Support async action arguments

Sources/Control/AsyncButton.swift

@@ -13,17 +13,18 @@ import SwiftUI
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, visionOS 1.0, *)
 public struct AsyncButton<Label: View>: AsyncControl {
     public typealias Base = Button<Label>
+    package typealias Value = ()
 
     private let priority: TaskPriority
     private let action: @Sendable () async -> Void
-    private let base: (_ trigger: _AsyncControlTrigger?) -> Base
+    private let base: (_ trigger: _AsyncControlTrigger<Value>?) -> Base
 
-    @State private var trigger: _AsyncControlTrigger? = nil
+    @State private var trigger: _AsyncControlTrigger<Value>? = nil
 
     private init(
         priority: TaskPriority,
         @_inheritActorContext action: @escaping @Sendable () async -> Void,
-        base: @escaping (_ trigger: _AsyncControlTrigger?) -> Base
+        base: @escaping (_ trigger: _AsyncControlTrigger<Value>?) -> Base
     ) {
         self.priority = priority
         self.action = action

Sources/Core/AsyncControl.swift

@@ -10,4 +10,5 @@ import SwiftUI
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, visionOS 1.0, *)
 package protocol AsyncControl: View {
     associatedtype Base: View
+    associatedtype Value
 }

Sources/Core/AsyncControlView.swift

@@ -8,17 +8,17 @@
 import SwiftUI
 
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, visionOS 1.0, *)
-package struct AsyncControlView<Base: View>: View {
+package struct AsyncControlView<Base: View, Value>: View {
     private let priority: TaskPriority
-    private let action: @Sendable () async -> Void
+    private let action: @Sendable (_ value: Value) async -> Void
     private let base: Base
 
-    @State private var idValue: Bool? = nil
+    @State private var idValue: IDValue? = nil
 
     @inlinable
     package init(
         priority: TaskPriority = .userInitiated,
-        @_inheritActorContext action: @escaping @Sendable () async -> Void,
+        @_inheritActorContext action: @escaping @Sendable (_ value: Value) async -> Void,
         base: Base
     ) {
         self.action = action
@@ -28,21 +28,28 @@ package struct AsyncControlView<Base: View>: View {
 
     package var body: some View {
         base
-            .preference(key: _AsyncControlTriggerPreferenceKey.self, value: .init(action: trigger))
+            .preference(key: _AsyncControlTriggerPreferenceKey.self, value: .init(action: trigger(newValue:)))
             .task(id: idValue, priority: priority, performAction)
     }
 
-    private func trigger() {
-        if idValue == nil {
-            idValue = true
-        } else {
-            idValue?.toggle()
-        }
+    private func trigger(newValue: Value) {
+        idValue = .init(value: newValue)
     }
 
     @Sendable
     private func performAction() async {
-        guard idValue != nil else { return }
-        await action()
+        guard let value = idValue?.value else { return }
+        await action(value)
+    }
+}
+
+extension AsyncControlView {
+    private struct IDValue: Identifiable, Equatable {
+        fileprivate let id = UUID()
+        fileprivate let value: Value
+
+        fileprivate static func == (lhs: Self, rhs: Self) -> Bool {
+            lhs.id == rhs.id
+        }
     }
 }

Sources/Core/_AsyncControlTrigger.swift

@@ -9,15 +9,19 @@ import Foundation
 
 /// - Warning: This `Equatable` compliance is a dummy implementation added for use in `SwiftUI.View.onPreferenceChange(_:perform:)`.
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, visionOS 1.0, *)
-package struct _AsyncControlTrigger: Equatable {
-    private let action: () -> Void
+package struct _AsyncControlTrigger<Value>: Equatable {
+    private let action: (_ value: Value) -> Void
 
-    init(action: @escaping () -> Void) {
+    init(action: @escaping (_ value: Value) -> Void) {
         self.action = action
     }
 
-    package func callAsFunction() {
-        action()
+    package func callAsFunction(_ value: Value) {
+        action(value)
+    }
+
+    package func callAsFunction() where Value == Void {
+        callAsFunction(())
     }
 
     package static func == (lhs: Self, rhs: Self) -> Bool {

Sources/Core/_AsyncControlTriggerPreferenceKey.swift

@@ -8,7 +8,7 @@
 import SwiftUI
 
 @available(iOS 15.0, macOS 12.0, macCatalyst 15.0, tvOS 15.0, watchOS 8.0, visionOS 1.0, *)
-package struct _AsyncControlTriggerPreferenceKey: PreferenceKey {
-    package static let defaultValue = _AsyncControlTrigger(action: {})
-    package static func reduce(value: inout _AsyncControlTrigger, nextValue: () -> _AsyncControlTrigger) {}
+package struct _AsyncControlTriggerPreferenceKey<Value>: PreferenceKey {
+    package static var defaultValue: _AsyncControlTrigger<Value> { fatalError("This property is not expected to be called.") }
+    package static func reduce(value: inout _AsyncControlTrigger<Value>, nextValue: () -> _AsyncControlTrigger<Value>) { fatalError("This function is not expected to be called.") }
 }