How to translate this objective c traitCollection to swift?

Question

I am trying to translate this code in objective C from this link, Sizing class for iPad portrait and Landscape Modes

Here is the code I am trying to translate:

@interface RDTraitCollectionOverrideViewController : UIViewController {
BOOL _willTransitionToPortrait;
UITraitCollection *_traitCollection_CompactRegular;
UITraitCollection *_traitCollection_AnyAny;
}

@end

@implementation RDTraitCollectionOverrideViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setUpReferenceSizeClasses];
}

- (void)setUpReferenceSizeClasses {
    UITraitCollection *traitCollection_hCompact = [UITraitCollection traitCollectionWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
UITraitCollection *traitCollection_vRegular = [UITraitCollection traitCollectionWithVerticalSizeClass:UIUserInterfaceSizeClassRegular];
_traitCollection_CompactRegular = [UITraitCollection traitCollectionWithTraitsFromCollections:@[traitCollection_hCompact, traitCollection_vRegular]];

UITraitCollection *traitCollection_hAny = [UITraitCollection traitCollectionWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
UITraitCollection *traitCollection_vAny = [UITraitCollection traitCollectionWithVerticalSizeClass:UIUserInterfaceSizeClassUnspecified];
_traitCollection_AnyAny = [UITraitCollection traitCollectionWithTraitsFromCollections:@[traitCollection_hAny, traitCollection_vAny]];
}

-(void)viewWillAppear:(BOOL)animated {
_willTransitionToPortrait = self.view.frame.size.height > self.view.frame.size.width;
}

- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
_willTransitionToPortrait = size.height > size.width;
}

-(UITraitCollection *)overrideTraitCollectionForChildViewController:(UIViewController *)childViewController {
UITraitCollection *traitCollectionForOverride =           (_willTransitionToPortrait) ? _traitCollection_CompactRegular :    _traitCollection_AnyAny;
return traitCollectionForOverride;
}
@end

And here is what I have, keep in mind I renamed some of the inital variables just under the class declaration:

import UIKit

class ViewController: UIViewController {

var willTransitionToPortrait:Bool = false
var compactRegular = UITraitCollection()
var anyAny = UITraitCollection()

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    setUpReferenceSizeClasses()
}

func setUpReferenceSizeClasses() {

    var traitCollection_hCompact = UITraitCollection(horizontalSizeClass: UIUserInterfaceSizeClass.Compact)
    var traitCollection_vRegular = UITraitCollection(verticalSizeClass: UIUserInterfaceSizeClass.Regular)
    compactRegular = UITraitCollection(traitsFromCollections: [traitCollection_hCompact, traitCollection_vRegular])

    var traitCollection_hAny = UITraitCollection(horizontalSizeClass: UIUserInterfaceSizeClass.Unspecified)
    var traitCollection_vAny = UITraitCollection(verticalSizeClass: UIUserInterfaceSizeClass.Unspecified)
    anyAny = UITraitCollection(traitsFromCollections: [traitCollection_hAny, traitCollection_vAny])
}

override func viewWillAppear(animated: Bool) {

    willTransitionToPortrait = self.view.frame.size.height > self.view.frame.size.width
}

override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {

    willTransitionToPortrait = size.height > size.width
}


func overrideTraitCollectionForChildViewController(UIViewController) -> childViewController {

    var traitCollectionForOverride = (willTransitionToPortrait) ? compactRegular : anyAny

    return traitCollectionForOverride;
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

I think I almost have it all but that last function I cant figure out what it translates to. Any help would be much appreciated.

score 3 · Accepted Answer · answered Jul 07 '15 at 20:07

I think you are missing "override" in the last function, try to replace with below code:

override func overrideTraitCollectionForChildViewController(childViewController: UIViewController) -> UITraitCollection! {
    //
}

Here is the complete code:

import UIKit

class ViewController: UIViewController {
    
    var willTransitionToPortrait:Bool = false
    var compactRegular = UITraitCollection()
    var anyAny = UITraitCollection()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        setUpReferenceSizeClasses()
    }
    
    func setUpReferenceSizeClasses() {
        
        var traitCollection_hCompact = UITraitCollection(horizontalSizeClass: UIUserInterfaceSizeClass.Compact)
        var traitCollection_vRegular = UITraitCollection(verticalSizeClass: UIUserInterfaceSizeClass.Regular)
        compactRegular = UITraitCollection(traitsFromCollections: [traitCollection_hCompact, traitCollection_vRegular])
        
        var traitCollection_hAny = UITraitCollection(horizontalSizeClass: UIUserInterfaceSizeClass.Unspecified)
        var traitCollection_vAny = UITraitCollection(verticalSizeClass: UIUserInterfaceSizeClass.Unspecified)
        anyAny = UITraitCollection(traitsFromCollections: [traitCollection_hAny, traitCollection_vAny])
    }
    
    override func viewWillAppear(animated: Bool) {
        
        willTransitionToPortrait = self.view.frame.size.height > self.view.frame.size.width
    }
    
    override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
        
        willTransitionToPortrait = size.height > size.width
    }
    
    override func overrideTraitCollectionForChildViewController(childViewController: UIViewController) -> UITraitCollection! {
    //
        var traitCollectionForOverride = (willTransitionToPortrait) ? compactRegular : anyAny
        
        return traitCollectionForOverride;
    }
    
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

How to translate this objective c traitCollection to swift?

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