/// <summary>
/// Draw the UI on screen.
/// </summary>
/// <param name="gameTime"></param>
public override void Draw(GameTime gameTime)
{
if (CurrentWindow != null)
{
_spriteBatch.Begin(SpriteSortMode.BackToFront);
CurrentWindow.Draw(_spriteBatch);
_spriteBatch.End();
}
base.Draw(gameTime);
}