/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"

interface nsIURI;
interface nsIFaviconDataCallback;

/**
 * Interface for accessing the favicon service asynchronously.
 *
 * @status EXPERIMENTAL
 */

[scriptable, uuid(f3530e8d-0016-4f56-91fe-28958a7ec296)]
interface mozIAsyncFavicons : nsISupports
{
  /**
   * Declares that a given page uses a favicon with the given URI and 
   * attempts to fetch and save the icon data by loading the favicon URI
   * through an async network request.
   *
   * If the icon data already exists, we won't try to reload the icon unless
   * aForceReload is true.  Similarly, if the icon is in the failed favicon
   * cache we won't do anything unless aForceReload is true, in which case
   * we'll try to reload the favicon.
   *
   * This function will only save favicons for pages that are already stored in
   * the database, like visited pages or bookmarks.  For any other URIs, it
   * will succeed but do nothing.  This function will also ignore the error
   * page favicon URI (see FAVICON_ERRORPAGE_URL below).
   *
   * Icons that fail to load will automatically be added to the failed favicon
   * cache, and this function will not save favicons for non-bookmarked URIs
   * when history is disabled.
   *
   * @note This function is identical to
   *       nsIFaviconService::setAndLoadFaviconForPage.
   *
   * @param aPageURI
   *        URI of the page whose favicon is being set.
   * @param aFaviconURI
   *        URI of the favicon to associate with the page.
   * @param aForceReload
   *        If aForceReload is false, we try to reload the favicon only if we
   *        don't have it or it has expired from the cache.  Setting
   *        aForceReload to true causes us to reload the favicon even if we
   *        have a usable copy.
   * @param aCallback
   *        Once we're done setting and/or fetching the favicon, we invoke this
   *        callback.
   *
   * @see nsIFaviconDataCallback in nsIFaviconService.idl.
   */
  void setAndFetchFaviconForPage(in nsIURI aPageURI,
                                 in nsIURI aFaviconURI,
                                 in boolean aForceReload,
                                 [optional] in nsIFaviconDataCallback aCallback);

  /**
   * Sets the data for a given favicon URI either by replacing existing data in
   * the database or taking the place of otherwise fetched icon data when
   * calling setAndFetchFaviconForPage later.
   *
   * Favicon data for favicon URIs that are not associated with a page URI via
   * setAndFetchFaviconForPage will be stored in memory, but may be expired at
   * any time, so you should make an effort to associate favicon URIs with page
   * URIs as soon as possible.
   *
   * It's better to not use this function for chrome: icon URIs since you can
   * reference the chrome image yourself. getFaviconLinkForIcon/Page will ignore
   * any associated data if the favicon URI is "chrome:" and just return the
   * same chrome URI.
   *
   * This function does NOT send out notifications that the data has changed.
   * Pages using this favicons that are visible in history or bookmarks views
   * will keep the old icon until they have been refreshed by other means.
   *
   * This function tries to optimize the favicon size, if it is bigger
   * than a defined limit we will try to convert it to a 16x16 png image.
   * If the conversion fails and favicon is still bigger than our max accepted
   * size it won't be saved.
   *
   * @param aFaviconURI
   *        URI of the favicon whose data is being set.
   * @param aData
   *        Binary contents of the favicon to save
   * @param aDataLength
   *        Length of binary data
   * @param aMimeType
   *        MIME type of the data to store.  This is important so that we know
   *        what to report when the favicon is used.  You should always set this
   *        param unless you are clearing an icon.
   * @param aExpiration
   *        Time in microseconds since the epoch when this favicon expires.
   *        Until this time, we won't try to load it again.
   * @throws NS_ERROR_FAILURE
   *         Thrown if the favicon is overbloated and won't be saved to the db.
   */
  void replaceFaviconData(in nsIURI aFaviconURI,
                          [const,array,size_is(aDataLen)] in octet aData,
                          in unsigned long aDataLen,
                          in AUTF8String aMimeType,
                          [optional] in PRTime aExpiration);

  /**
   * Same as replaceFaviconData but the data is provided by a string
   * containing a data URL.
   *
   * @see replaceFaviconData
   *
   * @param aFaviconURI
   *        URI of the favicon whose data is being set.
   * @param aDataURL
   *        string containing a data URL that represents the contents of
   *        the favicon to save
   * @param aExpiration
   *        Time in microseconds since the epoch when this favicon expires.
   *        Until this time, we won't try to load it again.
   * @throws NS_ERROR_FAILURE
   *         Thrown if the favicon is overbloated and won't be saved to the db.
   */
  void replaceFaviconDataFromDataURL(in nsIURI aFaviconURI,
                                     in AString aDataURL,
                                     [optional] in PRTime aExpiration);

  /**
   * Retrieves the favicon URI associated to the given page, if any.
   *
   * @param aPageURI
   *        URI of the page whose favicon URI we're looking up.
   * @param aCallback
   *        This callback is always invoked to notify the result of the lookup.
   *        The aURI parameter will be the favicon URI, or null when no favicon
   *        is associated with the page or an error occurred while fetching it.
   *
   * @note When the callback is invoked, aDataLen will be always 0, aData will
   *       be an empty array, and aMimeType will be an empty string, regardless
   *       of whether a favicon is associated with the page.
   *
   * @see nsIFaviconDataCallback in nsIFaviconService.idl.
   */
  void getFaviconURLForPage(in nsIURI aPageURI,
                            in nsIFaviconDataCallback aCallback);

  /**
   * Retrieves the favicon URI and data associated to the given page, if any.
   *
   * @param aPageURI
   *        URI of the page whose favicon URI and data we're looking up.
   * @param aCallback
   *        This callback is always invoked to notify the result of the lookup.  The aURI
   *        parameter will be the favicon URI, or null when no favicon is
   *        associated with the page or an error occurred while fetching it.  If
   *        aURI is not null, the other parameters may contain the favicon data.
   *        However, if no favicon data is currently associated with the favicon
   *        URI, aDataLen will be 0, aData will be an empty array, and aMimeType
   *        will be an empty string.
   *
   * @see nsIFaviconDataCallback in nsIFaviconService.idl.
   */
  void getFaviconDataForPage(in nsIURI aPageURI,
                             in nsIFaviconDataCallback aCallback);
};
