Update ranges depending on the room list position

src/domain/session/leftpanel/LeftPanelViewModel.js

@@ -30,6 +30,7 @@ export class LeftPanelViewModel extends ViewModel {
     constructor(options) {
         super(options);
         const {rooms, invites, compareFn, sync} = options;
+        this._sync = sync;
         const sync3List = new Sync3ObservableList(sync, rooms);
         const list = new ConcatList(invites.sortValues((a,b) => a.compare(b)), sync3List);
         this._tileViewModelsMap = this._mapTileViewModels(list);
@@ -151,8 +152,7 @@ export class LeftPanelViewModel extends ViewModel {
         }
     }
 
-    // TODO: used in sync v3
     loadRoomRange(range) {
-
+        this._sync.loadRange(range.start, range.end);
     }
 }

src/matrix/Sync3.ts

@@ -135,6 +135,33 @@ export class Sync3 {
         this.totalRooms = 0;
     }
 
+    loadRange(start, end) {
+        let range = [start, end];
+        if (end < this.ranges[0][1]) {
+            // asked to load a range we are already loading, ignore
+            // E.g [0-20] and [5-15]
+            return;
+        }
+        // Somewhat elaborate bounds checking:
+        // - Ensure we start above the first range, bumping the start index if necessary.
+        // - Ensure bumping the start didn't cause overlap on ranges, bumping the end if necessary.
+        if (start < this.ranges[0][1]) {
+            // overlapping range e.g 0-20 and 15-30, so bump up this range to one above the first range
+            start = this.ranges[0][1] + 1;
+        }
+        if (start >= end) { // E.g [20,20] or [25,20]
+            end += 1;
+        }
+        if (this.ranges.length === 1) {
+            this.ranges.push([]);
+        }
+        this.ranges[1][0] = start;
+        this.ranges[1][1] = end;
+        console.log("new ranges: ", JSON.stringify(this.ranges), this.roomIndexToRoomId);
+        // interrupt the sync request to send up the new ranges
+        this.currentRequest?.abort();
+    }
+
     // Start syncing. Probably call this at startup once you have an access_token.
     // If we're already syncing, this does nothing.
     start(): void {