     fileprivate lazy var _navigationTitleItemView: UIView = _createGeneralContainerView()
     fileprivate lazy var _navigationItemView: UIView = _createGeneralContainerView()
     fileprivate lazy var _effectView: UIVisualEffectView = _createGenetalEffectView()
+    fileprivate var _offsetPositionsUpToEndIndex: [CGFloat] = []
     
     private var _titleItemsPreviewPanGesture: UIPanGestureRecognizer!
     
     fileprivate var _navigationBackItem: _TabNavigationBackItem = _TabNavigationBackItem(image:#imageLiteral(resourceName: "back_indicator"))
     fileprivate var _navigationItems: [TabNavigationItem] = []
-    fileprivate var _navigationTitleItems: [TabNavigationTitleItem] = []
+    fileprivate var _navigationTitleItems: [TabNavigationTitleItem] = [] { didSet { _offsetPositionsUpToEndIndex = _calculatedPositionsUptoTitleItemAtEndIndex() } }
     fileprivate var _navigationTitleActionItems: [TabNavigationTitleActionItem] = []
     
     fileprivate var _selectedTitleItemIndex: Int = 0 {

}

extension TabNavigationBar: UIScrollViewDelegate {
    public func scrollViewDidScroll(_ scrollView: UIScrollView) {
        guard !scrollView.isDragging, !scrollView.isTracking, !scrollView.isDecelerating else {
            return
        }
        
        let _offsetX = scrollView.contentOffset.x
        
        let _offsetPositionsUpToEndIndex = _calculatedPositionsUptoTitleItemAtEndIndex()
        
        for (_index, _titleItem) in _navigationTitleItems.enumerated() {
            let _offsetPosition = _offsetPositionsUpToEndIndex[_index]

        }
        
        _calculateWidthConstantOfContentAlignmentView()
        _offsetPositionsUpToEndIndex = _calculatedPositionsUptoTitleItemAtEndIndex()
        
        return (true, item)
    }
