Selected values don't line up. Not sure if it is the PickerView or Apple, but here it is, none-the-less.

When I click on the number 9 in the first picker it does this.

If i scroll all pickers to the top (0) then back to the correct value, then it looks correct.

Thereafter it seems to work correctly.

I had a crash with bad access in the setup method, where it's running in the background thread.

Unfortunately I didn't save the exception.

It was on the simulator and only happened once out of maybe 30 starts but I really don't want this to happen in my app on a customer's device. Especially because it was so rare. Those bugs are hard / impossible to debug.

IMO it's a mistake to do anything asynchronously that has to do with views. Views must be modified in the main thread. They are single threaded. I recall this being mentioned in Apple's documentation somewhere too.

Submitting this as change request - integrate it if you agree, or not if you don't ;)

I am grateful you wrote this code, so this is giving back.

The main goal when I started to change PickerView control was to implement custom view items for a project. I ended up implementing a lot more than that. I don't know whether you'll agree with all the changes that I did but I'm sending this pull request because I really like the result.

Summary of what I've done:

• Added support for custom view items
• Added compatibility with Objective-C
• Added optional for function delegates that aren't mandatory
• For every function delegate that has row parameter added an index parameter. This parameter is pretty handy when dealing with an infinite PickerView. row is the indexPath.row from the internal tableView while index is the index considering indexPath.row % items.count
• Added a new function delegate to know when a row was tapped: pickerView(PickerView, didTapRow row: Int, index: Int)
• Changed the name of some function delegates to conform with Apple's UIPickerViewDelegate. The names of function delegates were working fine but I prefer to work with their names as close as Apple's.

I know, there's a lot of changes. I should have separated each implementation but I changed the control directly while I was developing the project that I mentioned before. Sorry for that.

I added the custom view option in the Example project for better reference and testing.

Resolves #4

Is there a way to programmatically scroll to a row or index, after the picker has loaded? I need to scroll to specific items, after the view has loaded, based on what the user selects in that View Controller

I've tried objectPicker.currentSelectedRow = 0

Any help is appreciated.

This project is amazing! It's very cool believe me! Maybe is possible have a version in objective.c or a demo project how to implement swift in objective.c?Many now use swift but I'm not so quick to learn😩

Thanks!

On iOS 11, an infinite list does not show the selected item anymore, and pressing on items does a really long scroll to the item.

This happens even on the example project included.

Hi, thank you so much for this, it's really helpful! I noticed that the default selected row is not the middle one. I think the problem is in this code:

Int(ceil(Float(numberOfRowsByDataSource) / 2.0))

Since the row is an index, you have to subtract 1 to numberOfRowsByDataSource, to get the middle one. For example if we have 5 items, ceil(2.5) is 3, but the middle item index is actually 2.

It would be great to have a public function (or delegate function) that lets you set the first selected item.

Thanks

Hi ! I meet a strange problem that "sometimes" it will crash due to beyond the data array.

Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 2 beyond bounds [0 .. 1]'

and the " bounds[0..1] " will be different every time, sometimes it's [0..0], sometimes it's [0..2] and [0..3],

hope you can help me !

I'm using with iOS 11 and Xcode 9 and when reloadPickerView() seems to be called my pickerView starts to act strange. The selection is off center from the overlay I have on with the standard style and my conditions for highlighted aren't met. Everything seems to get shifted up in position also.

In the PickerView.swift, I am in an endless loop here, which locks up my app. I'm returning 0 for the pickerViewNumberOfRows delegate, because the user has not yet entered any data. I set the delegate and datasource in viewDidLoad().

`fileprivate func selectedNearbyToMiddleRow(_ row: Int) { currentSelectedRow = row tableView.reloadData()

    repeat {
        // This line adjust the contentInset to UIEdgeInsetZero because when the PickerView are inside of a UIViewController 
        // presented by a UINavigation controller, the tableView contentInset is affected.
        tableView.contentInset = UIEdgeInsets.zero
        
        let indexOfSelectedRow = visibleIndexOfSelectedRow()
        tableView.setContentOffset(CGPoint(x: 0.0, y: CGFloat(indexOfSelectedRow) * rowHeight), animated: false)
        
        delegate?.pickerView?(self, didSelectRow: currentSelectedRow, index: currentSelectedIndex)
        
    } while !(numberOfRowsByDataSource > 0 && tableView.numberOfRows(inSection: 0) > 0)
}`

Whenever I update the list of values I want in the PickerView I have to scroll the current value out of view before they update.

I'm changing the PresentationType to updater the list, is this correct or am I missing something?

I'm trying to use this library in SwiftUI but there seems to be an issue. When I present the picker, nothing is shown. I set breakpoint and cellForRowAtIndexPath is never called.

I searched online and another person is having the same exact issue: https://stackoverflow.com/questions/57297895/swiftui-uitableview-cellforrowatindexpath-never-called-in-uiviewrepresentable

Here is the code in StackOverflow that is very similar to mine that doesn't work:

struct FruitPicker: UIViewRepresentable {
    @Binding var fruits: [Fruit]
    @Binding var selectedFruit: Fruit

    class Coordinator: NSObject, PickerViewDelegate, PickerViewDataSource {
        @Binding var fruits: [Fruit]
        @Binding var selectedFruit: Fruit

        init(fruits: Binding<[Fruit]>, selectedFruit: Binding<Fruit>) {
            self._fruits = fruits
            self._selectedFruit = selectedFruit
        }

        func pickerViewNumberOfRows(_ pickerView: PickerView) -> Int {
            return self.fruits.count
        }

        func pickerViewHeightForRows(_ pickerView: PickerView) -> CGFloat {
            return 50
        }

        func pickerView(_ pickerView: PickerView, titleForRow row: Int) -> String {
            return self.fruits[row].name
        }

        func pickerView(_ pickerView: PickerView, didSelectRow row: Int) {
            self.selectedFruit = self.fruits[row]
        }
    }

    func makeCoordinator() -> FruitPicker.Coordinator {
        return Coordinator(fruits: self.$fruits, selectedFruit: self.$selectedFruit)
    }

    func makeUIView(context: UIViewRepresentableContext<FruitPicker>) -> PickerView {
        let pickerView = PickerView()

        pickerView.delegate = context.coordinator
        pickerView.dataSource = context.coordinator

        return pickerView
    }

    func updateUIView(_ pickerView: PickerView, context: UIViewRepresentableContext<FruitPicker>) {

    }
}

Could you please help out with this?

I would like to animate highlighting in styleForLabel, so i've overrides this method like this: if highlighted { UIView.animate(withDuration: 0.5, animations: { label.transform = CGAffineTransform(scaleX: 1, y: 1) }) } else { UIView.animate(withDuration: 0.5, animations: { label.transform = CGAffineTransform(scaleX: 1/2.5, y: 1/2.5) }) } But this gives me negative effect - it tries to animate labels before the view appears... So i decided to give my VC an extra property - var beginAnimating = false, and set this to true in viewDidApear. Unfortunately this is not working as I expect =( Please give me some advices with this issue. Thanks!

Some people reach me out reporting about some properties which aren't working when PickerView is implemented in an Objective-C project.

The known properties with issues:

• scrollingStyle: When its set to .Infinite, or rawValue 1, it causes a crash.
• selectionStyle: Not working.
• currentSelectedRow: Usually it sets a initial selected value to PickerView but its not appearing as a public property when exposed to Objective-C (even if it is declared as public in PickerView).

Unfortunately I can't fix this right now, so I'm opening this issue as a [help-wanted].

If you can help, please interact here and/or submit a pull request.

Thanks.