[CM-1189] add intrinsic content size, rename header view

Mark Pospesel · mpospese · commit 1fbb04943d32 · 2023-02-23T14:57:41.000+01:00
diff --git a/Sources/YCalendarPicker/Classes/YCalendarPicker+Appearance.swift b/Sources/YCalendarPicker/Classes/YCalendarPicker+Appearance.swift
@@ -48,10 +48,10 @@ extension YCalendarPicker {
         ///   - selectedDayAppearance: Appearance for selected day. Default is `.Defaults.selected`.
         ///   - disabledDayAppearance: Appearance for disabled day. Default is `.Defaults.disabled`.
         ///   - bookedDayAppearance: Appearance for already booked day. Default is `Defaults.booked`.
-        ///   - weekdayStyle: Typography and text color for weekdays name. Default is `DefaultStyles.weekday`.
+        ///   - weekdayStyle: Typography and text color for weekday names. Default is `DefaultStyles.weekday`.
         ///   - previousImage: Previous button image. Default is `Appearance.defaultPreviousImage`.
         ///   - nextImage: Next button image. Default is `Appearance.defaultNextImage`.
-        ///   - monthStyle: Typography and text color for Month name in header. Default is `DefaultStyles.month`.
+        ///   - monthStyle: Typography and text color for Month name. Default is `DefaultStyles.month`.
         ///   - backgroundColor: Background color for calendar view. Default is `.systemBackground`.
         public init(
             normalDayAppearance: Day = .Defaults.normal,
diff --git a/Sources/YCalendarPicker/Classes/YCalendarPicker.swift b/Sources/YCalendarPicker/Classes/YCalendarPicker.swift
@@ -82,6 +82,37 @@ public class YCalendarPicker: UIControl {
         super.init(coder: coder)
         addCalendarView()
     }
+
+    /// Calculates the intrinsic size of the calendar picker
+    override public var intrinsicContentSize: CGSize {
+        let monthLayout = appearance.monthStyle.typography.generateLayout(
+            maximumScaleFactor: MonthView.maximumScaleFactor,
+            compatibleWith: traitCollection
+        )
+        let weekdayLayout = appearance.weekdayStyle.typography.generateLayout(
+            maximumScaleFactor: WeekdayView.maximumScaleFactor,
+            compatibleWith: traitCollection
+        )
+
+        let daySize = DayView.size.outset(by: NSDirectionalEdgeInsets(all: DayView.padding))
+
+        let width = 7 * daySize.width
+
+        let monthHeight = max(monthLayout.lineHeight, MonthView.minimumButtonSize.height)
+        let weekdayHeight = weekdayLayout.lineHeight + (2 * WeekdayView.verticalPadding)
+        let daysHeight = 6 * daySize.height
+        let height = monthHeight + weekdayHeight + daysHeight
+
+        return CGSize(width: width, height: height)
+    }
+
+    /// Adjusts the intrinsic content size on Dynamic Type changes
+    override public func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
+        super.traitCollectionDidChange(previousTraitCollection)
+        if traitCollection.hasDifferentFontAppearance(comparedTo: previousTraitCollection) {
+            invalidateIntrinsicContentSize()
+        }
+    }
 }
 
 private extension YCalendarPicker {
diff --git a/Sources/YCalendarPicker/Views/DayView.swift b/Sources/YCalendarPicker/Views/DayView.swift
@@ -10,6 +10,13 @@ import SwiftUI
 import YMatterType
 
 struct DayView {
+    /// maximum scale factor of the month-year text label
+    static let maximumScaleFactor: CGFloat = 1.5
+    /// size of each day
+    static let size = CGSize(width: 40, height: 40)
+    /// horizontal and vertical padding around day view circles
+    static let padding: CGFloat = 2
+
     let appearance: YCalendarPicker.Appearance
     let dateItem: CalendarMonthItem
     let locale: Locale
@@ -27,18 +34,18 @@ extension DayView: View {
             TextStyleLabel(dateItem.day, typography: appearance.typography, configuration: { label in
                 label.isUserInteractionEnabled = true
                 label.textAlignment = .center
-                label.maximumScaleFactor = 1.5
+                label.maximumScaleFactor = DayView.maximumScaleFactor
                 label.textColor = appearance.foregroundColor
             })
-            Spacer().frame(minWidth: 40, minHeight: 40)
+            Spacer().frame(minWidth: DayView.size.width, minHeight: DayView.size.height)
         }
         .background(
             Circle()
                 .stroke(Color(appearance.borderColor), lineWidth: appearance.borderWidth)
                 .background(Circle().foregroundColor(Color(appearance.backgroundColor)))
         )
-        .padding(.horizontal, 2.0)
-        .padding(.vertical, 2.0)
+        .padding(.horizontal, DayView.padding)
+        .padding(.vertical, DayView.padding)
         .onTapGesture {
             guard dateItem.isEnabled else { return }
             selectedDate = dateItem.date
diff --git a/Sources/YCalendarPicker/Views/MonthView.swift b/Sources/YCalendarPicker/Views/MonthView.swift
@@ -1,5 +1,5 @@
 //
-//  CalendarHeaderView.swift
+//  MonthView.swift
 //  YCalendarPicker
 //
 //  Created by Sahil Saini on 29/11/22.
@@ -9,11 +9,16 @@
 import SwiftUI
 import YMatterType
 
-/// Calendar header for month and year
-internal struct CalendarHeaderView {
+/// Displays current month and year together with previous and next buttons
+internal struct MonthView {
+    /// maximum scale factor of the month-year text label
+    static let maximumScaleFactor: CGFloat = 1.5
+    /// minimum size for previous and next buttons
+    static let minimumButtonSize = CGSize(width: 44, height: 44)
+
     @Binding var currentDate: Date
     var appearance: YCalendarPicker.Appearance
-    let headerDateFormat: String
+    let dateFormat: String
     let minimumDate: Date?
     let maximumDate: Date?
     let locale: Locale
@@ -38,17 +43,17 @@ internal struct CalendarHeaderView {
     }
 }
 
-extension CalendarHeaderView: View {
+extension MonthView: View {
     var body: some View {
-        getHeader()
+        getMonthView()
     }
     
     @ViewBuilder
-    func getHeader() -> some View {
+    func getMonthView() -> some View {
         HStack {
             TextStyleLabel(getMonthAndYear(), typography: appearance.monthStyle.typography, configuration: { label in
                 label.textColor = appearance.monthStyle.textColor
-                label.maximumScaleFactor = 1.5
+                label.maximumScaleFactor = MonthView.maximumScaleFactor
             })
             
             Spacer()
@@ -61,7 +66,10 @@ extension CalendarHeaderView: View {
                         .foregroundColor(Color(appearance.monthStyle.textColor))
                         .opacity(isPreviousButtonDisabled ? 0.5 : 1.0)
                 })
-                .frame(minWidth: 44, minHeight: 44)
+                .frame(
+                    minWidth: MonthView.minimumButtonSize.width,
+                    minHeight: MonthView.minimumButtonSize.height
+                )
                 .disabled(isPreviousButtonDisabled)
                 .accessibilityLabel(YCalendarPicker.Strings.previousMonthA11yLabel.localized)
                 Button(action: {
@@ -71,7 +79,10 @@ extension CalendarHeaderView: View {
                         .foregroundColor(Color(appearance.monthStyle.textColor))
                         .opacity(isNextButtonDisabled ? 0.5 : 1.0)
                 })
-                .frame(minWidth: 44, minHeight: 44)
+                .frame(
+                    minWidth: MonthView.minimumButtonSize.width,
+                    minHeight: MonthView.minimumButtonSize.height
+                )
                 .disabled(isNextButtonDisabled)
                 .accessibilityLabel(YCalendarPicker.Strings.nextMonthA11yLabel.localized)
             }
@@ -98,16 +109,16 @@ extension CalendarHeaderView: View {
     }
     
     func getMonthAndYear() -> String {
-        currentDate.toString(withTemplate: headerDateFormat, locale: locale) ?? ""
+        currentDate.toString(withTemplate: dateFormat, locale: locale) ?? ""
     }
 }
 
-struct CalendarHeaderView_Previews: PreviewProvider {
+struct MonthView_Previews: PreviewProvider {
     static var previews: some View {
-        CalendarHeaderView(
+        MonthView(
             currentDate: .constant(Date()),
             appearance: .default,
-            headerDateFormat: "MMMMyyyy",
+            dateFormat: "MMMMyyyy",
             minimumDate: nil,
             maximumDate: nil,
             locale: Locale(identifier: "pt_BR")
diff --git a/Sources/YCalendarPicker/Views/WeekdayView.swift b/Sources/YCalendarPicker/Views/WeekdayView.swift
@@ -11,7 +11,12 @@ import YMatterType
 
 /// WeekdayView is the view shown for weekday names at top of days/dates
 internal struct WeekdayView {
-    var firstWeekday = 0
+    /// maximum scale factor of the week day text labels
+    static let maximumScaleFactor: CGFloat = 1.33
+    /// vertical padding around week day text labels
+    static let verticalPadding: CGFloat = 2
+
+    var firstWeekday: Int
     var appearance: YCalendarPicker.Appearance
     let weekdayNames: [String]
     
@@ -42,14 +47,14 @@ extension WeekdayView: View {
                 getWeekText(for: index.modulo(7))
             }
         }
-        .padding(.vertical, 2)
+        .padding(.vertical, WeekdayView.verticalPadding)
     }
     
     @ViewBuilder
     func getWeekText(for index: Int) -> some View {
         TextStyleLabel(weekdayNames[index], typography: appearance.weekdayStyle.typography, configuration: { label in
             label.textAlignment = .center
-            label.maximumScaleFactor = 1.33
+            label.maximumScaleFactor = WeekdayView.maximumScaleFactor
             label.textColor = appearance.weekdayStyle.textColor
         })
     }
diff --git a/Sources/YCalendarPicker/Views/YCalendarView.swift b/Sources/YCalendarPicker/Views/YCalendarView.swift
@@ -105,9 +105,9 @@ extension YCalendarView: View {
     /// :nodoc:
     public var body: some View {
         VStack(spacing: 0) {
-            getHeader()
+            getMonthView()
             getWeekdayView()
-            getDateView()
+            getDaysView()
         }.gesture(
             DragGesture().onEnded({ value in
                 currentDate = getCurrentDateAfterSwipe(swipeValue: value.translation)
@@ -116,21 +116,24 @@ extension YCalendarView: View {
         .background(Color(self.appearance.backgroundColor))
     }
     
-    /// This function creates a header view
-    /// - Returns: A view with month name, next and previous month button
     @ViewBuilder
-    func getHeader() -> some View {
-        CalendarHeaderView(
+    func getMonthView() -> some View {
+        MonthView(
             currentDate: $currentDate,
             appearance: appearance,
-            headerDateFormat: headerDateFormat,
+            dateFormat: headerDateFormat,
             minimumDate: minimumDate,
             maximumDate: maximumDate,
             locale: locale
         )
     }
-    
-    func getDateView() -> some View {
+
+    @ViewBuilder
+    func getWeekdayView() -> some View {
+        WeekdayView(firstWeekday: firstWeekday, appearance: appearance, locale: locale)
+    }
+
+    func getDaysView() -> some View {
         var allDates = currentDate.getAllDatesForSelectedMonth(firstWeekIndex: firstWeekday.modulo(7))
         allDates = allDates.map { dateItem -> CalendarMonthItem in
             var newItem = dateItem
@@ -161,11 +164,6 @@ extension YCalendarView: View {
             monthDidChange(newValue.dateOnly)
         }
     }
-    
-    @ViewBuilder
-    func getWeekdayView() -> some View {
-        WeekdayView(firstWeekday: firstWeekday, appearance: appearance, locale: locale)
-    }
 }
 
 extension YCalendarView {
diff --git a/Tests/YCalendarPickerTests/Classes/YCalendarPickerTests.swift b/Tests/YCalendarPickerTests/Classes/YCalendarPickerTests.swift
@@ -105,6 +105,37 @@ final class YCalendarPickerTests: XCTestCase {
         sut2.calendarView.monthDidChange(date1)
         XCTAssertNotEqual(sut.calendarView.currentDate, date2)
     }
+
+    func testIntrinsicContentSize() {
+        let sut = makeSUT()
+
+        let size = sut.intrinsicContentSize
+        let daySize = DayView.size.outset(by: NSDirectionalEdgeInsets(all: DayView.padding))
+        let monthHeight = MonthView.minimumButtonSize.height
+        let weekdayHeight = sut.appearance.weekdayStyle.typography.lineHeight + 2 * WeekdayView.verticalPadding
+        let daysHeight = 6 * daySize.height
+
+        XCTAssertEqual(size.width, 7 * daySize.width)
+        XCTAssertEqual(size.height, monthHeight + weekdayHeight + daysHeight)
+    }
+
+    func testRespondsToDynamicTypeChanges() {
+        let sut = makeSUT()
+
+        let oldSize = sut.intrinsicContentSize
+
+        // create some nested view controllers so that we can override traits
+        let (parent, child) = makeNestedViewControllers(subview: sut)
+
+        let traits = UITraitCollection(preferredContentSizeCategory: .accessibilityExtraExtraExtraLarge) // really large
+        parent.setOverrideTraitCollection(traits, forChild: child)
+        sut.traitCollectionDidChange(traits)
+        
+        let newSize = sut.intrinsicContentSize
+
+        XCTAssertEqual(newSize.width, oldSize.width)
+        XCTAssertGreaterThan(newSize.height, oldSize.height)
+    }
 }
 
 private extension YCalendarPickerTests {
@@ -116,7 +147,7 @@ private extension YCalendarPickerTests {
         line: UInt = #line
     ) -> YCalendarPicker {
         let sut = YCalendarPicker(minimumDate: minDate, maximumDate: maxDate)
-        trackForMemoryLeaks(sut, file: file, line: line)
+        trackForMemoryLeak(sut, file: file, line: line)
         return sut
     }
     
@@ -130,7 +161,32 @@ private extension YCalendarPickerTests {
             return nil
         }
         guard let coder = try? NSKeyedUnarchiver(forReadingFrom: data) else { return nil }
-        trackForMemoryLeaks(sut, file: file, line: line)
+        trackForMemoryLeak(sut, file: file, line: line)
         return YCalendarPicker(coder: coder)
     }
+
+    /// Create nested view controllers containing the view to be tested so that we can override traits
+    func makeNestedViewControllers(
+        subview: UIView,
+        file: StaticString = #filePath,
+        line: UInt = #line
+    ) -> (parent: UIViewController, child: UIViewController) {
+        let parent = UIViewController()
+        let child = UIViewController()
+        parent.addChild(child)
+        parent.view.addSubview(child.view)
+
+        // constrain child controller view to parent
+        child.view.constrainEdges()
+
+        child.view.addSubview(subview)
+
+        // constrain subview to child view center
+        subview.constrainCenter()
+
+        trackForMemoryLeak(parent, file: file, line: line)
+        trackForMemoryLeak(child, file: file, line: line)
+
+        return (parent, child)
+    }
 }
diff --git a/Tests/YCalendarPickerTests/Test Helpers/XCTestCase+MemoryLeakTracking.swift b/Tests/YCalendarPickerTests/Test Helpers/XCTestCase+MemoryLeakTracking.swift
@@ -9,7 +9,7 @@
 import XCTest
 
 extension XCTestCase {
-    func trackForMemoryLeaks(_ instance: AnyObject, file: StaticString = #filePath, line: UInt = #line) {
+    func trackForMemoryLeak(_ instance: AnyObject, file: StaticString = #filePath, line: UInt = #line) {
         addTeardownBlock { [weak instance] in
             XCTAssertNil(
                 instance,
diff --git a/Tests/YCalendarPickerTests/Views/MonthViewTests.swift b/Tests/YCalendarPickerTests/Views/MonthViewTests.swift
diff --git a/Tests/YCalendarPickerTests/Views/YCalendarViewTests.swift b/Tests/YCalendarPickerTests/Views/YCalendarViewTests.swift
