Add wide accessory view to ShyHeaderView

ios/FluentUI.Demo/FluentUI.Demo/Demos/NavigationControllerDemoController.swift

@@ -15,6 +15,7 @@ class NavigationControllerDemoController: DemoController {
         addTitle(text: "Large Title with Primary style")
         container.addArrangedSubview(createButton(title: "Show without accessory", action: #selector(showLargeTitle)))
         container.addArrangedSubview(createButton(title: "Show with collapsible search bar", action: #selector(showLargeTitleWithShyAccessory)))
+        container.addArrangedSubview(createButton(title: "Show with collapsible search bar and pill segmented control", action: #selector(showLargeTitleWithShyAccessoryAndSecondaryAccessory)))
         container.addArrangedSubview(createButton(title: "Show with fixed search bar", action: #selector(showLargeTitleWithFixedAccessory)))
         container.addArrangedSubview(createButton(title: "Show without an avatar", action: #selector(showLargeTitleWithoutAvatar)))
         container.addArrangedSubview(createButton(title: "Show with a custom leading button", action: #selector(showLargeTitleWithCustomLeadingButton)))
@@ -56,6 +57,9 @@ class NavigationControllerDemoController: DemoController {
         addTitle(text: "Top Accessory View")
         container.addArrangedSubview(createButton(title: "Show with top search bar for large screen width", action: #selector(showWithTopSearchBar)))
 
+        addTitle(text: "Top Accessory View with shy wide accessory view")
+        container.addArrangedSubview(createButton(title: "Show with top search bar for large screen width with a shy pill segment control", action: #selector(showWithTopSearchBarWithShySecondaryAccessoryView)))
+
         addTitle(text: "Change Style Periodically")
         container.addArrangedSubview(createButton(title: "Change the style every second", action: #selector(showSearchChangingStyleEverySecond)))
     }
@@ -87,6 +91,10 @@ class NavigationControllerDemoController: DemoController {
         presentController(withTitleStyle: .largeLeading, accessoryView: createAccessoryView(), contractNavigationBarOnScroll: true)
     }
 
+    @objc func showLargeTitleWithShyAccessoryAndSecondaryAccessory() {
+        presentController(withTitleStyle: .largeLeading, accessoryView: createAccessoryView(), secondaryAccessoryView: createSecondaryAccessoryView(), contractNavigationBarOnScroll: true)
+    }
+
     @objc func showLargeTitleWithFixedAccessory() {
         presentController(withTitleStyle: .largeLeading, accessoryView: createAccessoryView(), contractNavigationBarOnScroll: false)
     }
@@ -189,6 +197,10 @@ class NavigationControllerDemoController: DemoController {
         presentController(withTitleStyle: .largeLeading, style: .system, accessoryView: createAccessoryView(with: .onSystemNavigationBar), showsTopAccessory: true, contractNavigationBarOnScroll: false)
     }
 
+    @objc func showWithTopSearchBarWithShySecondaryAccessoryView() {
+        presentController(withTitleStyle: .largeLeading, style: .system, accessoryView: createAccessoryView(with: .onSystemNavigationBar), secondaryAccessoryView: createSecondaryAccessoryView(), showsTopAccessory: true, contractNavigationBarOnScroll: true)
+    }
+
     @objc func showSearchChangingStyleEverySecond() {
         presentController(withTitleStyle: .largeLeading, style: .system, accessoryView: createAccessoryView(with: .onSystemNavigationBar), showsTopAccessory: true, contractNavigationBarOnScroll: false, updateStylePeriodically: true)
     }
@@ -207,6 +219,7 @@ class NavigationControllerDemoController: DemoController {
                                    subtitle: String? = nil,
                                    style: NavigationBar.Style = .primary,
                                    accessoryView: UIView? = nil,
+                                   secondaryAccessoryView: UIView? = nil,
                                    showsTopAccessory: Bool = false,
                                    contractNavigationBarOnScroll: Bool = true,
                                    showShadow: Bool = true,
@@ -219,6 +232,7 @@ class NavigationControllerDemoController: DemoController {
         content.navigationItem.navigationBarStyle = style
         content.navigationItem.navigationBarShadow = showShadow ? .automatic : .alwaysHidden
         content.navigationItem.accessoryView = accessoryView
+        content.navigationItem.secondaryAccessoryView = secondaryAccessoryView
         content.navigationItem.topAccessoryViewAttributes = NavigationBarTopSearchBarAttributes()
         content.navigationItem.contentScrollView = contractNavigationBarOnScroll ? content.tableView : nil
         content.showsTopAccessoryView = showsTopAccessory
@@ -295,6 +309,16 @@ class NavigationControllerDemoController: DemoController {
         return searchBar
     }
 
+    private func createSecondaryAccessoryView() -> UIView {
+        let segmentControl = createSegmentedControl(compatibleWith: .system)
+        let stackView = UIStackView()
+        stackView.addArrangedSubview(segmentControl)
+        stackView.layoutMargins = UIEdgeInsets(top: 10, left: 16, bottom: 10, right: 16)
+        stackView.isLayoutMarginsRelativeArrangement = true
+        stackView.backgroundColor = view.fluentTheme.color(.background1)
+        return stackView
+    }
+
     private func createSegmentedControl(compatibleWith style: NavigationBar.Style) -> UIView {
         let segmentItems: [SegmentItem] = [
             SegmentItem(title: "First"),
@@ -481,6 +505,7 @@ class RootViewController: UIViewController, UITableViewDataSource, UITableViewDe
     }
 
     var showsTopAccessoryView: Bool = false
+    var secondaryAccessoryView: UIView?
 
     var personaData: PersonaData = {
         let personaData = PersonaData(name: "Kat Larsson", image: UIImage(named: "avatar_kat_larsson"))
@@ -835,13 +860,20 @@ class RootViewController: UIViewController, UITableViewDataSource, UITableViewDe
 extension RootViewController: SearchBarDelegate {
     func searchBarDidBeginEditing(_ searchBar: SearchBar) {
         searchBar.progressSpinner.state.isAnimating = false
+        if navigationItem.secondaryAccessoryView != nil && !showsTopAccessoryView {
+            secondaryAccessoryView = navigationItem.secondaryAccessoryView
+            navigationItem.secondaryAccessoryView = nil
+        }
     }
 
     func searchBar(_ searchBar: SearchBar, didUpdateSearchText newSearchText: String?) {
     }
 
     func searchBarDidCancel(_ searchBar: SearchBar) {
         searchBar.progressSpinner.state.isAnimating = false
+        if secondaryAccessoryView != nil && !showsTopAccessoryView {
+            navigationItem.secondaryAccessoryView = secondaryAccessoryView
+        }
     }
 
     func searchBarDidRequestSearch(_ searchBar: SearchBar) {

ios/FluentUI/Navigation/Shy Header/ShyHeaderController.swift

@@ -45,6 +45,7 @@ class ShyHeaderController: UIViewController {
     }
 
     private var accessoryViewObservation: NSKeyValueObservation?
+    private var secondaryAccessoryViewObservation: NSKeyValueObservation?
 
     private var navigationBarCenterObservation: NSKeyValueObservation?
     private var navigationBarStyleObservation: NSKeyValueObservation?
@@ -101,6 +102,10 @@ class ShyHeaderController: UIViewController {
         accessoryViewObservation = contentViewController.navigationItem.observe(\UINavigationItem.accessoryView) { [weak self] item, _ in
             self?.shyHeaderView.accessoryView = item.accessoryView
         }
+
+        secondaryAccessoryViewObservation = contentViewController.navigationItem.observe(\UINavigationItem.secondaryAccessoryView) { [weak self] item, _ in
+            self?.shyHeaderView.secondaryAccessoryView = item.secondaryAccessoryView
+        }
     }
 
     required init?(coder aDecoder: NSCoder) {
@@ -211,8 +216,10 @@ class ShyHeaderController: UIViewController {
     }
 
     private func setupShyHeaderView() {
-        shyHeaderView.accessoryView = contentViewController.navigationItem.accessoryView
-        shyHeaderView.navigationBarShadow = contentViewController.navigationItem.navigationBarShadow
+        let navigationItem = contentViewController.navigationItem
+        shyHeaderView.accessoryView = navigationItem.accessoryView
+        shyHeaderView.secondaryAccessoryView = navigationItem.secondaryAccessoryView
+        shyHeaderView.navigationBarShadow = navigationItem.navigationBarShadow
         shyHeaderView.paddingView = paddingView
         shyHeaderView.parentController = self
         shyHeaderView.maxHeightChanged = { [weak self] in

ios/FluentUI/Navigation/Shy Header/ShyHeaderView.swift

@@ -72,6 +72,7 @@ class ShyHeaderView: UIView, TokenizedControlInternal {
         tokenSet.registerOnUpdate(for: self) { [weak self] in
             self?.updateColors()
         }
+        self.initSecondaryContentStackView()
     }
 
     override func willMove(toWindow newWindow: UIWindow?) {
@@ -125,6 +126,13 @@ class ShyHeaderView: UIView, TokenizedControlInternal {
         willSet {
             accessoryView?.removeFromSuperview()
             contentStackView.removeFromSuperview()
+            // When there is no accessoryView, the top anchor of the secondaryContentStackView should be equal to
+            // the top anchor of the parent view.
+            if let secondaryContentStackViewTopAnchorConstraint {
+                NSLayoutConstraint.activate([
+                    secondaryContentStackViewTopAnchorConstraint
+                ])
+            }
         }
         didSet {
             if let newContentView = accessoryView {
@@ -135,13 +143,39 @@ class ShyHeaderView: UIView, TokenizedControlInternal {
         }
     }
 
-    var maxHeight: CGFloat {
+    var secondaryAccessoryView: UIView? {
+        willSet {
+            secondaryAccessoryView?.removeFromSuperview()
+        }
+        didSet {
+            if let newContentView = secondaryAccessoryView {
+                secondaryContentStackView.addArrangedSubview(newContentView)
+            }
+            maxHeightChanged?()
+        }
+    }
+
+    var accessoryViewHeight: CGFloat {
         if accessoryView == nil {
             return maxHeightNoAccessory
         } else {
             return contentTopInset + Constants.accessoryHeight + contentBottomInset
         }
     }
+
+    var secondaryAccessoryViewHeight: CGFloat {
+        guard let secondaryAccessoryView else {
+            return 0.0
+        }
+
+        let secondaryAccessoryViewSize = secondaryAccessoryView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize)
+        return secondaryAccessoryViewSize.height
+    }
+
+    var maxHeight: CGFloat {
+        return accessoryViewHeight + secondaryAccessoryViewHeight
+    }
+
     private var maxHeightNoAccessory: CGFloat {
         if traitCollection.verticalSizeClass == .compact {
             return traitCollection.horizontalSizeClass == .compact ? Constants.maxHeightNoAccessoryCompact : Constants.maxHeightNoAccessoryCompactForLargePhone
@@ -186,6 +220,9 @@ class ShyHeaderView: UIView, TokenizedControlInternal {
     }
 
     private let contentStackView = UIStackView()
+    private var contentStackViewHeightConstraint: NSLayoutConstraint?
+    private let secondaryContentStackView = UIStackView()
+    private var secondaryContentStackViewTopAnchorConstraint: NSLayoutConstraint?
     private let shadow = Separator()
 
     private var needsShadow: Bool {
@@ -222,12 +259,45 @@ class ShyHeaderView: UIView, TokenizedControlInternal {
 
     private func initContentStackView() {
         contentStackView.isLayoutMarginsRelativeArrangement = true
+        contentStackView.translatesAutoresizingMaskIntoConstraints = false
         addSubview(contentStackView)
-        contentStackView.fitIntoSuperview(usingConstraints: true)
+
+        // When there is a accessoryView, the top anchor of the secondaryContentStackView should be equal to
+        // the bottom anchor of contentStackView.
+        if let secondaryContentStackViewTopAnchorConstraint {
+            NSLayoutConstraint.deactivate([
+                secondaryContentStackViewTopAnchorConstraint
+            ])
+        }
+
+        let heightConstraint = contentStackView.heightAnchor.constraint(equalToConstant: accessoryViewHeight)
+        contentStackViewHeightConstraint = heightConstraint
+        NSLayoutConstraint.activate([
+            contentStackView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            contentStackView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            contentStackView.topAnchor.constraint(equalTo: topAnchor),
+            contentStackView.bottomAnchor.constraint(equalTo: secondaryContentStackView.topAnchor),
+            heightConstraint
+        ])
         updateContentInsets()
         contentStackView.addInteraction(UILargeContentViewerInteraction())
     }
 
+    private func initSecondaryContentStackView() {
+        secondaryContentStackView.translatesAutoresizingMaskIntoConstraints = false
+        addSubview(secondaryContentStackView)
+        let topAnchorConstraint = secondaryContentStackView.topAnchor.constraint(equalTo: topAnchor)
+        secondaryContentStackViewTopAnchorConstraint = topAnchorConstraint
+        NSLayoutConstraint.activate([
+            secondaryContentStackView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            secondaryContentStackView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            topAnchorConstraint,
+            secondaryContentStackView.bottomAnchor.constraint(equalTo: bottomAnchor)
+        ])
+
+        secondaryContentStackView.addInteraction(UILargeContentViewerInteraction())
+    }
+
     private func initShadow() {
         let shadowView = shadow
         shadowView.translatesAutoresizingMaskIntoConstraints = false

ios/FluentUI/Navigation/UINavigationItem+Navigation.swift

@@ -8,6 +8,7 @@ import UIKit
 @objc public extension UINavigationItem {
     private struct AssociatedKeys {
         static var accessoryView: UInt8 = 0
+        static var secondaryAccessoryView: UInt8 = 0
         static var titleAccessory: UInt8 = 0
         static var titleImage: UInt8 = 0
         static var topAccessoryView: UInt8 = 0
@@ -31,6 +32,18 @@ import UIKit
         }
     }
 
+    /// An wide accessory view that can be shown as a subview of ShyHeaderView but doesn't have leading, trailing
+    /// and bottom insets. So it can appear as being part of the content view but still contract and expand as part of
+    /// the shy header.
+    var secondaryAccessoryView: UIView? {
+        get {
+            return objc_getAssociatedObject(self, &AssociatedKeys.secondaryAccessoryView) as? UIView
+        }
+        set {
+            objc_setAssociatedObject(self, &AssociatedKeys.secondaryAccessoryView, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+        }
+    }
+
     /// Defines an accessory shown after the title or subtitle in a navigation bar. When defined, this gives the indication that the title can be tapped to show additional information.
     var titleAccessory: NavigationBarTitleAccessory? {
         get {