Function initSimulateButton

examples/connectivity/src/ui.ts:183–211

(onToggle: SimulateCallback)

 * Returns a cleanup function to remove the event listener.
 */
export function initSimulateButton(onToggle: SimulateCallback): () => void {
    const btn = document.getElementById("simulate-btn") as HTMLButtonElement | null;
    if (!btn) {
        return () => {};
    }

    let isSimulatingFailure = false;

    function handleClick() {
        isSimulatingFailure = !isSimulatingFailure;

        if (isSimulatingFailure) {
            btn!.textContent = LABEL_RESTORE_CONNECTION;
            btn!.classList.add("simulate-btn--restoring");
            onToggle("connectionLost");
        } else {
            btn!.textContent = LABEL_SIMULATE_FAILURE;
            btn!.classList.remove("simulate-btn--restoring");
            onToggle("connectionRestored");
        }
    }

    btn.addEventListener("click", handleClick);

    // Return cleanup so main.ts can remove the listener on dispose
    return () => {
        btn.removeEventListener("click", handleClick);
    };
}