Touches should cancel function for UITableView is not called

Question

I have a table view that has a UIImage and some UIButton objects in each TableView cell. When I scroll the table view, it works quite well overall. However, if I touch one of the UIButton items to scroll the table view, the UIButton seems to steal the touches and the table view does not scroll. Instead the UIButton items appears to be selected instead. I would like to be able to scroll the table view even when the user touches buttons when starting to scroll. So, I searched for solutions here, tried the following.

extension UITableView {

    override public func touchesShouldCancel(in view: UIView) -> Bool {

        print("the touchesShouldCancel function is called.")

        if view is UIButton {
            return true
        }

        return super.touchesShouldCancel(in: view)
    }

}

However, it doesn't work. The function does not even get called whenever I scroll the table view. What am I missing here? I would greatly appreciate your input. Thanks all.

Jawad Ali · Accepted Answer · 2020-07-11T20:13:43.847

2

Subclass UITableView Set tableView canCancelContentTouches to true as per Apple docs

The scroll view does not call this method if the value of the canCancelContentTouches property is false

class YourTableView:UITableView {

    override func awakeFromNib() {
        canCancelContentTouches = true
        delaysContentTouches = false
    }

    override func touchesShouldCancel(in view: UIView) -> Bool {
        
    }
}

edited Jul 11 '20 at 20:13

answered Jul 11 '20 at 19:44

Jawad Ali

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Subclassing doesn't seem to make any difference. I just tried your code, but the buttons in the tableview cells still steal scroll touches. Thanks though. – Gilbert Tyler Jul 11 '20 at 20:11
have you set `canCancelContentTouches` – Jawad Ali Jul 11 '20 at 20:12
yes, as your code includes it. Also, in my IB, canCancelContentTouches is checked. – Gilbert Tyler Jul 11 '20 at 20:13
also add `delaysContentTouches = false` updated my answer with that – Jawad Ali Jul 11 '20 at 20:14
Wow! It is working now as I wanted. Thank you very much. Could you please tell me what difference the subclassing really makes as opposed to just overriding with extension as I did originally? – Gilbert Tyler Jul 11 '20 at 20:20

score 1 · Answer 2 · answered Jul 11 '20 at 19:42

1

You need to make a UITableView subclass

class SubTbl:UITableView {
   // add your method
}

Then assign it to that table in IB or use it in code

answered Jul 11 '20 at 19:42

Shehata Gamal

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Touches should cancel function for UITableView is not called

2 Answers2