modules/libpref/nsIPrefService.idl

   1 /* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   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 "nsISupports.idl"
   7 #include "nsIPrefBranch.idl"
   8
   9 interface nsIFile;
  10
  11 /**
  12  * A helper function for reading access statistics for preferences.
  13  * See nsIPrefService.readStats for more details.
  14  */
  15 [function, scriptable, uuid(c3f0cedc-e244-4316-b33a-80306a1c35a1)]
  16 interface nsIPrefStatsCallback : nsISupports
  17 {
  18   void visit(in ACString prefName, in unsigned long accessCount);
  19 };
  20
  21 [scriptable, uuid(0a2dbc02-2218-4687-b151-33d890676e00)]
  22 interface nsIPrefObserver : nsISupports
  23 {
  24   /**
  25    * Invoked when a string preference is witnessed.  kind will be "Default" or "User".
  26    */
  27   void onStringPref(in string kind, in string name, in string value, in boolean isSticky, in boolean isLocked);
  28
  29   /**
  30    * Invoked when a integer preference is witnessed.  kind will be "Default" or "User".
  31    */
  32   void onIntPref(in string kind, in string name, in long value, in boolean isSticky, in boolean isLocked);
  33
  34   /**
  35    * Invoked when a boolean preference is witnessed.  kind will be "Default" or "User".
  36    */
  37   void onBoolPref(in string kind, in string name, in boolean value, in boolean isSticky, in boolean isLocked);
  38
  39   /**
  40    * Invoked when the prefs parser encounters an error.
  41    */
  42   void onError(in string message);
  43 };
  44
  45 /**
  46  * The nsIPrefService interface is the main entry point into the back end
  47  * preferences management library. The preference service is directly
  48  * responsible for the management of the preferences files and also facilitates
  49  * access to the preference branch object which allows the direct manipulation
  50  * of the preferences themselves.
  51  *
  52  * @see nsIPrefBranch
  53  */
  54
  55 [scriptable, uuid(1f84fd56-3956-40df-b86a-1ea01402ee96)]
  56 interface nsIPrefService : nsISupports
  57 {
  58   /**
  59    * Called to completely flush and re-initialize the preferences system.
  60    *
  61    * @throws Error The preference service failed to restart correctly.
  62    */
  63   void resetPrefs();
  64
  65   /**
  66    * Called to write current preferences state to a file.
  67    *
  68    * @param aFile The file to be written.
  69    *
  70    * @note
  71    * If nullptr is passed in for the aFile parameter the preference data is
  72    * written out to the current preferences file (usually prefs.js.)
  73    *
  74    * @throws Error File failed to write.
  75    *
  76    * @see readUserPrefsFromFile
  77    * @see nsIFile
  78    */
  79   void savePrefFile(in nsIFile aFile);
  80
  81   /**
  82    * Called to write current preferences state to a file off of the main thread.
  83    * This differs from savePrefFile in that null is not accepted for the aFile
  84    * parameter, and aFile cannot be pointing at the current preferences file.
  85    *
  86    * The backup will be written to disk off of the main thread, unless the
  87    * preferences service is not configured to write to disk off of the main
  88    * thread.
  89    *
  90    * @param aFile The file to be written.
  91    * @returns A DOM promise that resolves when the backup is complete.
  92    *
  93    * @see readUserPrefsFromFile
  94    * @see nsIFile
  95    */
  96   [implicit_jscontext]
  97   Promise backupPrefFile(in nsIFile aFile);
  98
  99   /**
 100    * Call to get a Preferences "Branch" which accesses user preference data.
 101    * Using a Set method on this object will always create or set a user
 102    * preference value. When using a Get method a user set value will be
 103    * returned if one exists, otherwise a default value will be returned.
 104    *
 105    * @param aPrefRoot The preference "root" on which to base this "branch".
 106    *                  For example, if the root "browser.startup." is used, the
 107    *                  branch will be able to easily access the preferences
 108    *                  "browser.startup.page", "browser.startup.homepage", or
 109    *                  "browser.startup.homepage_override" by simply requesting
 110    *                  "page", "homepage", or "homepage_override". nullptr or ""
 111    *                  may be used to access to the entire preference "tree".
 112    *
 113    * @return nsIPrefBranch The object representing the requested branch.
 114    *
 115    * @see getDefaultBranch
 116    */
 117   nsIPrefBranch getBranch(in string aPrefRoot);
 118
 119   /**
 120    * Call to get a Preferences "Branch" which accesses only the default
 121    * preference data. Using a Set method on this object will always create or
 122    * set a default preference value. When using a Get method a default value
 123    * will always be returned.
 124    *
 125    * @param aPrefRoot The preference "root" on which to base this "branch".
 126    *                  For example, if the root "browser.startup." is used, the
 127    *                  branch will be able to easily access the preferences
 128    *                  "browser.startup.page", "browser.startup.homepage", or
 129    *                  "browser.startup.homepage_override" by simply requesting
 130    *                  "page", "homepage", or "homepage_override". nullptr or ""
 131    *                  may be used to access to the entire preference "tree".
 132    *
 133    * @note
 134    * Few consumers will want to create default branch objects. Many of the
 135    * branch methods do nothing on a default branch because the operations only
 136    * make sense when applied to user set preferences.
 137    *
 138    * @return nsIPrefBranch The object representing the requested default branch.
 139    *
 140    * @see getBranch
 141    */
 142   nsIPrefBranch getDefaultBranch(in string aPrefRoot);
 143
 144   /**
 145    * The preference service is 'dirty' if there are changes to user preferences
 146    * that have not been written to disk
 147    */
 148   readonly attribute boolean dirty;
 149
 150   /**
 151    * Read in the preferences specified in a default preference file. This
 152    * method does not clear preferences that were already set, but it may
 153    * overwrite existing preferences.
 154    *
 155    * @param aFile The file to be read.
 156    *
 157    * @throws Error File failed to read or contained invalid data.
 158    * @note This method is intended for internal unit testing only!
 159    */
 160   void readDefaultPrefsFromFile(in nsIFile aFile);
 161
 162   /**
 163    * Like readDefaultPrefsFromFile, but for a user prefs file.
 164    */
 165   void readUserPrefsFromFile(in nsIFile aFile);
 166
 167   /**
 168    * Usage statistics for performance tests. This function takes a function
 169    * that is passed (preferenceName, accessCount) as arguments for every
 170    * recorded preference. You can use this function to build e.g. a JS object
 171    * holding that data.
 172    *
 173    * This is not implemented in non-debug builds and will throw an error.
 174    */
 175   void readStats(in nsIPrefStatsCallback callback);
 176
 177   /**
 178    * Reset usage statistics for performance tests.
 179    *
 180    * This is not implemented in non-debug builds and will throw an error.
 181    */
 182   void resetStats();
 183
 184   /**
 185    * Parse the given bytes, invoking callbacks on the given observer.
 186    *
 187    * This method does not modify any preferences.
 188    *
 189    * @param bytes The data to parse.  This data may be UTF-8 encoded, but is not
 190    *              required to be so: the prefs parser will determine the encoding
 191    *              automatically.
 192    * @param observer The observer to invoke callbacks on.  Parsing errors will
 193    *                 be reported via the onError callback.
 194    * @param pathLabel An optional string with which to label errors.
 195    */
 196   void parsePrefsFromBuffer(in Array<uint8_t> bytes,
 197                             in nsIPrefObserver observer,
 198                             [optional] in string pathLabel);
 199
 200   /**
 201    * Last modified time of the user pref file when initially read, in
 202    * milliseconds. Can be 0 (unix epoch) if the file didn't exist when we
 203    * started.
 204    */
 205   readonly attribute PRTime userPrefsFileLastModifiedAtStartup;
 206 };
 207
 208 %{C++
 209
 210 #define NS_PREFSERVICE_CID                             \
 211   { /* {1cd91b88-1dd2-11b2-92e1-ed22ed298000} */       \
 212     0x91ca2441,                                        \
 213     0x050f,                                            \
 214     0x4f7c,                                            \
 215     { 0x9d, 0xf8, 0x75, 0xb4, 0x0e, 0xa4, 0x01, 0x56 } \
 216   }
 217
 218 #define NS_PREFSERVICE_CONTRACTID "@mozilla.org/preferences-service;1"
 219
 220 /**
 221  * Notification sent before reading the default user preferences files.
 222  */
 223 #define NS_PREFSERVICE_READ_TOPIC_ID "prefservice:before-read-userprefs"
 224
 225 /**
 226  * Notification sent when after reading app-provided default
 227  * preferences, but before user profile override defaults are loaded.
 228  */
 229 #define NS_PREFSERVICE_APPDEFAULTS_TOPIC_ID "prefservice:after-app-defaults"
 230
 231 %}