Add CustomScrollView backed by single cell List

Author: intitni

Copilot for Xcode/DebugView.swift

@@ -9,6 +9,7 @@ final class DebugSettings: ObservableObject {
     var preCacheOnFileOpen: Bool
     @AppStorage(\.runNodeWithInteractiveLoggedInShell)
     var runNodeWithInteractiveLoggedInShell: Bool
+    @AppStorage(\.useCustomScrollViewWorkaround) var useCustomScrollViewWorkaround
     init() {}
 }
 
@@ -30,6 +31,10 @@ struct DebugSettingsView: View {
                     Text("Run node with interactive logged-in bash")
                 }
                 .toggleStyle(.switch)
+                Toggle(isOn: $settings.useCustomScrollViewWorkaround) {
+                    Text("Use custom scroll view workaround for smooth scrolling")
+                }
+                .toggleStyle(.switch)
             }
         }.buttonStyle(.copilot)
     }

Core/Sources/Preferences/Keys.swift

@@ -174,6 +174,7 @@ public struct UserDefaultPreferenceKeys {
     public var preCacheOnFileOpen: FeatureFlags.PreCacheOnFileOpen { .init() }
     public var runNodeWithInteractiveLoggedInShell: FeatureFlags
         .RunNodeWithInteractiveLoggedInShell { .init() }
+    public var useCustomScrollViewWorkaround: FeatureFlags.UseCustomScrollViewWorkaround { .init() }
 }
 
 public enum FeatureFlags {
@@ -191,4 +192,9 @@ public enum FeatureFlags {
         public let defaultValue = true
         public let key = "FeatureFlag-RunNodeWithInteractiveLoggedInShell"
     }
+    
+    public struct UseCustomScrollViewWorkaround: UserDefaultPreferenceKey {
+        public let defaultValue = true
+        public let key = "FeatureFlag-UseCustomScrollViewWorkaround"
+    }
 }

Core/Sources/SuggestionWidget/NSScrollView/CustomScrollView.swift

@@ -0,0 +1,61 @@
+import AppKit
+import SwiftUI
+import Combine
+
+/// Used to workaround a SwiftUI bug. https://github.com/intitni/CopilotForXcode/issues/122
+struct CustomScrollView<Content: View>: View {
+    @ViewBuilder var content: () -> Content
+    @State var height: Double = 100
+    @AppStorage(\.useCustomScrollViewWorkaround) var useNSScrollViewWrapper
+
+    var body: some View {
+        if useNSScrollViewWrapper {
+            List {
+                content()
+                    .listRowInsets(EdgeInsets(top: 0, leading: -8, bottom: 0, trailing: -8))
+            }
+            .listStyle(.plain)
+            .frame(idealHeight: height)
+            .background {
+                ComputeHeight(height: $height) {
+                    content()
+                }
+                .frame(maxWidth: .infinity)
+                .opacity(0)
+            }
+        } else {
+            ScrollView {
+                content()
+            }
+        }
+    }
+}
+
+private struct ComputeHeight<Content: View>: NSViewRepresentable {
+    @Binding var height: Double
+    @ViewBuilder var content: () -> Content
+
+    func makeNSView(context: Context) -> NSView {
+        let view = NSView()
+        return view
+    }
+
+    func updateNSView(_ nsView: NSView, context: Context) {
+        updateHeight(nsView)
+    }
+    
+    func updateHeight(_ nsView: NSView) {
+        let contentView = content()
+        let hostingView = NSHostingView(
+            rootView: contentView.frame(width: nsView.frame.width == 0 ? 200 : nsView.frame.width)
+        )
+        let size = hostingView.fittingSize
+        print(size)
+
+        if height != size.height {
+            Task { @MainActor in
+                height = size.height
+            }
+        }
+    }
+}

Core/Sources/SuggestionWidget/SuggestionPanelContent/ChatPanel.swift

@@ -78,7 +78,7 @@ struct ChatPanelMessages: View {
     }
 
     var body: some View {
-        ScrollView {
+        CustomScrollView {
             vstack {
                 let r = 8 as Double
 
@@ -103,7 +103,7 @@ struct ChatPanelMessages: View {
                                 .stroke(Color(nsColor: .separatorColor), lineWidth: 1)
                         }
                     }
-                    .buttonStyle(.plain)
+                    .buttonStyle(.borderless)
                     .scaleEffect(x: -1, y: 1, anchor: .center)
                 }
 
@@ -403,7 +403,7 @@ struct CopyButton: View {
                 )
                 .padding(4)
         }
-        .buttonStyle(.plain)
+        .buttonStyle(.borderless)
     }
 }
 

Core/Sources/SuggestionWidget/SuggestionPanelContent/CodeBlockSuggestionPanel.swift

@@ -48,7 +48,7 @@ struct CodeBlockSuggestionPanel: View {
 
     var body: some View {
         VStack(spacing: 0) {
-            ScrollView {
+            CustomScrollView {
                 CodeBlock(
                     code: suggestion.code,
                     language: suggestion.language,

Core/Sources/SuggestionWidget/SuggestionPanelContent/PromptToCodePanel.swift

@@ -7,7 +7,7 @@ struct PromptToCodePanel: View {
 
     var body: some View {
         VStack(spacing: 0) {
-            ScrollView {
+            CustomScrollView {
                 VStack(spacing: 0) {
                     if !provider.errorMessage.isEmpty {
                         Text(provider.errorMessage)