// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
$!MEMBERS

$if DART2JS
  num get deltaY {
    if (JS('bool', '#.deltaY !== undefined', this)) {
      // W3C WheelEvent
      return this._deltaY;
    } else if (JS('bool', '#.wheelDelta !== undefined', this)) {
      // Chrome and IE
      return this._wheelDelta;
    } else if (JS('bool', '#.detail !== undefined', this)) {
      // Firefox

      // Handle DOMMouseScroll case where it uses detail and the axis to
      // differentiate.
      if (JS('bool', '#.axis == MouseScrollEvent.VERTICAL_AXIS', this)) {
        var detail = this._detail;
        // Firefox is normally the number of lines to scale (normally 3)
        // so multiply it by 40 to get pixels to move, matching IE & WebKit.
        if (detail < 100) {
          return detail * 40;
        }
        return detail;
      }
      return 0;
    }
    throw new UnsupportedError(
        'deltaY is not supported');
  }

  num get deltaX {
    if (JS('bool', '#.deltaX !== undefined', this)) {
      // W3C WheelEvent
      return this._deltaX;
    } else if (JS('bool', '#.wheelDeltaX !== undefined', this)) {
      // Chrome
      return this._wheelDeltaX;
    } else if (JS('bool', '#.detail !== undefined', this)) {
      // Firefox and IE.
      // IE will have detail set but will not set axis.

      // Handle DOMMouseScroll case where it uses detail and the axis to
      // differentiate.
      if (JS('bool', '#.axis !== undefined && #.axis == MouseScrollEvent.HORIZONTAL_AXIS', this, this)) {
        var detail = this._detail;
        // Firefox is normally the number of lines to scale (normally 3)
        // so multiply it by 40 to get pixels to move, matching IE & WebKit.
        if (detail < 100) {
          return detail * 40;
        }
        return detail;
      }
      return 0;
    }
    throw new UnsupportedError(
        'deltaX is not supported');
  }

  int get deltaMode {
    if (JS('bool', '!!#.deltaMode', this)) {
      // If not available then we're poly-filling and doing pixel scroll.
      return 0;
    }
    return this._deltaMode;
  }

  num get _deltaY => JS('num', '#.deltaY', this);
  num get _deltaX => JS('num', '#.deltaX', this);
  num get _wheelDelta => JS('num', '#.wheelDelta', this);
  num get _wheelDeltaX => JS('num', '#.wheelDeltaX', this);
  num get _detail => JS('num', '#.detail', this);
  int get _deltaMode => JS('int', '#.deltaMode', this);

$else
  num get deltaX => $dom_wheelDeltaX;
  num get deltaY => $dom_wheelDeltaY;
  int get deltaMode => 0;

$endif
}