fix(KAN-71): correct Apple navigation gestures and scroll bounds

native/src-tauri/gen/apple/Sources/kanbangit-native/WorkspaceViewController.swift

@@ -24,7 +24,7 @@ func installIOSWorkspace() {
     }
 }
 
-final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKUIDelegate, UITextFieldDelegate {
+final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKUIDelegate, UITextFieldDelegate, UIGestureRecognizerDelegate {
     private let defaults: UserDefaults
     private let serverKey = "ios.activeServer"
     private(set) var server: WorkspaceServer?
@@ -40,8 +40,9 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
     private let connectButton = UIButton(type: .system)
     private let resumeButton = UIButton(type: .system)
     private let toolbar = UIToolbar()
-    private var historyObservation: NSKeyValueObservation?
-    private var backButton: UIBarButtonItem!
+    private var gestureStart = CGPoint.zero
+    private var gestureAllowed = false
+    private var gestureRevision = 0
     private var appearance: UISegmentedControl!
 
     init(defaults: UserDefaults = .standard) {
@@ -94,7 +95,7 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
         launcher.isHidden = true
         launcher.accessibilityIdentifier = "serverSettings"
         launcher.keyboardDismissMode = .interactive
-        launcher.alwaysBounceVertical = true
+        launcher.bounces = false
         view.addSubview(launcher)
         launcher.translatesAutoresizingMaskIntoConstraints = false
         NSLayoutConstraint.activate([
@@ -164,11 +165,9 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
         toolbar.isHidden = true
         toolbar.translatesAutoresizingMaskIntoConstraints = false
         view.addSubview(toolbar)
-        backButton = UIBarButtonItem(title: text("back"), style: .plain, target: self, action: #selector(goBack))
-        backButton.accessibilityIdentifier = "workspaceBack"
         let settings = UIBarButtonItem(title: text("serverSettings"), style: .plain, target: self, action: #selector(showSettings))
         settings.accessibilityIdentifier = "showServerSettings"
-        toolbar.items = [backButton, UIBarButtonItem(systemItem: .flexibleSpace), settings]
+        toolbar.items = [UIBarButtonItem(systemItem: .flexibleSpace), settings]
         NSLayoutConstraint.activate([
             toolbar.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
             toolbar.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
@@ -203,7 +202,6 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
         guard let data = try? JSONEncoder().encode(selected) else { status.text = text("storageError"); return }
         defaults.set(data, forKey: serverKey)
         timeout?.cancel()
-        historyObservation = nil
         workspace?.stopLoading()
         workspace?.navigationDelegate = nil
         workspace?.removeFromSuperview()
@@ -211,11 +209,24 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
         server = selected
         let configuration = WKWebViewConfiguration()
         configuration.websiteDataStore = WKWebsiteDataStore(forIdentifier: selected.profile)
-        // Remote content receives a plain WKWebView, with no native message handlers or Tauri bridge.
+        let scriptURL = Bundle(for: WorkspaceViewController.self).url(forResource: "workspace-navigation", withExtension: "js")!
+        let script = try! String(contentsOf: scriptURL, encoding: .utf8)
+        configuration.userContentController.addUserScript(WKUserScript(source: script, injectionTime: .atDocumentStart, forMainFrameOnly: true))
+        // Remote content receives no native message handlers or Tauri bridge.
         let webview = WKWebView(frame: .zero, configuration: configuration)
         webview.navigationDelegate = self
         webview.uiDelegate = self
-        webview.allowsBackForwardNavigationGestures = true
+        // Native WebKit swipes can skip async pushState entries. One edge recognizer
+        // owns each gesture and traverses the same history that Inertia restores.
+        webview.allowsBackForwardNavigationGestures = false
+        webview.scrollView.bounces = false
+        for edge: UIRectEdge in [.left, .right] {
+            let gesture = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(navigateGesture(_:)))
+            gesture.edges = edge
+            gesture.delegate = self
+            webview.addGestureRecognizer(gesture)
+            webview.scrollView.panGestureRecognizer.require(toFail: gesture)
+        }
         webview.accessibilityIdentifier = "workspace"
         webview.translatesAutoresizingMaskIntoConstraints = false
         webview.isHidden = true
@@ -227,9 +238,6 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
             webview.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
         ])
         workspace = webview
-        historyObservation = webview.observe(\.canGoBack, options: [.initial, .new]) { [weak self] view, _ in
-            self?.backButton.isEnabled = view.canGoBack
-        }
         view.endEditing(true)
         address.text = url.absoluteString
         launcher.isHidden = true
@@ -275,10 +283,46 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
         launcher.isHidden = true
         toolbar.isHidden = false
         workspace?.isHidden = false
-        backButton.isEnabled = workspace?.canGoBack == true
     }
 
-    @objc private func goBack() { if workspace?.canGoBack == true { workspace?.goBack() } }
+    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldReceive touch: UITouch) -> Bool {
+        guard gestureRecognizer is UIScreenEdgePanGestureRecognizer, let webview = workspace else { return false }
+        gestureStart = touch.location(in: webview)
+        gestureAllowed = false
+        gestureRevision += 1
+        let revision = gestureRevision
+        webview.evaluateJavaScript("window.__kanbanNavigation?.canSwipe(\(gestureStart.x), \(gestureStart.y)) === true") { [weak self, weak gestureRecognizer] result, _ in
+            guard let self, self.gestureRevision == revision, self.workspace === webview else { return }
+            self.gestureAllowed = result as? Bool == true
+            // Release the scroll view immediately when a board, field or overlay owns the touch.
+            if !self.gestureAllowed, gestureRecognizer?.state == .possible { gestureRecognizer?.state = .failed }
+        }
+        return true
+    }
+
+    func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
+        guard let edge = gestureRecognizer as? UIScreenEdgePanGestureRecognizer,
+              let webview = workspace, !webview.isHidden, gestureAllowed else { return false }
+        let velocity = edge.velocity(in: webview)
+        return abs(velocity.x) > abs(velocity.y)
+            && (edge.edges == .left ? webview.canGoBack && velocity.x > 0 : webview.canGoForward && velocity.x < 0)
+    }
+
+    @objc private func navigateGesture(_ gesture: UIScreenEdgePanGestureRecognizer) {
+        guard gesture.state == .ended, let webview = workspace else { return }
+        let direction = gesture.edges == .left ? -1 : 1
+        let distance = gesture.translation(in: webview).x * CGFloat(-direction)
+        let velocity = gesture.velocity(in: webview).x * CGFloat(-direction)
+        guard distance > webview.bounds.width * 0.25 || (distance > 30 && velocity > 500) else { return }
+        navigateHistory(direction, from: gestureStart)
+    }
+
+    func navigateHistory(_ direction: Int, from point: CGPoint) {
+        guard let webview = workspace,
+              direction == -1 ? webview.canGoBack : webview.canGoForward else { return }
+        let script = "if (window.__kanbanNavigation?.canSwipe(\(point.x), \(point.y))) window.__kanbanNavigation.step(\(direction))"
+        webview.evaluateJavaScript(script, completionHandler: nil)
+    }
 
     func webView(_ webView: WKWebView, decidePolicyFor action: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
         guard webView === workspace, let url = action.request.url else { decisionHandler(.cancel); return }
@@ -320,7 +364,6 @@ final class WorkspaceViewController: UIViewController, WKNavigationDelegate, WKU
         connectButton.setTitle(text("openWorkspace"), for: .normal)
         status.text = text("connected")
         resumeButton.isHidden = false
-        backButton.isEnabled = webView.canGoBack
         if firstLoad { showWorkspace() }
     }