Fix app freeze

This commit fixes an issue where the app would occasionally freeze.

The filtered holders were being initialized and registered directly from a SwiftUI
initializer, which would sometimes cause hundreds of instances to be
initialized and registered and never removed by `onDisappear`.

The issue was fixed by initializing such objects with `StateObject`,
which brings it a more stable identity that lives as long as the SwiftUI
view it is in, and by placing the init/deinit registration/clean-up logic
in the filtered holder object itself, better matching the lifecycle and
preventing resource leakage.

Changelog-Fixed: Fixed an issue that would occasionally cause the app to freeze
Closes: https://github.com/damus-io/damus/issues/3383
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

damus/Features/Timeline/Views/InnerTimelineView.swift

@@ -10,17 +10,14 @@ import SwiftUI
 
 struct InnerTimelineView: View {
     var events: EventHolder
-    @ObservedObject var filteredEvents: EventHolder.FilteredHolder
+    @StateObject var filteredEvents: EventHolder.FilteredHolder
-    var filteredEventHolderId: UUID
     let state: DamusState
 
     init(events: EventHolder, damus: DamusState, filter: @escaping (NostrEvent) -> Bool, apply_mute_rules: Bool = true) {
         self.events = events
         self.state = damus
         let filter = apply_mute_rules ? { filter($0) && !damus.mutelist_manager.is_event_muted($0) } : filter
-        let filteredEvents = EventHolder.FilteredHolder(filter: filter)
+        _filteredEvents = StateObject.init(wrappedValue: EventHolder.FilteredHolder(filter: filter, parent: events))
-        self.filteredEvents = filteredEvents
-        self.filteredEventHolderId = events.add(filteredHolder: filteredEvents)
     }
     
     var event_options: EventViewOptions {
@@ -65,11 +62,6 @@ struct InnerTimelineView: View {
                 }
             }
         }
-        .onDisappear {
-            self.events.removeFilteredHolder(id: self.filteredEventHolderId)
-        }
-        //.padding(.horizontal)
-        
     }
 }
 

damus/Shared/Utilities/EventHolder.swift

@@ -56,16 +56,20 @@ class EventHolder: ObservableObject, ScrollQueue {
         
         has_event.insert(ev.id)
         
+        var changed = false
+        
         if insert_uniq_sorted_event_created(events: &self.events, new_ev: ev) {
-            return true
+            changed = true
         }
-        for (id, filteredView) in self.filteredHolders {
+        
+        for (_, filteredView) in self.filteredHolders {
             filteredView.insert(event: ev)
         }
         
-        return false
+        return changed
     }
     
+    @MainActor
     private func insert_queued(_ ev: NostrEvent) -> Bool {
         if has_event.contains(ev.id) {
             return false
@@ -79,6 +83,7 @@ class EventHolder: ObservableObject, ScrollQueue {
         return true
     }
     
+    @MainActor
     func flush() {
         guard !incoming.isEmpty else {
             return
@@ -89,7 +94,7 @@ class EventHolder: ObservableObject, ScrollQueue {
             if insert_uniq_sorted_event_created(events: &events, new_ev: event) {
                 changed = true
             }
-            for (id, filteredHolder) in self.filteredHolders {
+            for (_, filteredHolder) in self.filteredHolders {
                 filteredHolder.insert(event: event)
             }
         }
@@ -107,7 +112,7 @@ class EventHolder: ObservableObject, ScrollQueue {
     func reset() {
         self.incoming = []
         self.events = []
-        for (id, filteredHolder) in filteredHolders {
+        for (_, filteredHolder) in filteredHolders {
             filteredHolder.update(events: [])
         }
     }
@@ -125,13 +130,26 @@ class EventHolder: ObservableObject, ScrollQueue {
         self.filteredHolders[id] = nil
     }
     
+    @MainActor
     class FilteredHolder: ObservableObject {
         @Published private(set) var events: [NostrEvent]
         let filter: (NostrEvent) -> Bool
+        private var id: UUID?
+        private weak var parent: EventHolder?
         
-        init(filter: @escaping (NostrEvent) -> Bool) {
+        init(filter: @escaping (NostrEvent) -> Bool, parent: EventHolder) {
             self.events = []
             self.filter = filter
+            self.parent = parent
+            self.id = parent.add(filteredHolder: self)
+        }
+        
+        deinit {
+            // Capture for async cleanup
+            guard let id = id, let parent = parent else { return }
+            Task { @MainActor in
+                parent.removeFilteredHolder(id: id)
+            }
         }
         
         func update(events: [NostrEvent]) {