Date picker

.github/workflows/build-test-and-docs.yml

@@ -52,7 +52,8 @@ jobs:
         swift build --target SpreadsheetExample && \
         swift build --target NotesExample && \
         swift build --target GtkExample && \
-        swift build --target PathsExample
+        swift build --target PathsExample && \
+        swift build --target DatePickerExample
 
     - name: Test
       run: swift test --test-product swift-cross-uiPackageTests
@@ -106,9 +107,10 @@ jobs:
             buildtarget PathsExample
 
             if [ $device_type != TV ]; then
-              # Slider is not implemented for tvOS
+              # Slider and DatePicker are not implemented for tvOS
               buildtarget ControlsExample
               buildtarget RandomNumberGeneratorExample
+              buildtarget DatePickerExample
             fi
 
             if [ $device_type = iPad ]; then
@@ -165,6 +167,7 @@ jobs:
         buildtarget PathsExample
         buildtarget ControlsExample
         buildtarget RandomNumberGeneratorExample
+        buildtarget DatePickerExample
         # TODO test whether this works on Catalyst
         # buildtarget SplitExample
 
@@ -295,7 +298,8 @@ jobs:
         swift build --target StressTestExample && \
         swift build --target SpreadsheetExample && \
         swift build --target NotesExample && \
-        swift build --target GtkExample
+        swift build --target GtkExample && \
+        swift build --target DatePickerExample
 
     - name: Test
       run: swift test --test-product swift-cross-uiPackageTests

Examples/Bundler.toml

@@ -64,3 +64,8 @@ version = '0.1.0'
 identifier = 'dev.swiftcrossui.HoverExample'
 product = 'HoverExample'
 version = '0.1.0'
+
+[apps.DatePickerExample]
+identifier = 'dev.swiftcrossui.DatePickerExample'
+product = 'DatePickerExample'
+version = '0.1.0'

Examples/Package.swift

@@ -76,6 +76,10 @@ let package = Package(
         .executableTarget(
             name: "HoverExample",
             dependencies: exampleDependencies
+        ),
+        .executableTarget(
+            name: "DatePickerExample",
+            dependencies: exampleDependencies
         )
     ]
 )

Examples/Sources/DatePickerExample/DatePickerApp.swift

@@ -0,0 +1,53 @@
+import DefaultBackend
+import Foundation
+import SwiftCrossUI
+
+#if canImport(SwiftBundlerRuntime)
+    import SwiftBundlerRuntime
+#endif
+
+@main
+@HotReloadable
+struct DatePickerApp: App {
+    @State var date = Date()
+    @State var style: DatePickerStyle? = .automatic
+
+    var allStyles: [DatePickerStyle]
+
+    init() {
+        allStyles = [.automatic]
+
+        if #available(iOS 14, macCatalyst 14, *) {
+            allStyles.append(.graphical)
+        }
+
+        #if !canImport(GtkBackend)
+            if #available(iOS 13.4, macCatalyst 13.4, *) {
+                allStyles.append(.compact)
+                #if os(iOS) || os(visionOS) || canImport(WinUIBackend)
+                    allStyles.append(.wheel)
+                #endif
+            }
+        #endif
+    }
+
+    var body: some Scene {
+        WindowGroup("Date Picker") {
+            VStack {
+                Text("Selected date: \(date)")
+
+                Picker(of: allStyles, selection: $style)
+
+                DatePicker(
+                    "Test Picker",
+                    selection: $date
+                )
+                .datePickerStyle(style ?? .automatic)
+
+                Button("Reset date") {
+                    date = Date()
+                }
+            }
+        }
+    }
+}

Package.swift

@@ -100,15 +100,15 @@ let package = Package(
         ),
         .package(
             url: "https://github.com/stackotter/swift-windowsappsdk",
-            revision: "ba6f0ec377b70d8be835d253102ff665a0e47d99"
+            revision: "f1c50892f10c0f7f635d3c7a3d728fd634ad001a"
         ),
         .package(
             url: "https://github.com/stackotter/swift-windowsfoundation",
             revision: "4ad57d20553514bcb23724bdae9121569b19f172"
         ),
         .package(
             url: "https://github.com/stackotter/swift-winui",
-            revision: "1695ee3ea2b7a249f6504c7f1759e7ec7a38eb86"
+            revision: "42c47f4e4129c8b5a5d9912f05e1168c924ac180"
         ),
         // .package(
         //     url: "https://github.com/stackotter/TermKit",

Sources/AppKitBackend/AppKitBackend.swift

@@ -349,6 +349,14 @@ public final class AppKitBackend: AppBackend {
             // Self.scrollBarWidth has changed
             action()
         }
+
+        NotificationCenter.default.addObserver(
+            forName: .NSSystemTimeZoneDidChange,
+            object: nil,
+            queue: .main
+        ) { _ in
+            action()
+        }
     }
 
     public func computeWindowEnvironment(
@@ -1689,6 +1697,80 @@ public final class AppKitBackend: AppBackend {
         let request = URLRequest(url: url)
         webView.load(request)
     }
+
+    public func createDatePicker() -> NSView {
+        let datePicker = CustomDatePicker()
+        datePicker.delegate = datePicker.strongDelegate
+        return datePicker
+    }
+
+    // Depending on the calendar, era is either necessary or must be omitted. Making the wrong
+    // choice for the current calendar means the cursor position is reset after every keystroke. I
+    // know of no simple way to tell whether NSDatePicker requires or forbids eras for a given
+    // calendar, so in lieu of that I have hardcoded the calendar identifiers.
+    private let calendarsWithEras: Set<Calendar.Identifier> = [
+        .buddhist, .coptic, .ethiopicAmeteAlem, .ethiopicAmeteMihret, .indian, .islamic,
+        .islamicCivil, .islamicTabular, .islamicUmmAlQura, .japanese, .persian, .republicOfChina,
+    ]
+
+    public func updateDatePicker(
+        _ datePicker: NSView,
+        environment: EnvironmentValues,
+        date: Date,
+        range: ClosedRange<Date>,
+        components: DatePickerComponents,
+        onChange: @escaping (Date) -> Void
+    ) {
+        let datePicker = datePicker as! CustomDatePicker
+
+        datePicker.isEnabled = environment.isEnabled
+        datePicker.textColor = environment.suggestedForegroundColor.nsColor
+
+        // If the time zone is set to autoupdatingCurrent, then the cursor position is reset after
+        // every keystroke. Thanks Apple
+        datePicker.timeZone =
+            environment.timeZone == .autoupdatingCurrent ? .current : environment.timeZone
+
+        // A couple properties cause infinite update loops if we assign to them on every update, so
+        // check their values first.
+        if datePicker.calendar != environment.calendar {
+            datePicker.calendar = environment.calendar
+        }
+
+        if datePicker.dateValue != date {
+            datePicker.dateValue = date
+        }
+
+        var elementFlags: NSDatePicker.ElementFlags = []
+        if components.contains(.date) {
+            elementFlags.insert(.yearMonthDay)
+            if calendarsWithEras.contains(environment.calendar.identifier) {
+                elementFlags.insert(.era)
+            }
+        }
+        if components.contains(.hourMinuteAndSecond) {
+            elementFlags.insert(.hourMinuteSecond)
+        } else {
+            elementFlags.insert(.hourMinute)
+        }
+
+        if datePicker.datePickerElements != elementFlags {
+            datePicker.datePickerElements = elementFlags
+        }
+
+        datePicker.strongDelegate.onChange = onChange
+
+        datePicker.minDate = range.lowerBound
+        datePicker.maxDate = range.upperBound
+
+        datePicker.datePickerStyle =
+            switch environment.datePickerStyle {
+                case .automatic, .compact:
+                    .textFieldAndStepper
+                case .graphical:
+                    .clockAndCalendar
+            }
+    }
 }
 
 final class NSCustomTapGestureTarget: NSView {
@@ -2191,3 +2273,19 @@ final class CustomWKNavigationDelegate: NSObject, WKNavigationDelegate {
         onNavigate?(url)
     }
 }
+
+final class CustomDatePicker: NSDatePicker {
+    var strongDelegate = CustomDatePickerDelegate()
+}
+
+final class CustomDatePickerDelegate: NSObject, NSDatePickerCellDelegate {
+    var onChange: ((Date) -> Void)?
+
+    func datePickerCell(
+        _: NSDatePickerCell,
+        validateProposedDateValue proposedDateValue: AutoreleasingUnsafeMutablePointer<NSDate>,
+        timeInterval _: UnsafeMutablePointer<TimeInterval>?
+    ) {
+        onChange?(proposedDateValue.pointee as Date)
+    }
+}