Rewrite entire timeline in AppKit

Mactrix.xcodeproj/project.pbxproj

@@ -343,7 +343,6 @@
 				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_STRICT_CONCURRENCY = complete;
-				SWIFT_STRICT_MEMORY_SAFETY = YES;
 				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
 				SWIFT_VERSION = 6.0;
 			};
@@ -396,7 +395,6 @@
 				STRING_CATALOG_GENERATE_SYMBOLS = YES;
 				SWIFT_EMIT_LOC_STRINGS = YES;
 				SWIFT_STRICT_CONCURRENCY = complete;
-				SWIFT_STRICT_MEMORY_SAFETY = YES;
 				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
 				SWIFT_VERSION = 6.0;
 			};

Mactrix/Extensions/NSColor+userID.swift

@@ -0,0 +1,10 @@
+import AppKit
+
+public extension NSColor {
+    convenience init(userID: String) {
+        unsafe self.init(named: String(
+            format: "Username%02d",
+            userID.unicodeScalars.reduce(0) { $0 + Int($1.value) } % 16 + 1
+        ))!
+    }
+}

Mactrix/Models/LiveTimeline.swift

@@ -2,7 +2,17 @@ import AsyncAlgorithms
 import Foundation
 import MatrixRustSDK
 import OSLog
-import SwiftUI
+
+/// Delegate subscribed to by the `NSTimelineView` to update the focused timeline row.
+@MainActor
+public protocol LiveTimelineFocusDelegate: AnyObject {
+    func focusTimelineEvent(id: EventOrTransactionId)
+}
+
+@MainActor
+protocol LiveTimelineDiffDelegate: AnyObject {
+    func timelineDidApply(diffs: [TimelineDiff])
+}
 
 @MainActor @Observable
 public final class LiveTimeline {
@@ -14,17 +24,15 @@ public final class LiveTimeline {
     @ObservationIgnored private var timelineHandle: TaskHandle?
     @ObservationIgnored private var paginateHandle: TaskHandle?
 
-    public var scrollPosition = ScrollPosition(idType: TimelineGroup.ID.self, edge: .bottom)
     public var errorMessage: String?
 
-    public private(set) var focusedTimelineEventId: EventOrTransactionId?
-    // public private(set) var focusedTimelineGroupId: String?
+    @ObservationIgnored public weak var focusDelegate: (any LiveTimelineFocusDelegate)?
+    @ObservationIgnored weak var diffDelegate: (any LiveTimelineDiffDelegate)?
 
     public var sendReplyTo: MatrixRustSDK.EventTimelineItem?
 
     public private(set) var timelineItems: [TimelineItem] = []
     public private(set) var loadedReplyDetails: [String: InReplyToDetails] = [:]
-    // public private(set) var timelineGroups: TimelineGroups = .init()
 
     public private(set) var paginating: PaginationStatus = .idle(hitTimelineStart: false)
     public private(set) var hitTimelineStart: Bool = false
@@ -157,7 +165,7 @@ public final class LiveTimeline {
 
     public func focusEvent(id eventId: EventOrTransactionId) {
         Logger.liveTimeline.info("focus event: \(eventId.id)")
-        focusedTimelineEventId = eventId
+        focusDelegate?.focusTimelineEvent(id: eventId)
     }
 }
 
@@ -194,6 +202,7 @@ extension LiveTimeline {
             hitTimelineStart = true
         }
 
+        diffDelegate?.timelineDidApply(diffs: diff)
         loadPendingReplyDetails()
     }
 

Mactrix/Models/MatrixClient.swift

@@ -255,19 +255,18 @@ extension MatrixClient: UI.ImageLoader {
         imageCache.setObject(image, forKey: key, cost: cost)
     }
 
-    func cachedImage(matrixUrl: String) -> Image? {
-        guard let nsImage = Self.imageCache.object(forKey: NSString(string: matrixUrl)) else { return nil }
-        return Image(nsImage: nsImage)
+    func cachedImage(matrixUrl: String) -> NSImage? {
+        return Self.imageCache.object(forKey: NSString(string: matrixUrl))
     }
 
-    func loadImage(matrixUrl: String, size: CGSize?) async throws -> Image? {
+    func loadImage(matrixUrl: String, size: CGSize?) async throws -> NSImage? {
         let cacheKey = if let size {
             NSString(string: "\(matrixUrl)_\(Int(size.width))x\(Int(size.height))")
         } else {
             NSString(string: matrixUrl)
         }
         if let cached = Self.imageCache.object(forKey: cacheKey) {
-            return Image(nsImage: cached)
+            return cached
         }
 
         let mediaSource = try MediaSource.fromUrl(url: matrixUrl)
@@ -284,7 +283,7 @@ extension MatrixClient: UI.ImageLoader {
         do {
             let nsImage = try imageData.toOrientedImage(contentType: imageData.computeMimeType())
             Self.setCachedImage(nsImage, forKey: cacheKey)
-            return Image(nsImage: nsImage)
+            return nsImage
         } catch {
             Logger.matrixClient.error("failed convert matrix media data to Image: \(error) \(imageData)")
             throw error

Mactrix/Models/WindowState.swift

@@ -83,15 +83,8 @@ final class WindowState {
             return
         }
 
-        /* guard let focusItem = roomTimeline.timelineItems?.first(where: { $0.asEvent()?.eventOrTransactionId.id == eventId }) else {
-             Logger.windowState.warning("focus message failed, message not found")
-             return
-         } */
-
         Logger.windowState.warning("scrolling to message \(eventId)")
-        withAnimation {
-            roomTimeline.scrollPosition.scrollTo(id: eventId)
-        }
+        roomTimeline.focusEvent(id: .eventId(eventId: eventId))
     }
 
     func focusThread(rootEventId: String) {

Mactrix/Views/ChatView/ChatInputView/ChatInputView.swift

@@ -31,7 +31,6 @@ struct ChatInputView: View {
 
         chatInput = ""
         replyTo = nil
-        timeline.scrollPosition.scrollTo(edge: .bottom)
     }
 
     private func saveDraft() async {