AVFoundation+Torch.swift

// Swift 2.0 port of Objective-C code: http://www.theappguruz.com/blog/onoff-flashlight-one-button-ios
// Usage: AVCaptureDevice.turnLight() 
// It does not work simultaneously with system turn of the torch

import AVFoundation

extension AVCaptureDevice {
    static func turnLight() {
        let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
        if ( device.isTorchModeSupported(AVCaptureTorchMode.On) && device.isTorchModeSupported(AVCaptureTorchMode.Off)) {
            do {
                try device.lockForConfiguration()
            } catch _ {
                print("Unable lock the torch")
                return
            }
            if device.torchMode == AVCaptureTorchMode.On {
                device.torchMode = AVCaptureTorchMode.Off
            } else {
                device.torchMode = AVCaptureTorchMode.On
            }
            device.unlockForConfiguration()
        }
    }
}