Add a menu item to the Debug menu to enable the Web Inspector

Just enables the "Inspect Element" item in a WKWebView's contextual menu at the moment.

Mac/AppDefaults.swift

@@ -36,6 +36,8 @@ struct AppDefaults {
 		static let timelineShowsSeparators = "CorreiaSeparators"
 		static let showTitleOnMainWindow = "KafasisTitleMode"
 		static let hideDockUnreadCount = "JustinMillerHideDockUnreadCount"
+
+		static let webInspectorEnabled = "WebInspectorEnabled"
 	}
 
 	private static let smallestFontSizeRawValue = FontSize.small.rawValue
@@ -138,6 +140,15 @@ struct AppDefaults {
 		return bool(for: Key.hideDockUnreadCount)
 	}
 
+	static var webInspectorEnabled: Bool {
+		get {
+			return bool(for: Key.webInspectorEnabled)
+		}
+		set {
+			setBool(for: Key.webInspectorEnabled, newValue)
+		}
+	}
+
 	static var timelineSortDirection: ComparisonResult {
 		get {
 			return sortDirection(for: Key.timelineSortDirection)

Mac/AppDelegate.swift

@@ -309,6 +309,9 @@ class AppDelegate: NSObject, NSApplicationDelegate, NSUserInterfaceValidations,
 		if item.action == #selector(showAddFeedWindow(_:)) || item.action == #selector(showAddFolderWindow(_:)) {
 			return !isDisplayingSheet && !AccountManager.shared.activeAccounts.isEmpty
 		}
+		if item.action == #selector(toggleWebInspectorEnabled(_:)) {
+			(item as! NSMenuItem).state = AppDefaults.webInspectorEnabled ? .on : .off
+		}
 		return true
 	}
 
@@ -525,6 +528,15 @@ extension AppDelegate {
 	@IBAction func debugSearch(_ sender: Any?) {
 		AccountManager.shared.defaultAccount.debugRunSearch()
 	}
+
+	@IBAction func toggleWebInspectorEnabled(_ sender: Any?) {
+		let newValue = !AppDefaults.webInspectorEnabled
+		AppDefaults.webInspectorEnabled = newValue
+		// An attached inspector can display incorrectly on certain setups (like mine); default to displaying in a separate window,
+		// And reset to a separate window when the preference is toggled off and on again in case the inspector is accidentally reattached.
+		UserDefaults.standard.set(false, forKey: "__WebInspectorPageGroupLevel1__.WebKit2InspectorStartsAttached")
+		NotificationCenter.default.post(name: .WebInspectorEnabledDidChange, object: newValue)
+	}
 }
 
 private extension AppDelegate {

Mac/Base.lproj/Main.storyboard

@@ -469,6 +469,13 @@
                                                 <action selector="debugSearch:" target="Ady-hI-5gd" id="HvM-F7-u7s"/>
                                             </connections>
                                         </menuItem>
+                                        <menuItem isSeparatorItem="YES" id="OOI-Hk-eqi"/>
+                                        <menuItem title="Enable Web Inspector" id="EwI-z4-ZA3">
+                                            <modifierMask key="keyEquivalentModifierMask"/>
+                                            <connections>
+                                                <action selector="toggleWebInspectorEnabled:" target="Voe-Tx-rLC" id="nsd-PV-Tz2"/>
+                                            </connections>
+                                        </menuItem>
                                     </items>
                                 </menu>
                             </menuItem>

Mac/MainWindow/Detail/DetailWebViewController.swift

@@ -27,6 +27,22 @@ final class DetailWebViewController: NSViewController, WKUIDelegate {
 			}
 		}
 	}
+
+	private var webInspectorEnabled: Bool {
+		get {
+			if let webView = webView {
+				let val: NSNumber? = webView.configuration.preferences.value(forKey: "developerExtrasEnabled") as? NSNumber
+				return val != nil ? val!.boolValue : false
+			}
+
+			return false
+		}
+		set {
+			if let webView = webView {
+				webView.configuration.preferences.setValue(newValue, forKey: "developerExtrasEnabled")
+			}
+		}
+	}
 	
 	private var waitingForFirstReload = false
 	private let keyboardDelegate = DetailKeyboardDelegate()
@@ -87,6 +103,12 @@ final class DetailWebViewController: NSViewController, WKUIDelegate {
 		webView.isHidden = true
 		waitingForFirstReload = true
 
+		webInspectorEnabled = AppDefaults.webInspectorEnabled
+
+		NotificationCenter.default.addObserver(forName: .WebInspectorEnabledDidChange, object: nil, queue: OperationQueue.main) { (notification) in
+			self.webInspectorEnabled = notification.object! as! Bool
+		}
+
 		reloadHTML()
 	}
 

Shared/AppNotifications.swift

@@ -13,6 +13,7 @@ extension Notification.Name {
 	static let InspectableObjectsDidChange = Notification.Name("TimelineSelectionDidChangeNotification")
 	static let UserDidAddFeed = Notification.Name("UserDidAddFeedNotification")
 	static let UserDidRequestSidebarSelection = Notification.Name("UserDidRequestSidebarSelectionNotification")
+	static let WebInspectorEnabledDidChange = Notification.Name("WebInspectorEnabledDidChange")
 }
 
 typealias UserInfoDictionary = [AnyHashable: Any]