Merge commit '7621e2f8dec938cf48181c8b10afc9b01f444e68' into beta

submodules/SwipeToDismissGesture/BUILD

@@ -0,0 +1,15 @@
+load("@build_bazel_rules_swift//swift:swift.bzl", "swift_library")
+
+swift_library(
+    name = "SwipeToDismissGesture",
+    module_name = "SwipeToDismissGesture",
+    srcs = glob([
+        "Sources/**/*.swift",
+    ]),
+    copts = [
+        "-warnings-as-errors",
+    ],
+    visibility = [
+        "//visibility:public",
+    ],
+)

submodules/SwipeToDismissGesture/Sources/SwipeToDismissGestureRecognizer.swift

@@ -0,0 +1,115 @@
+import Foundation
+import UIKit
+import UIKit.UIGestureRecognizerSubclass
+
+private func traceScrollView(view: UIView, point: CGPoint) -> UIScrollView? {
+    for subview in view.subviews {
+        let subviewPoint = view.convert(point, to: subview)
+        if subview.frame.contains(point), let result = traceScrollView(view: subview, point: subviewPoint) {
+            return result
+        }
+    }
+    if let scrollView = view as? UIScrollView {
+        return scrollView
+    }
+    return nil
+}
+
+private final class InternalGestureRecognizerDelegate: NSObject, UIGestureRecognizerDelegate {
+    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
+        return true
+    }
+    
+    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
+        if otherGestureRecognizer is UIPanGestureRecognizer {
+            return true
+        }
+        return false
+    }
+}
+
+public class SwipeToDismissGestureRecognizer: UIGestureRecognizer, UIGestureRecognizerDelegate {
+    private let internalDelegate = InternalGestureRecognizerDelegate()
+    
+    private var beginPosition = CGPoint()
+    
+    override public init(target: Any?, action: Selector?) {
+        super.init(target: target, action: action)
+        
+        self.delegate = self.internalDelegate
+    }
+    
+    override public func reset() {
+        super.reset()
+        
+        self.state = .possible
+    }
+    
+    override public func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
+        super.touchesBegan(touches, with: event)
+        
+        guard let touch = touches.first, let view = self.view else {
+            self.state = .failed
+            return
+        }
+        
+        var found = false
+        let point = touch.location(in: self.view)
+        if let scrollView = traceScrollView(view: view, point: point) {
+            let contentOffset = scrollView.contentOffset
+            let contentInset = scrollView.contentInset
+            if contentOffset.y.isLessThanOrEqualTo(contentInset.top) {
+                found = true
+            }
+        }
+        if found {
+            self.beginPosition = point
+        } else {
+            self.state = .failed
+        }
+    }
+    
+    override public func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
+        super.touchesMoved(touches, with: event)
+        
+        guard let touch = touches.first, let view = self.view else {
+            self.state = .failed
+            return
+        }
+        
+        let point = touch.location(in: self.view)
+        
+        let translation = CGPoint(x: point.x - self.beginPosition.x, y: point.y - self.beginPosition.y)
+        
+        if self.state == .possible {
+            if abs(translation.x) > 5.0 {
+                self.state = .failed
+                return
+            }
+            var lockDown = false
+            let point = touch.location(in: self.view)
+            if let scrollView = traceScrollView(view: view, point: point) {
+                let contentOffset = scrollView.contentOffset
+                let contentInset = scrollView.contentInset
+                if contentOffset.y.isLessThanOrEqualTo(contentInset.top) {
+                    lockDown = true
+                }
+            }
+            if lockDown {
+                if translation.y > 2.0 {
+                    self.state = .began
+                }
+            } else {
+                self.state = .failed
+            }
+        } else {
+            self.state = .changed
+        }
+    }
+    
+    override public func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
+        super.touchesEnded(touches, with: event)
+        
+        self.state = .failed
+    }
+}