// Called once in its life time
    private void Awake()
    {
        this.cursor        = this.GetComponent <Image>();
        this.rectTransform = this.GetComponent <RectTransform>();

        this.mouseScreenBehaviour    = this.GetComponent <MouseScreenBehaviour>();
        this.mouseSelectionBehaviour = this.GetComponent <MouseSelectionBehaviour>();

        this.mousePosition = new MousePosition();
    }
    /**
     * <summary>
     * On left mouse up
     * </summary>
     *
     * <returns>
     * void
     * </returns>
     */
    private void OnLeftMouseUp()
    {
        // Stop scrolling, if the mouse is over UI or in build mode.
        if (!this.drag)
        {
            return;
        }

        // Is pointer up on the component panels UI, stop the selection
        if (ComponentPanelsUI.OnUI)
        {
            this.drag = false;
            this.HideSelectionArea();

            return;
        }

        RectTransform areaRect = this.area.GetComponent <RectTransform>();

        // Set final mouse position
        this.mousePosition.SetFinalPosition(this.transform.position);

        Bounds cameraViewportBounds = MouseScreenBehaviour.GetViewportBounds(
            this.mousePosition.GetInitialPosition(),
            this.mousePosition.GetFinalPosition()
            );

        ResourcesManagerBehaviour.UnselectResource();
        BuildingsManagerBehaviour.UnselectBuilding();

        UnitsManagerBehaviour.UnselectGameObjects();

        this.mouseSelectionBehaviour.SelectGameObjects(UnitsManagerBehaviour.Visibles, cameraViewportBounds);

        this.drag = false;
        this.HideSelectionArea();
    }