From 9ec31def92b2557b046bad93748b04f77030b9bd Mon Sep 17 00:00:00 2001
From: Michael Wolz <m.wolz@snapaddy.com>
Date: Thu, 6 Jun 2024 17:10:53 +0200
Subject: [PATCH] fix(ios): use native camera selection for optimal focus

The CameraController now prioritizes `builtInTripleCamera` and similar options to select the best fitting camera. This enhances continuous auto-focus on newer iPhones, especially Pro models.

Closes: capacitor-community/camera-preview#324
Addresses: capacitor-community/camera-preview#256
---
 ios/Plugin/CameraController.swift | 43 +++++++++++++++++--------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/ios/Plugin/CameraController.swift b/ios/Plugin/CameraController.swift
index a09e72a0..795e5e21 100644
--- a/ios/Plugin/CameraController.swift
+++ b/ios/Plugin/CameraController.swift
@@ -45,25 +45,29 @@ extension CameraController {
         }
 
         func configureCaptureDevices() throws {
-
-            let session = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .unspecified)
-
-            let cameras = session.devices.compactMap { $0 }
-            guard !cameras.isEmpty else { throw CameraControllerError.noCamerasAvailable }
-
-            for camera in cameras {
-                if camera.position == .front {
-                    self.frontCamera = camera
-                }
-
-                if camera.position == .back {
-                    self.rearCamera = camera
-
-                    try camera.lockForConfiguration()
-                    camera.focusMode = .continuousAutoFocus
-                    camera.unlockForConfiguration()
-                }
-            }
+            // For the front camera we are simply using the default one. iOS will automatically provide the best fit here
+            self.frontCamera = AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .front)
+            
+            // For the rear camera we'll use a discovery session that will follow the list of "best" cameras to choose from
+            let deviceTypes: [AVCaptureDevice.DeviceType] = [
+                .builtInTripleCamera,
+                .builtInDualWideCamera,
+                .builtInDualCamera,
+                .builtInWideAngleCamera,
+            ]
+    
+            let discoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: deviceTypes, mediaType: AVMediaType.video, position: .back)
+            
+            // We then define the first camera as rear camera. The devices are already sorted based on the provided device types
+            // See: https://developer.apple.com/documentation/avfoundation/capture_setup/choosing_a_capture_device#2958877
+            guard let rearCamera = discoverySession.devices.first else { throw CameraControllerError.noCamerasAvailable }
+    
+            try rearCamera.lockForConfiguration()
+            rearCamera.focusMode = .continuousAutoFocus
+            rearCamera.unlockForConfiguration()
+            
+            self.rearCamera = rearCamera
+            
             if disableAudio == false {
                 self.audioDevice = AVCaptureDevice.default(for: AVMediaType.audio)
             }
@@ -138,7 +142,6 @@ extension CameraController {
                 try configureDeviceInputs()
                 try configurePhotoOutput()
                 try configureDataOutput()
-                // try configureVideoOutput()
             } catch {
                 DispatchQueue.main.async {
                     completionHandler(error)