RoomListItemViewModel rebuilt the "Move to section" submenu list via
getCustomSectionData() inside every snapshot rebuild - i.e. on every
notification, name, tag or call update of every live room item - even
though the available sections only change when the custom section
settings change. Each call rebuilds the record from settings and does
an O(spaces) existence check per section.
Cache the available sections (tag + name) in the view model and
rebuild them only from the settings watchers; per-room snapshots now
only derive the cheap isSelected flag. Also watch
RoomList.CustomSectionData so section renames propagate to the
submenu (previously only the order setting was watched).
Florian DurosandGitHub
1d32b838ac