
 193   NS_PRECONDITION(_retval, "Null out param");
 194
 195   *_retval = (FindSheetByURI(mSheets[aSheetType], sheetURI) >= 0);
 196
 197   return NS_OK;
 198 }
 199
 200 NS_IMETHODIMP
 201 nsStyleSheetService::UnregisterSheet(nsIURI *sheetURI, PRUint32 aSheetType)
 202 {
 203   NS_ENSURE_ARG(aSheetType == AGENT_SHEET || aSheetType == USER_SHEET);
 204   NS_ENSURE_ARG_POINTER(sheetURI);
 205
 206   PRInt32 foundIndex = FindSheetByURI(mSheets[aSheetType], sheetURI);
 207   NS_ENSURE_TRUE(foundIndex >= 0, NS_ERROR_INVALID_ARG);
 208   nsCOMPtr<nsIStyleSheet> sheet = mSheets[aSheetType][foundIndex];
 209   mSheets[aSheetType].RemoveObjectAt(foundIndex);
 210
 211   const char* message = (aSheetType == AGENT_SHEET) ?
 212       "agent-sheet-removed" : "user-sheet-removed";
 213   nsCOMPtr<nsIObserverService> serv =
 214     mozilla::services::GetObserverService();
 215   if (serv)
 216     serv->NotifyObservers(sheet, message, nsnull);
 217
 218   return NS_OK;
 219 }