present/dismiss Peek programatically

[mshibanami]

This PR is for presenting/dismissing Peek programmatically via UIAlertController or whatever that is presented by a shake gesture.

Honestly, I'm not really sure this is an appropriate approach. Please ask any questions, thanks.

Context of this PR

Not only Peek, but there are other debugging libraries like CocoaDebug or in-house one. To manage all of them in an app, I usually add a debug menu that is shown by a shake gesture.
So I wrote code like this:

extension UIViewController {
    open override func motionBegan(_ motion: UIEvent.EventSubtype, with event: UIEvent?) {
        super.motionBegan(motion, with: event)

        let alert = UIAlertController(title: "Debug Mode", message: nil, preferredStyle: .actionSheet)

        alert.addAction(UIAlertAction(title: "Peek", style: .default) { action in
            let window = UIApplication.shared.windows.first
            if Peek.isAlreadyPresented {
                window?.peek.dismiss()
            } else {
                window?.peek.present()
            }
        })
        alert.addAction(UIAlertAction(title: "CocoaDebug", style: .default) { action in
            // present/dismiss CocoaDebug
        })
        alert.addAction(UIAlertAction(title: "Another Debug Tool", style: .default) { action in
            // present/dismiss another debug tool
        })
        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))

        view.window?.rootViewController?.present(alert, animated: true, completion: nil)
    }
}

This is what I'd like to implement with the above code:

But currently, this doesn't work after presenting PeekViewController once because its motionBegan doesn't call its super method.

So I added code that calls it. Also, I added none to PeekActivationMode not to handle shake gesture and volume controls by Peek.

Checklist

• Latest changes from develop have been merged
• Conflicts have been resolved
• The branch is pointing to develop
• SwiftLint hasn't reported any issues.

[shaps80]

Sorry for the delayed response.

Hmmm... I’ve implemented something similar before myself. However I found it to be project specific most of the time.

There is a protocol for activation, I wonder if this is just a specific implementation of that we should use. I.e. AlertActivationController. Thoughts?