/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Alec Flett <alecf@netscape.com>
 *   Brian Nesse <bnesse@netscape.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsISupports.idl"
#include "nsIPrefBranch.idl"

interface nsIFile;

/**
 * The nsIPrefService interface is the main entry point into the back end
 * preferences management library. The preference service is directly
 * responsible for the management of the preferences files and also facilitates
 * access to the preference branch object which allows the direct manipulation
 * of the preferences themselves.
 *
 * @see nsIPrefBranch
 * 
 * @status FROZEN
 */

[scriptable, uuid(decb9cc7-c08f-4ea5-be91-a8fc637ce2d2)]
interface nsIPrefService : nsISupports
{
  /**
   * Called to read in the preferences specified in a user preference file.
   *
   * @param aFile The file to be read.
   *
   * @note
   * If nsnull is passed in for the aFile parameter the default preferences
   * file(s) [prefs.js, user.js] will be read and processed.
   *
   * @return NS_OK File was read and processed.
   * @return Other File failed to read or contained invalid data.
   *
   * @see savePrefFile
   * @see nsIFile
   */
  void readUserPrefs(in nsIFile aFile);

  /**
   * Called to completely flush and re-initialize the preferences system.
   *
   * @return NS_OK The preference service was re-initialized correctly.
   * @return Other The preference service failed to restart correctly.
   */
  void resetPrefs();

  /**
   * Called to reset all preferences with user set values back to the
   * application default values.
   *
   * @return NS_OK Always.
   */
  void resetUserPrefs();

  /**
   * Called to write current preferences state to a file.
   *
   * @param aFile The file to be written.
   *
   * @note
   * If nsnull is passed in for the aFile parameter the preference data is
   * written out to the current preferences file (usually prefs.js.)
   *
   * @return NS_OK File was written.
   * @return Other File failed to write.
   *
   * @see readUserPrefs
   * @see nsIFile
   */
  void savePrefFile(in nsIFile aFile);


  /**
   * Call to get a Preferences "Branch" which accesses user preference data.
   * Using a Set method on this object will always create or set a user
   * preference value. When using a Get method a user set value will be
   * returned if one exists, otherwise a default value will be returned.
   *
   * @param aPrefRoot The preference "root" on which to base this "branch".
   *                  For example, if the root "browser.startup." is used, the
   *                  branch will be able to easily access the preferences
   *                  "browser.startup.page", "browser.startup.homepage", or
   *                  "browser.startup.homepage_override" by simply requesting
   *                  "page", "homepage", or "homepage_override". nsnull or "" 
   *                  may be used to access to the entire preference "tree".
   *
   * @return nsIPrefBranch The object representing the requested branch.
   *
   * @see getDefaultBranch
   */
  nsIPrefBranch getBranch(in string aPrefRoot);

  /**
   * Call to get a Preferences "Branch" which accesses only the default 
   * preference data. Using a Set method on this object will always create or
   * set a default preference value. When using a Get method a default value
   * will always be returned.
   *
   * @param aPrefRoot The preference "root" on which to base this "branch".
   *                  For example, if the root "browser.startup." is used, the
   *                  branch will be able to easily access the preferences
   *                  "browser.startup.page", "browser.startup.homepage", or
   *                  "browser.startup.homepage_override" by simply requesting
   *                  "page", "homepage", or "homepage_override". nsnull or "" 
   *                  may be used to access to the entire preference "tree".
   *
   * @note
   * Few consumers will want to create default branch objects. Many of the
   * branch methods do nothing on a default branch because the operations only
   * make sense when applied to user set preferences.
   *
   * @return nsIPrefBranch The object representing the requested default branch.
   *
   * @see getBranch
   */
  nsIPrefBranch getDefaultBranch(in string aPrefRoot);

};

%{C++

#define NS_PREFSERVICE_CID                             \
  { /* {1cd91b88-1dd2-11b2-92e1-ed22ed298000} */       \
    0x1cd91b88,                                        \
    0x1dd2,                                            \
    0x11b2,                                            \
    { 0x92, 0xe1, 0xed, 0x22, 0xed, 0x29, 0x80, 0x00 } \
  }

#define NS_PREFSERVICE_CONTRACTID "@mozilla.org/preferences-service;1"
#define NS_PREFSERVICE_CLASSNAME "Preferences Server"

/**
 * Notification sent before reading the default user preferences files.
 */
#define NS_PREFSERVICE_READ_TOPIC_ID "prefservice:before-read-userprefs"

/**
 * Notification sent when resetPrefs has been called, but before the actual
 * reset process occurs.
 */
#define NS_PREFSERVICE_RESET_TOPIC_ID "prefservice:before-reset"

%}
