struct EventCellView: CellableView {
    typealias VM = ViewModel

    // MARK: ViewModel
    struct ViewModel: ICEventable { ... }


    // MARK: View
    var viewModel: ViewModel
    
    init(_ viewModel: ViewModel) {
        self.viewModel = viewModel
    }
    
    var body: some View {
        ...
    }
}

struct ViewModel: ICEventable { 
    private(set) var id: String = UUID().uuidString
    var text: String

    var startDate: Date
    var endDate: Date?
    var intraStartDate: Date
    var intraEndDate: Date
    var editState: EditState?
    var isAllDay: Bool
    
    
    init(text: String, start: Date, end: Date?, isAllDay: Bool = false, editState: EditState? = nil) {
        ...
    }
    
    // ! Make sure copy current object, otherwise view won't display properly when SwiftUI View is updated.
    func copy() -> EventCellView.ViewModel {
        var copy = ViewModel(text: text, start: startDate, end: endDate, isAllDay: isAllDay, editState: editState)
        ...
        return copy
    }
    
    static func create(from eventable: EventCellView.ViewModel?, state: EditState?) -> EventCellView.ViewModel {
        if var model = eventable?.copy() {
            model.editState = state
            return model
        }
        return ViewModel(text: "New", start: Date(), end: nil, editState: state)
    }
}

final class EventCell: ViewHostingCell<EventCellView> {
    override init(frame: CGRect) {
        super.init(frame: frame)
    }
}

struct ContentView: View {
    @State var events: [EventCellView.VM] = []
    @State var didTapToday: Bool = false
    @ObservedObject var settings: ICViewSettings = ICViewSettings(
        numOfDays: 3, 
        initDate: Date(), 
        scrollType: .sectionScroll, 
        moveTimeMinInterval: 15, 
        timeRange: (1, 23), 
        withVibration: true
    )

    var body: some View {
        InfiniteCalendar<EventCellView, EventCell, ICViewSettings>(events: $events, settings: settings, didTapToday: $didTapToday)
    }
}

InfiniteCalendar<EventCellView, EventCell, Settings>(events: $events, settings: settings, didTapToday: $didTapToday)
.onCurrentDateChanged { date in
    currentDate = date
}

InfiniteCalendar<EventCellView, EventCell, Settings>(events: $events, settings: settings, didTapToday: $didTapToday)
.onItemSelected { item in
    selectedItem = item
}

InfiniteCalendar<EventCellView, EventCell, Settings>(events: $events, settings: settings, didTapToday: $didTapToday)
.onEventAdded { item in
    events.append(item)
}

InfiniteCalendar<EventCellView, EventCell, Settings>(events: $events, settings: settings, didTapToday: $didTapToday)
.onEventMoved { item in
    if let index = events.firstIndex(where: {$0.id == item.id}) {
        events[index] = item
    }
}

InfiniteCalendar<EventCellView, EventCell, Settings>(events: $events, settings: settings, didTapToday: $didTapToday)
.onEventCanceled { item in
    print("Canceled some event gesture for \(item.id).")
}

//* When you customize, set two of classes to custom class you created.
// TimeHeader 
associatedtype TimeHeaderView: ICTimeHeaderView
associatedtype TimeHeader: ICTimeHeader<TimeHeaderView>

// DateHeader
associatedtype DateHeaderView: ICDateHeaderView
associatedtype DateHeader: ICDateHeader<DateHeaderView>

// DateHeaderCorner
associatedtype DateCornerView: ICDateCornerView
associatedtype DateCorner: ICDateCorner<DateCornerView>

// AllDayHeader
associatedtype AllDayHeaderView: ICAllDayHeaderView
associatedtype AllDayHeader: ICAllDayHeader<AllDayHeaderView>

// AllDayHeaderCorner
associatedtype AllDayCornerView: ICAllDayCornerView
associatedtype AllDayCorner: ICAllDayCorner<AllDayCornerView>

// Timeline
associatedtype TimelineView: ICTimelineView
associatedtype Timeline: ICTimeline<TimelineView>

// TimeHeaderBackground
associatedtype TimeHeaderBackgroundView: ICTimeHeaderBackgroundView
associatedtype TimeHeaderBackground: ICTimeHeaderBackground<TimeHeaderBackgroundView>

// DateHeaderBackground
associatedtype DateHeaderBackgroundView: ICDateHeaderBackgroundView
associatedtype DateHeaderBackground: ICDateHeaderBackground<DateHeaderBackgroundView>

// AllDayHeaderBackground
associatedtype AllDayHeaderBackgroundView: ICAllDayHeaderBackgroundView
associatedtype AllDayHeaderBackground: ICAllDayHeaderBackground<AllDayHeaderBackgroundView>

// DateHeader should be inherited `ICDateHeader`.
class CustomDateHeader: ICDateHeader<CustomDateHeaderView> {}

// CustomView should be inherited `ICDateHeaderView`.
struct CustomDateHeaderView: ICDateHeaderView {
    public typealias Item = ICDateHeaderItem

    var item: Item
    
    public init(_ item: Item) {
        self.item = item
    }
    
    public var body: some View {
        ...
    }
}

class CustomSettings: ICSettings {
    @Published public var numOfDays: Int = 1
    @Published public var initDate: Date = Date()
    @Published public var scrollType: ScrollType = .pageScroll
    @Published public var moveTimeMinInterval: Int = 15
    @Published public var timeRange: (startTime: Int, endTime: Int) = (1, 23)
    @Published public var withVibrateFeedback: Bool = true
    
    required public init() {}
    
    ...
}

class CustomSettings: ICSettings {
    typealias DateHeaderView = CustomDateHeaderView
    typealias DateHeader = CustomDateHeader
    ...
}

...

@State var events: [EventCellView.VM] = SampleData().events
@State var didTapToday: Bool = false
@ObservedObject var settings: CustomSettings = CustomSettings()

var body: some View {
    InfiniteCalendar<EventCellView, EventCell, CustomSettings>(events: $events, settings: settings, didTapToday: $didTapToday)
}

...