feat(assistant): animate copy confirmation icons

Frameworks/TermindPresentation/AssistantCompactToolDetails.swift

@@ -36,7 +36,7 @@ public struct AssistantCompactToolDetails: View {
                         expanded ? AppStrings.Assistant.showLess.swiftUIKey : AppStrings.Assistant.showMore.swiftUIKey
                     ) { expanded.toggle() }
                     .accessibilityIdentifier("AssistantTool.More")
-                    Button(AppStrings.Common.copy.swiftUIKey, systemImage: "doc.on.doc") { copy(preview.fullText) }
+                    AssistantCopyButton(text: preview.fullText, copy: copy)
                         .accessibilityIdentifier("AssistantTool.Copy")
                 }
                 .font(.caption)

Frameworks/TermindPresentation/AssistantCopyButton.swift

@@ -0,0 +1,47 @@
+import SwiftUI
+
+public struct AssistantCopyButton: View {
+    private let text: String
+    private let minimumLabelSize: CGFloat?
+    private let copy: (String) -> Void
+    @State private var copied = false
+    @State private var copyID = UUID()
+
+    public init(text: String, minimumLabelSize: CGFloat? = nil, copy: @escaping (String) -> Void) {
+        self.text = text
+        self.minimumLabelSize = minimumLabelSize
+        self.copy = copy
+    }
+
+    public var body: some View {
+        Button {
+            copy(text)
+            copied = true
+            copyID = UUID()
+        } label: {
+            Label {
+                Text(AppStrings.Common.copy)
+            } icon: {
+                // Keep the copy glyph's layout footprint when the narrower checkmark appears.
+                Image(systemName: "doc.on.doc")
+                    .hidden()
+                    .overlay {
+                        Image(systemName: copied ? "checkmark" : "doc.on.doc")
+                            .contentTransition(.symbolEffect(.replace))
+                    }
+            }
+            .frame(minWidth: minimumLabelSize, minHeight: minimumLabelSize)
+            .contentShape(.rect)
+        }
+        .accessibilityValue(Text(copied ? AppStrings.Common.copied : AppStrings.Common.copy))
+        .task(id: copyID) {
+            guard copied else { return }
+            do { try await Task.sleep(for: .seconds(1.4)) } catch { return }
+            copied = false
+        }
+        .onChange(of: text) { _, _ in
+            copied = false
+            copyID = UUID()
+        }
+    }
+}

Frameworks/TermindPresentation/AssistantToolDetails.swift

@@ -70,7 +70,7 @@ public struct AssistantToolDetails: View {
                 HStack {
                     Text(AppStrings.Assistant.outputShortenedForDisplay).font(.caption2).foregroundStyle(.secondary)
                     if let copy {
-                        Button(AppStrings.Common.copy.swiftUIKey, systemImage: "doc.on.doc") { copy(preview.full) }
+                        AssistantCopyButton(text: preview.full, copy: copy)
                             .font(.caption).frame(minHeight: 44)
                     }
                 }

TFI/Features/AI/MobileAssistantConversation.swift

@@ -681,8 +681,8 @@ struct MobileAssistantConversation: View {
                     .foregroundStyle(.red)
                     .textSelection(.enabled)
                     .frame(maxWidth: .infinity, alignment: .leading)
-                Button(AppStrings.Common.copy.swiftUIKey, systemImage: "doc.on.doc") {
-                    UIPasteboard.general.string = failure.reason
+                AssistantCopyButton(text: failure.reason) {
+                    UIPasteboard.general.string = $0
                 }
                 .labelStyle(.iconOnly)
                 .buttonStyle(.plain)
@@ -809,9 +809,13 @@ struct MobileAssistantConversation: View {
                 }
             }
 
-            messageAction(AppStrings.Common.copy, systemImage: "doc.on.doc") {
-                UIPasteboard.general.string = message.text
+            AssistantCopyButton(text: message.text, minimumLabelSize: 44) {
+                UIPasteboard.general.string = $0
             }
+            .font(.caption)
+            .labelStyle(.iconOnly)
+            .buttonStyle(.plain)
+            .foregroundStyle(.secondary)
 
             if let origin = message.origin {
                 let presentation = MobileAssistantAgentOriginPresentation(

TFM/Features/AI/TranscriptNativeRows.swift

@@ -2813,8 +2813,26 @@ private class NativeButton: NSButton {
     @objc private func run() { handler?() }
 }
 
+@MainActor
+private final class NativeCopyButtonCell: NSButtonCell {
+    // The image view draws the symbol so it can use the system replacement transition.
+    // Retain the cell's image and metrics for the existing button layout.
+    override func drawImage(_ image: NSImage, withFrame frame: NSRect, in controlView: NSView) {}
+}
+
+@MainActor
+private final class NativeCopySymbolView: NSImageView {
+    override func hitTest(_ point: NSPoint) -> NSView? { nil }
+}
+
 @MainActor
 private final class NativeCopyButton: NativeButton {
+    override class var cellClass: AnyClass? {
+        get { NativeCopyButtonCell.self }
+        set {}
+    }
+
+    private let symbolView = NativeCopySymbolView()
     private let copiedImage = NSImage(
         systemSymbolName: "checkmark",
         accessibilityDescription: String(localized: AppStrings.Common.copied)
@@ -2831,16 +2849,28 @@ private final class NativeCopyButton: NativeButton {
         image = copyImage
         imagePosition = .imageOnly
         toolTip = help
+        setAccessibilityLabel(help)
         widthAnchor.constraint(equalToConstant: 28).isActive = true
         heightAnchor.constraint(equalToConstant: 28).isActive = true
+        symbolView.image = copyImage
+        symbolView.imageScaling = .scaleNone
+        symbolView.symbolConfiguration = NSImage.SymbolConfiguration(
+            pointSize: NSFont.systemFontSize(for: controlSize),
+            weight: .regular
+        )
+        symbolView.setAccessibilityElement(false)
+        addSubview(symbolView)
         handler = { [weak self] in
             guard copyToPasteboard(text), let self else { return }
-            image = copiedImage
+            showSymbol(copiedImage)
             toolTip = String(localized: AppStrings.Common.copied)
+            setAccessibilityValue(toolTip)
             resetWorkItem?.cancel()
             let work = DispatchWorkItem { [weak self] in
-                self?.image = self?.copyImage
-                self?.toolTip = String(localized: AppStrings.Common.copy)
+                guard let self else { return }
+                showSymbol(copyImage)
+                toolTip = String(localized: AppStrings.Common.copy)
+                setAccessibilityValue(nil)
             }
             resetWorkItem = work
             DispatchQueue.main.asyncAfter(deadline: .now() + 1.4, execute: work)
@@ -2848,4 +2878,18 @@ private final class NativeCopyButton: NativeButton {
     }
     @available(*, unavailable)
     required init?(coder: NSCoder) { fatalError() }
+
+    override func layout() {
+        super.layout()
+        symbolView.frame = bounds
+    }
+
+    private func showSymbol(_ image: NSImage?) {
+        guard let image, symbolView.image !== image else { return }
+        if NSWorkspace.shared.accessibilityDisplayShouldReduceMotion {
+            symbolView.image = image
+        } else {
+            symbolView.setSymbolImage(image, contentTransition: .replace)
+        }
+    }
 }