scheduleRender method
void
scheduleRender()
Schedules a render to occur at the end of the current microtask turn.
Multiple calls to this method before the microtask executes are
coalesced into a single _render call. This avoids redundant renders
when several state-changing messages are processed in one
_drainMessageQueue loop or when a burst of events (resize, timer,
resume) fire on the same event-loop tick.
For startup paths and explicit repaint requests that must render
synchronously, call _render or _forceRender directly instead.
Implementation
void scheduleRender() {
if (_needsRender) return;
_needsRender = true;
scheduleMicrotask(_flushRender);
}