private void moveCursor()
        {
            //Move the cursor
            bool cursorMovedWithMouse = false;

#if MOUSE
            //If user moves the mouse then show it
            MouseState mouse = Mouse.GetState();
            if (mouse.X != lastMouseX && mouse.Y != lastMouseY)
            {
                //TODO: Doesn't seem to actually show the mouse until you move outside
                //the window and back in.
                Game.IsMouseVisible = true;
            }

            //if the mouse is visible then track the cursor with the mouse
            if (Game.IsMouseVisible)
            {
                //Find which marble is under the cursor
                cursorMovedWithMouse = moveCursorWithMouse(mouse.X, mouse.Y);
                lastMouseX           = mouse.X;
                lastMouseY           = mouse.Y;
            }
#endif

            //Move the cursor with keyboard/gamepad
            bool cursorMovedWithGamePad = false;

            if (InputHelper.GamePads[PlayerIndex.One].LeftPressed)
            {
                cursorMovedWithGamePad = FindNextMarbleX(-1);
            }
            if (InputHelper.GamePads[PlayerIndex.One].RightPressed)
            {
                cursorMovedWithGamePad = FindNextMarbleX(1);
            }
            if (InputHelper.GamePads[PlayerIndex.One].UpPressed)
            {
                cursorMovedWithGamePad = FindNextMarbleY(-1);
            }
            if (InputHelper.GamePads[PlayerIndex.One].DownPressed)
            {
                cursorMovedWithGamePad = FindNextMarbleY(1);
            }

            //if anything moved we play the move sound
            if (cursorMovedWithGamePad || cursorMovedWithMouse)
            {
                Sound.Play(SoundEntry.Navigate);
                FindSelectedMarbles();
            }

#if MOUSE
            //If the user goes back to moving with the keyboard/gamepad
            //then hide the mouse
            if (cursorMovedWithGamePad)
            {
                Game.IsMouseVisible = false;
            }
#endif
        }
        /// <summary>
        /// Called when the GameComponent needs to be updated.
        /// Game Board update performs animation on the marbles, checks for cursor
        /// movement. Most of the game logic is here or called from here
        /// </summary>
        /// <param name="gameTime">Current game time</param>
        public override void Update(GameTime gameTime)
        {
            if (gameTime == null)
            {
                return;
            }

            base.Update(gameTime);

            if (!GameOver)
            {
                Marble.UpdateStatic(gameTime);

                foreach (Marble marble in Marbles)
                {
                    if (marble != null)
                    {
                        marble.Update(gameTime);
                    }
                }

                switch (AnimationState)
                {
                case Animation.Breaking:
                {
                    //Fade the score
                    scoreFadeFactor = (float)((gameTime.TotalGameTime -
                                               scoreFadeStart.TotalGameTime).TotalSeconds /
                                              Marble.BreakTime);

                    //Wait until all marbles are broken.
                    bool stillBreaking = false;
                    foreach (Marble marble in Marbles)
                    {
                        if (marble != null)
                        {
                            if (marble.Animation == Animation.Breaking)
                            {
                                stillBreaking = true;
                                break;
                            }
                        }
                    }

                    //Done breaking - do the 'fall' and 'slide'
                    if (!stillBreaking)
                    {
                        FallAndSlide();
                        totalSelected = 0;
                        FindCursorPosition();
                        FindSelectedMarbles();
                        Sound.Play(SoundEntry.LandMarbles);
                        AnimationState = Animation.None;
                    }
                    break;
                }

                case Animation.None:
                {
                    moveCursor();
                    BreakMarbles(gameTime);
                    break;
                }
                }
            }
        }