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 *
 * 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.org code.
 *
 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Blake Ross <blaker@netscape.com>
 *   Ben Goodger <ben@netscape.com>
 *
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// Keeps track of ongoing downloads, in the form of nsIDownload's. 

#include "nsISupports.idl"

interface nsIDOMWindow;
interface nsIURI;
interface nsILocalFile;
interface nsIDownload;
interface nsICancelable;
interface nsIMIMEInfo;
interface nsIDownloadProgressListener;
interface nsISimpleEnumerator;
interface mozIStorageConnection;

[scriptable, uuid(b0ba9b75-2aad-4293-8680-3fc66b13e546)]
interface nsIDownloadManager : nsISupports {
  // Download States
  const short DOWNLOAD_NOTSTARTED       = -1;
  const short DOWNLOAD_QUEUED           = 5;
  const short DOWNLOAD_DOWNLOADING      = 0;
  const short DOWNLOAD_FINISHED         = 1;
  const short DOWNLOAD_FAILED           = 2;
  const short DOWNLOAD_CANCELED         = 3;
  const short DOWNLOAD_PAUSED           = 4;

  const short DOWNLOAD_TYPE_DOWNLOAD    = 0;

  /**
   * Creates an nsIDownload and adds it to be managed by the download manager.
   *
   * @param aSource The source URI of the transfer. Must not be null.
   *
   * @param aTarget The target URI of the transfer. Must not be null.
   *
   * @param aDisplayName The user-readable description of the transfer.
   *                     Can be empty.
   *
   * @param aMIMEInfo The MIME info associated with the target,
   *                  including MIME type and helper app when appropriate.
   *                  This parameter is optional.
   *
   * @param startTime Time when the download started
   *
   * @param aTempFile The location of a temporary file; i.e. a file in which
   *                  the received data will be stored, but which is not
   *                  equal to the target file. (will be moved to the real
   *                  target by the caller, when the download is finished)
   *                  May be null.
   *
   * @param aCancelable An object that can be used to abort the download.
   *                    Must not be null.
   *
   * @return The newly created download item with the passed-in properties.
   *
   * @note This does not actually start a download.  If you want to add and
   *       start a download, you need to create an nsIWebBrowserPersist, pass it
   *       as the aCancelable object, call this method, set the progressListener
   *       as the returned download object, then call saveURI.
   */
  nsIDownload addDownload(in short aDownloadType, 
                          in nsIURI aSource,
                          in nsIURI aTarget,
                          in AString aDisplayName,
                          in nsIMIMEInfo aMIMEInfo,
                          in PRTime aStartTime,
                          in nsILocalFile aTempFile,
                          in nsICancelable aCancelable);

  /**
   * Retrieves a download managed by the download manager.  This can be one that
   * is in progress, or one that has completed in the past and is stored in the
   * database.
   *
   * @param aID The unique ID of the download.
   * @return The download with the specified ID.
   * @throws NS_ERROR_NOT_AVAILABLE if the download is not in the database.
   */
  nsIDownload getDownload(in unsigned long aID);

  /**
   * Cancels the download with the specified ID if it's currently in-progress.
   * This calls cancel(NS_BINDING_ABORTED) on the nsICancelable provided by the
   * download.
   *
   * @param aID The unique ID of the download.
   * @throws NS_ERROR_FAILURE if the download is not in-progress.
   */
  void cancelDownload(in unsigned long aID);

  /**
   * Removes the download with the specified id if it's not currently
   * in-progress.  Whereas cancelDownload simply cancels the transfer, but
   * retains information about it, removeDownload removes all knowledge of it.
   *
   * @param aID The unique ID of the download.
   * @throws NS_ERROR_FAILURE if the download is active.
   */
  void removeDownload(in unsigned long aID);

  /**
   * Pause the specified download.
   *
   * @param aID The unique ID of the download.
   * @throws NS_ERROR_FAILURE if the download is not in-progress.
   */
  void pauseDownload(in unsigned long aID);

  /**
   * Resume the specified download.
   *
   * @param aID The unique ID of the download.
   * @throws NS_ERROR_FAILURE if the download is not in-progress.
   */
  void resumeDownload(in unsigned long aID);

  /**
   * Retries a failed download.
   *
   * @param aID The unique ID of the download.
   * @throws NS_ERROR_NOT_AVAILALE if the download id is not known.
   * @throws NS_ERROR_FAILURE if the download is not in the following states:
   *           nsIDownloadManager::DOWNLOAD_CANCELED
   *           nsIDownloadManager::DOWNLOAD_FAILED
   */
  void retryDownload(in unsigned long aID);

  /** 
   * Opens the Download Manager front end, selecting the specified download.
   * 
   * @param aParent   The parent, or opener, of the front end (optional).
   * @param aID The unique ID of the download to be selected.
   * @see nsIWindowWatcher::openWindow for behavior of null aParent.
   * @throws NS_ERROR_FAILURE if the Download Manager does not know about the
   *         download.
   */
  void open(in nsIDOMWindow aParent, in unsigned long aID);

  /**
   * The database connection to the downloads database.
   */
  readonly attribute mozIStorageConnection DBConnection;

  /** 
   * Whether or not there are downloads that can be cleaned up (removed)
   * i.e. downloads that have completed, have failed or have been canceled. 
   */
  readonly attribute boolean canCleanUp;

  /** 
   * Removes completed, failed, and canceled downloads from the list. 
   */
  void cleanUp();

  /** 
   * The number of files currently being downloaded.
   */
  readonly attribute long activeDownloadCount;

  /**
   * An enumeration of active nsIDownloads
   */
  readonly attribute nsISimpleEnumerator activeDownloads;

  /**
   * Adds a listener from the download manager.
   */
  void addListener(in nsIDownloadProgressListener aListener);

  /**
   * Removes a listener from the download manager.
   */
  void removeListener(in nsIDownloadProgressListener aListener);
};


