Orientation.swift

/*Copyright (c) 2016, Andrew Walz.
 
 Redistribution and use in source and binary forms, with or without modification,are permitted provided that the following conditions are met:
 
 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 
 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
 documentation and/or other materials provided with the distribution.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */

import Foundation
import AVFoundation
import UIKit
import CoreMotion


class Orientation  {
    
    var shouldUseDeviceOrientation: Bool  = false
    
    fileprivate var deviceOrientation : UIDeviceOrientation?
    fileprivate let coreMotionManager = CMMotionManager()
    
    init() {
        coreMotionManager.accelerometerUpdateInterval = 0.1
    }
    
    func start() {
        self.deviceOrientation = UIDevice.current.orientation
        coreMotionManager.startAccelerometerUpdates(to: .main) { [weak self] (data, error) in
            guard let data = data else {
                return
            }
            self?.handleAccelerometerUpdate(data: data)
        }
    }
  
    func stop() {
        self.coreMotionManager.stopAccelerometerUpdates()
        self.deviceOrientation = nil
    }
    
    func getImageOrientation(forCamera: SwiftyCamViewController.CameraSelection) -> UIImage.Orientation {
        guard shouldUseDeviceOrientation, let deviceOrientation = self.deviceOrientation else { return forCamera == .rear ? .right : .leftMirrored }
        
        switch deviceOrientation {
        case .landscapeLeft:
            return forCamera == .rear ? .up : .downMirrored
        case .landscapeRight:
            return forCamera == .rear ? .down : .upMirrored
        case .portraitUpsideDown:
            return forCamera == .rear ? .left : .rightMirrored
        default:
            return forCamera == .rear ? .right : .leftMirrored
        }
    }
    
    func getPreviewLayerOrientation() -> AVCaptureVideoOrientation {
        // Depends on layout orientation, not device orientation
        switch UIApplication.shared.statusBarOrientation {
        case .portrait, .unknown:
            return AVCaptureVideoOrientation.portrait
        case .landscapeLeft:
            return AVCaptureVideoOrientation.landscapeLeft
        case .landscapeRight:
            return AVCaptureVideoOrientation.landscapeRight
        case .portraitUpsideDown:
            return AVCaptureVideoOrientation.portraitUpsideDown
        }
    }
    
    func getVideoOrientation() -> AVCaptureVideoOrientation? {
        guard shouldUseDeviceOrientation, let deviceOrientation = self.deviceOrientation else { return nil }
        
        switch deviceOrientation {
        case .landscapeLeft:
            return .landscapeRight
        case .landscapeRight:
            return .landscapeLeft
        case .portraitUpsideDown:
            return .portraitUpsideDown
        default:
            return .portrait
        }
    }
    
    private func handleAccelerometerUpdate(data: CMAccelerometerData){
        if(abs(data.acceleration.y) < abs(data.acceleration.x)){
            if(data.acceleration.x > 0){
                deviceOrientation = UIDeviceOrientation.landscapeRight
            } else {
                deviceOrientation = UIDeviceOrientation.landscapeLeft
            }
        } else{
            if(data.acceleration.y > 0){
                deviceOrientation = UIDeviceOrientation.portraitUpsideDown
            } else {
                deviceOrientation = UIDeviceOrientation.portrait
            }
        }
    }
}