Build a Dynamic Face Filter App with Auto Layout and Stack Views
Auto Layout and Stack Views are powerful tools for creating responsive and adaptive interfaces in iOS apps. In this tutorial, we will build a fun Face Filter App where users can apply different face filters (like sunglasses, hats, or mustaches) to their live camera feed. This app will use Auto Layout to adapt to different screen sizes and Stack Views to organize filter selection buttons.
📌 Features of Our Face Filter App
- Uses Auto Layout to position UI elements dynamically.
- Uses Stack Views to arrange filter buttons neatly.
- Displays a live camera feed with filters applied in real-time.
- Allows users to switch filters easily using a horizontal button stack.
1. Setting Up the Xcode Project
- Open Xcode and create a new iOS App project.
- Choose UIKit with Storyboard (since Auto Layout and Stack Views are best demonstrated this way).
- Name the project "FaceFun".
- Enable Camera permissions in
Info.plist
:- Add
NSCameraUsageDescription
with the value:"We need access to your camera for face filters."
- Add
2. Designing the UI with Auto Layout & Stack Views
Step 1: Add the Camera Preview
- Open Main.storyboard.
- Drag a
UIView
onto the View Controller. - Set constraints:
- Top: 20 points from safe area.
- Leading & Trailing: 0 points (full width).
- Height: Equal to the screen width (square).
Step 2: Add the Stack View for Filter Buttons
- Drag a
UIStackView
below the camera preview. - Inside the Stack View, add three UIButtons (e.g., sunglasses, mustache, and hat icons).
- Set Stack View properties:
- Axis: Horizontal
- Alignment: Center
- Distribution: Equal Spacing
- Spacing: 20
- Set constraints:
- Leading & Trailing: 20 points.
- Bottom: 40 points from the safe area.
3. Connecting UI Elements in Code
Open ViewController.swift and connect the UI elements
import UIKit
import AVFoundation
class ViewController: UIViewController {
@IBOutlet weak var cameraView: UIView!
@IBOutlet weak var filterStackView: UIStackView!
var captureSession: AVCaptureSession!
var previewLayer: AVCaptureVideoPreviewLayer!
var filterImageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
setupCamera()
setupFilterImageView()
}
func setupCamera() {
captureSession = AVCaptureSession()
guard let videoCaptureDevice = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front) else { return }
let videoInput = try? AVCaptureDeviceInput(device: videoCaptureDevice)
if captureSession.canAddInput(videoInput!) {
captureSession.addInput(videoInput!)
}
let videoOutput = AVCaptureVideoDataOutput()
if captureSession.canAddOutput(videoOutput) {
captureSession.addOutput(videoOutput)
}
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.videoGravity = .resizeAspectFill
previewLayer.frame = cameraView.bounds
cameraView.layer.addSublayer(previewLayer)
captureSession.startRunning()
}
func setupFilterImageView() {
filterImageView = UIImageView(frame: cameraView.bounds)
filterImageView.contentMode = .scaleAspectFit
cameraView.addSubview(filterImageView)
}
@IBAction func applyFilter(_ sender: UIButton) {
switch sender.tag {
case 0:
filterImageView.image = UIImage(named: "sunglasses")
case 1:
filterImageView.image = UIImage(named: "mustache")
case 2:
filterImageView.image = UIImage(named: "hat")
default:
filterImageView.image = nil
}
}
}
4. Running the App
- Build and run the app on a real iPhone (since the camera doesn’t work in the simulator).
- Tap the buttons to apply fun face filters!
5. Enhancing the UI with Animations
Add a fun bounce animation when switching filters:
func applyFilterAnimation() {
UIView.animate(withDuration: 0.3, animations: {
self.filterImageView.transform = CGAffineTransform(scaleX: 1.2, y: 1.2)
}) { _ in
UIView.animate(withDuration: 0.3) {
self.filterImageView.transform = .identity
}
}
}
@IBAction func applyFilter(_ sender: UIButton) {
applyFilterAnimation()
switch sender.tag {
case 0:
filterImageView.image = UIImage(named: "sunglasses")
case 1:
filterImageView.image = UIImage(named: "mustache")
case 2:
filterImageView.image = UIImage(named: "hat")
default:
filterImageView.image = nil
}
}
Conclusion
🎉 You’ve built a cool and interactive Face Filter App using Auto Layout and Stack Views!
📌 What You Learned:
✅ How to use Auto Layout to position elements dynamically.
✅ How to use Stack Views for organizing buttons neatly.
✅ How to display a live camera feed and overlay images.
✅ How to apply filters with animations.
🚀 Next Steps:
🔹 Add a Snapchat-style face detection using Vision API.
🔹 Implement a save button to capture filtered photos.
🔹 Improve UI with more filters & themes.
Now you have an awesome Face Filter app that’s fun to use and demonstrates key iOS layout techniques! 😎📱