/* 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"

/**
 * When we send a mozbrowserasyncscroll event (an instance of CustomEvent), we
 * use an instance of this interface as the event's detail.
 * [left, top, width, height]: The portion of the page which is currently 
 * visible onscreen in CSS pixels.
 * [scrollWidth, scrollHeight]: The content width/height in CSS pixels.
 *
 * top + height may be larger than scrollHeight.
 * This indicates that the content is over-scrolled, which occurs when the
 * page "rubber-bands" after being scrolled all the way to the bottom.
 * Similarly, left + width may be greater than scrollWidth, 
 * and both left and top may be negative.
 */
[scriptable, uuid(d0c13577-31e6-4701-b9b7-3535bbe19fe6)]
interface nsIAsyncScrollEventDetail : nsISupports
{
  readonly attribute float top;
  readonly attribute float left;
  readonly attribute float width;
  readonly attribute float height;
  readonly attribute float scrollWidth;
  readonly attribute float scrollHeight;
};