FSCalendar content getting squished when I switch scope to month - ios

Question

My FSCalendar's content shrinks when I switch its scope from week to month if there is a view that's constrained to its bottom anchor.
Here is a quick gif to show what exactly is happening
I have tried everything at this point. Using calendar.setScope() instead of calendar.scope =, constraining attachedToCalendarView.topAnchor to calendar.bottomAnchor calendar.contentView.bottomAnchor, and calendar.daysContainer.bottomAnchor, even turning attachedToCalendarView 's constraints on and off depending on whether it's week scope or scope month.
Not sure what else to try. Here is the code:
import UIKit
import FSCalendar
class TestController : UIViewController, FSCalendarDataSource, FSCalendarDelegate, FSCalendarDelegateAppearance {
fileprivate weak var calendar: FSCalendar!
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
setUp()
}
#objc func switchCalendarScope(){
if self.calendar.scope == FSCalendarScope.month {
self.calendar.scope = FSCalendarScope.week
} else {
self.calendar.scope = FSCalendarScope.month
}
}
func setUp(){
let calendar = FSCalendar()
calendar.dataSource = self
calendar.delegate = self
self.calendar = calendar
self.calendar.scope = .week
self.calendar.locale = Locale(identifier: "en_EN")
self.calendar.calendarHeaderView.calendar.locale = Locale(identifier: "en_EN")
self.calendar.adjustsBoundingRectWhenChangingMonths = true
let testingView = UIView()
testingView.backgroundColor = .red
let attachedToCalendarView = UIView()
attachedToCalendarView.backgroundColor = .blue
view.addSubview(calendar)
view.addSubview(testingView)
view.addSubview(attachedToCalendarView)
self.calendar.translatesAutoresizingMaskIntoConstraints = false
self.calendar.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
self.calendar.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
self.calendar.widthAnchor.constraint(equalToConstant: view.bounds.size.width).isActive = true
self.calendar.heightAnchor.constraint(equalToConstant: 300).isActive = true
testingView.translatesAutoresizingMaskIntoConstraints = false
testingView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
testingView.widthAnchor.constraint(equalToConstant: view.bounds.size.width).isActive = true
testingView.heightAnchor.constraint(equalToConstant: 20).isActive = true
attachedToCalendarView.translatesAutoresizingMaskIntoConstraints = false
attachedToCalendarView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
// Attaching this view's topAnchor to the calendar's bottom anchor
attachedToCalendarView.topAnchor.constraint(equalTo: self.calendar.contentView.bottomAnchor).isActive = true
attachedToCalendarView.widthAnchor.constraint(equalToConstant: view.bounds.size.width).isActive = true
attachedToCalendarView.heightAnchor.constraint(equalToConstant: 20).isActive = true
// Title and button to toggle the calendar scope
self.navigationItem.title = "Test"
self.navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Toggle", style: .done, target: self, action: #selector(switchCalendarScope))
}
}

Answer 1

Well, I couldn't figure out how to fix the problem itself but I did find a workaround. I placed the calendar inside of an empty container view (just a simple UIView) and attached attachedToCalendarView to the container's bottomAnchor instead of the calendar's itself.
Do note however that using setScope, which animates the transition, still causes the same issue. For it to work you have to set it manually like calendar.scope = x
example:
#objc func switchCalendarScope(){
if self.calendar.scope == FSCalendarScope.month {
// self.calendar.setScope(FSCalendarScope.week, animated: true) // this will cause the calendar to be squished again
self.calendar.scope = .week
movingConstraint.constant = view.safeAreaLayoutGuide.layoutFrame.size.height * -0.20
} else {
// self.calendar.setScope(FSCalendarScope.month, animated: true)
self.calendar.scope = .month
movingConstraint.constant = 0
}
}