Rear-camera torch (flashlight) on/off. No permission required on either platform — the torch is toggled directly, without opening a camera session.

Usage

def handle_event("toggle_light", _params, socket) do
  on? = not socket.assigns.light_on
  {:noreply, socket |> Mob.Torch.set(on?) |> assign(:light_on, on?)}
end

on/1 and off/1 are conveniences over set/2.

On a device with no rear flash (most tablets, the iOS simulator) this is a no-op, not an error — check the hardware yourself if you need to hide the control. The torch is a shared hardware resource: the OS turns it off when the app is backgrounded, and an active camera capture can override it. This module is fire-and-forget and does not read the state back — the app owns the on/off boolean and should re-assert it after resuming if it needs to persist.

iOS: AVCaptureDevice.torchMode via lockForConfiguration. Android: CameraManager.setTorchMode on the rear camera that reports a flash unit.