Allow support for using an image after instantiation (#251)

* Allow support for using an image after instantiation * Make ScannerViewController public so it can be accessed * SwiftLint fixes * Code review feedback Co-authored-by: Erik Villegas <erik.villegas@carvana.com>
WeTransfer · Jul 7, 2020 · 4b94435 · 4b94435
1 parent e7b1755
commit 4b94435
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Showing 2 changed files with 46 additions and 28 deletions.
diff --git a/WeScan/ImageScannerController.swift b/WeScan/ImageScannerController.swift
@@ -76,29 +76,10 @@ public final class ImageScannerController: UINavigationController {
 
         // If an image was passed in by the host app (e.g. picked from the photo library), use it instead of the document scanner.
         if let image = image {
-
-            var detectedQuad: Quadrilateral?
-
-            // Whether or not we detect a quad, present the edit view controller after attempting to detect a quad.
-            // *** Vision *requires* a completion block to detect rectangles, but it's instant.
-            // *** When using Vision, we'll present the normal edit view controller first, then present the updated edit view controller later.
-
-            guard let ciImage = CIImage(image: image) else { return }
-            let orientation = CGImagePropertyOrientation(image.imageOrientation)
-            let orientedImage = ciImage.oriented(forExifOrientation: Int32(orientation.rawValue))
-            if #available(iOS 11.0, *) {
-
-                // Use the VisionRectangleDetector on iOS 11 to attempt to find a rectangle from the initial image.
-                VisionRectangleDetector.rectangle(forImage: ciImage, orientation: orientation) { (quad) in
-                    detectedQuad = quad?.toCartesian(withHeight: orientedImage.extent.height)
-                    let editViewController = EditScanViewController(image: image, quad: detectedQuad, rotateImage: false)
-                    self.setViewControllers([editViewController], animated: true)
-                }
-            } else {
-                // Use the CIRectangleDetector on iOS 10 to attempt to find a rectangle from the initial image.
-                detectedQuad = CIRectangleDetector.rectangle(forImage: ciImage)?.toCartesian(withHeight: orientedImage.extent.height)
+            detect(image: image) { [weak self] detectedQuad in
+                guard let self = self else { return }
                 let editViewController = EditScanViewController(image: image, quad: detectedQuad, rotateImage: false)
-                setViewControllers([editViewController], animated: false)
+                self.setViewControllers([editViewController], animated: false)
             }
         }
     }
@@ -111,6 +92,42 @@ public final class ImageScannerController: UINavigationController {
         fatalError("init(coder:) has not been implemented")
     }
 
+    private func detect(image: UIImage, completion: @escaping (Quadrilateral?) -> Void) {
+        // Whether or not we detect a quad, present the edit view controller after attempting to detect a quad.
+        // *** Vision *requires* a completion block to detect rectangles, but it's instant.
+        // *** When using Vision, we'll present the normal edit view controller first, then present the updated edit view controller later.
+
+        guard let ciImage = CIImage(image: image) else { return }
+        let orientation = CGImagePropertyOrientation(image.imageOrientation)
+        let orientedImage = ciImage.oriented(forExifOrientation: Int32(orientation.rawValue))
+
+        if #available(iOS 11.0, *) {
+            // Use the VisionRectangleDetector on iOS 11 to attempt to find a rectangle from the initial image.
+            VisionRectangleDetector.rectangle(forImage: ciImage, orientation: orientation) { (quad) in
+                let detectedQuad = quad?.toCartesian(withHeight: orientedImage.extent.height)
+                completion(detectedQuad)
+            }
+        } else {
+            // Use the CIRectangleDetector on iOS 10 to attempt to find a rectangle from the initial image.
+            let detectedQuad = CIRectangleDetector.rectangle(forImage: ciImage)?.toCartesian(withHeight: orientedImage.extent.height)
+            completion(detectedQuad)
+        }
+    }
+
+    public func useImage(image: UIImage) {
+        guard topViewController is ScannerViewController else { return }
+
+        detect(image: image) { [weak self] detectedQuad in
+            guard let self = self else { return }
+            let editViewController = EditScanViewController(image: image, quad: detectedQuad, rotateImage: false)
+            self.setViewControllers([editViewController], animated: true)
+        }
+    }
+
+    public func resetScanner() {
+        setViewControllers([ScannerViewController()], animated: true)
+    }
+
     private func setupConstraints() {
         let blackFlashViewConstraints = [
             blackFlashView.topAnchor.constraint(equalTo: view.topAnchor),

diff --git a/WeScan/Scan/ScannerViewController.swift b/WeScan/Scan/ScannerViewController.swift
@@ -10,7 +10,7 @@ import UIKit
 import AVFoundation
 
 /// The `ScannerViewController` offers an interface to give feedback to the user regarding quadrilaterals that are detected. It also gives the user the opportunity to capture an image with a detected rectangle.
-final class ScannerViewController: UIViewController {
+public final class ScannerViewController: UIViewController {
 
     private var captureSessionManager: CaptureSessionManager?
     private let videoPreviewLayer = AVCaptureVideoPreviewLayer()
@@ -67,10 +67,11 @@ final class ScannerViewController: UIViewController {
 
     // MARK: - Life Cycle
 
-    override func viewDidLoad() {
+    override public func viewDidLoad() {
         super.viewDidLoad()
 
         title = nil
+        view.backgroundColor = UIColor.black
 
         setupViews()
         setupNavigationBar()
@@ -83,7 +84,7 @@ final class ScannerViewController: UIViewController {
         NotificationCenter.default.addObserver(self, selector: #selector(subjectAreaDidChange), name: Notification.Name.AVCaptureDeviceSubjectAreaDidChange, object: nil)
     }
 
-    override func viewWillAppear(_ animated: Bool) {
+    override public func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
         setNeedsStatusBarAppearanceUpdate()
 
@@ -95,13 +96,13 @@ final class ScannerViewController: UIViewController {
         navigationController?.navigationBar.barStyle = .blackTranslucent
     }
 
-    override func viewDidLayoutSubviews() {
+    override public func viewDidLayoutSubviews() {
         super.viewDidLayoutSubviews()
 
         videoPreviewLayer.frame = view.layer.bounds
     }
 
-    override func viewWillDisappear(_ animated: Bool) {
+    override public func viewWillDisappear(_ animated: Bool) {
         super.viewWillDisappear(animated)
         UIApplication.shared.isIdleTimerDisabled = false
 
@@ -201,7 +202,7 @@ final class ScannerViewController: UIViewController {
         CaptureSession.current.removeFocusRectangleIfNeeded(focusRectangle, animated: true)
     }
 
-    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
+    override public func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
         super.touchesBegan(touches, with: event)
 
         guard  let touch = touches.first else { return }