Fix layout for calendars where first week day is different from Monday. Related issue #18

Author: ilia3546

Sources/Extensions/Calendar+LastWeekday.swift

@@ -0,0 +1,16 @@
+//
+//  File.swift
+//  
+//
+//  Created by Ilya Kharlamov on 9/12/22.
+//
+
+import Foundation
+
+internal extension Calendar {
+    var lastWeekday: Int {
+        let numDays = self.weekdaySymbols.count
+        let res = (self.firstWeekday + numDays - 1) % numDays
+        return res != 0 ? res : self.weekdaySymbols.count
+    }
+}

Sources/Models/Config.swift

@@ -32,6 +32,13 @@ public struct FastisConfig {
 
     private init() {}
 
+    /**
+     Base calendar used to build a view
+     
+     Default value — `.current`
+     */
+    public var calendar: Calendar = .current
+
     /// Base view controller (`cancelButtonTitle`, `doneButtonTitle`, etc.)
     public var controller = FastisConfig.Controller()
 

Sources/Views/Controller.swift

@@ -94,7 +94,7 @@ open class FastisController<Value: FastisValue>: UIViewController, JTACMonthView
     }()
 
     private lazy var weekView: WeekView = {
-        let view = WeekView(config: self.config.weekView)
+        let view = WeekView(calendar: self.config.calendar, config: self.config.weekView)
         view.translatesAutoresizingMaskIntoConstraints = false
         return view
     }()
@@ -139,7 +139,6 @@ open class FastisController<Value: FastisValue>: UIViewController, JTACMonthView
     private let dayCellReuseIdentifier = "DayCellReuseIdentifier"
     private let monthHeaderReuseIdentifier = "MonthHeaderReuseIdentifier"
     private var viewConfigs: [IndexPath: DayCell.ViewConfig] = [:]
-    private var currentCalendar: Calendar = .autoupdatingCurrent
     private var privateMinimumDate: Date?
     private var privateMaximumDate: Date?
     private var privateSelectMonthOnHeaderTap: Bool = false
@@ -347,7 +346,8 @@ open class FastisController<Value: FastisValue>: UIViewController, JTACMonthView
             let newConfig = DayCell.makeViewConfig(for: cellState,
                                                    minimumDate: self.privateMinimumDate,
                                                    maximumDate: self.privateMaximumDate,
-                                                   rangeValue: self.value as? FastisRange)
+                                                   rangeValue: self.value as? FastisRange,
+                                                   calendar: self.config.calendar)
             self.viewConfigs[indexPath] = newConfig
             cell.applyConfig(self.config)
             cell.configure(for: newConfig)
@@ -399,23 +399,23 @@ open class FastisController<Value: FastisValue>: UIViewController, JTACMonthView
                 let dateRangeChangesDisabled = !allowDateRangeChanges
                 let rangeSelected = !currentValue.fromDate.isInSameDay(date: currentValue.toDate)
                 if dateRangeChangesDisabled && rangeSelected {
-                    newValue = .from(date.startOfDay(in: self.currentCalendar), to: date.endOfDay(in: self.currentCalendar))
-                } else if date.isInSameDay(in: self.currentCalendar, date: currentValue.fromDate) {
-                    let newToDate = date.endOfDay(in: self.currentCalendar)
+                    newValue = .from(date.startOfDay(in: self.config.calendar), to: date.endOfDay(in: self.config.calendar))
+                } else if date.isInSameDay(in: self.config.calendar, date: currentValue.fromDate) {
+                    let newToDate = date.endOfDay(in: self.config.calendar)
                     newValue = .from(currentValue.fromDate, to: newToDate)
-                } else if date.isInSameDay(in: self.currentCalendar, date: currentValue.toDate) {
-                    let newFromDate = date.startOfDay(in: self.currentCalendar)
+                } else if date.isInSameDay(in: self.config.calendar, date: currentValue.toDate) {
+                    let newFromDate = date.startOfDay(in: self.config.calendar)
                     newValue = .from(newFromDate, to: currentValue.toDate)
                 } else if date < currentValue.fromDate {
-                    let newFromDate = date.startOfDay(in: self.currentCalendar)
+                    let newFromDate = date.startOfDay(in: self.config.calendar)
                     newValue = .from(newFromDate, to: currentValue.toDate)
                 } else {
-                    let newToDate = date.endOfDay(in: self.currentCalendar)
+                    let newToDate = date.endOfDay(in: self.config.calendar)
                     newValue = .from(currentValue.fromDate, to: newToDate)
                 }
 
             } else {
-                newValue = .from(date.startOfDay(in: self.currentCalendar), to: date.endOfDay(in: self.currentCalendar))
+                newValue = .from(date.startOfDay(in: self.config.calendar), to: date.endOfDay(in: self.config.calendar))
             }
 
             self.value = newValue as? Value
@@ -441,30 +441,30 @@ open class FastisController<Value: FastisValue>: UIViewController, JTACMonthView
 
         let dateFormatter = DateFormatter()
         dateFormatter.dateFormat = "yyyy MM dd"
-        dateFormatter.timeZone = self.currentCalendar.timeZone
-        dateFormatter.locale = self.currentCalendar.locale
+        dateFormatter.timeZone = self.config.calendar.timeZone
+        dateFormatter.locale = self.config.calendar.locale
         var startDate = dateFormatter.date(from: "2000 01 01")!
         var endDate = dateFormatter.date(from: "2030 12 01")!
 
         if let maximumDate = self.privateMaximumDate,
-            let endOfNextMonth = self.currentCalendar.date(byAdding: .month, value: 2, to: maximumDate)?
-                .endOfMonth(in: self.currentCalendar) {
+            let endOfNextMonth = self.config.calendar.date(byAdding: .month, value: 2, to: maximumDate)?
+                .endOfMonth(in: self.config.calendar) {
             endDate = endOfNextMonth
         }
 
         if let minimumDate = self.privateMinimumDate,
-            let startOfPreviousMonth = self.currentCalendar.date(byAdding: .month, value: -2, to: minimumDate)?
-                .startOfMonth(in: self.currentCalendar) {
+            let startOfPreviousMonth = self.config.calendar.date(byAdding: .month, value: -2, to: minimumDate)?
+                .startOfMonth(in: self.config.calendar) {
             startDate = startOfPreviousMonth
         }
 
         let parameters = ConfigurationParameters(startDate: startDate,
                                                  endDate: endDate,
                                                  numberOfRows: 6,
-                                                 calendar: self.currentCalendar,
+                                                 calendar: self.config.calendar,
                                                  generateInDates: .forAllMonths,
                                                  generateOutDates: .tillEndOfRow,
-                                                 firstDayOfWeek: .monday,
+                                                 firstDayOfWeek: nil,
                                                  hasStrictBoundaries: true)
         return parameters
     }
@@ -475,16 +475,16 @@ open class FastisController<Value: FastisValue>: UIViewController, JTACMonthView
         header.configure(for: range.start)
         if self.privateSelectMonthOnHeaderTap, Value.mode == .range {
             header.tapHandler = {
-                var fromDate = range.start.startOfMonth(in: self.currentCalendar)
-                var toDate = range.start.endOfMonth(in: self.currentCalendar)
+                var fromDate = range.start.startOfMonth(in: self.config.calendar)
+                var toDate = range.start.endOfMonth(in: self.config.calendar)
                 if let minDate = self.minimumDate {
                     if toDate < minDate { return } else if fromDate < minDate {
-                        fromDate = minDate.startOfDay(in: self.currentCalendar)
+                        fromDate = minDate.startOfDay(in: self.config.calendar)
                     }
                 }
                 if let maxDate = self.maximumDate {
                     if fromDate > maxDate { return } else if toDate > maxDate {
-                        toDate = maxDate.endOfDay(in: self.currentCalendar)
+                        toDate = maxDate.endOfDay(in: self.config.calendar)
                     }
                 }
                 let newValue: FastisRange = .from(fromDate, to: toDate)

Sources/Views/DayCell.swift

@@ -133,7 +133,13 @@ class DayCell: JTACDayCell {
         NSLayoutConstraint.activate(self.rangeViewBottomAnchorConstraints)
     }
 
-    public static func makeViewConfig(for state: CellState, minimumDate: Date?, maximumDate: Date?, rangeValue: FastisRange?) -> ViewConfig {
+    public static func makeViewConfig(
+        for state: CellState,
+        minimumDate: Date?,
+        maximumDate: Date?,
+        rangeValue: FastisRange?,
+        calendar: Calendar
+    ) -> ViewConfig {
 
         var config = ViewConfig()
 
@@ -162,10 +168,10 @@ class DayCell: JTACDayCell {
 
                 if showRangeView {
 
-                    if state.day == .monday {
+                    if state.day.rawValue == calendar.firstWeekday {
                         config.rangeView.leftSideState = .rounded
                         config.rangeView.rightSideState = .squared
-                    } else if state.day == .sunday {
+                    } else if state.day.rawValue == calendar.lastWeekday {
                         config.rangeView.leftSideState = .squared
                         config.rangeView.rightSideState = .rounded
                     } else {
@@ -201,10 +207,10 @@ class DayCell: JTACDayCell {
             case .left, .right, .middle:
                 config.isSelectedViewHidden = position == .middle
 
-                if position == .right && state.day == .monday {
+                if position == .right && state.day.rawValue == calendar.firstWeekday {
                     config.rangeView.leftSideState = .rounded
 
-                } else if position == .left && state.day == .sunday {
+                } else if position == .left && state.day.rawValue == calendar.lastWeekday {
                     config.rangeView.rightSideState = .rounded
 
                 } else if position == .left {
@@ -213,11 +219,11 @@ class DayCell: JTACDayCell {
                 } else if position == .right {
                     config.rangeView.leftSideState = .squared
 
-                } else if state.day == .monday {
+                } else if state.day.rawValue == calendar.firstWeekday {
                     config.rangeView.leftSideState = .rounded
                     config.rangeView.rightSideState = .squared
 
-                } else if state.day == .sunday {
+                } else if state.day.rawValue == calendar.lastWeekday {
                     config.rangeView.leftSideState = .squared
                     config.rangeView.rightSideState = .rounded
 

Sources/Views/WeekView.swift

@@ -26,11 +26,13 @@ class WeekView: UIView {
     // MARK: - Variables
 
     private let config: FastisConfig.WeekView
+    private let calendar: Calendar
 
     // MARK: - Lifecycle
 
-    init(config: FastisConfig.WeekView) {
+    init(calendar: Calendar, config: FastisConfig.WeekView) {
         self.config = config
+        self.calendar = calendar
         super.init(frame: .zero)
         self.configureUI()
         self.configureSubviews()
@@ -50,9 +52,11 @@ class WeekView: UIView {
     }
 
     private func configureSubviews() {
-        var weekDays = self.config.calendar.shortWeekdaySymbols
-        weekDays.append(weekDays.remove(at: 0))
-        for weekdaySymbol in weekDays {
+        let numDays = self.calendar.shortStandaloneWeekdaySymbols.count
+        let first = self.calendar.firstWeekday - 1
+        let end = first + numDays - 1
+        let days = (first...end).map({ self.calendar.shortStandaloneWeekdaySymbols[$0 % numDays] })
+        for weekdaySymbol in days {
             self.stackView.addArrangedSubview(self.makeWeekLabel(for: weekdaySymbol))
         }
         self.addSubview(self.stackView)
@@ -95,6 +99,7 @@ extension FastisConfig {
 
          Default value — `.current`
          */
+        @available(*, unavailable, message: "Use FastisConfig.calendar propery instead")
         public var calendar: Calendar = .current
 
         /**