CODEWITHSUNDEEP
iosswiftuitableview
Reinier Melian
Reinier Melian

Reputation: 20804

Is possible set one Class as UIScrollViewDelegate and another as UITableViewDelegate of one UITableView

I have an UITableView and I need that another class be notified if UITableView is scrolled but I need that my UIViewController respond for the "normals" UITableViewDelegate methods such as func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloatby example, its this even possible?

Upvotes: 3

Views: 711

Answers (5)

ULazdins
ULazdins

Reputation: 2035

It is possible by implementing a a wrapper class that routes selector calls to one or other delegate.

Here is a working gist that solves the problem: https://gist.github.com/ULazdins/71a2bfd474c7f6fe9d0e61a749271247

Upvotes: 1

Shehata Gamal
Shehata Gamal

Reputation: 100541

You can have a delagate to inform the other class of the scroll event

func scrollViewDidScroll(_ scrollView: UIScrollView) {

    delegate?.tableScrolled(_ scrollView: UIScrollView) 

}

Upvotes: 1

Frankie
Frankie

Reputation: 11928

We solved this through delegates in the following way:

protocol OtherClasscrollDelegate: class {
    func scrollViewDidScroll(_ scrollView: UIScrollView)
    func scrollViewWillBeginDragging(_ scrollView: UIScrollView)
}

class OtherClass: OtherClasscrollDelegate {

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        ....
    }

    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        ....
    }
}

class ViewController {
    weak var otherClassScrollDelegate: OtherClasscrollDelegate?
}

extension ViewController: UIScrollViewDelegate {

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        self.otherClassScrollDelegate?.scrollViewDidScroll(scrollView)
    }

    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
        self.otherClassScrollDelegate?.scrollViewWillBeginDragging(scrollView)
    }
}

extension ViewController: UITableViewDataSource, UITableViewDelegate {

    func tableView(_: UITableView, numberOfRowsInSection _: Int) -> Int {
        ....
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        ....
    }
}

Upvotes: 3

rmaddy
rmaddy

Reputation: 318934

Since there is only one delegate property and since UITableViewDelegate extends UIScrollViewDelegate, you can only set one object as the delegate.

What you can do is have your view controller implement the table view delegate methods as needed and also have your view controller implement the scroll view delegate methods. But simply have those call the corresponding methods in the other class you have.

Here's a rough example:

class MyViewController: UITableViewDelegate {
    // lots of other stuff
    let myScrollViewDelegate = YourScrollViewDelegate()

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        myScrollViewDelegate.scrollViewDidScroll(scrollView)
    }
}

Upvotes: 3

Vollan
Vollan

Reputation: 1915

It's not possible to split the scrollViewDelegate and tableViewDelegate Into 2 different classes. What you could do is to have it in 1 class, and setup a notificationCenter oberserver in which you send the needed data as a NSNotification to the class that needs it.

Upvotes: 1

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