Interop with UINavigationController user instantiated popping

ReSwiftRouter.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		1ADD0D9B1F041625004B2FD7 /* NavigationController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1ADD0D9A1F041625004B2FD7 /* NavigationController.swift */; };
 		254B3BAD1D3AD6DD00B1E4F0 /* RouteHashSpec.swift in Sources */ = {isa = PBXBuildFile; fileRef = 254B3BAC1D3AD6DD00B1E4F0 /* RouteHashSpec.swift */; };
 		254B3BAE1D3AD6DD00B1E4F0 /* RouteHashSpec.swift in Sources */ = {isa = PBXBuildFile; fileRef = 254B3BAC1D3AD6DD00B1E4F0 /* RouteHashSpec.swift */; };
 		254B3BAF1D3AD6DD00B1E4F0 /* RouteHashSpec.swift in Sources */ = {isa = PBXBuildFile; fileRef = 254B3BAC1D3AD6DD00B1E4F0 /* RouteHashSpec.swift */; };
@@ -94,6 +95,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		1ADD0D9A1F041625004B2FD7 /* NavigationController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = NavigationController.swift; path = ReSwiftRouter/NavigationController.swift; sourceTree = SOURCE_ROOT; };
 		254B3BAC1D3AD6DD00B1E4F0 /* RouteHashSpec.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = RouteHashSpec.swift; path = ReSwiftRouterTests/RouteHashSpec.swift; sourceTree = SOURCE_ROOT; };
 		25C0A9C51C50AF6400139FA7 /* Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; name = Info.plist; path = ReSwiftRouter/Info.plist; sourceTree = SOURCE_ROOT; };
 		25C0A9C61C50AF6400139FA7 /* NavigationActions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = NavigationActions.swift; path = ReSwiftRouter/NavigationActions.swift; sourceTree = SOURCE_ROOT; };
@@ -220,6 +222,7 @@
 				25C0A9C61C50AF6400139FA7 /* NavigationActions.swift */,
 				25C0A9C71C50AF6400139FA7 /* NavigationReducer.swift */,
 				25C0A9C81C50AF6400139FA7 /* NavigationState.swift */,
+				1ADD0D9A1F041625004B2FD7 /* NavigationController.swift */,
 				25C0A9C91C50AF6400139FA7 /* ReSwiftRouter.h */,
 				25C0A9CA1C50AF6400139FA7 /* Routable.swift */,
 				25C0A9CB1C50AF6400139FA7 /* Router.swift */,
@@ -774,6 +777,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				25C0A9CE1C50AF6400139FA7 /* NavigationReducer.swift in Sources */,
+				1ADD0D9B1F041625004B2FD7 /* NavigationController.swift in Sources */,
 				25C0A9CF1C50AF6400139FA7 /* NavigationState.swift in Sources */,
 				25C0A9D21C50AF6400139FA7 /* Router.swift in Sources */,
 				25C0A9CD1C50AF6400139FA7 /* NavigationActions.swift in Sources */,

ReSwiftRouter/NavigationController.swift

@@ -0,0 +1,104 @@
+//
+//  NavigationController.swift
+//  ReSwiftRouter
+//
+//  Created by Taras Vozniuk on 29/06/2017.
+//  Copyright © 2017 Benjamin Encz. All rights reserved.
+//
+
+import UIKit
+
+// dummy view controller returned when popViewController is canceled
+public final class PopWasIgnored: UIViewController {}
+
+open class NavigationController: UINavigationController {
+
+    fileprivate var isSwipping: Bool = false
+
+    // indicates that backButton was pressed when set to false
+    fileprivate var isPerformingPop: Bool = false
+
+    override open func viewDidLoad() {
+        super.viewDidLoad()
+        self.interactivePopGestureRecognizer?.addTarget(self, action: #selector(NavigationController.handlePopSwipe))
+        self.delegate = self
+    }
+
+    override open func popViewController(animated: Bool) -> UIViewController? {
+
+        // when swipping we are discarding all subsequent popViewController calls
+        guard !self.isSwipping else {
+            return PopWasIgnored()
+        }
+
+        self.isPerformingPop = true
+        return super.popViewController(animated: animated)
+    }
+
+    // will be called after popViewController call
+    func handlePopSwipe(){
+        self.isSwipping = true
+    }
+
+    /// should be overriden
+    /// normally you should dispatch SetRouteAction here
+    open func popRoute(){
+        print("WARNING: \(#function) should to be overriden")
+    }
+}
+
+extension NavigationController: UINavigationControllerDelegate {
+
+    public func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
+        self.isSwipping = false
+    }
+}
+
+extension NavigationController: UINavigationBarDelegate {
+
+    // if overriden navigationController popViewController won't be called before this method
+    // on back button press
+    // isPerformingPop will be false here in this case
+    public func navigationBar(_ navigationBar: UINavigationBar, shouldPop item: UINavigationItem) -> Bool {
+        defer { isPerformingPop = false }
+
+        // changeRoute is performed:
+        // 1. back button was pressed
+        // 2. pop swipe was triggerred
+        if !isPerformingPop || self.isSwipping {
+            self.popRoute()
+        }
+
+        // don't remove the navigationItem if navigationController
+        // is not going to be popped
+        return isPerformingPop
+    }
+}
+
+extension UINavigationController {
+
+    open func pushViewController(_ viewController: UIViewController, animated: Bool, completion: @escaping () -> Void) {
+
+        self.pushViewController(viewController, animated: animated)
+
+        guard animated, let coordinator = self.transitionCoordinator else {
+            completion()
+            return
+        }
+
+        coordinator.animate(alongsideTransition: nil) { _ in completion() }
+    }
+
+    open func popViewController(animated: Bool, completion: @escaping () -> Void) -> UIViewController? {
+
+        let popped = self.popViewController(animated: animated)
+
+        guard animated, let coordinator = self.transitionCoordinator else {
+            completion()
+            return popped
+        }
+
+        coordinator.animate(alongsideTransition: nil) { _ in completion() }
+        return popped
+    }
+}