iOS: Presenting a view controller in landscape right from a view controller supporting only portrait mode after rotating the iphone

Question

I have one app always presenting in Portrait mode (in the summary of the Xcode project, only the portrait orientation is supported).

Now what I want to do is when I\

Answer 1

I finally solved this problem, I suppose there are alternatives but this one works fine:

In fact I kept only Portrait in the orientation restrictions. Then when I turn the phone in landscape right or left, I call my ARViewController modally, but before loading it I force this view controller to landscape (in viewWillAppear) by making an appropriate rotation like here:

- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self transformView2ToLandscape];}

-(void) transformView2ToLandscape {

NSInteger rotationDirection;
UIDeviceOrientation currentOrientation = [[UIDevice currentDevice] orientation];

if(currentOrientation == UIDeviceOrientationLandscapeLeft){
    rotationDirection = 1;
}else {
    rotationDirection = -1;
}

CGAffineTransform transform = [arController.viewController.view transform];
transform = CGAffineTransformRotate(transform, degreesToRadians(rotationDirection * 90));
[arController.viewController.view setTransform: transform];}

Edit: In Swift 4

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    transformViewToLansdcape()
}

func transformViewToLansdcape(){
    var rotationDir : Int
    if(UIDeviceOrientationIsLandscape(UIDevice.current.orientation)){
        rotationDir = 1
    }else{
        rotationDir = -1
    }
    var transform = self.view.transform
    //90 for landscapeLeft and 270 for landscapeRight
    transform = transform.rotated(by: (rotationDir*270).degreesToRadians)
    self.view.transform = transform
}

extension BinaryInteger {
    var degreesToRadians: CGFloat {
        return CGFloat(Int(self)) * .pi / 180
    }
}