Range Selection

Although the implementation is up to you, two things are necessary.

Place this code in your viewDidLoad() function

calendarView.allowsMultipleSelection  = true
calendarView.rangeSelectionWillBeUsed = true

The following delegate function is your first place to implement date ranges. Basically, you are checking to see what is your cell’s selected position and applying the necessary changes.

func calendar(_ calendar: JTAppleCalendarView, didSelectDate date: Date, cell: JTAppleDayCellView?, cellState: CellState) {
   let myCustomCell = cell as! CellView // You created the cell view if you followed the tutorial
   switch cellState.selectedPosition() {
        case .full, .left, .right:
            myCustomCell.selectedView.isHidden = false
            myCustomCell.selectedView.backgroundColor = UIColor.yellow // Or you can put what ever you like for your rounded corners, and your stand-alone selected cell
        case .middle:
            myCustomCell.selectedView.isHidden = false
            myCustomCell.selectedView.backgroundColor = UIColor.blue // Or what ever you want for your dates that land in the middle
        default:
            myCustomCell.selectedView.isHidden = true
            myCustomCell.selectedView.backgroundColor = nil // Have no selection when a cell is not selected
   }
}

This code also has to be placed the following 2 other delegate functions.

func calendar(_ calendar: JTAppleCalendarView, willDisplayCell cell: JTAppleDayCellView, date: Date, cellState: CellState) {
    // Place code here
}
func calendar(_ calendar: JTAppleCalendarView, didDeselectDate date: Date, cell: JTAppleDayCellView?, cellState: CellState) {
    // Place code here
}

Therefore since we do not want code duplication, lets create a separate function to handle the range selection. Change all the code you have done above to look like the following.

func handleSelection(cell: JTAppleDayCellView?, cellState: CellState) {
   let myCustomCell = cell as! CellView // You created the cell view if you followed the tutorial
   switch cellState.selectedPosition() {
        case .full, .left, .right:
            myCustomCell.selectedView.isHidden = false
            myCustomCell.selectedView.backgroundColor = UIColor.yellow // Or you can put what ever you like for your rounded corners, and your stand-alone selected cell
        case .middle:
            myCustomCell.selectedView.isHidden = false
            myCustomCell.selectedView.backgroundColor = UIColor.blue // Or what ever you want for your dates that land in the middle
        default:
            myCustomCell.selectedView.isHidden = true
            myCustomCell.selectedView.backgroundColor = nil // Have no selection when a cell is not selected
   }

}
func calendar(_ calendar: JTAppleCalendarView, didSelectDate date: Date, cell: JTAppleDayCellView?, cellState: CellState) {
   handleSelection(cell: cell, cellState: cellState)
}
func calendar(_ calendar: JTAppleCalendarView, didDeselectDate date: Date, cell: JTAppleDayCellView?, cellState: CellState) {
    handleSelection(cell: cell, cellState: cellState)
}
func calendar(_ calendar: JTAppleCalendarView, willDisplayCell cell: JTAppleDayCellView, date: Date, cellState: CellState) {
    handleSelection(cell: cell, cellState: cellState)
}

Complete.

Two-Tap range selection

But what if your calendar has a range selection design that behaves like this?

  1. User taps first date
  2. User taps second date
  3. Your App should now select a range of dates from the start date to the end date.

You can accomplish this is what ever way you wish, but here is a rough example.

var firstDate: Date?

func calendar(_ calendar: JTAppleCalendarView, didSelectDate date: Date, cell: JTAppleDayCellView?, cellState: CellState) {
    if firstDate != nil {
       calendarView.selectDates(from: firstDate!, to: date,  triggerSelectionDelegate: false, keepSelectionIfMultiSelectionAllowed: true)
    } else {
       firstDate = date
    }
}

Continuous range selection

If you want your users to select dates in a fluid motion or using any other kind of gestures, then you will need to add gestures to your calendar. Here is an example adding long-press gesture.

You can code this any way you wish. Here is my rough sample code:

In your viewDidLoad() setup your gesture however you wish.

override func viewDidLoad() {
	calendarView.allowsMultipleSelection = true
	let panGensture = UILongPressGestureRecognizer(target: self, action: #selector(didStartRangeSelecting(gesture:)))
	panGensture.minimumPressDuration = 0.5
	calendarView.addGestureRecognizer(panGensture)
	calendarView.rangeSelectionWillBeUsed = true 
}

Then create the function to be executed

var rangeSelectedDates: [Date] = []
func didStartRangeSelecting(gesture: UILongPressGestureRecognizer) {
    let point = gesture.location(in: gesture.view!)
    rangeSelectedDates = calendarView.selectedDates
    if let cellState = calendarView.cellStatus(at: point) {
        let date = cellState.date
        if !rangeSelectedDates.contains(date) {
            let dateRange = calendarView.generateDateRange(from: rangeSelectedDates.first ?? date, to: date)
            for aDate in dateRange {
                if !rangeSelectedDates.contains(aDate) {
                    rangeSelectedDates.append(aDate)
                }
            }
            calendarView.selectDates(from: rangeSelectedDates.first!, to: date, keepSelectionIfMultiSelectionAllowed: true)
        } else {
            let indexOfNewlySelectedDate = rangeSelectedDates.index(of: date)! + 1
            let lastIndex = rangeSelectedDates.endIndex
            let followingDay = testCalendar.date(byAdding: .day, value: 1, to: date)!
            calendarView.selectDates(from: followingDay, to: rangeSelectedDates.last!, keepSelectionIfMultiSelectionAllowed: false)
            rangeSelectedDates.removeSubrange(indexOfNewlySelectedDate..<lastIndex)
        }
    }
    
    if gesture.state == .ended {
        rangeSelectedDates.removeAll()
    }
}