Can I handle the double tap in UITabbarController

Question

I need to handle the double tap action to get back from a navigation path represented with a custom view.

Usually the double tap dismisses the nested topmost controller in the navigation controller's stack. I'd like to handle this action and do something else.

Placing code in (BOOL)tabBarController:shouldSelectViewController: does not help as there is no difference between the single and double tap.

Thanks.

Answer 1

I had to add a tapCounter in the tabBarController:shouldSelectViewController: implementation:

self.tapCounter++;


// rule out possibility when the user taps on two different tabs very fast
BOOL hasTappedTwiceOnOneTab = NO;

if(self.previousHandledViewController == viewController) {

    hasTappedTwiceOnOneTab = YES;
}

self.previousHandledViewController = viewController;


// this code is called in the case when the user tapped twice faster then tapTimeRange
CGFloat tapTimeRange = 0.3;



        if(self.tapCounter == 2 && hasTappedTwiceOnOneTab) {


            // do something when tapped twice 

            self.tapCounter = 0;
            return NO; // or YES when you want the default engine process the event

        } else if(self.tapCounter == 1) {

            __block BOOL isSameViewControllerSelected = self.selectedViewController == viewController;
            if(isSameViewControllerSelected) {
                // do something when tapped once
            }

            dispatch_after_delay_on_main_queue(tapTimeRange, ^{

                self.tapCounter = 0; // reset the counter in case there is a single tap followed with another one, but with longer time then tapTimeRange
            });

            return NO; // or YES when you want the default engine process the event 
        }

This works nicely without any private api calls. But I'd like to know if there is a better and a less complicated way.