/* 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"

/**
 * nsISessionStore keeps track of the current browsing state - i.e.
 * tab history, cookies, scroll state, form data, and window features
 * - and allows to restore everything into one window.
 */

[scriptable, uuid(934697e4-3807-47f8-b6c9-6caa8d83ccd1)]
interface nsISessionStartup: nsISupports
{
  /**
   * Return a promise that is resolved once initialization
   * is complete.
   */
  readonly attribute jsval onceInitialized;

  // Get session state
  readonly attribute jsval state;

  /**
   * Determines whether there is a pending session restore. Should only be
   * called after initialization has completed.
   */
  boolean doRestore();

  /**
   * Determines whether automatic session restoration is enabled for this
   * launch of the browser. This does not include crash restoration, and will
   * return false if restoration will only be caused by a crash.
   */
  boolean isAutomaticRestoreEnabled();

  /**
   * Returns whether we will restore a session that ends up replacing the
   * homepage. The browser uses this to not start loading the homepage if
   * we're going to stop its load anyway shortly after.
   *
   * This is meant to be an optimization for the average case that loading the
   * session file finishes before we may want to start loading the default
   * homepage. Should this be called before the session file has been read it
   * will just return false.
   */
  readonly attribute bool willOverrideHomepage;

  /**
   * What type of session we're restoring.
   * NO_SESSION       There is no data available from the previous session
   * RECOVER_SESSION  The last session crashed. It will either be restored or
   *                  about:sessionrestore will be shown.
   * RESUME_SESSION   The previous session should be restored at startup
   * DEFER_SESSION    The previous session is fine, but it shouldn't be restored
   *                  without explicit action (with the exception of pinned tabs)
   */
  const unsigned long NO_SESSION = 0;
  const unsigned long RECOVER_SESSION = 1;
  const unsigned long RESUME_SESSION = 2;
  const unsigned long DEFER_SESSION = 3;

  readonly attribute unsigned long sessionType;
  readonly attribute bool previousSessionCrashed;
};