Cannot get internal UIScrollView [Swift]

[Ashkan-Sarlak]

Hi Stefan, thank you for your contribution to the iOS programmers community

I have a problem with the library. I've switched recently from UIPageViewController to this library, to have more control over paging animation, specifically I need a slower damping, when a page swipes. So as the README says I should access the internal scrollview and:

SCPageViewController().scrollView.setDecelerationRate(.normal)

, but Xcode says: Value of type 'SCPageViewController' has no member 'scrollView' I've seen the code and I know there is such member, I can get other members like 'layouter' but not this one that I really care about.

So, do you have any idea about this problem?

[stefanceriu]

Hi there and thank you, it's always nice seeing other people use your components.

I think all you have to do is import it into your bridging header, like in the swift demo here https://github.com/stefanceriu/SCPageViewController/blob/master/Demo/SwiftDemo/SwiftDemo-Bridging-Header.h#L12

This issue might also be of interest: Remove deceleration delay when paging

Cheers

[Ashkan-Sarlak]

Thanks, In my case I had to add this line to the generated '.h' file of my sub-project (of my multi module project):

#import "SCScrollView/SCScrollView.h"

Also, can you elaborate more on the approach you introduced in the second link? 'fast' deceleration is just like a regular page controller. 'normal' one is boringly slow. I want something in between. As a matter of fact I was thinking the transition animations will effect the scroll view, but it seems it only works when I manually switch pages

[stefanceriu]

The idea is nothing groundbreaking but it might involve a lot more math than you're prepared to write 😁 1) Get the target content offset and velocity from scrollViewWillEndDragging:withVelocity:targetContentOffset: 2) Intercept scrollViewDidEndDragging:willDecelerate: and stop the scroll view from its normal deceleration 3) Use a custom timing function in the - (void)setContentOffset:(CGPoint)contentOffset easingFunction:(id<SCEasingFunctionProtocol>)easingFunction duration:(CFTimeInterval)duration completion:(void(^)(void))completion; method to take it to its final resting place. The trick is to that you'll need to match the easing function perfectly to the velocity you got in step 1) to get a fluid animation.

Hope this makes sense 🙃

[Ashkan-Sarlak]

Hey man, I really need to implement this functionality. The problem is that I can not set a custom delegate for scrollView, delegate methods does not get called. Also (successfully) setting this delegate I believe will break the core functionality of the library. I tried overriding these methods in my custom class which inherits from SCPageViewController, but these methods are not visible. Any ideas?

[stefanceriu]

Well you could subclass the pageViewController and override those scrollView delegate methods, you could swizzle them or even go as far as creating your own scrollView and modifying the the pageViewController to take it as a dependency.