point based nearBottom

apps/ios/Shared/Model/ChatModel.swift

@@ -897,21 +897,14 @@ final class ChatModel: ObservableObject {
 
     func unreadChatItemCounts(itemsInView: Set<String>) -> UnreadChatItemCounts {
         var i = 0
-        var totalBelow = 0
         var unreadBelow = 0
         while i < im.reversedChatItems.count - 1 && !itemsInView.contains(im.reversedChatItems[i].viewId) {
-            totalBelow += 1
             if im.reversedChatItems[i].isRcvNew {
                 unreadBelow += 1
             }
             i += 1
         }
-        return UnreadChatItemCounts(
-            // TODO these thresholds account for the fact that items are still "visible" while
-            // covered by compose area, they should be replaced with the actual height in pixels below the screen.
-            isNearBottom: totalBelow < 15,
-            unreadBelow: unreadBelow
-        )
+        return UnreadChatItemCounts(unreadBelow: unreadBelow)
     }
 
     func topItemInView(itemsInView: Set<String>) -> ChatItem? {
@@ -935,7 +928,6 @@ struct NTFContactRequest {
 }
 
 struct UnreadChatItemCounts: Equatable {
-    var isNearBottom: Bool
     var unreadBelow: Int
 }
 

apps/ios/Shared/Views/Chat/ChatView.swift

@@ -395,7 +395,11 @@ struct ChatView: View {
         let cInfo = chat.chatInfo
         let mergedItems = filtered(im.reversedChatItems)
         return GeometryReader { g in
-            ReverseList(items: mergedItems, scrollState: $scrollModel.state) { ci in
+            ReverseList(
+                items: mergedItems,
+                scrollState: $scrollModel.state,
+                isFarFromBottom: $scrollModel.isFarFromBottom
+            ) { ci in
                 let voiceNoFrame = voiceWithoutFrame(ci)
                 let maxWidth = cInfo.chatType == .group
                                 ? voiceNoFrame
@@ -470,10 +474,7 @@ struct ChatView: View {
         private var bag = Set<AnyCancellable>()
 
         init() {
-            unreadChatItemCounts = UnreadChatItemCounts(
-                isNearBottom: true,
-                unreadBelow: 0
-            )
+            unreadChatItemCounts = UnreadChatItemCounts(unreadBelow: 0)
             events
                 .receive(on: DispatchQueue.global(qos: .background))
                 .scan(Set<String>()) { itemsInView, event in
@@ -537,7 +538,7 @@ struct ChatView: View {
                 .onTapGesture {
                     scrollModel.scrollToBottom()
                 }
-            } else if !counts.isNearBottom {
+            } else if scrollModel.isFarFromBottom {
                 circleButton {
                     Image(systemName: "chevron.down")
                         .foregroundColor(theme.colors.primary)

apps/ios/Shared/Views/Chat/ReverseList.swift

@@ -14,6 +14,7 @@ struct ReverseList<Item: Identifiable & Hashable & Sendable, Content: View>: UIV
     let items: Array<Item>
 
     @Binding var scrollState: ReverseListScrollModel<Item>.State
+    @Binding var isFarFromBottom: Bool
 
     /// Closure, that returns user interface for a given item
     let content: (Item) -> Content
@@ -175,16 +176,22 @@ struct ReverseList<Item: Identifiable & Hashable & Sendable, Content: View>: UIV
             )
         }
 
+        override func scrollViewDidScroll(_ scrollView: UIScrollView) {
+            let adjustedOffset = tableView.contentOffset.y + InvertedTableView.inset
+            if representer.isFarFromBottom {
+                if adjustedOffset < 800 {
+                    DispatchQueue.main.async { self.representer.isFarFromBottom = false }
+                }
+            } else if adjustedOffset > 1000 {
+                DispatchQueue.main.async { self.representer.isFarFromBottom = true }
+            }
+        }
+
         private var isNearBottom: Bool {
             let adjustedOffset = tableView.contentOffset.y + InvertedTableView.inset
             return adjustedOffset > 0 && adjustedOffset < 500
         }
 
-        private var isFarFromBottom: Bool {
-            let adjustedOffset = tableView.contentOffset.y + InvertedTableView.inset
-            return adjustedOffset > 1000
-        }
-
         private var itemId: Item.ID?
         private var retainedItems: [Item]?
         private var updateInProgress = false
@@ -217,7 +224,7 @@ struct ReverseList<Item: Identifiable & Hashable & Sendable, Content: View>: UIV
             itemCount = items.count
         }
 
-        func _update(items: Array<Item>, animated: Bool, completion: (() -> Void)? = nil) {
+        private func _update(items: [Item], animated: Bool, completion: (() -> Void)? = nil) {
             var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
             snapshot.appendSections([.main])
             snapshot.appendItems(items)
@@ -281,6 +288,7 @@ class ReverseListScrollModel<Item: Identifiable>: ObservableObject {
     }
 
     @Published var state: State = .atDestination
+    @Published var isFarFromBottom: Bool = false
 
     func scrollToNextPage() {
         state = .scrollingTo(.nextPage)