iOS - Background view is consuming touch events - ios

Question

I'll start by describing how the screen looks. It is a UIPageViewController that covers 100% of the screen and a UIView (on top of the page vc) that covers 20% of the screen. Easy, right? basically UIView is over UIPageViewController.
So, I'm adding said UIPageViewController programatically to my view controller with self.view.addSubview(pageVC.view). but the UIView is defined in the interface builder
For this reason, since the UIPageViewController is added last it covers the UIView which forced me to call myUIView.layer.zPosition = 1 so that the UIView is visible.
The problem is any touch made on the UIView is instead consumed by the UIPageViewController. how can I solve this?

Answer 1

The layer property of a particular view is only used for the rendering of that specific view. That's the reason why changes to the layer won't impact anything regarding the interaction with that specific view.
However, the -sendSubviewToBack: and -bringSubviewToFront: methods on UIView were designed to achieve exactly what you are looking for. Here you can read the docs for them.
I wrote this piece of code so that you can test what this method is doing. Try to comment/uncomment the last line or changing the order in which the subviews are added to get a better understanding of how it works.
UIView *firstView = [[UIView alloc] initWithFrame:CGRectMake(200, 200, 100, 100)];
UIView *secondView = [[UIView alloc] initWithFrame:CGRectMake(200, 200, 150, 150)];
firstView.backgroundColor = [UIColor greenColor];
secondView.backgroundColor = [UIColor redColor];
[self.view addSubview:firstView];
[self.view addSubview:secondView];
UITapGestureRecognizer *firstTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(firstTap)];
UITapGestureRecognizer *secondTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(secondTap)];
[firstView addGestureRecognizer:firstTap];
[secondView addGestureRecognizer:secondTap];
[self.view sendSubviewToBack:secondView];