Added swipe to zoom

CHANGELOG.md

@@ -1,5 +1,11 @@
 # CHANGELOG
 
+## Version 2.3.0
+- Added support to vertically swipt to zoom
+- Added ```swipeToZoom``` property
+- Added support for inverting zoom directions for swipeToZoom
+- Added ```swipeToZoomInverted``` property
+
 ## Version 2.2.2
 - Fixed issue with landscape orientation 
 - Fixed issue with SwiftyCam crashing by multiple double-tap camera switching

DemoSwiftyCam/DemoSwiftyCam/ViewController.swift

@@ -27,7 +27,6 @@ class ViewController: SwiftyCamViewController, SwiftyCamViewControllerDelegate {
 		cameraDelegate = self
 		maximumVideoDuration = 10.0
         shouldUseDeviceOrientation = true
-
 		addButtons()
 	}
 

README.md

@@ -274,13 +274,25 @@ A value of **0.0** will allow for unlimited video recording via the SwiftyCamBut
 
 ## Camera Zoom
 
-SwiftyCam supports digital zoom of the camera session via pinch gestures. The gestures work similar to the default iOS app and will zoom to the maximum supported zoom level. Camera zoom is only supported on the rear facing camera. AVFoundation does not currently support front facing camera zoom. To disable this feature, change the `pinchToZoom` property:
+SwiftyCam supports digital zoom of the camera session via pinch and pan gestures. The gestures work similar to the default iOS app and will zoom to the maximum supported zoom level. Camera zoom is only supported on the rear facing camera. AVFoundation does not currently support front facing camera zoom. To disable this feature, change the `pinchToZoom` property:
 
 ```swift
 pinchToZoom = false
 ```   
 
-By default, **pinchToZoom** is enabled.
+By default, ```pinchToZoom``` is enabled.
+
+SwiftyCam also supports the ability to zoom the rear facing camera with vertical pan gestures. To disable this feature, change the `swipeToZoom` property:
+
+```swift
+swipeToZoom = false
+```   
+
+By default, ```swipeToZoom``` is enabled. The default gestures zoom in the capture session with a downward swipe, and zoom out with an upward swipe. This can be reversed by changing the ```swipeToZoomInverted``` property:
+
+```swift
+swipeToZoomInverted = true
+``` 
 
 You can also restrict the amount that the rear facing camera can zoom. To do this, use the         `maxZoomScale` property:
 
@@ -288,7 +300,7 @@ You can also restrict the amount that the rear facing camera can zoom. To do thi
 maxZoomScale = 2.0
 ```   
 
-By default, `maxZoomScale` is set to **4.0**.
+By default, `maxZoomScale` is set to **infinite**. The actual maximum zoom level is determined by the device's [videoMaxZoomFactor](https://developer.apple.com/reference/avfoundation/avcapturedeviceformat/1624635-videomaxzoomfactor).
 
 ## Camera Focus
 

Source/SwiftyCamViewController.swift

@@ -109,9 +109,9 @@ open class SwiftyCamViewController: UIViewController {
 
 	public var pinchToZoom                       = true
 
-	/// Sets the maximum zoom scale allowed during Pinch gesture
+	/// Sets the maximum zoom scale allowed during gestures gesture
 
-	public var maxZoomScale				         = CGFloat(4.0)
+	public var maxZoomScale				         = CGFloat.greatestFiniteMagnitude
   
 	/// Sets whether Tap to Focus and Tap to Adjust Exposure is enabled for the capture session
 
@@ -131,6 +131,14 @@ open class SwiftyCamViewController: UIViewController {
 
 	public var doubleTapCameraSwitch            = true
     
+    /// Sets whether swipe vertically to zoom is supported
+    
+    public var swipeToZoom                     = true
+    
+    /// Sets whether swipe vertically gestures should be inverted
+    
+    public var swipeToZoomInverted             = false
+
 	/// Set default launch camera
 
 	public var defaultCamera                   = CameraSelection.rear
@@ -210,13 +218,16 @@ open class SwiftyCamViewController: UIViewController {
 
 	fileprivate var flashView                    : UIView?
     
+    /// Pan Translation
+    
+    fileprivate var previousPanTranslation       : CGFloat = 0.0
+
 	/// Last changed orientation
 
 	fileprivate var deviceOrientation            : UIDeviceOrientation?
 
 	/// Disable view autorotation for forced portrait recorindg
 
-
 	override open var shouldAutorotate: Bool {
 		return false
 	}
@@ -227,7 +238,7 @@ open class SwiftyCamViewController: UIViewController {
 
 	override open func viewDidLoad() {
 		super.viewDidLoad()
-		previewLayer = PreviewView(frame: self.view.frame)
+		previewLayer = PreviewView(frame: view.bounds)
 
 		// Add Gesture Recognizers
 
@@ -1060,6 +1071,48 @@ extension SwiftyCamViewController {
 		switchCamera()
 	}
     
+    @objc private func panGesture(pan: UIPanGestureRecognizer) {
+        
+        guard swipeToZoom == true && self.currentCamera == .rear else {
+            //ignore pan
+            return
+        }
+        let currentTranslation    = pan.translation(in: view).y
+        let translationDifference = currentTranslation - previousPanTranslation
+        
+        do {
+            let captureDevice = AVCaptureDevice.devices().first as? AVCaptureDevice
+            try captureDevice?.lockForConfiguration()
+            
+            let currentZoom = captureDevice?.videoZoomFactor ?? 0.0
+            
+            if swipeToZoomInverted == true {
+                zoomScale = min(maxZoomScale, max(1.0, min(currentZoom - (translationDifference / 75),  captureDevice!.activeFormat.videoMaxZoomFactor)))
+            } else {
+                zoomScale = min(maxZoomScale, max(1.0, min(currentZoom + (translationDifference / 75),  captureDevice!.activeFormat.videoMaxZoomFactor)))
+
+            }
+            
+            captureDevice?.videoZoomFactor = zoomScale
+            
+            // Call Delegate function with current zoom scale
+            DispatchQueue.main.async {
+                self.cameraDelegate?.swiftyCam(self, didChangeZoomLevel: self.zoomScale)
+            }
+            
+            captureDevice?.unlockForConfiguration()
+            
+        } catch {
+            print("[SwiftyCam]: Error locking configuration")
+        }
+        
+        if pan.state == .ended || pan.state == .failed || pan.state == .cancelled {
+            previousPanTranslation = 0.0
+        } else {
+            previousPanTranslation = currentTranslation
+        }
+    }
+
 	/**
 	Add pinch gesture recognizer and double tap gesture recognizer to currentView
 
@@ -1081,6 +1134,10 @@ extension SwiftyCamViewController {
 		doubleTapGesture.numberOfTapsRequired = 2
 		doubleTapGesture.delegate = self
 		view.addGestureRecognizer(doubleTapGesture)
+        
+        let panGesture = UIPanGestureRecognizer(target: self, action: #selector(panGesture(pan:)))
+        panGesture.delegate = self
+        view.addGestureRecognizer(panGesture)
 	}
 }