Adaptive Layout for iPad

Question

I follow this article to create responsive layout in ios. Creating responsive user interfaces for iOS 8 .

It works great on iPhone. Now I will not have the same effect on the iPad. But for iPad, responsive layout doesn't work.
Here is a screenshot of the application in iPhone5 (the green square represents view1, and the yellow box represents view2)
1.Portrait mode

2. Landscape mode
   

Question : How to achieve the same effect for the iPad?
Extended Question: How do I set the initial orientation of the iPad in landscape mode?

Answer 1

iPad , .

, IBOutlet, , , :

@IBOutlet var landscapeConstraints: [NSLayoutConstraint]!
@IBOutlet var portraitConstraints: [NSLayoutConstraint]!

, , iPad, ACTIVE Constraints IBOutlet. , , ACTIVE- LandscapeConstraints IBOutlet.

viewWillTransitionToSize:

    override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
        let transitionToLandscape = size.width > size.height 
        let constraintsToUninstall = transitionToLandscape ? ortraitConstraints : landscapeConstraints 
        let constraintsToInstall = transitionToLandscape ? landscapeConstraints : portraitConstraints

        view.layoutIfNeeded()
        coordinator.animateAlongsideTransition({
            _ in
            NSLayoutConstraint.deactivateConstraints(constraintsToUninstall) 
            NSLayoutConstraint.activateConstraints(constraintsToInstall) 
            self.view.layoutIfNeeded()
        }, completion: nil)
}

//, :

, , , , , , .

//

, viewWillAppear / :

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

        let transitionToLandscape = view.frame.size.width > view.frame.size.height

        let constraintsToUninstall = transitionToLandscape ? portraitConstraints : landscapeConstraints
        let constraintsToInstall = transitionToLandscape ? landscapeConstraints : portraitConstraints

        view.layoutIfNeeded()
        NSLayoutConstraint.deactivateConstraints(constraintsToUninstall)
        NSLayoutConstraint.activateConstraints(constraintsToInstall)
    }