Landscape Only App on iPad

I was run into the situation to develop an app that only support landscape mode. So here are the list of common to do list.

1. Check Landscape Left, Landscape Right to be checked on Target > General > Deployment Info
2. Override var shouldAutorotate: Bool to return true for UIWindow's root view controller.
3. Override var supportedInterfaceOrientations: UIInterfaceOrientationMask to return .landscape for UIWindow's root view controller.

I cannot post the whole project on github. So, I extracted the key potions from the project. I made a two targets.

To make my life a bit easier, I provide such static function to my AppDelegate.

class AppDelegate: UIResponder, UIApplicationDelegate {
	// ...
	static var supportedInterfaceOrientations: UIInterfaceOrientationMask {
		return .landscape
	}
}

My view controller looks like this.

class MyViewController: UIViewController {
	// ...
	override var shouldAutorotate: Bool {
		let value = true
		print("\(type(of: self)): \(#function), value=\(value)")
		return value
	}

	override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
		let value = AppDelegate.supportedInterfaceOrientations
		print("\(type(of: self)): \(#function), value=\(value)")
		return value
	}
}

I use subclass of UINavigationController to override some methods as follows.

class MyNavigationController: UINavigationController {
	// ...
	override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
		let value =  self.topViewController?.supportedInterfaceOrientations ?? AppDelegate.supportedInterfaceOrientations
		print("\(type(of: self)): \(#function), value=\(value)")
		return value
	}

	override var shouldAutorotate: Bool {
		let value = topViewController?.shouldAutorotate ?? true
		print("\(type(of: self)): \(#function), value=\(value)")
		return value
	}

Here is the belief description of the two targets.

Target	Description
test1	MyViewController is the root view controller
test2	MyNavigationController is the root view controller

Once you tested, you will find that it stays on landscape mode on iPhone, by it kept rotating between landscape and portrait mode on iPad.

I figured out even supportedInterfaceOrientations method didn't get called on iPad (on iPhone it is being called). Hey, I set only landscape orientation is enabled on info.plist how could it happen.

I was thinking about post this project for someone to help, then while I am composing this README, I found the answer to nail it. OK, I will not include that on this project yet. If someone would like to try, clone this repository to try, and find the answer from the end of this document and try fix it.

Have a good day.

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• [SupportedInterfaceOrientations not called in iPad] (https://stackoverflow.com/questions/35274428/supportedinterfaceorientations-not-called-in-ipad)