1  export enum WheelDirection {
 2    None,
 3    Top,
 4    Bottom,
 5  }
 6  
 7  export class WheelDirectionUrl {
 8    public static toInt(wheelDirection: WheelDirection): number {
 9      switch (wheelDirection) {
10        case WheelDirection.None:
11          return 0
12  
13        case WheelDirection.Top:
14          return -1
15  
16        case WheelDirection.Bottom:
17          return 1
18      }
19    }
20  }