UIPopoverPresentationController on iOS 8 iPhone

You can override the default adaptive behaviour (UIModalPresentationFullScreen in compact horizontal environment, i.e. iPhone) using the adaptivePresentationStyleForPresentationController: method available through UIPopoverPresentationController.delegate.

UIPresentationController uses this method to ask the new presentation style to use, which in your case, simply returning UIModalPresentationNone will cause the UIPopoverPresentationController to render as a popover instead of fullscreen.

Here's an example of the popover using a segue setup in storyboard from a UIBarButtonItem to "present modally" a UIViewController

class SomeViewController: UIViewController, UIPopoverPresentationControllerDelegate {

    // override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) { // swift < 3.0
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "PopoverSegue" {
            if let controller = segue.destinationViewController as? UIViewController {
                controller.popoverPresentationController.delegate = self
                controller.preferredContentSize = CGSize(width: 320, height: 186)                
            }
        }
    }

    // MARK: UIPopoverPresentationControllerDelegate

    //func adaptivePresentationStyleForPresentationController(controller: UIPresentationController!) -> UIModalPresentationStyle { // swift < 3.0
    func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
        // Return no adaptive presentation style, use default presentation behaviour
        return .None
    }
}

This trick was mentioned in WWDC 2014 session 214 "View Controller Advancement in iOS8" (36:30)

If anybody wants to present a popover with code only, you can use the following approach.

OBJECTIVE - C

Declare a property of UIPopoverPresentationController:

@property(nonatomic,retain)UIPopoverPresentationController *dateTimePopover8;

Use the following method to present the popover from UIButton:

- (IBAction)btnSelectDatePressed:(id)sender
{
    UINavigationController *destNav = [[UINavigationController alloc] initWithRootViewController:dateVC];/*Here dateVC is controller you want to show in popover*/
    dateVC.preferredContentSize = CGSizeMake(280,200);
    destNav.modalPresentationStyle = UIModalPresentationPopover;
    _dateTimePopover8 = destNav.popoverPresentationController;
    _dateTimePopover8.delegate = self;
    _dateTimePopover8.sourceView = self.view;
    _dateTimePopover8.sourceRect = sender.frame;
    destNav.navigationBarHidden = YES;
    [self presentViewController:destNav animated:YES completion:nil];
}

Use the following method to present the popover from UIBarButtonItem:

- (IBAction)btnSelectDatePressed:(id)sender
{
    UINavigationController *destNav = [[UINavigationController alloc] initWithRootViewController:dateVC];/*Here dateVC is controller you want to show in popover*/
    dateVC.preferredContentSize = CGSizeMake(280,200);
    destNav.modalPresentationStyle = UIModalPresentationPopover;
    _dateTimePopover8 = destNav.popoverPresentationController;
    _dateTimePopover8.delegate = self;
    _dateTimePopover8.sourceView = self.view;
     CGRect frame = [[sender valueForKey:@"view"] frame];
    frame.origin.y = frame.origin.y+20;
    _dateTimePopover8.sourceRect = frame;
    destNav.navigationBarHidden = YES;
    [self presentViewController:destNav animated:YES completion:nil];
}

Implement this delegate method too in your view controller:

- (UIModalPresentationStyle) adaptivePresentationStyleForPresentationController: (UIPresentationController * ) controller {
    return UIModalPresentationNone;
}

To dismiss this popover, simply dismiss the view controller. Below is the code to dismiss the view controller:

-(void)hideIOS8PopOver
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

SWIFT

Use the following method to present the popover from UIButon:

func filterBooks(sender: UIButon)
    {
        let filterVC =  FilterDistanceViewController(nibName: "FilterDistanceViewController", bundle: nil)
        var filterDistanceViewController = UINavigationController(rootViewController: filterVC)
        filterDistanceViewController.preferredContentSize = CGSizeMake(300, 205)
        let popoverPresentationViewController = filterDistanceViewController.popoverPresentationController
        popoverPresentationViewController?.permittedArrowDirections = .Any
        popoverPresentationViewController?.delegate = self
        popoverPresentationController?.barButtonItem = self.navigationItem.rightBarButtonItem
        popoverPresentationViewController!.sourceView = self.view;
        popoverPresentationViewController!.sourceRect = sender.frame

        filterDistanceViewController.modalPresentationStyle = UIModalPresentationStyle.Popover
        filterDistanceViewController.navigationBarHidden = true
        self.presentViewController(filterDistanceViewController, animated: true, completion: nil)
    }

Use the following method to present the popover from UIBarButtonItem:

func filterBooks(sender: UIBarButtonItem)
    {
        let filterVC =  FilterDistanceViewController(nibName: "FilterDistanceViewController", bundle: nil)
        var filterDistanceViewController = UINavigationController(rootViewController: filterVC)
        filterDistanceViewController.preferredContentSize = CGSizeMake(300, 205)
        let popoverPresentationViewController = filterDistanceViewController.popoverPresentationController
        popoverPresentationViewController?.permittedArrowDirections = .Any
        popoverPresentationViewController?.delegate = self
        popoverPresentationController?.barButtonItem = self.navigationItem.rightBarButtonItem
        popoverPresentationViewController!.sourceView = self.view;
        var frame:CGRect = sender.valueForKey("view")!.frame
        frame.origin.y = frame.origin.y+20
        popoverPresentationViewController!.sourceRect = frame

        filterDistanceViewController.modalPresentationStyle = UIModalPresentationStyle.Popover
        filterDistanceViewController.navigationBarHidden = true
        self.presentViewController(filterDistanceViewController, animated: true, completion: nil)
    }

Implement this delegate method too in your view controller:

func adaptivePresentationStyleForPresentationController(controller: UIPresentationController) -> UIModalPresentationStyle{
        return .None
    }

Please make sure to add delegate UIPopoverPresentationControllerDelegate in .h/.m/.swift file

PROBLEM: iPhone popover displays fullscreen and does not respect preferredContentSize value.

SOLUTION: Contrary to what Apple suggests in the UIPopoverPresentationController Class reference, presenting the view controller after getting a reference to the popover presentation controller and configuring it.

// Get the popover presentation controller and configure it.
//...

// Present the view controller using the popover style.
[self presentViewController:myPopoverViewController animated: YES completion: nil];