Creating a Custom Calendar for iPhone and iPad

Introduction

In this article, we will explore how to create a custom calendar for both iPhone and iPad. We will cover the basics of creating a calendar app, as well as add some advanced features such as displaying images on calendar tiles.

Prerequisites

Before we begin, make sure you have a good understanding of iOS development with Swift or Objective-C. This article will focus on using Swift, but many concepts can be applied to Objective-C as well.

Setting Up the Project

To create our custom calendar app, we need to set up a new project in Xcode. Create a new Single View App project and give it a name, such as “CustomCalendar”.

Step 1: Choose Your Calendar Type

There are several types of calendars that can be used for iPhone and iPad apps. The most common ones are:

Gregorian calendar: This is the most widely used calendar in the world and is commonly used by most devices.
Islamic calendar: This calendar is used to determine Islamic holidays and events.
Hebrew calendar: This calendar is used to determine Jewish holidays and events.

For this example, we will use the Gregorian calendar.

Creating the Calendar View

To create our custom calendar view, we need to add a UITableView to our app’s main view. We will also add some UI components to display dates and images.

Step 1: Create the Table View Controller

Open your ViewController.swift file and replace its content with the following code:

import UIKit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    // MARK: - Properties
    
    let calendarData = [
        Date(), Date(), Date(),
        Date(), Date(), Date(),
        Date(), Date(), Date()
    ]

    var tableView: UITableView!
    var calendarView: CalendarView!

    override func viewDidLoad() {
        super.viewDidLoad()

        setupTableView()
        setupCalendarView()
    }

    // MARK: - Setup Table View
    
    func setupTableView() {
        tableView = UITableView(frame: .zero, style: .plain)
        view.addSubview(tableView)

        tableView.dataSource = self
        tableView.delegate = self

        NSLayoutConstraint.activate([
            tableView.topAnchor.constraint(equalTo: view.topAnchor),
            tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            tableView.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])
    }

    // MARK: - Setup Calendar View
    
    func setupCalendarView() {
        calendarView = CalendarView(frame: .zero, style: .plain)

        view.addSubview(calendarView)

        NSLayoutConstraint.activate([
            calendarView.topAnchor.constraint(equalTo: view.topAnchor),
            calendarView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            calendarView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            calendarView.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])
    }
}

Step 2: Create the Calendar View

Create a new CalendarView.swift file and add the following code:

import UIKit

class CalendarView: UIView {

    let cellWidth: CGFloat = 100
    let cellHeight: CGFloat = 100
    var calendarData = [Date]()
    var calendarImages = [UIImage]()

    override init(frame: CGRect) {
        super.init(frame: frame)

        setupCalendar()
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // MARK: - Setup Calendar
    
    func setupCalendar() {
        for i in 0...2 {
            let date = Date()
            calendarData.append(date)
            let image = UIImage(named: "image\(i)")
            if image == nil {
                continue
            }
            calendarImages.append(image!)
        }

        self.backgroundColor = .white

        let layout = UICollectionViewFlowLayout()

        let collectionView = UICollectionView(frame: .zero, layout: layout)
        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cell")
        collectionView.isPagingEnabled = true

        NSLayoutConstraint.activate([
            collectionView.topAnchor.constraint(equalTo: superview!.topAnchor),
            collectionView.leadingAnchor.constraint(equalTo: superview!.leadingAnchor),
            collectionView.bottomAnchor.constraint(equalTo: superview!.bottomAnchor),
            collectionView.trailingAnchor.constraint(equalTo: superview!.trailingAnchor)
        ])

        collectionView.delegate = self
        collectionView.dataSource = self

        addSubview(collectionView)
    }
}

Step 3: Implement Data Source and Delegate Methods

Open your CalendarView.swift file and add the following code:

extension CalendarView: UICollectionViewDataSource, UICollectionViewDelegate {

    func numberOfItemsInCollectionView(_ collectionView: UICollectionView) -> Int {
        return calendarData.count
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 1
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)

        if calendarData[indexPath.item] == Date() {
            cell.backgroundColor = .blue
        } else {
            cell.backgroundColor = .white
        }

        return cell
    }
}

Adding Images to Calendar Tiles

To add images to our calendar tiles, we need to use the UIImage class. We can create a new image and add it to our calendar view by setting its image property.

Step 1: Create an Image

Open your project’s assets folder and create a new image named “image0.png”. This will be used as our first calendar tile image.

Step 2: Set the Image in the Calendar View

Replace the following code in your CalendarView.swift file with the following:

// MARK: - Setup Calendar
    
func setupCalendar() {
    // ...

    for i in 0...2 {
        let date = Date()
        calendarData.append(date)
        let image = UIImage(named: "image\(i)")
        if image == nil {
            continue
        }
        calendarImages.append(image!)

        // Set the image in the calendar view
        var cell = collectionView?.cellAtPosition(indexPath.item, for: indexPath) as? UICollectionViewCell
        cell?.layer.backgroundColor = .white
        cell?.layer.cornerRadius = 10
        cell?.layer.shadowColor = UIColor.black.cgColor
        cell?.layer.shadowOpacity = 0.5
        cell?.layer.shadowRadius = 3
    }

    // ...
}

Conclusion

In this article, we have learned how to create a custom calendar for iPhone and iPad using Swift. We covered the basics of creating a calendar app, as well as add some advanced features such as displaying images on calendar tiles.

Remember to replace the image names with your own image names and adjust the code according to your needs.

Next Steps

In the next article, we will cover more advanced topics in iOS development, including animations and gestures. Stay tuned!

Last modified on 2023-07-08