useTorch

Source: packages/sdk/src/hardware/useTorch.ts

Operates the rear camera flash LED through Android CameraManager.setTorchMode and, on Android 13+, turnOnTorchWithStrengthLevel for variable brightness. State follows the system torch callback, so a Quick Settings toggle is reflected here. Nothing is simulated: without the PixelNative module isAvailable is false and every action refuses.

Verified on Pixel 11 Pro: camera id 0, 21 strength levels; the camera HAL logs Torch for camera id 0 turned on. It reads torch capabilities on mount and subscribes to onTorchState. On unmount it clears any strobe timer and switches the LED off.

Signature

function useTorch(): {
 isAvailable: boolean;
 isTorchOn: boolean;
 isStrobing: boolean;
 maxStrengthLevel: number | null;
 error: string | null;
 source: TelemetrySource;
 setTorch: (on: boolean, strengthLevel?: number) => Promise<boolean>;
 toggleTorch: () => Promise<boolean>;
 startStrobe: (intervalMs?: number) => void;
 stopStrobe: () => void;
};

Outputs

Field	Type	Description
isAvailable	boolean	true when a rear camera with a flash unit exists and the native module is present. Gate every control on this.
isTorchOn	boolean	Whether the LED is on, from CameraManager.TorchCallback — so it also tracks Quick Settings.
isStrobing	boolean	Whether the strobe timer is running.
maxStrengthLevel	number | null	Highest value setTorch accepts as strengthLevel on Android 13+; 21 on this device. null when the platform does not report it.
error	string | null	Why the last action failed, e.g. hardware unavailable.
source	TelemetrySource	'hardware' when the torch is usable, 'unavailable' otherwise.

Functions

Function	Inputs	Returns	Description
setTorch(on, strengthLevel?)	on: boolean — desired state. strengthLevel?: number — brightness from 1 to maxStrengthLevel, honoured on Android 13+ and ignored below it. Omit for the device default.	Promise<boolean> — true when the call was accepted, false when the hardware is unavailable or the call threw (see error)	Drives the physical LED.
toggleTorch()	none	Promise<boolean> — the state the torch is in afterwards	Inverts the current state, stopping any strobe first.
startStrobe(intervalMs?)	intervalMs?: number — half-period in milliseconds, default 150, clamped to a minimum of 120 because the camera HAL needs roughly 50–100 ms per switch	void	Toggles the hardware torch on a timer. Replaces any strobe already running.
stopStrobe()	none	void	Cancels the timer and switches the LED off.

Example

const torch = useTorch();
<HapticButton title={torch.isTorchOn ? 'Torch off' : 'Torch on'} onPress={() => torch.toggleTorch()} disabled={!torch.isAvailable} />
<HapticButton title="Dim" onPress={() => torch.setTorch(true, 1)} />