pub fn flush_now()Expand description
Force a synchronous fixpoint drain now, even inside an open batch. Event dispatch wraps
handlers in a batch (day-core), so a handler that needs its writes to drain immediately — namely
with_animation, whose ambient animation must be live while the resulting patches apply —
cannot rely on the batch’s own close (that runs later, after the scope ends). This temporarily
drops the batch depth so flush_sync runs, then restores it. No-op if a drain is already in
progress (the writes fold into it); harmless if nothing is pending.