Popover with ModalPresentationStyle is not centered in iOS 7 iPad

Question

I have a problem with iOS 7 that seems to be a bug or I just don\'t do something right. I have modalViewController that appears as a popover on iPad with ModalPresentationStyle.

Answer 1

I went about this slightly differently using a subclassed navigation controller and AutoLayout in Swift, to center the view in the superview at a set width and height. My particular case needed iPad and iOS7-8 support (there's some constants specific to my project in this code, but you get the idea) ...

class CenteredModalNavigationController: UINavigationController {

    // MARK:- Methods

    override func viewDidLoad() {
        super.viewDidLoad()
        preferredContentSize = CGSizeMake(320, 480) // iOS8 only
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        // iOS7 support for iPad custom sized form-sheet modal.
        if kDeviceiOS7 && kDeviceiPad {
            if view.superview == nil {
                Log.warning("Failed to find superview")
                return
            }
            view.superview!.setTranslatesAutoresizingMaskIntoConstraints(false)

            // Give the superview constraints to center the view inside it.
            var viewBindingsDict: NSMutableDictionary = NSMutableDictionary()
            viewBindingsDict.setValue(view, forKey: "view")
            viewBindingsDict.setValue(view.superview!, forKey: "superview")
            let centerXConstraints = NSLayoutConstraint.constraintsWithVisualFormat("V:[superview]-(<=1)-[view]",
                options: .AlignAllCenterX,
                metrics: nil,
                views: viewBindingsDict)
            view.superview!.addConstraints(centerXConstraints)

            let centerYConstraints = NSLayoutConstraint.constraintsWithVisualFormat("H:[superview]-(<=1)-[view]",
                options: .AlignAllCenterY,
                metrics: nil,
                views: viewBindingsDict)
            view.superview!.addConstraints(centerYConstraints)

            // Now give it a width/height and it should float in the middle of our superview.
            AutoLayoutHelper.addWidthConstraint(view,
                aSuperView: view.superview!,
                width: 320)
            AutoLayoutHelper.addHeightConstraint(view,
                aSuperView: view.superview!,
                height: 480)
        }
    }

    override func prefersStatusBarHidden() -> Bool {
        return true
    }

    override func disablesAutomaticKeyboardDismissal() -> Bool {
        // DEVNOTE: Because this is shown in a modal, this is required to stop keyboard dismiss issues.
        return true
    }

}

...

class AutoLayoutHelper: NSObject {

    class func addHeightConstraint(aChildView:UIView, aSuperView:UIView, height:CGFloat) {
        var constraint = NSLayoutConstraint(item: aChildView,
            attribute: NSLayoutAttribute.Height,
            relatedBy: NSLayoutRelation.Equal,
            toItem: nil,
            attribute: NSLayoutAttribute.NotAnAttribute,
            multiplier: 1.0,
            constant: height)
        aSuperView.addConstraint(constraint)
    }

    class func addWidthConstraint(aChildView:UIView, aSuperView:UIView, width:CGFloat) {
        var constraint = NSLayoutConstraint(item: aChildView,
            attribute: NSLayoutAttribute.Width,
            relatedBy: NSLayoutRelation.Equal,
            toItem: nil,
            attribute: NSLayoutAttribute.NotAnAttribute,
            multiplier: 1.0,
            constant: width)
        aSuperView.addConstraint(constraint)
    }

}