Remove a UITapGestureRecognizer from a view without having a strong pointer to it

Question

I have a UITapGestureRecognizer (TapGes) on the UIWindow with target on a UIViewController (vc).

I don't and I can't have a strong pointer to TapGes from vc. So after certain time vc is going to dealloc (when its done) and at this point I would like to remove TapGes from the UIWindow but I haven't found a way to do so.

If it was a view I would do something like:

1. Set a Tag to that view
2. Iterate on UIWindow subviews
3. Find the UIView with that tag
4. Remove it from superview

The problem is that UITapGestureRecognizer does not have a way of identify it like tag.

Is there a solution to this problem with the conditions:

• Not having a strong pointer to UITapGestureRecognizer
• Not adding an aux view on to UIWindow to add the UITapGestureRecognizer to it and then remove this view.

Thank you.

Answer 1

You can enumerate all the gestures of UIWindow when your viewController is deallocated and compare the target of each of them with self , then remove the UITapGestureRecognizer.

How to get the target of UITapGestureRecognizer, there are two solutions:

First solution: Subclass UITapGestureRecognizer, add a weak property named myTarget to keep the target and override the method - (void)addTarget:(id)target action:(SEL)action

- (void)addTarget:(id)target action:(SEL)action
{
    [super addTarget:target action:action] ;
    _myTarget = target ;
}

If you use first solution, you should check if the gesture recognizer is kind of your subclass using isKindOfClass:.

Second solution :Referenced from here

NSMutableArray *targets = [myGes valueForKeyPath:@"_targets"];
id targetContainer = targets[0];//get first target for example
id targetOfMyGes = [targetContainer valueForKeyPath:@"_target"];
NSLog(@"%@", targetOfMyGes );//you can see reference for target object