feat: add support for gesture recognizer autocapture (#196)

* Fix indentation issue

* feat: add user interactions capture

* fix: fix typo

* fix: remove support for UITextField action message capture

* refactor: add dispatch once for method swizzling

* fix: remove support for UISlider to reduce noise

* feat: add support for UITextField and UISlider event capture

* style: remove return keyword for one line functions

* fix: fix typo

* feat: add support for text field gained/lost focus

* fix: fix lint

* fix: remove tag as textfield title

* refactor: refactor title and shouldTrack

* refactor: add a protocol to track control elements

* refactor: guard on action name

* feat: add support for uitextview capture

* fix: disable action method tracking support for UITextView

* fix: fix lint issue

* style: remove amp_ prefix from objc methods

* feat: add support for gesture recognizers autocapture

* fix: fix lint issue

* fix: exclude unsupported gestures in tvos

Sources/Amplitude/Constants.swift

@@ -101,6 +101,7 @@ public struct Constants {
     static let AMP_APP_TARGET_VIEW_CLASS = "\(AMP_AMPLITUDE_PREFIX)Target View Class"
     static let AMP_APP_TARGET_TEXT = "\(AMP_AMPLITUDE_PREFIX)Target Text"
     static let AMP_APP_HIERARCHY = "\(AMP_AMPLITUDE_PREFIX)Hierarchy"
+    static let AMP_APP_GESTURE_RECOGNIZER = "\(AMP_AMPLITUDE_PREFIX)Gesture Recognizer"
 
     public struct Configuration {
         public static let FLUSH_QUEUE_SIZE = 30

Sources/Amplitude/Events/UserInteractionEvent.swift

@@ -8,7 +8,8 @@ public class UserInteractionEvent: BaseEvent {
         action: String,
         targetViewClass: String,
         targetText: String? = nil,
-        hierarchy: String
+        hierarchy: String,
+        gestureRecognizer: String? = nil
     ) {
         self.init(eventType: Constants.AMP_USER_INTERACTION_EVENT, eventProperties: [
             Constants.AMP_APP_VIEW_CONTROLLER: viewController,
@@ -17,7 +18,8 @@ public class UserInteractionEvent: BaseEvent {
             Constants.AMP_APP_ACTION: action,
             Constants.AMP_APP_TARGET_VIEW_CLASS: targetViewClass,
             Constants.AMP_APP_TARGET_TEXT: targetText,
-            Constants.AMP_APP_HIERARCHY: hierarchy
+            Constants.AMP_APP_HIERARCHY: hierarchy,
+            Constants.AMP_APP_GESTURE_RECOGNIZER: gestureRecognizer
         ])
     }
 }

Sources/Amplitude/Plugins/iOS/UIKitUserInteractions.swift

@@ -6,42 +6,23 @@ class UIKitUserInteractions {
 
     private static let lock = NSLock()
 
-    private static let addNotificationObservers: () = {
+    private static let addNotificationObservers: Void = {
         NotificationCenter.default.addObserver(UIKitUserInteractions.self, selector: #selector(didBeginEditing), name: UITextField.textDidBeginEditingNotification, object: nil)
         NotificationCenter.default.addObserver(UIKitUserInteractions.self, selector: #selector(didEndEditing), name: UITextField.textDidEndEditingNotification, object: nil)
         NotificationCenter.default.addObserver(UIKitUserInteractions.self, selector: #selector(didBeginEditing), name: UITextView.textDidBeginEditingNotification, object: nil)
         NotificationCenter.default.addObserver(UIKitUserInteractions.self, selector: #selector(didEndEditing), name: UITextView.textDidEndEditingNotification, object: nil)
     }()
 
-    private static let swizzleSendAction: () = {
-        let applicationClass = UIApplication.self
-
-        let originalSelector = #selector(UIApplication.sendAction)
-        let swizzledSelector = #selector(UIApplication.amp_sendAction)
-
-        guard
-            let originalMethod = class_getInstanceMethod(applicationClass, originalSelector),
-            let swizzledMethod = class_getInstanceMethod(applicationClass, swizzledSelector)
-        else { return }
-
-        let originalImp = method_getImplementation(originalMethod)
-        let swizzledImp = method_getImplementation(swizzledMethod)
-
-        class_replaceMethod(applicationClass,
-            swizzledSelector,
-            originalImp,
-            method_getTypeEncoding(originalMethod))
-        class_replaceMethod(applicationClass,
-            originalSelector,
-            swizzledImp,
-            method_getTypeEncoding(swizzledMethod))
+    private static let setupMethodSwizzling: Void = {
+        swizzleMethod(UIApplication.self, from: #selector(UIApplication.sendAction), to: #selector(UIApplication.amp_sendAction))
+        swizzleMethod(UIGestureRecognizer.self, from: #selector(setter: UIGestureRecognizer.state), to: #selector(UIGestureRecognizer.amp_setState))
     }()
 
     static func register(_ amplitude: Amplitude) {
         lock.withLock {
             amplitudeInstances.add(amplitude)
         }
-        swizzleSendAction
+        setupMethodSwizzling
         addNotificationObservers
     }
 
@@ -60,6 +41,25 @@ class UIKitUserInteractions {
             $0.track(event: userInteractionEvent)
         }
     }
+
+    private static func swizzleMethod(_ cls: AnyClass?, from original: Selector, to swizzled: Selector) {
+        guard
+            let originalMethod = class_getInstanceMethod(cls, original),
+            let swizzledMethod = class_getInstanceMethod(cls, swizzled)
+        else { return }
+
+        let originalImp = method_getImplementation(originalMethod)
+        let swizzledImp = method_getImplementation(swizzledMethod)
+
+        class_replaceMethod(cls,
+            swizzled,
+            originalImp,
+            method_getTypeEncoding(originalMethod))
+        class_replaceMethod(cls,
+            original,
+            swizzledImp,
+            method_getTypeEncoding(swizzledMethod))
+    }
 }
 
 extension UIApplication {
@@ -84,6 +84,46 @@ extension UIApplication {
     }
 }
 
+extension UIGestureRecognizer {
+    @objc func amp_setState(_ state: UIGestureRecognizer.State) {
+        amp_setState(state)
+
+        guard state == .ended, let view else { return }
+
+        let gestureType = switch self {
+        case is UITapGestureRecognizer: "Tap"
+        case is UISwipeGestureRecognizer: "Swipe"
+        case is UIPanGestureRecognizer: "Pan"
+        case is UILongPressGestureRecognizer: "Long Press"
+#if !os(tvOS)
+        case is UIPinchGestureRecognizer: "Pinch"
+        case is UIRotationGestureRecognizer: "Rotation"
+        case is UIScreenEdgePanGestureRecognizer: "Screen Edge Pan"
+#endif
+        default: "Custom Gesture"
+        }
+
+        let userInteractionEvent = eventFromData(with: gestureType, from: view)
+
+        UIKitUserInteractions.amplitudeInstances.allObjects.forEach {
+            $0.track(event: userInteractionEvent)
+        }
+    }
+
+    func eventFromData(with action: String, from view: UIView) -> UserInteractionEvent {
+        let viewData = view.extractData(with: action)
+        return UserInteractionEvent(
+            viewController: viewData.viewController,
+            title: viewData.title,
+            accessibilityLabel: viewData.accessibilityLabel,
+            action: viewData.action,
+            targetViewClass: viewData.targetViewClass,
+            targetText: viewData.targetText,
+            hierarchy: viewData.hierarchy,
+            gestureRecognizer: descriptiveTypeName)
+    }
+}
+
 extension UIView {
     private static let viewHierarchyDelimiter = " -> "
 
@@ -125,15 +165,17 @@ extension UIView {
 }
 
 extension UIResponder {
-    var descriptiveTypeName: String {
-        String(describing: type(of: self))
-    }
-
     var owningViewController: UIViewController? {
         return self as? UIViewController ?? next?.owningViewController
     }
 }
 
+extension NSObject {
+    var descriptiveTypeName: String {
+        String(describing: type(of: self))
+    }
+}
+
 protocol ActionTrackable {
     var amp_title: String? { get }
     func amp_shouldTrack(_ action: Selector, for event: UIEvent?) -> Bool