Fixes https://github.com/vector-im/riot-web/issues/14798 (part 2)
This is in two parts itself: The `RoomSublist` needs to break its references to the `RoomListStore`, so it now clones the room arrays. The `Algorithm` is the other part, which is slightly more complicated.
It turns out that we weren't handling splicing as a change in the `ImportanceAlgorithm`, therefore the `Algorithm` wasn't really feeling like it needed to change anything. Further, the `Algorithm` was using the wrong reference to where it should be dumping rooms (`this.cachedRooms` is a getter which returns a different object depending on conditions), so having fixed that we need to ensure that the filtered and sticky maps are also updated when we remove a room. Because we send the new tag through a Timeline update, we'll end up updating the tag later on and don't need to update the filter and sticky collections.
Fixes https://github.com/vector-im/riot-web/issues/14799
We were checking to see if the tags were visible at render time, but we needed to ensure that they were(n't) included when checking for diffs. This introduces a new kind of object cloning for semantic reasons.
This also fixes the selection indicator being a bit off on custom tags.
This reduces the update cost of rooms changing, and fixes a bug where when a sublist became filtered it would change the notification count of the sublist.
This does change the expected usage of the state store to ensuring that only one place updates the rooms on the list states, which is currently the room list store. Ideally the state store could listen to the room list store to update itself, however due to a complicated require() loop it is not possible.
In 9969b01c5f we stopped updating the sublist whenever we felt like it, which indirectly froze message previews for room tiles (badges, unread state, etc were unaffected because that is managed by a different store). To fix this, we simply have to listen for changes and perform an update.
In 7b97c3032b we reduced the RoomList updates to just added/removed sublists, but didn't consider that we might also have to handle lengths of those sublists changing enough for us to fix the sticky headers.
Any time we though that the room list had to re-render we were dynamically creating a new addRoomFn, which would signal to the sublist that it needed to re-render.
The only reason we wrap the function from the aesthetics is to provide theoretical tiling/multiaccount support through use of different dispatchers, however considering that's not a reality yet we can just use a default dispatcher when none is supplied.
This cuts the render time in half (from ~448ms to ~200ms on my account) per received event, as we're no longer re-mounting the entire room list and instead just the section(s) we care about.
Fixes https://github.com/vector-im/riot-web/issues/14091
Design needs work, however this is behind labs anyways. This re-implements the behaviour of the old room list.
The implementation ended up being a lot easier due to early confusion with what the TagOrderStore and TagPanel take care of. Turns out they don't deal with tags, but groups. As such, we don't need to do anything with filtering (though we keep some sanity checks in place for safety), and just have to wire up the CustomRoomTagPanel and CustomRoomTagStore.
