Fix #284: Support Multi-tap and Long Press Gestures

Source/model/scene/Group.swift

@@ -114,6 +114,15 @@ open class Group: Node {
 
         return shouldCheck
     }
+
+    override func shouldCheckForLongTap() -> Bool {
+        var shouldCheck = super.shouldCheckForLongTap()
+        contents.forEach { node in
+            shouldCheck = shouldCheck || node.shouldCheckForLongTap()
+        }
+
+        return shouldCheck
+    }
 
     override func shouldCheckForPan() -> Bool {
         var shouldCheck = super.shouldCheckForPan()

Source/model/scene/Node.swift

@@ -64,8 +64,13 @@ open class Node: Drawable {
     var touchPressedHandlers = [ChangeHandler<TouchEvent>]()
     var touchMovedHandlers = [ChangeHandler<TouchEvent>]()
     var touchReleasedHandlers = [ChangeHandler<TouchEvent>]()
+
+    var prevTouchCount: Int = 0
+    var prevTouchTimer: Timer?
+    var isLongTapInProgress = false
 
-    var tapHandlers = [ChangeHandler<TapEvent>]()
+    var tapHandlers = [Int : [ChangeHandler<TapEvent>]]()
+    var longTapHandlers = [ChangeHandler<TapEvent>]()
     var panHandlers = [ChangeHandler<PanEvent>]()
     var rotateHandlers = [ChangeHandler<RotateEvent>]()
     var pinchHandlers = [ChangeHandler<PinchEvent>]()
@@ -109,16 +114,33 @@ open class Node: Drawable {
         }
     }
 
-    @discardableResult public func onTap(_ f: @escaping (TapEvent) -> Void) -> Disposable {
+    @discardableResult public func onTap(tapCount: Int = 1, f: @escaping (TapEvent) -> Void) -> Disposable {
         let handler = ChangeHandler<TapEvent>(f)
-        tapHandlers.append(handler)
+        if var handlers = tapHandlers[tapCount] {
+            handlers.append(handler)
+        } else {
+            tapHandlers[tapCount] = [handler]
+        }
 
         return Disposable { [weak self]  in
-            guard let index = self?.tapHandlers.index(of: handler) else {
+            guard let index = self?.tapHandlers[tapCount]?.index(of: handler) else {
                 return
             }
 
-            self?.tapHandlers.remove(at: index)
+            self?.tapHandlers[tapCount]?.remove(at: index)
+        }
+    }
+
+    @discardableResult public func onLongTap(_ f: @escaping (TapEvent) -> Void) -> Disposable {
+        let handler = ChangeHandler<TapEvent>(f)
+        longTapHandlers.append(handler)
+
+        return Disposable { [weak self] in
+            guard let index = self?.longTapHandlers.index(of: handler) else {
+                return
+            }
+
+            self?.longTapHandlers.remove(at: index)
         }
     }
 
@@ -174,9 +196,61 @@ open class Node: Drawable {
     func handleTouchMoved(_ event: TouchEvent) {
         touchMovedHandlers.forEach { handler in handler.handle(event) }
     }
-
+
+    // MARK: - Multiple tap handling
+
     func handleTap( _ event: TapEvent ) {
-        tapHandlers.forEach { handler in handler.handle(event) }
+        if isLongTapInProgress {
+            prevTouchCount = 0
+            return
+        }
+        if prevTouchTimer != nil {
+            prevTouchTimer?.invalidate()
+            prevTouchTimer = nil
+        }
+        prevTouchCount += 1
+
+        for tapCount in tapHandlers.keys {
+            if tapCount > prevTouchCount { // wait some more - there is a recognizer for even more taps
+                prevTouchTimer = Timer.scheduledTimer(timeInterval: 0.3, target: self, selector: #selector(onTouchTimer), userInfo: event, repeats: false)
+                return
+            }
+        }
+
+        for (tapCount, handlers) in tapHandlers {
+            if tapCount == prevTouchCount { // nothing to wait for - max tap count reached
+                handlers.forEach { handler in handler.handle(event) }
+                prevTouchCount = 0
+            }
+        }
+
+    }
+
+    @objc func onTouchTimer(timer: Timer) {
+        if isLongTapInProgress {
+            prevTouchCount = 0
+            return
+        }
+        for touchCount in tapHandlers.keys.sorted(by: {$0>$1}) {
+            if touchCount <= prevTouchCount, let event = timer.userInfo as? TapEvent {
+                // no more taps coming, settle for next best thing
+                for _ in 0..<prevTouchCount/touchCount { // might need to call it multiple times
+                    tapHandlers[touchCount]?.forEach { handler in handler.handle(event) }
+                }
+                break
+            }
+        }
+        prevTouchCount = 0
+    }
+
+    // MARK: - Helpers
+
+    func handleLongTap( _ event: TapEvent, touchBegan: Bool ) {
+        isLongTapInProgress = touchBegan
+        if touchBegan {
+            return
+        }
+        longTapHandlers.forEach { handler in handler.handle(event) }
     }
 
     func handlePan( _ event: PanEvent ) {
@@ -206,6 +280,10 @@ open class Node: Drawable {
     func shouldCheckForTap() -> Bool {
         return !tapHandlers.isEmpty
     }
+
+    func shouldCheckForLongTap() -> Bool {
+        return !longTapHandlers.isEmpty
+    }
 
     func shouldCheckForPan() -> Bool {
         return !panHandlers.isEmpty

Source/model/scene/SceneUtils.swift

@@ -24,6 +24,7 @@ class SceneUtils {
 		shape.touchReleasedHandlers = from.touchReleasedHandlers
 
 		shape.tapHandlers = from.tapHandlers
+        shape.longTapHandlers = from.longTapHandlers
 		shape.panHandlers = from.panHandlers
 		shape.rotateHandlers = from.rotateHandlers
 		shape.pinchHandlers = from.pinchHandlers

Source/views/MacawView.swift

@@ -125,22 +125,26 @@ open class MacawView: MView, MGestureRecognizerDelegate {
         self.animationCache = AnimationCache(sceneLayer: layer)
 
         let tapRecognizer = MTapGestureRecognizer(target: self, action: #selector(MacawView.handleTap))
+        let longTapRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(MacawView.handleLongTap(recognizer:)))
         let panRecognizer = MPanGestureRecognizer(target: self, action: #selector(MacawView.handlePan))
         let rotationRecognizer = MRotationGestureRecognizer(target: self, action: #selector(MacawView.handleRotation))
         let pinchRecognizer = MPinchGestureRecognizer(target: self, action: #selector(MacawView.handlePinch))
 
         tapRecognizer.delegate = self
+        longTapRecognizer.delegate = self
         panRecognizer.delegate = self
         rotationRecognizer.delegate = self
         pinchRecognizer.delegate = self
 
         tapRecognizer.cancelsTouchesInView = false
+        longTapRecognizer.cancelsTouchesInView = false
         panRecognizer.cancelsTouchesInView = false
         rotationRecognizer.cancelsTouchesInView = false
         pinchRecognizer.cancelsTouchesInView = false
 
         self.removeGestureRecognizers()
         self.addGestureRecognizer(tapRecognizer)
+        self.addGestureRecognizer(longTapRecognizer)
         self.addGestureRecognizer(panRecognizer)
         self.addGestureRecognizer(rotationRecognizer)
         self.addGestureRecognizer(pinchRecognizer)
@@ -321,6 +325,43 @@ open class MacawView: MView, MGestureRecognizerDelegate {
         }
     }
 
+    // MARK: - Tap
+
+    @objc func handleLongTap(recognizer: UILongPressGestureRecognizer) {
+        if !self.node.shouldCheckForLongTap() {
+            return
+        }
+
+        guard let renderer = renderer else {
+            return
+        }
+
+        let location = recognizer.location(in: self)
+        var foundNodes = [Node]()
+
+        localContext { ctx in
+            guard let foundNode = renderer.findNodeAt(location: location, ctx: ctx) else {
+                return
+            }
+
+            var parent: Node? = foundNode
+            while parent != .none {
+                if parent!.shouldCheckForTap() {
+                    foundNodes.append(parent!)
+                }
+
+                parent = nodesMap.parents(parent!).first
+            }
+        }
+
+        foundNodes.forEach { node in
+            let inverted = node.place.invert()!
+            let loc = location.applying(RenderUtils.mapTransform(inverted))
+            let event = TapEvent(node: node, location: Point(x: Double(loc.x), y: Double(loc.y)))
+            node.handleLongTap(event, touchBegan: recognizer.state == .began)
+        }
+    }
+
     // MARK: - Pan
 
     @objc func handlePan(recognizer: MPanGestureRecognizer) {