Detect Double Tap on UITabbarControler Item to scroll table view up

Question

I using TableView under Tab Bar My requirement is to scroll table view up when user double tap on tab bar item for selected view controller

this is my code

 func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool
{

    if tabBarController.viewControllers!.index(of: viewController) == 0 {
        if let navigationController = viewController as? UINavigationController{
            if let streamController = navigationController.viewControllers.last as? StreamViewController
            {
                streamController.tableViewStream.setContentOffset(CGPoint(x: 0, y: 0), animated: false)

            }
        }
        return true
    }

}

But this is causing to scroll table up when user even single tap on item, due to this I am note able to retain scroll position.

So what I want is

1.If user scroll the table and go on another tab and come back again by single tap scroll position should remain same

2.If user tap double any time on tab tab bar item the list should be scroll to top

Lu_ Lu_ · Accepted Answer · 2017-05-25T07:33:06

In your code i would add checking if this view controller is already selected

if tabBarController.viewControllers!.index(of: viewController) == 0 {

    if self.selectedIndex != 0 { return true }

    if let navigationController = viewController as? UINavigationController{
        if let streamController = navigationController.viewControllers.last as? StreamViewController
        {
            streamController.tableViewStream.setContentOffset(CGPoint(x: 0, y: 0), animated: false)

        }
    }
    return true
}

Detect Double Tap on UITabbarControler Item to scroll table view up

1 Answers