fixes application freeze on startup

app/src/main/java/org/thunderdog/challegram/data/TGChat.java

@@ -78,6 +78,8 @@
 import tgx.td.TdExt;
 
 public class TGChat implements TdlibStatusManager.HelperTarget, ContentPreview.RefreshCallback, Counter.Callback, ReactionLoadListener, Destroyable, TdlibUi.MessageProvider {
+  private static final int ARCHIVE_PREVIEW_CHAT_LIMIT = 3;
+
   private static final int FLAG_HAS_PREFIX = 1;
   private static final int FLAG_TEXT_DRAFT = 1 << 4;
   private static final int FLAG_SHOW_VERIFY = 1 << 5;
@@ -1308,7 +1310,11 @@ public void setText () {
     if (isArchive()) {
       List<TextEntity> entities = new ArrayList<>();
       StringBuilder b = new StringBuilder();
+      final int[] addedChatCount = new int[1];
       archive.iterate(chat -> {
+        if (addedChatCount[0] >= ARCHIVE_PREVIEW_CHAT_LIMIT) {
+          return;
+        }
         if (b.length() > 0) {
           b.append(Lang.getConcatSeparator());
         }
@@ -1319,6 +1325,7 @@ public void setText () {
             .setCustomColorSet(TextColorSets.Regular.NORMAL)
           );
         }
+        addedChatCount[0]++;
       });
       if (b.length() == 0) {
         b.append(Lang.pluralBold(R.string.xChats, archive.totalCount()));

app/src/main/java/org/thunderdog/challegram/ui/ChatsController.java

@@ -687,7 +687,7 @@ public void onChatListChanged (TdlibChatList chatList, @ChangeFlags int changeFl
             if (BitwiseUtils.setFlag(changeFlags, ChangeFlags.ITEM_METADATA_CHANGED, false) != 0) {
               runOnUiThreadOptional(() -> {
                 adapter.setNeedArchive(chatList.totalCount() > 0);
-                adapter.updateArchive(ChatsAdapter.ARCHIVE_UPDATE_ALL);
+                scheduleArchiveUpdate(ChatsAdapter.ARCHIVE_UPDATE_ALL);
               });
             }
           }
@@ -710,9 +710,7 @@ public void onChatListItemChanged (TdlibChatList chatList, TdApi.Chat chat, @Ite
               default:
                 return;
             }
-            runOnUiThreadOptional(() ->
-              adapter.updateArchive(reason)
-            );
+            scheduleArchiveUpdate(reason);
           }
         };
         adapter.setNeedArchive(archiveList.totalCount() > 0);
@@ -778,9 +776,37 @@ private void displayChats (List<TdlibChatListSlice.Entry> entries) {
   private boolean hideArchive, archiveCollapsed;
   private TdlibChatList archiveList;
   private ChatListListener archiveListListener;
+  private int pendingArchiveUpdateReason = -1;
+  private boolean archiveUpdateScheduled;
 
   private int chatScrollState = RecyclerView.SCROLL_STATE_IDLE;
 
+  private int mergeArchiveUpdateReason (int currentReason, int newReason) {
+    if (currentReason == -1) {
+      return newReason;
+    }
+    if (currentReason == newReason) {
+      return currentReason;
+    }
+    return ChatsAdapter.ARCHIVE_UPDATE_ALL;
+  }
+
+  private void scheduleArchiveUpdate (int reason) {
+    pendingArchiveUpdateReason = mergeArchiveUpdateReason(pendingArchiveUpdateReason, reason);
+    if (archiveUpdateScheduled) {
+      return;
+    }
+    archiveUpdateScheduled = true;
+    runOnUiThreadOptional(() -> {
+      archiveUpdateScheduled = false;
+      int pendingReason = pendingArchiveUpdateReason;
+      pendingArchiveUpdateReason = -1;
+      if (pendingReason != -1 && adapter != null) {
+        adapter.updateArchive(pendingReason);
+      }
+    });
+  }
+
   public boolean isPullingArchive () {
     if (!hideArchive || adapter == null || !adapter.hasArchive())
       return false;