Take photo after autofocusing automatically AVCapture - ios

Question

I want to do this: When the camera is focused, the app will take picture automatically. But I found there's no way to detect if the camera is focused.
i'm using AVFoundation for taking the picture
i'm new to iOS don't know how to code it
can anyone help me for this issue

Answer 1

import UIKit
import AVFoundation
class ViewController: UIViewController {
let captureSession = AVCaptureSession()
let stillImageOutput = AVCaptureStillImageOutput()
var error: NSError?
override func viewDidLoad() {
super.viewDidLoad()
let devices = AVCaptureDevice.devices().filter{ $0.hasMediaType(AVMediaTypeVideo) && $0.position == AVCaptureDevicePosition.Back }
if let captureDevice = devices.first as? AVCaptureDevice {
captureSession.addInput(AVCaptureDeviceInput(device: captureDevice, error: &error))
captureSession.sessionPreset = AVCaptureSessionPresetPhoto
captureSession.startRunning()
stillImageOutput.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG]
if captureSession.canAddOutput(stillImageOutput) {
captureSession.addOutput(stillImageOutput)
}
if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {
previewLayer.bounds = view.bounds
previewLayer.position = CGPointMake(view.bounds.midX, view.bounds.midY)
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
let cameraPreview = UIView(frame: CGRectMake(0.0, 0.0, view.bounds.size.width, view.bounds.size.height))
cameraPreview.layer.addSublayer(previewLayer)
cameraPreview.addGestureRecognizer(UITapGestureRecognizer(target: self, action:"saveToCamera:"))
//get instance of phone camera
let captureDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
//try to enable auto focus
if(captureDevice!.isFocusModeSupported(.continuousAutoFocus)) {
try! captureDevice!.lockForConfiguration()
captureDevice!.focusMode = .continuousAutoFocus
captureDevice!.unlockForConfiguration()
view.addSubview(cameraPreview)
}
}
}
}
func saveToCamera(sender: UITapGestureRecognizer) {
if let videoConnection = stillImageOutput.connectionWithMediaType(AVMediaTypeVideo) {
stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection) {
(imageDataSampleBuffer, error) -> Void in
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)
UIImageWriteToSavedPhotosAlbum(UIImage(data: imageData), nil, nil, nil)
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}