Change the way height of custom scroll view is computed

Author: intitni

Core/Sources/SuggestionWidget/CustomScrollView/CustomScrollView.swift

@@ -1,27 +1,46 @@
 import AppKit
-import SwiftUI
 import Combine
+import SwiftUI
+
+struct CustomScrollViewHeightPreferenceKey: PreferenceKey {
+    static var defaultValue: Double = 0
+    static func reduce(value: inout Double, nextValue: () -> Double) {
+        value = nextValue() + value
+    }
+}
+
+struct CustomScrollViewUpdateHeightModifier: ViewModifier {
+    func body(content: Content) -> some View {
+        content
+            .background {
+                GeometryReader { proxy in
+                    Color.clear
+                        .preference(
+                            key: CustomScrollViewHeightPreferenceKey.self,
+                            value: proxy.size.height
+                        )
+                }
+            }
+    }
+}
 
 /// 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
+    @State var height: Double = 10
     @AppStorage(\.useCustomScrollViewWorkaround) var useNSScrollViewWrapper
 
     var body: some View {
         if useNSScrollViewWrapper {
             List {
                 content()
                     .listRowInsets(EdgeInsets(top: 0, leading: -8, bottom: 0, trailing: -8))
+                    .modifier(CustomScrollViewUpdateHeightModifier())
             }
             .listStyle(.plain)
-            .frame(idealHeight: height)
-            .background {
-                ComputeHeight(height: $height) {
-                    content()
-                }
-                .frame(maxWidth: .infinity)
-                .opacity(0)
+            .frame(idealHeight: max(10, height))
+            .onPreferenceChange(CustomScrollViewHeightPreferenceKey.self) { newHeight in
+                height = newHeight
             }
         } else {
             ScrollView {
@@ -30,31 +49,3 @@ struct CustomScrollView<Content: View>: View {
         }
     }
 }
-
-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
-
-        if height != size.height {
-            Task { @MainActor in
-                height = size.height
-            }
-        }
-    }
-}