/**
 * Shared "flash this pin/region" timing driver for the `anchor.selected` bridge event.
 * Every canvas renderer uses this to give "Go to file" visible feedback once it's panned
 * the view onto the right spot. Renderer-specific visuals (color, scale, DOM class,
 * material) live in each canvas; this only owns the on/off timing.
 */
export function pulse(cycles: number, intervalMs: number, onPhase: (on: boolean) => void, onDone: () => void): void {
  let i = 0
  const step = (): void => {
    onPhase(i % 2 === 0)
    i++
    if (i < cycles * 2) setTimeout(step, intervalMs)
    else onDone()
  }
  step()
}