This abstracts the separate timelines in a Matrix {@link Room} into a single iterable thing.\n * It keeps track of the start and endpoints of the window, which can be advanced with the help\n * of pagination requests.\n *\n *
Before the window is useful, it must be initialised by calling {@link TimelineWindow#load}.\n *\n *
Note that the window will not automatically extend itself when new events\n * are received from /sync; you should arrange to call {@link TimelineWindow#paginate}\n * on {@link RoomEvent.Timeline} events.\n *\n * @param client - MatrixClient to be used for context/pagination\n * requests.\n *\n * @param timelineSet - The timelineSet to track\n *\n * @param opts - Configuration options for this window\n */\n public constructor(\n private readonly client: MatrixClient,\n private readonly timelineSet: EventTimelineSet,\n opts: IOpts = {},\n ) {\n this.windowLimit = opts.windowLimit || 1000;\n }\n\n /**\n * Initialise the window to point at a given event, or the live timeline\n *\n * @param initialEventId - If given, the window will contain the\n * given event\n * @param initialWindowSize - Size of the initial window\n */\n public load(initialEventId?: string, initialWindowSize = 20): Promise This returns true if we either have more events, or if we have a\n * pagination token which means we can paginate in that direction. It does not\n * necessarily mean that there are more events available in that direction at\n * this time.\n *\n * @param direction - EventTimeline.BACKWARDS to check if we can\n * paginate backwards; EventTimeline.FORWARDS to check if we can go forwards\n *\n * @returns true if we can paginate in the given direction\n */\n public canPaginate(direction: Direction): boolean {\n const tl = this.getTimelineIndex(direction);\n\n if (!tl) {\n debuglog(\"TimelineWindow: no timeline yet\");\n return false;\n }\n\n if (direction == EventTimeline.BACKWARDS) {\n if (tl.index > tl.minIndex()) {\n return true;\n }\n } else {\n if (tl.index < tl.maxIndex()) {\n return true;\n }\n }\n\n const hasNeighbouringTimeline = tl.timeline.getNeighbouringTimeline(direction);\n const paginationToken = tl.timeline.getPaginationToken(direction);\n return Boolean(hasNeighbouringTimeline) || Boolean(paginationToken);\n }\n\n /**\n * Attempt to extend the window\n *\n * @param direction - EventTimeline.BACKWARDS to extend the window\n * backwards (towards older events); EventTimeline.FORWARDS to go forwards.\n *\n * @param size - number of events to try to extend by. If fewer than this\n * number are immediately available, then we return immediately rather than\n * making an API call.\n *\n * @param makeRequest - whether we should make API calls to\n * fetch further events if we don't have any at all. (This has no effect if\n * the room already knows about additional events in the relevant direction,\n * even if there are fewer than 'size' of them, as we will just return those\n * we already know about.)\n *\n * @param requestLimit - limit for the number of API requests we\n * should make.\n *\n * @returns Promise which resolves to a boolean which is true if more events\n * were successfully retrieved.\n */\n public async paginate(\n direction: Direction,\n size: number,\n makeRequest = true,\n requestLimit = DEFAULT_PAGINATE_LOOP_LIMIT,\n ): Promise