[macOS] Fix ObjC export of MultilinePillPickerView

Sources/FluentUI_macOS/Components/MultilinePillPicker/MultilinePillPickerView.swift

@@ -49,6 +49,6 @@ public final class MultilinePillPickerView: ControlHostingView {
 	private func updatePicker() {
 		let picker = MultilinePillPicker(labels: labels, action: action)
 			.disabled(!isEnabled)
-		rootView = AnyView(picker)
+		hostingView.rootView = AnyView(picker)
 	}
 }

Sources/FluentUI_macOS/Core/ControlHostingView.swift

@@ -6,32 +6,54 @@
 import AppKit
 import SwiftUI
 
-/// Common wrapper for hosting and exposing SwiftUI components to AppKit-based clients.
-open class ControlHostingView: NSHostingView<AnyView> {
+/// Common wrapper for hosting and exposing SwiftUI components to UIKit-based clients.
+open class ControlHostingView: NSView {
+
+	/// The intrinsic content size of the wrapped SwiftUI view.
+	@objc public override var intrinsicContentSize: CGSize {
+		// Our desired size should always be the same as our hosted view.
+		return hostingView.intrinsicContentSize
+	}
+
 	/// Initializes and returns an instance of `ControlHostingContainer` that wraps `controlView`.
 	///
 	/// Unfortunately this class can't use Swift generics, which are incompatible with Objective-C interop. Instead we have to wrap
 	/// the control view in an `AnyView.`
 	///
 	/// - Parameter controlView: An `AnyView`-wrapped component to host.
-	/// - Parameter safeAreaRegions: Passthrough to the respective property on NSHostingView.
+	/// - Parameter safeAreaRegions: Passthrough to the respective property on UIHostingController.
 	/// Indicates which safe area regions the underlying hosting controller should add to its view.
 	public init(_ controlView: AnyView, safeAreaRegions: SafeAreaRegions = .all) {
-		super.init(rootView: controlView)
+		hostingView = NSHostingView.init(rootView: controlView)
 		if #available(macOS 13.3, *) {
-			self.sizingOptions = [.intrinsicContentSize]
-			self.safeAreaRegions = safeAreaRegions
+			hostingView.sizingOptions = [.intrinsicContentSize]
+			hostingView.safeAreaRegions = safeAreaRegions
 		}
 
-		layer?.backgroundColor = .clear
-		translatesAutoresizingMaskIntoConstraints = false
+		super.init(frame: .zero)
+
+		self.configureHostedView()
 	}
 
-	@MainActor @preconcurrency required public init?(coder: NSCoder) {
+	required public init?(coder: NSCoder) {
 		preconditionFailure("init(coder:) has not been implemented")
 	}
-
-	@MainActor @preconcurrency required public init(rootView: AnyView) {
-		preconditionFailure("init(rootView:) has not been implemented")
+
+	let hostingView: NSHostingView<AnyView>
+
+	/// Adds `hostingController.view` to ourselves as a subview, and enables necessary constraints.
+	private func configureHostedView() {
+		hostingView.layer?.backgroundColor = NSColor.clear.cgColor
+
+		addSubview(hostingView)
+		hostingView.translatesAutoresizingMaskIntoConstraints = false
+
+		let requiredConstraints = [
+			hostingView.leadingAnchor.constraint(equalTo: leadingAnchor),
+			hostingView.trailingAnchor.constraint(equalTo: trailingAnchor),
+			hostingView.bottomAnchor.constraint(equalTo: bottomAnchor),
+			hostingView.topAnchor.constraint(equalTo: topAnchor)
+		]
+		self.addConstraints(requiredConstraints)
 	}
 }