/modules/libpref/public/nsIPrefBranch.idl
http://github.com/zpao/v8monkey · IDL · 440 lines · 39 code · 30 blank · 371 comment · 0 complexity · 3c6c0457fcaa20c3e7addc152c1ecbc2 MD5 · raw file
- /* -*- 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"
- interface nsIObserver;
- /**
- * The nsIPrefBranch interface is used to manipulate the preferences data. This
- * object may be obtained from the preferences service (nsIPrefService) and
- * used to get and set default and/or user preferences across the application.
- *
- * This object is created with a "root" value which describes the base point in
- * the preferences "tree" from which this "branch" stems. Preferences are
- * accessed off of this root by using just the final portion of the preference.
- * For example, if this object is created with the root "browser.startup.",
- * the preferences "browser.startup.page", "browser.startup.homepage",
- * and "browser.startup.homepage_override" can be accessed by simply passing
- * "page", "homepage", or "homepage_override" to the various Get/Set methods.
- *
- * @see nsIPrefService
- */
- [scriptable, uuid(7df46a54-d8b0-448e-903c-4341a1b2499c)]
- interface nsIPrefBranch : nsISupports
- {
- /**
- * Values describing the basic preference types.
- *
- * @see getPrefType
- */
- const long PREF_INVALID = 0;
- const long PREF_STRING = 32;
- const long PREF_INT = 64;
- const long PREF_BOOL = 128;
- /**
- * Called to get the root on which this branch is based, such as
- * "browser.startup."
- */
- readonly attribute string root;
- /**
- * Called to determine the type of a specific preference.
- *
- * @param aPrefName The preference to get the type of.
- *
- * @return long A value representing the type of the preference. This
- * value will be PREF_STRING, PREF_INT, or PREF_BOOL.
- */
- long getPrefType(in string aPrefName);
- /**
- * Called to get the state of an individual boolean preference.
- *
- * @param aPrefName The boolean preference to get the state of.
- *
- * @return boolean The value of the requested boolean preference.
- *
- * @see setBoolPref
- */
- boolean getBoolPref(in string aPrefName);
- /**
- * Called to set the state of an individual boolean preference.
- *
- * @param aPrefName The boolean preference to set the state of.
- * @param aValue The boolean value to set the preference to.
- *
- * @return NS_OK The value was successfully set.
- * @return Other The value was not set or is the wrong type.
- *
- * @see getBoolPref
- */
- void setBoolPref(in string aPrefName, in boolean aValue);
- /**
- * Called to get the state of an individual string preference.
- *
- * @param aPrefName The string preference to retrieve.
- *
- * @return string The value of the requested string preference.
- *
- * @see setCharPref
- */
- string getCharPref(in string aPrefName);
- /**
- * Called to set the state of an individual string preference.
- *
- * @param aPrefName The string preference to set.
- * @param aValue The string value to set the preference to.
- *
- * @return NS_OK The value was successfully set.
- * @return Other The value was not set or is the wrong type.
- *
- * @see getCharPref
- */
- void setCharPref(in string aPrefName, in string aValue);
- /**
- * Called to get the state of an individual integer preference.
- *
- * @param aPrefName The integer preference to get the value of.
- *
- * @return long The value of the requested integer preference.
- *
- * @see setIntPref
- */
- long getIntPref(in string aPrefName);
- /**
- * Called to set the state of an individual integer preference.
- *
- * @param aPrefName The integer preference to set the value of.
- * @param aValue The integer value to set the preference to.
- *
- * @return NS_OK The value was successfully set.
- * @return Other The value was not set or is the wrong type.
- *
- * @see getIntPref
- */
- void setIntPref(in string aPrefName, in long aValue);
- /**
- * Called to get the state of an individual complex preference. A complex
- * preference is a preference which represents an XPCOM object that can not
- * be easily represented using a standard boolean, integer or string value.
- *
- * @param aPrefName The complex preference to get the value of.
- * @param aType The XPCOM interface that this complex preference
- * represents. Interfaces currently supported are:
- * - nsILocalFile
- * - nsISupportsString (UniChar)
- * - nsIPrefLocalizedString (Localized UniChar)
- * @param aValue The XPCOM object into which to the complex preference
- * value should be retrieved.
- *
- * @return NS_OK The value was successfully retrieved.
- * @return Other The value does not exist or is the wrong type.
- *
- * @see setComplexValue
- */
- void getComplexValue(in string aPrefName, in nsIIDRef aType,
- [iid_is(aType), retval] out nsQIResult aValue);
- /**
- * Called to set the state of an individual complex preference. A complex
- * preference is a preference which represents an XPCOM object that can not
- * be easily represented using a standard boolean, integer or string value.
- *
- * @param aPrefName The complex preference to set the value of.
- * @param aType The XPCOM interface that this complex preference
- * represents. Interfaces currently supported are:
- * - nsILocalFile
- * - nsISupportsString (UniChar)
- * - nsIPrefLocalizedString (Localized UniChar)
- * @param aValue The XPCOM object from which to set the complex preference
- * value.
- *
- * @return NS_OK The value was successfully set.
- * @return Other The value was not set or is the wrong type.
- *
- * @see getComplexValue
- */
- void setComplexValue(in string aPrefName, in nsIIDRef aType, in nsISupports aValue);
- /**
- * Called to clear a user set value from a specific preference. This will, in
- * effect, reset the value to the default value. If no default value exists
- * the preference will cease to exist.
- *
- * @param aPrefName The preference to be cleared.
- *
- * @note
- * This method does nothing if this object is a default branch.
- *
- * @return NS_OK The user preference was successfully cleared.
- */
- void clearUserPref(in string aPrefName);
- /**
- * Called to lock a specific preference. Locking a preference will cause the
- * preference service to always return the default value regardless of
- * whether there is a user set value or not.
- *
- * @param aPrefName The preference to be locked.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on the default branch.
- *
- * @return NS_OK The preference was successfully locked.
- * @return Other The preference does not exist or an error occurred.
- *
- * @see unlockPref
- */
- void lockPref(in string aPrefName);
- /**
- * Called to check if a specific preference has a user value associated to
- * it.
- *
- * @param aPrefName The preference to be tested.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on the user branch.
- *
- * @note
- * If a preference was manually set to a value that equals the default value,
- * then the preference no longer has a user set value, i.e. it is
- * considered reset to its default value.
- * In particular, this method will return false for such a preference and
- * the preference will not be saved to a file by nsIPrefService.savePrefFile.
- *
- * @return boolean true The preference has a user set value.
- * false The preference only has a default value.
- */
- boolean prefHasUserValue(in string aPrefName);
- /**
- * Called to check if a specific preference is locked. If a preference is
- * locked calling its Get method will always return the default value.
- *
- * @param aPrefName The preference to be tested.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on the default branch.
- *
- * @return boolean true The preference is locked.
- * false The preference is not locked.
- *
- * @see lockPref
- * @see unlockPref
- */
- boolean prefIsLocked(in string aPrefName);
- /**
- * Called to unlock a specific preference. Unlocking a previously locked
- * preference allows the preference service to once again return the user set
- * value of the preference.
- *
- * @param aPrefName The preference to be unlocked.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on the default branch.
- *
- * @return NS_OK The preference was successfully unlocked.
- * @return Other The preference does not exist or an error occurred.
- *
- * @see lockPref
- */
- void unlockPref(in string aPrefName);
- /**
- * Called to remove all of the preferences referenced by this branch.
- *
- * @param aStartingAt The point on the branch at which to start the deleting
- * preferences. Pass in "" to remove all preferences
- * referenced by this branch.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on both.
- *
- * @return NS_OK The preference(s) were successfully removed.
- * @return Other The preference(s) do not exist or an error occurred.
- */
- void deleteBranch(in string aStartingAt);
- /**
- * Returns an array of strings representing the child preferences of the
- * root of this branch.
- *
- * @param aStartingAt The point on the branch at which to start enumerating
- * the child preferences. Pass in "" to enumerate all
- * preferences referenced by this branch.
- * @param aCount Receives the number of elements in the array.
- * @param aChildArray Receives the array of child preferences.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on both.
- *
- * @return NS_OK The preference list was successfully retrieved.
- * @return Other The preference(s) do not exist or an error occurred.
- */
- void getChildList(in string aStartingAt,
- [optional] out unsigned long aCount,
- [array, size_is(aCount), retval] out string aChildArray);
- /**
- * Called to reset all of the preferences referenced by this branch to their
- * default values.
- *
- * @param aStartingAt The point on the branch at which to start the resetting
- * preferences to their default values. Pass in "" to
- * reset all preferences referenced by this branch.
- *
- * @note
- * This method can be called on either a default or user branch but, in
- * effect, always operates on the user branch.
- *
- * @return NS_OK The preference(s) were successfully reset.
- * @return Other The preference(s) do not exist or an error occurred.
- */
- void resetBranch(in string aStartingAt);
- /**
- * Add a preference change observer. On preference changes, the following
- * arguments will be passed to the nsIObserver.observe() method:
- * aSubject - The nsIPrefBranch object (this)
- * aTopic - The string defined by NS_PREFBRANCH_PREFCHANGE_TOPIC_ID
- * aData - The name of the preference which has changed, relative to
- * the |root| of the aSubject branch.
- *
- * aSubject.get*Pref(aData) will get the new value of the modified
- * preference. For example, if your observer is registered with
- * addObserver("bar.", ...) on a branch with root "foo.", modifying
- * the preference "foo.bar.baz" will trigger the observer, and aData
- * parameter will be "bar.baz".
- *
- * @param aDomain The preference on which to listen for changes. This can
- * be the name of an entire branch to observe.
- * e.g. Holding the "root" prefbranch and calling
- * addObserver("foo.bar.", ...) will observe changes to
- * foo.bar.baz and foo.bar.bzip
- * @param aObserver The object to be notified if the preference changes.
- * @param aHoldWeak true Hold a weak reference to |aObserver|. The object
- * must implement the nsISupportsWeakReference
- * interface or this will fail.
- * false Hold a strong reference to |aObserver|.
- *
- * @note
- * Registering as a preference observer can open an object to potential
- * cyclical references which will cause memory leaks. These cycles generally
- * occur because an object both registers itself as an observer (causing the
- * branch to hold a reference to the observer) and holds a reference to the
- * branch object for the purpose of getting/setting preference values. There
- * are 3 approaches which have been implemented in an attempt to avoid these
- * situations.
- * 1) The nsPrefBranch object supports nsISupportsWeakReference. Any consumer
- * may hold a weak reference to it instead of a strong one.
- * 2) The nsPrefBranch object listens for xpcom-shutdown and frees all of the
- * objects currently in its observer list. This ensures that long lived
- * objects (services for example) will be freed correctly.
- * 3) The observer can request to be held as a weak reference when it is
- * registered. This insures that shorter lived objects (say one tied to an
- * open window) will not fall into the cyclical reference trap.
- *
- * @note
- * The list of registered observers may be changed during the dispatch of
- * nsPref:changed notification. However, the observers are not guaranteed
- * to be notified in any particular order, so you can't be sure whether the
- * added/removed observer will be called during the notification when it
- * is added/removed.
- *
- * @note
- * It is possible to change preferences during the notification.
- *
- * @note
- * It is not safe to change observers during this callback in Gecko
- * releases before 1.9. If you want a safe way to remove a pref observer,
- * please use an nsITimer.
- *
- * @see nsIObserver
- * @see removeObserver
- */
- void addObserver(in string aDomain, in nsIObserver aObserver,
- in boolean aHoldWeak);
- /**
- * Remove a preference change observer.
- *
- * @param aDomain The preference which is being observed for changes.
- * @param aObserver An observer previously registered with addObserver().
- *
- * @note
- * Note that you must call removeObserver() on the same nsIPrefBranch
- * instance on which you called addObserver() in order to remove aObserver;
- * otherwise, the observer will not be removed.
- *
- * @see nsIObserver
- * @see addObserver
- */
- void removeObserver(in string aDomain, in nsIObserver aObserver);
- };
- %{C++
- #define NS_PREFBRANCH_CONTRACTID "@mozilla.org/preferencesbranch;1"
- #define NS_PREFBRANCH_CLASSNAME "Preferences Branch"
- /**
- * Notification sent when a preference changes.
- */
- #define NS_PREFBRANCH_PREFCHANGE_TOPIC_ID "nsPref:changed"
- %}