Add view builder closures for custom views (#268)

CHANGELOG.md

@@ -12,7 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added a `multiDaySelectionDragHandler`, enabling developers to implement multiple-day-selection via a drag gesture (similar to multi-select in the iOS Photos app)
 - Added the ability to change the aspect ratio of individual day-of-the-week items
 - Added support for self-sizing month headers
-- Added a new `setContent(_:animated:)` function, allowing people to perform animated content updates
+- Added a new `setContent(_:animated:)` function, enabling developers to perform animated content updates
 
 ### Fixed
 - Fixed an issue that could cause the calendar to programmatically scroll to a month or day to which it had previously scrolled

Example/HorizonCalendarExample/HorizonCalendarExample/Demo View Controllers/SwiftUIScreenDemoViewController.swift

@@ -96,32 +96,24 @@ struct SwiftUIScreenDemo: View {
     .verticalDayMargin(8)
     .horizontalDayMargin(8)
 
-    .monthHeaderItemProvider { month in
+    .monthHeaders { month in
       let monthHeaderText = monthDateFormatter.string(from: calendar.date(from: month.components)!)
       if case .vertical = monthsLayout {
-        return HStack {
+        HStack {
           Text(monthHeaderText)
             .font(.title2)
           Spacer()
         }
         .padding()
-        .calendarItemModel
       } else {
-        return Text(monthHeaderText)
+        Text(monthHeaderText)
           .font(.title2)
           .padding()
-          .calendarItemModel
       }
     }
 
-    .dayItemProvider { day in
-      let isSelected: Bool
-      if let selectedDayRange {
-        isSelected = day == selectedDayRange.lowerBound || day == selectedDayRange.upperBound
-      } else {
-        isSelected = false
-      }
-      return SwiftUIDayView(dayNumber: day.day, isSelected: isSelected).calendarItemModel
+    .days { day in
+      SwiftUIDayView(dayNumber: day.day, isSelected: isDaySelected(day))
     }
 
     .dayRangeItemProvider(for: selectedDateRanges) { dayRangeLayoutContext in
@@ -172,7 +164,6 @@ struct SwiftUIScreenDemo: View {
     }
 
     .frame(maxWidth: 375, maxHeight: .infinity)
-
   }
 
   // MARK: Private
@@ -195,6 +186,14 @@ struct SwiftUIScreenDemo: View {
     return [selectedStartDate...selectedEndDate]
   }
 
+  private func isDaySelected(_ day: Day) -> Bool {
+    if let selectedDayRange {
+      return day == selectedDayRange.lowerBound || day == selectedDayRange.upperBound
+    } else {
+      return false
+    }
+  }
+
 }
 
 // MARK: - SwiftUIScreenDemo_Previews