APIs for making a custom presentation is annoying. Boilerplate code makes people's fingers hurt, at least mine.
What a presentation really needs? or what we really care about?
- presenting & presented view's layout
- present & dismiss animation
- some other extra info like dimming.
every item above has a default impl provided by system. That's why the delegate methods related to presentation can not be implemented or can return nil.
we have to provide UIViewControllerTransitioningDelegate for custom presentation process, UIViewControllerAnimatedTransitioning for present & dismiss animations, subclass of UIPresentationController for adding dimming or sth else.
XPresentation makes these easier with some free utils layout, animation and a basic UIPresentationController. these can satisfy many presentation needs. You can always write your own impl for any part of presentation.
once again, I just make the procss easier.
before you present a UIViewController, call configPresentation to provide your custom behaviour:
viewController.configPresentation { config in
config.presentAnimation = Presentation.BasicAnimation.spring(
action: .present(Presentation.Layouts.center(width: .percent(0.75), height: .value(300))),
animator: Presentation.Animations.fadeIn()
)
config.dismissAnimation = Presentation.BasicAnimation.normal(
action: .dismiss,
animator: Presentation.Animations.fadeOut()
)
config.controller = Presentation.basicPresentationController()
}Notice, all things here are provided as utils, you can always provide your own.
Then, you can present the viewController just as usual:
present(viewController, animated: true, completion: nil)
Notice a very important thing: BasicAnimation provided here uses @autoclosure on the animator parameter.
some times we want to present a page, but the logic cannot be controlled very well. the API presentXXX & dismissXXX are easy to make problems.
one solution is to make another window where the page is presented in. That is:
- make a window with specified level.
- set a rootViewController with clear background color.
- make window visible.
- present your page using the rootViewController.
since this is another window, other windows such as app's main window is not affected. you can still perform present or push/pop in other windows. for example, every time user click a notification to enter your app, you want to show a page related to the notification, you can use a new window to present the page.
let window = PresentationWindow(level: UIWindow.Level(1988), preferredStatusBarStyle: .lightContent)
window.present(yourPage)
when dismissed, app's main window will be set the keyWindow.
popover is AutoLayout unfriendly. page size must be provided by preferredContentSize, it's also the same property to change page size.
the util api provided is just a simple configuration wrapper.