perf(ThreadListView): Remove nested if

Mail/Utils/AdaptivePanelViewModifier.swift

@@ -31,17 +31,34 @@ struct AdaptivePanelViewModifier<Item: Identifiable, PanelContent: View>: ViewMo
     @Binding var item: Item?
     @ViewBuilder var panelContent: (Item) -> PanelContent
 
+    enum AdaptiveSizeType {
+        case compact
+        case regular
+    }
+
     func body(content: Content) -> some View {
-        if isCompactWindow {
-            content.floatingPanel(item: $item) { item in
+        content
+            .floatingPanel(item: getBindingForSize(.compact)) { item in
                 panelContent(item)
             }
-        } else {
-            content.popover(item: $item) { item in
+            .popover(item: getBindingForSize(.regular)) { item in
                 panelContent(item)
                     .padding()
                     .frame(idealWidth: 400)
             }
-        }
+    }
+
+    func getBindingForSize(_ size: AdaptiveSizeType) -> Binding<Item?> {
+        // We can't use if statement in this modifier because this creates performance issues in the List:
+        // => SwiftUI needs to  create each element of the list before rendering if an if statement is present)
+        Binding(get: {
+            if isCompactWindow && size == .compact || !isCompactWindow && size == .regular {
+                return item
+            } else {
+                return nil
+            }
+        }, set: { newItem in
+            item = newItem
+        })
     }
 }

Mail/Views/Thread List/ThreadListSwipeAction.swift

@@ -110,25 +110,24 @@ struct ThreadListSwipeActions: ViewModifier {
     let multipleSelectionViewModel: ThreadListMultipleSelectionViewModel
 
     func body(content: Content) -> some View {
-        if viewModel.folder.role == .draft {
-            content
-                .swipeActions(edge: .trailing) {
-                    edgeActions([.delete])
-                }
-        } else {
-            content
-                .swipeActions(edge: .leading) {
+        content
+            .swipeActions(edge: .leading) {
+                if viewModel.folder.role != .draft {
                     edgeActions([swipeFullLeading, swipeLeading])
                 }
-                .swipeActions(edge: .trailing) {
+            }
+            .swipeActions(edge: .trailing) {
+                if viewModel.folder.role == .draft {
+                    edgeActions([.delete])
+                } else {
                     edgeActions([swipeFullTrailing, swipeTrailing])
                 }
-                .actionsPanel(actionsTarget: $actionsTarget)
-                .sheet(item: $moveAction) { moveAction in
-                    MoveEmailView(moveAction: moveAction)
-                        .sheetViewStyle()
-                }
-        }
+            }
+            .actionsPanel(actionsTarget: $actionsTarget)
+            .sheet(item: $moveAction) { moveAction in
+                MoveEmailView(moveAction: moveAction)
+                    .sheetViewStyle()
+            }
     }
 
     @MainActor @ViewBuilder

Mail/Views/Thread List/ThreadListView.swift

@@ -57,7 +57,7 @@ struct ThreadListView: View {
 
     @Binding private var editedMessageDraft: Draft?
     @Binding private var messageReply: MessageReply?
-    
+
     private var shouldDisplayEmptyView: Bool {
         viewModel.folder.lastUpdate != nil && viewModel.sections.isEmpty && !viewModel.isLoadingPage
     }
@@ -129,7 +129,6 @@ struct ThreadListView: View {
                                                isSelected: viewModel.selectedThread?.uid == thread.uid,
                                                isMultiSelected: multipleSelectionViewModel.selectedItems
                                                    .contains { $0.id == thread.id })
-                                    .id(thread.id)
                             }
                         } header: {
                             if threadDensity != .compact {