Merge pull request #91 from hyperoslo/feature/camera-position

Feature: camera position button

BarcodeScanner.xcodeproj/project.pbxproj

@@ -12,6 +12,7 @@
 		D50BE3E91C9FE7A80000A34C /* [email protected] in Resources */ = {isa = PBXBuildFile; fileRef = D50BE3E51C9FE7A80000A34C /* [email protected] */; };
 		D50BE3EA1C9FE7A80000A34C /* [email protected] in Resources */ = {isa = PBXBuildFile; fileRef = D50BE3E61C9FE7A80000A34C /* [email protected] */; };
 		D50BE3EB1C9FE7A80000A34C /* [email protected] in Resources */ = {isa = PBXBuildFile; fileRef = D50BE3E71C9FE7A80000A34C /* [email protected] */; };
+		D5349DF8201E42D900CD53EA /* [email protected] in Resources */ = {isa = PBXBuildFile; fileRef = D5349DF7201E42D900CD53EA /* [email protected] */; };
 		D55281B62016758F00FF3CDD /* HeaderViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D55281B52016758F00FF3CDD /* HeaderViewController.swift */; };
 		D55281B8201675D500FF3CDD /* MessageViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D55281B7201675D500FF3CDD /* MessageViewController.swift */; };
 		D55281BA2016770800FF3CDD /* CameraViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D55281B92016770800FF3CDD /* CameraViewController.swift */; };
@@ -31,6 +32,7 @@
 		D50BE3E51C9FE7A80000A34C /* [email protected] */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "[email protected]"; sourceTree = "<group>"; };
 		D50BE3E61C9FE7A80000A34C /* [email protected] */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "[email protected]"; sourceTree = "<group>"; };
 		D50BE3E71C9FE7A80000A34C /* [email protected] */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "[email protected]"; sourceTree = "<group>"; };
+		D5349DF7201E42D900CD53EA /* [email protected] */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "[email protected]"; sourceTree = "<group>"; };
 		D55281B52016758F00FF3CDD /* HeaderViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HeaderViewController.swift; sourceTree = "<group>"; };
 		D55281B7201675D500FF3CDD /* MessageViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MessageViewController.swift; sourceTree = "<group>"; };
 		D55281B92016770800FF3CDD /* CameraViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CameraViewController.swift; sourceTree = "<group>"; };
@@ -60,6 +62,7 @@
 		D50BE3E31C9FE7A80000A34C /* Images */ = {
 			isa = PBXGroup;
 			children = (
+				D5349DF7201E42D900CD53EA /* [email protected] */,
 				D50BE3E51C9FE7A80000A34C /* [email protected] */,
 				D50BE3E61C9FE7A80000A34C /* [email protected] */,
 				D50BE3E71C9FE7A80000A34C /* [email protected] */,
@@ -215,6 +218,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				D50BE3E91C9FE7A80000A34C /* [email protected] in Resources */,
+				D5349DF8201E42D900CD53EA /* [email protected] in Resources */,
 				D50BE3EB1C9FE7A80000A34C /* [email protected] in Resources */,
 				D50BE3EA1C9FE7A80000A34C /* [email protected] in Resources */,
 			);

README.md

@@ -181,12 +181,16 @@ viewController.messageViewController.textLabel.textColor = .black
 **Camera**
 ```swift
 let viewController = BarcodeScannerViewController()
-viewController.barCodeFocusViewType = .animated
+// Change focus view style
+viewController.cameraViewController.barCodeFocusViewType = .animated
+// Show camera position button
+viewController.cameraViewController.showsCameraButton = true
+// Set settings button text
 let title = NSAttributedString(
   string: "Settings",
   attributes: [.font: UIFont.boldSystemFont(ofSize: 17), .foregroundColor : UIColor.white]
 )
-viewController.settingButton.setAttributedTitle(title, for: UIControlState())
+viewController.cameraViewController.settingButton.setAttributedTitle(title, for: UIControlState())
 ```
 
 **Metadata**

Sources/Controllers/BarcodeScannerViewController.swift

@@ -5,7 +5,11 @@ import AVFoundation
 
 /// Delegate to handle the captured code.
 public protocol BarcodeScannerCodeDelegate: class {
-  func scanner(_ controller: BarcodeScannerViewController, didCaptureCode code: String, type: String)
+  func scanner(
+    _ controller: BarcodeScannerViewController,
+    didCaptureCode code: String,
+    type: String
+  )
 }
 
 /// Delegate to report errors.
@@ -28,6 +32,7 @@ public protocol BarcodeScannerDismissalDelegate: class {
  - Not found error message
  */
 open class BarcodeScannerViewController: UIViewController {
+  private static let footerHeight: CGFloat = 75
 
   // MARK: - Public properties
 
@@ -66,9 +71,9 @@ open class BarcodeScannerViewController: UIViewController {
   public private(set) lazy var cameraViewController: CameraViewController = .init()
 
   // Constraints that are activated when the view is used as a footer.
-  private lazy var collapsedConstraints: [NSLayoutConstraint] = self.makeCollapsedMessageConstraints()
+  private lazy var collapsedConstraints: [NSLayoutConstraint] = self.makeCollapsedConstraints()
   // Constraints that are activated when the view is used for loading animation and error messages.
-  private lazy var expandedConstraints: [NSLayoutConstraint] = self.makeExpandedMessageConstraints()
+  private lazy var expandedConstraints: [NSLayoutConstraint] = self.makeExpandedConstraints()
 
   private var messageView: UIView {
     return messageViewController.view
@@ -220,7 +225,10 @@ private extension BarcodeScannerViewController {
     NSLayoutConstraint.activate(
       cameraView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
       cameraView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
-      cameraView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
+      cameraView.bottomAnchor.constraint(
+        equalTo: view.bottomAnchor,
+        constant: -BarcodeScannerViewController.footerHeight
+      )
     )
 
     if navigationController != nil {
@@ -241,7 +249,7 @@ private extension BarcodeScannerViewController {
     }
   }
 
-  private func makeExpandedMessageConstraints() -> [NSLayoutConstraint] {
+  private func makeExpandedConstraints() -> [NSLayoutConstraint] {
     return [
       messageView.topAnchor.constraint(equalTo: view.topAnchor),
       messageView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
@@ -250,12 +258,14 @@ private extension BarcodeScannerViewController {
     ]
   }
 
-  private func makeCollapsedMessageConstraints() -> [NSLayoutConstraint] {
+  private func makeCollapsedConstraints() -> [NSLayoutConstraint] {
     return [
       messageView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
       messageView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
       messageView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
-      messageView.heightAnchor.constraint(equalToConstant: 75)
+      messageView.heightAnchor.constraint(
+        equalToConstant: BarcodeScannerViewController.footerHeight
+      )
     ]
   }
 }

Sources/Controllers/CameraViewController.swift

@@ -19,6 +19,11 @@ public final class CameraViewController: UIViewController {
 
   /// Focus view type.
   public var barCodeFocusViewType: FocusViewType = .animated
+  public var showsCameraButton: Bool = false {
+    didSet {
+      cameraButton.isHidden = showsCameraButton
+    }
+  }
   /// `AVCaptureMetadataOutput` metadata object types.
   var metadata = [AVMetadataObject.ObjectType]()
 
@@ -30,6 +35,8 @@ public final class CameraViewController: UIViewController {
   public private(set) lazy var flashButton: UIButton = .init(type: .custom)
   /// Button that opens settings to allow camera usage.
   public private(set) lazy var settingsButton: UIButton = self.makeSettingsButton()
+  // Button to switch between front and back camera.
+  public private(set) lazy var cameraButton: UIButton = self.makeCameraButton()
 
   // Constraints for the focus view when it gets smaller in size.
   private var regularFocusViewConstraints = [NSLayoutConstraint]()
@@ -41,7 +48,7 @@ public final class CameraViewController: UIViewController {
   /// Video preview layer.
   private var videoPreviewLayer: AVCaptureVideoPreviewLayer?
   /// Video capture device. This may be nil when running in Simulator.
-  private lazy var captureDevice: AVCaptureDevice! = AVCaptureDevice.default(for: .video)
+  private var captureDevice: AVCaptureDevice?
   /// Capture session.
   private lazy var captureSession: AVCaptureSession = AVCaptureSession()
   // Service used to check authorization status of the capture device
@@ -62,6 +69,14 @@ public final class CameraViewController: UIViewController {
     }
   }
 
+  private var frontCameraDevice: AVCaptureDevice? {
+    return AVCaptureDevice.devices(for: .video).first(where: { $0.position == .front })
+  }
+
+  private var backCameraDevice: AVCaptureDevice? {
+    return AVCaptureDevice.default(for: .video)
+  }
+
   // MARK: - Initialization
 
   deinit {
@@ -73,31 +88,21 @@ public final class CameraViewController: UIViewController {
   public override func viewDidLoad() {
     super.viewDidLoad()
     view.backgroundColor = .black
-
     videoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
-    videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
+    videoPreviewLayer?.videoGravity = .resizeAspectFill
 
     guard let videoPreviewLayer = videoPreviewLayer else {
       return
     }
 
     view.layer.addSublayer(videoPreviewLayer)
-    view.addSubviews(settingsButton, flashButton, focusView)
+    view.addSubviews(settingsButton, flashButton, focusView, cameraButton)
 
     torchMode = .off
     focusView.isHidden = true
     setupCamera()
     setupConstraints()
-
-    flashButton.addTarget(self, action: #selector(flashButtonDidPress), for: .touchUpInside)
-    settingsButton.addTarget(self, action: #selector(settingsButtonDidPress), for: .touchUpInside)
-
-    NotificationCenter.default.addObserver(
-      self,
-      selector: #selector(appWillEnterForeground),
-      name: NSNotification.Name.UIApplicationWillEnterForeground,
-      object: nil
-    )
+    setupActions()
   }
 
   public override func viewDidAppear(_ animated: Bool) {
@@ -149,19 +154,49 @@ public final class CameraViewController: UIViewController {
 
   // MARK: - Actions
 
+  private func setupActions() {
+    flashButton.addTarget(
+      self,
+      action: #selector(handleFlashButtonTap),
+      for: .touchUpInside
+    )
+    settingsButton.addTarget(
+      self,
+      action: #selector(handleSettingsButtonTap),
+      for: .touchUpInside
+    )
+    cameraButton.addTarget(
+      self,
+      action: #selector(handleCameraButtonTap),
+      for: .touchUpInside
+    )
+
+    NotificationCenter.default.addObserver(
+      self,
+      selector: #selector(appWillEnterForeground),
+      name: NSNotification.Name.UIApplicationWillEnterForeground,
+      object: nil
+    )
+  }
+
   /// `UIApplicationWillEnterForegroundNotification` action.
   @objc private func appWillEnterForeground() {
     torchMode = .off
     animateFocusView()
   }
 
   /// Opens setting to allow camera usage.
-  @objc private func settingsButtonDidPress() {
+  @objc private func handleSettingsButtonTap() {
     delegate?.cameraViewControllerDidTapSettingsButton(self)
   }
 
+  /// Swaps camera position.
+  @objc private func handleCameraButtonTap() {
+    swapCamera()
+  }
+
   /// Sets the next torch mode.
-  @objc private func flashButtonDidPress() {
+  @objc private func handleFlashButtonTap() {
     torchMode = torchMode.next
   }
 
@@ -179,7 +214,8 @@ public final class CameraViewController: UIViewController {
       }
 
       if error == nil {
-        strongSelf.setupSession()
+        strongSelf.setupSessionInput(for: .back)
+        strongSelf.setupSessionOutput()
         strongSelf.delegate?.cameraViewControllerDidSetupCaptureSession(strongSelf)
       } else {
         strongSelf.delegate?.cameraViewControllerDidFailToSetupCaptureSession(strongSelf)
@@ -188,16 +224,34 @@ public final class CameraViewController: UIViewController {
   }
 
   /// Sets up capture input, output and session.
-  private func setupSession() {
-    guard let captureDevice = captureDevice, !isSimulatorRunning else {
+  private func setupSessionInput(for position: AVCaptureDevice.Position) {
+    guard !isSimulatorRunning else {
+      return
+    }
+
+    guard let device = position == .front ? frontCameraDevice : backCameraDevice else {
       return
     }
 
     do {
-      let input = try AVCaptureDeviceInput(device: captureDevice)
-      captureSession.addInput(input)
+      let newInput = try AVCaptureDeviceInput(device: device)
+      captureDevice = device
+      // Swap capture device inputs
+      captureSession.beginConfiguration()
+      if let currentInput = captureSession.inputs.first as? AVCaptureDeviceInput {
+        captureSession.removeInput(currentInput)
+      }
+      captureSession.addInput(newInput)
+      captureSession.commitConfiguration()
     } catch {
       delegate?.cameraViewController(self, didReceiveError: error)
+      return
+    }
+  }
+
+  private func setupSessionOutput() {
+    guard !isSimulatorRunning else {
+      return
     }
 
     let output = AVCaptureMetadataOutput()
@@ -209,6 +263,14 @@ public final class CameraViewController: UIViewController {
     view.setNeedsLayout()
   }
 
+  /// Switch front/back camera.
+  private func swapCamera() {
+    guard let input = captureSession.inputs.first as? AVCaptureDeviceInput else {
+      return
+    }
+    setupSessionInput(for: input.device.position == .back ? .front : .back)
+  }
+
   // MARK: - Animations
 
   /// Performs focus view animation.
@@ -248,25 +310,34 @@ private extension CameraViewController {
         flashButton.trailingAnchor.constraint(
           equalTo: view.safeAreaLayoutGuide.trailingAnchor,
           constant: -13
+        ),
+        cameraButton.bottomAnchor.constraint(
+          equalTo: view.safeAreaLayoutGuide.bottomAnchor,
+          constant: -30
         )
       )
     } else {
       NSLayoutConstraint.activate(
         flashButton.topAnchor.constraint(equalTo: view.topAnchor, constant: 30),
-        flashButton.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -13)
+        flashButton.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -13),
+        cameraButton.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -30)
       )
     }
 
-    let flashButtonSize: CGFloat = 37
+    let imageButtonSize: CGFloat = 37
 
     NSLayoutConstraint.activate(
-      flashButton.widthAnchor.constraint(equalToConstant: flashButtonSize),
-      flashButton.heightAnchor.constraint(equalToConstant: flashButtonSize),
+      flashButton.widthAnchor.constraint(equalToConstant: imageButtonSize),
+      flashButton.heightAnchor.constraint(equalToConstant: imageButtonSize),
 
       settingsButton.centerXAnchor.constraint(equalTo: view.centerXAnchor),
       settingsButton.centerYAnchor.constraint(equalTo: view.centerYAnchor),
       settingsButton.widthAnchor.constraint(equalToConstant: 150),
-      settingsButton.heightAnchor.constraint(equalToConstant: 50)
+      settingsButton.heightAnchor.constraint(equalToConstant: 50),
+
+      cameraButton.widthAnchor.constraint(equalToConstant: 48),
+      cameraButton.heightAnchor.constraint(equalToConstant: 48),
+      cameraButton.trailingAnchor.constraint(equalTo: flashButton.trailingAnchor)
     )
 
     setupFocusViewConstraints()
@@ -345,6 +416,13 @@ private extension CameraViewController {
     button.sizeToFit()
     return button
   }
+
+  func makeCameraButton() -> UIButton {
+    let button = UIButton(type: .custom)
+    button.setImage(imageNamed("cameraRotate"), for: UIControlState())
+    button.isHidden = showsCameraButton
+    return button
+  }
 }
 
 // MARK: - AVCaptureMetadataOutputObjectsDelegate