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@Krishna
Forked from mecid/Calendar.swift
Created July 2, 2020 23:50
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Calendar view in SwiftUI
import SwiftUI
fileprivate extension DateFormatter {
static var month: DateFormatter {
let formatter = DateFormatter()
formatter.dateFormat = "MMMM"
return formatter
}
static var monthAndYear: DateFormatter {
let formatter = DateFormatter()
formatter.dateFormat = "MMMM yyyy"
return formatter
}
}
fileprivate extension Calendar {
func generateDates(
inside interval: DateInterval,
matching components: DateComponents
) -> [Date] {
var dates: [Date] = []
dates.append(interval.start)
enumerateDates(
startingAfter: interval.start,
matching: components,
matchingPolicy: .nextTime
) { date, _, stop in
if let date = date {
if date < interval.end {
dates.append(date)
} else {
stop = true
}
}
}
return dates
}
}
struct WeekView<DateView>: View where DateView: View {
@Environment(\.calendar) var calendar
let week: Date
let content: (Date) -> DateView
init(week: Date, @ViewBuilder content: @escaping (Date) -> DateView) {
self.week = week
self.content = content
}
private var days: [Date] {
guard
let weekInterval = calendar.dateInterval(of: .weekOfYear, for: week)
else { return [] }
return calendar.generateDates(
inside: weekInterval,
matching: DateComponents(hour: 0, minute: 0, second: 0)
)
}
var body: some View {
HStack {
ForEach(days, id: \.self) { date in
HStack {
if self.calendar.isDate(self.week, equalTo: date, toGranularity: .month) {
self.content(date)
} else {
self.content(date).hidden()
}
}
}
}
}
}
struct MonthView<DateView>: View where DateView: View {
@Environment(\.calendar) var calendar
let month: Date
let showHeader: Bool
let content: (Date) -> DateView
init(
month: Date,
showHeader: Bool = true,
@ViewBuilder content: @escaping (Date) -> DateView
) {
self.month = month
self.content = content
self.showHeader = showHeader
}
private var weeks: [Date] {
guard
let monthInterval = calendar.dateInterval(of: .month, for: month)
else { return [] }
return calendar.generateDates(
inside: monthInterval,
matching: DateComponents(hour: 0, minute: 0, second: 0, weekday: calendar.firstWeekday)
)
}
private var header: some View {
let component = calendar.component(.month, from: month)
let formatter = component == 1 ? DateFormatter.monthAndYear : .month
return Text(formatter.string(from: month))
.font(.title)
.padding()
}
var body: some View {
VStack {
if showHeader {
header
}
ForEach(weeks, id: \.self) { week in
WeekView(week: week, content: self.content)
}
}
}
}
struct CalendarView<DateView>: View where DateView: View {
@Environment(\.calendar) var calendar
let interval: DateInterval
let content: (Date) -> DateView
init(interval: DateInterval, @ViewBuilder content: @escaping (Date) -> DateView) {
self.interval = interval
self.content = content
}
private var months: [Date] {
calendar.generateDates(
inside: interval,
matching: DateComponents(day: 1, hour: 0, minute: 0, second: 0)
)
}
var body: some View {
ScrollView(.vertical, showsIndicators: false) {
VStack {
ForEach(months, id: \.self) { month in
MonthView(month: month, content: self.content)
}
}
}
}
}
struct RootView: View {
@Environment(\.calendar) var calendar
private var year: DateInterval {
calendar.dateInterval(of: .year, for: Date())!
}
var body: some View {
CalendarView(interval: year) { date in
Text("30")
.hidden()
.padding(8)
.background(Color.blue)
.clipShape(Circle())
.padding(.vertical, 4)
.overlay(
Text(String(self.calendar.component(.day, from: date)))
)
}
}
}
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