Lifecycle
The isActive
prop​
The Camera's isActive
property can be used to pause the session (isActive={false}
) while still keeping the session "warm". This is more desirable than completely unmounting the camera, since resuming the session (isActive={true}
) will be much faster than re-mounting the camera view.
For example, you want to pause the camera when the user navigates to another page or minimizes the app since otherwise the camera continues to run in the background without the user seeing it, causing significant battery drain. Also, on iOS a green dot indicates the user that the camera is still active, possibly causing the user to raise privacy concerns. (See "About the orange and green indicators in your iPhone status bar")
For example, you might want to pause the Camera when the user minimizes the app (useAppState()
) or navigates to a new screen (useIsFocused()
):
function App() {
const isFocused = useIsFocused()
const appState = useAppState()
const isActive = isFocused && appState === "active"
return <Camera {...props} isActive={isActive} />
}
Interruptions​
VisionCamera gracefully handles Camera interruptions such as incoming calls, phone overheating, a different app opening the Camera, etc., and will automatically resume the Camera once it becomes available again.