Hiding the master view controller with UISplitViewController in iOS8

Question

I have an iOS7 application, which was based on the Xcode master-detail template, that I am porting to iOS8. One area that has changed a lot is the UISplitViewControlle

Answer 1

Extend the UISplitViewController as follows:

extension UISplitViewController {
    func toggleMasterView() {
        let barButtonItem = self.displayModeButtonItem()
        UIApplication.sharedApplication().sendAction(barButtonItem.action, to: barButtonItem.target, from: nil, forEvent: nil)
    }
}

In didSelectRowAtIndexPath or prepareForSegue, do the following:

self.splitViewController?.toggleMasterView()

This will smoothly slide the master view out of the way.

I got the idea of using the displayModeButtonItem() from this post and I am simulating a tap on it per this post.

I am not really happy with this solution, since it seems like a hack. But it works well and there seems to be no alternative yet.

Answer 2

I was able to have the desired behavior in a Xcode 6.3 Master-Detail Application (universal) project by adding the following code in the MasterViewController's - prepareForSegue:sender: method:

if view.traitCollection.userInterfaceIdiom == .Pad && splitViewController?.displayMode == .PrimaryOverlay {
    let animations: () -> Void = {
        self.splitViewController?.preferredDisplayMode = .PrimaryHidden
    }
    let completion: Bool -> Void = { _ in
        self.splitViewController?.preferredDisplayMode = .Automatic
    }
    UIView.animateWithDuration(0.3, animations: animations, completion: completion)
}

The complete - prepareForSegue:sender: implementation should look like this:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "showDetail" {
        if let indexPath = self.tableView.indexPathForSelectedRow() {
            let object = objects[indexPath.row] as! NSDate
            let controller = (segue.destinationViewController as! UINavigationController).topViewController as! DetailViewController
            controller.detailItem = object
            controller.navigationItem.leftBarButtonItem = self.splitViewController?.displayModeButtonItem()
            controller.navigationItem.leftItemsSupplementBackButton = true

            if view.traitCollection.userInterfaceIdiom == .Pad && splitViewController?.displayMode == .PrimaryOverlay {
                let animations: () -> Void = {
                    self.splitViewController?.preferredDisplayMode = .PrimaryHidden
                }
                let completion: Bool -> Void = { _ in
                    self.splitViewController?.preferredDisplayMode = .Automatic
                }
                UIView.animateWithDuration(0.3, animations: animations, completion: completion)
            }
        }
    }
}

Using traitCollection may also be an alternative/supplement to displayMode in some projects. For example, the following code also works for a Xcode 6.3 Master-Detail Application (universal) project:

let traits = view.traitCollection
if traits.userInterfaceIdiom == .Pad && traits.horizontalSizeClass == .Regular {
    let animations: () -> Void = {
        self.splitViewController?.preferredDisplayMode = .PrimaryHidden
    }
    let completion: Bool -> Void = { _ in
        self.splitViewController?.preferredDisplayMode = .Automatic
    }
    UIView.animateWithDuration(0.3, animations: animations, completion: completion)
}

Answer 3

Swift 4 update:

Insert it into prepare(for segue: ...

if splitViewController?.displayMode == .primaryOverlay {
    let animations: () -> Void = {
        self.splitViewController?.preferredDisplayMode = .primaryHidden
    }
    let completion: (Bool) -> Void = { _ in
        self.splitViewController?.preferredDisplayMode = .automatic
    }
    UIView.animate(withDuration: 0.3, animations: animations, completion: completion)
}

Answer 4

Modifying the answers above this is all I needed in a method of my detail view controller that configured the view:

 [self.splitViewController setPreferredDisplayMode:UISplitViewControllerDisplayModePrimaryHidden];

Of course it lacks the grace of animation.