A custom picker lets you pick an option from its auto scrolling menu without lifting your finger up.

You can either use the @IBDesignable picker button DragMenuPicker or create your own with DragMenuView which implements all picker logic.

• iOS 9.0+
• Swift 3.0+

pod 'DragMenuPicker'

Create a DragMenuPicker from either storyboard or programmatically.
Set its title and items property to shown in menu.
Set its didSelectItem property or implement dragMenuView(_ dragMenuView: DragMenuView, didSelect item: String, at index: Int) delegate method to set your action after picking.
You can also set its direction, either horizontal or vertical with margins to screen edges.

horizontalDragPicker?.title = "Horizontal Picker"
horizontalDragPicker?.items = ["First", "Second", "Third", "Fourth", "Other", "Another", "Item 2", "Item 3"]
horizontalDragPicker?.direction = .horizontal
horizontalDragPicker?.margins = 20
horizontalDragPicker?.menuDelegate = self
horizontalDragPicker?.didSelectItem = { item, index in
  print("\(item) selected at index \(index)")
}

DragMenuPicker shows DragMenuView with DragMenuItemViews inside when you touch down the picker. It disappears after you pick something from menu or cancel picking by lifting your finger up outside of the menu.

They are heavily customisable. You can set applyStyle property which callbacks you prototype menu and item that you can style and it applies it to menu.

Also there are @IBInspectable properties on DragMenuPicker that you can style basic properties inside storyboard.