Add collapsible session list sidebar

.gitignore

@@ -18,3 +18,4 @@ Pods/
 Carthage
 Provisioning
 TeamID.xcconfig
+CLAUDE.md

WWDC/Bootstrap/AppCoordinator.swift

@@ -248,6 +248,15 @@ final class AppCoordinator: Logging, Signposting {
         videosController.listViewController.$selectedSession.assign(to: &self.$videosSelectedSessionViewModel)
         scheduleController.splitViewController.listViewController.$selectedSession.assign(to: &self.$scheduleSelectedSessionViewModel)
 
+        // Enable the sidebar toggle only on tabs that have a session-list sidebar.
+        tabController.$activeTabVar
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] activeTab in
+                guard let self else { return }
+                self.windowController.titleBarViewController.sidebarToggleButton.isEnabled = activeTab.hasSidebar
+            }
+            .store(in: &cancellables)
+
         Publishers.CombineLatest3(
             tabController.$activeTabVar,
             $videosSelectedSessionViewModel,

WWDC/Controllers/Base/MainWindowController.swift

@@ -23,6 +23,9 @@ enum MainWindowTab: Int, WWDCTab {
     }
 
     var hidesWindowTitleBar: Bool { self == .explore }
+
+    /// Whether this tab shows the collapsible session-list sidebar.
+    var hasSidebar: Bool { self == .schedule || self == .videos }
 }
 
 extension Notification.Name {
@@ -41,7 +44,14 @@ final class MainWindowController: WWDCWindowController {
         return NSScreen.main?.visibleFrame.insetBy(dx: 50, dy: 120) ??
                NSRect(x: 0, y: 0, width: 1200, height: 600)
     }
-    public var sidebarInitWidth: CGFloat?
+
+    /// Shared, session-only sidebar layout state so both tabs agree and a
+    /// lazily-loaded tab adopts the current state. Not persisted across launches.
+    struct SidebarState {
+        var initialWidth: CGFloat?
+        var collapsed = false
+    }
+    var sidebarState = SidebarState()
 
     override func loadWindow() {
         let mask: NSWindow.StyleMask = [.titled, .resizable, .miniaturizable, .closable, .fullSizeContentView]

WWDC/Controllers/Base/TitleBarViewController.swift

@@ -6,12 +6,22 @@
 //  Copyright © 2018 Guilherme Rambo. All rights reserved.
 //
 
-import Foundation
+import Cocoa
+import OSLog
 
 final class TitleBarViewController: NSTitlebarAccessoryViewController {
 
     private var horizontalPositioningConstraints = [NSLayoutConstraint]()
 
+    /// Fallback leading inset used until the traffic-light buttons can be measured.
+    private static let trafficLightInset: CGFloat = 76
+
+    /// Gap between the rightmost traffic-light (zoom) button and the sidebar toggle.
+    private static let trafficLightGap: CGFloat = 8
+
+    /// Leading constraint for the toggle button; its constant tracks the traffic lights.
+    private var leadingButtonConstraint: NSLayoutConstraint?
+
     private var centerOffset: CGFloat = 0 {
         didSet {
             horizontalPositioningConstraints.forEach { $0.constant = centerOffset }
@@ -32,6 +42,58 @@ final class TitleBarViewController: NSTitlebarAccessoryViewController {
         return v
     }()
 
+    private lazy var leadingContainer: NSView = {
+        let v = NSView()
+        v.translatesAutoresizingMaskIntoConstraints = false
+
+        return v
+    }()
+
+    private static let log = Logger(subsystem: Bundle.main.bundleIdentifier ?? "io.wwdc.app", category: "TitleBarViewController")
+
+    private static func makeToggleSymbol() -> NSImage {
+        guard let image = NSImage(systemSymbolName: "sidebar.left", accessibilityDescription: "Toggle Sidebar") else {
+            assertionFailure("Missing system symbol: sidebar.left")
+            log.error("Missing system symbol sidebar.left; falling back to a text glyph for the sidebar toggle")
+            return fallbackToggleSymbol()
+        }
+        // withSymbolConfiguration returns nil if the configuration can't be applied;
+        // fall back to the unconfigured symbol rather than a blank image.
+        return image.withSymbolConfiguration(.init(pointSize: 15, weight: .regular)) ?? image
+    }
+
+    /// Visible last-resort glyph so the toggle button never renders blank if the
+    /// system symbol is unavailable.
+    private static func fallbackToggleSymbol() -> NSImage {
+        let glyph = "◧" as NSString
+        let attributes: [NSAttributedString.Key: Any] = [
+            .font: NSFont.systemFont(ofSize: 15, weight: .regular),
+            .foregroundColor: NSColor.labelColor
+        ]
+        let glyphSize = glyph.size(withAttributes: attributes)
+        let image = NSImage(size: NSSize(width: ceil(glyphSize.width), height: ceil(glyphSize.height)))
+        image.lockFocus()
+        glyph.draw(at: .zero, withAttributes: attributes)
+        image.unlockFocus()
+        image.isTemplate = true
+        return image
+    }
+
+    /// Sidebar collapse/expand toggle. Fires `toggleSidebar:` up the responder chain
+    /// so it reaches the active tab's split view controller. Exposed so the coordinator
+    /// can disable it on tabs that have no sidebar (Explore).
+    lazy var sidebarToggleButton: NSButton = {
+        let b = NSButton(image: Self.makeToggleSymbol(), target: nil, action: #selector(NSSplitViewController.toggleSidebar(_:)))
+        b.translatesAutoresizingMaskIntoConstraints = false
+        b.isBordered = false
+        b.imagePosition = .imageOnly
+        b.setButtonType(.momentaryChange)
+        b.imageScaling = .scaleProportionallyDown
+        b.toolTip = "Toggle Sidebar"
+
+        return b
+    }()
+
     var statusViewController: NSViewController? {
         didSet {
             replace(child: oldValue, with: statusViewController, inContainer: statusContainer)
@@ -57,14 +119,27 @@ final class TitleBarViewController: NSTitlebarAccessoryViewController {
     override func loadView() {
         let view = NSView()
 
+        view.addSubview(leadingContainer)
         view.addSubview(tabBarContainer)
         view.addSubview(statusContainer)
 
+        leadingContainer.addSubview(sidebarToggleButton)
+
+        let leadingConstraint = leadingContainer.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: Self.trafficLightInset)
+        leadingConstraint.isActive = true
+        leadingButtonConstraint = leadingConstraint
+        leadingContainer.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
+        leadingContainer.heightAnchor.constraint(equalTo: view.heightAnchor).isActive = true
+
+        sidebarToggleButton.leadingAnchor.constraint(equalTo: leadingContainer.leadingAnchor).isActive = true
+        sidebarToggleButton.trailingAnchor.constraint(equalTo: leadingContainer.trailingAnchor).isActive = true
+        sidebarToggleButton.centerYAnchor.constraint(equalTo: leadingContainer.centerYAnchor).isActive = true
+
         let centerXConstraint = tabBarContainer.centerXAnchor.constraint(equalTo: view.centerXAnchor)
         centerXConstraint.isActive = true
         horizontalPositioningConstraints.append(centerXConstraint)
         tabBarContainer.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
-        tabBarContainer.leadingAnchor.constraint(greaterThanOrEqualTo: view.leadingAnchor).isActive = true
+        tabBarContainer.leadingAnchor.constraint(greaterThanOrEqualTo: leadingContainer.trailingAnchor, constant: 8).isActive = true
         tabBarContainer.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor).isActive = true
 
         statusContainer.leadingAnchor.constraint(equalTo: tabBarContainer.trailingAnchor).isActive = true
@@ -85,6 +160,17 @@ final class TitleBarViewController: NSTitlebarAccessoryViewController {
         let windowBounds = window.convertFromScreen(window.frame)
         let localWindowBounds = view.convert(windowBounds, from: nil)
         centerOffset = localWindowBounds.midX - view.bounds.midX
+
+        // Tuck the sidebar toggle right up against the rightmost traffic-light (zoom) button.
+        if let constraint = leadingButtonConstraint,
+           let zoomButton = window.standardWindowButton(.zoomButton),
+           let buttonSuperview = zoomButton.superview {
+            let frameInWindow = buttonSuperview.convert(zoomButton.frame, to: nil)
+            let newConstant = view.convert(frameInWindow, from: nil).maxX + Self.trafficLightGap
+            if abs(constraint.constant - newConstant) > 0.5 {
+                constraint.constant = newConstant
+            }
+        }
     }
 
     func replace(child: NSViewController?, with newChild: NSViewController?, inContainer container: NSView) {

WWDC/Controllers/Sessions/SessionsSplitViewController.swift

@@ -23,6 +23,13 @@ final class SessionsSplitViewController: NSSplitViewController {
     var setupDone = false
     private var cancellables: Set<AnyCancellable> = []
 
+    /// The split view item hosting the session list sidebar. Retained so its
+    /// collapsed state can be toggled, observed and synced across tabs.
+    private var sidebarItem: NSSplitViewItem!
+
+    /// Guards against feedback loops while mirroring collapse state from another tab.
+    private var isSyncingCollapse = false
+
     init(windowController: MainWindowController, listViewController: SessionsTableViewController) {
         self.windowController = windowController
         self.listViewController = listViewController
@@ -39,6 +46,14 @@ final class SessionsSplitViewController: NSSplitViewController {
                 self?.syncSplitView(notification: notification)
             }
             .store(in: &cancellables)
+
+        NotificationCenter
+            .default
+            .publisher(for: .sideBarCollapseSyncNotification)
+            .sink { [weak self] notification in
+                self?.applyCollapseSync(notification: notification)
+            }
+            .store(in: &cancellables)
     }
 
     required init?(coder: NSCoder) {
@@ -51,22 +66,48 @@ final class SessionsSplitViewController: NSSplitViewController {
         view.wantsLayer = true
 
         let listItem = NSSplitViewItem(sidebarWithViewController: listViewController)
-        listItem.canCollapse = false
+        listItem.canCollapse = true
+        sidebarItem = listItem
         let detailItem = NSSplitViewItem(viewController: detailViewController)
 
         addSplitViewItem(listItem)
         addSplitViewItem(detailItem)
 
         listViewController.view.setContentHuggingPriority(.defaultHigh, for: .horizontal)
         detailViewController.view.setContentHuggingPriority(.defaultLow, for: .horizontal)
+
+        // Mirror collapse state to the other tab's split view so both stay consistent
+        // during a session. Catches both the toggleSidebar: action and drag-to-collapse.
+        listItem
+            .publisher(for: \.isCollapsed)
+            .dropFirst()
+            .removeDuplicates()
+            .sink { [weak self] collapsed in
+                guard let self, !self.isSyncingCollapse else { return }
+                // Record the shared session state so the other (possibly not-yet-loaded) tab adopts it.
+                self.windowController.sidebarState.collapsed = collapsed
+                NotificationCenter.default.post(
+                    name: .sideBarCollapseSyncNotification,
+                    object: self.splitView,
+                    userInfo: ["collapsed": collapsed]
+                )
+            }
+            .store(in: &cancellables)
     }
 
     override func viewWillAppear() {
         super.viewWillAppear()
 
         if !setupDone {
-            if let sidebarInitWidth = windowController.sidebarInitWidth {
-                splitView.setPosition(sidebarInitWidth, ofDividerAt: 0)
+            if let initWidth = windowController.sidebarState.initialWidth {
+                splitView.setPosition(initWidth, ofDividerAt: 0)
+            }
+            // Adopt the shared collapsed state in case it changed in another tab before
+            // this one was lazily loaded.
+            if sidebarItem.isCollapsed != windowController.sidebarState.collapsed {
+                isSyncingCollapse = true
+                sidebarItem.isCollapsed = windowController.sidebarState.collapsed
+                isSyncingCollapse = false
             }
             setupDone = true
         }
@@ -87,11 +128,19 @@ final class SessionsSplitViewController: NSSplitViewController {
 #endif
 
         guard notificationSourceSplitView !== splitView else {
-            // If own split view is altered, change split view initialisation width for other tabs
-            windowController.sidebarInitWidth = notificationSourceSplitView.subviews[targetSubviewIndex].bounds.width
+            // If own split view is altered, change split view initialisation width for other tabs.
+            // Skip while collapsed so the ~0pt collapsed width is never persisted as the sidebar width.
+            if !sidebarItem.isCollapsed, notificationSourceSplitView.subviews.indices.contains(targetSubviewIndex) {
+                windowController.sidebarState.initialWidth = notificationSourceSplitView.subviews[targetSubviewIndex].bounds.width
+            }
             return
         }
-        guard splitView.subviews.count > 0, notificationSourceSplitView.subviews.count > 0 else {
+        // If THIS tab's sidebar is already collapsed, skip applying the incoming width.
+        // Width-sync is throttled 250 ms so a trailing notification can arrive after
+        // the collapse-sync; calling setPosition here would re-expand the sidebar.
+        guard !sidebarItem.isCollapsed else { return }
+        guard splitView.subviews.indices.contains(targetSubviewIndex),
+              notificationSourceSplitView.subviews.indices.contains(targetSubviewIndex) else {
             return
         }
         guard splitView.subviews[targetSubviewIndex].bounds.width != notificationSourceSplitView.subviews[targetSubviewIndex].bounds.width else {
@@ -108,12 +157,30 @@ final class SessionsSplitViewController: NSSplitViewController {
     override func splitViewDidResizeSubviews(_ notification: Notification) {
         guard isResizingSplitView == false else { return }
         guard setupDone else { return }
+        // Don't broadcast a width sync for a collapse/expand; collapse state has its own sync.
+        guard !sidebarItem.isCollapsed else { return }
 
         // This notification should only be posted in response to user input
         NotificationCenter.default.post(name: .sideBarSizeSyncNotification, object: splitView, userInfo: nil)
     }
+
+    /// Mirrors a collapse/expand performed in another tab's split view onto this one.
+    private func applyCollapseSync(notification: Notification) {
+        // The split view item only exists once this tab's view has loaded. A not-yet-loaded
+        // tab will adopt the shared state via windowController.sidebarState.collapsed in viewWillAppear.
+        guard let sidebarItem else { return }
+        guard let sourceSplitView = notification.object as? NSSplitView, sourceSplitView !== splitView else { return }
+        guard let collapsed = notification.userInfo?["collapsed"] as? Bool else { return }
+        guard sidebarItem.isCollapsed != collapsed else { return }
+
+        // The inactive tab isn't visible, so apply directly without animation.
+        isSyncingCollapse = true
+        sidebarItem.isCollapsed = collapsed
+        isSyncingCollapse = false
+    }
 }
 
 extension Notification.Name {
     public static let sideBarSizeSyncNotification = NSNotification.Name("WWDCSplitViewSizeSyncNotification")
+    public static let sideBarCollapseSyncNotification = NSNotification.Name("WWDCSidebarCollapseSyncNotification")
 }

WWDC/Resources/Base.lproj/Main.storyboard

@@ -557,6 +557,13 @@
                                                 <action selector="viewVideos:" target="Ady-hI-5gd" id="xWC-aO-kEM"/>
                                             </connections>
                                         </menuItem>
+                                        <menuItem isSeparatorItem="YES" id="wwd-c0-sb0"/>
+                                        <menuItem title="Hide Sidebar" keyEquivalent="s" id="wwd-c0-sb1">
+                                            <modifierMask key="keyEquivalentModifierMask" control="YES" command="YES"/>
+                                            <connections>
+                                                <action selector="toggleSidebar:" target="Ady-hI-5gd" id="wwd-c0-sb2"/>
+                                            </connections>
+                                        </menuItem>
                                         <menuItem isSeparatorItem="YES" id="eT5-6l-QRY"/>
                                         <menuItem title="Reload" keyEquivalent="r" id="VAB-X3-ZCo">
                                             <connections>