KvadrantListPickerPage

The page a picker with more than five options opens, rather than unfolding in place.

Full is the common case and Expanded is the exception, which is the wrong way round from how this library was built: Windows Phone's own Settings pages went to a page far more often than they grew a list under a caption. ListPicker.cs makes the trip a real frame navigation — OpenPickerPage walks Application.Current.RootVisual as PhoneApplicationFrame and calls Navigate(PickerPageUri) — and on the way back it reads SelectedItem off the page and commits it.

This library owns no navigator and this composable does not change that. A component library with a back stack is a component library that fights every application's. What is here is the content of that page; a caller routes to it with whatever it already uses, and the phone's own back button dismisses it because it is a real destination rather than an overlay. An overlay would have needed no routing and would have swallowed back, which is the most reliable way to make an application feel foreign on Android.

What is transcribed and what is not. The navigation shape, the selection commit and the threshold are ListPicker.cs. The page chrome is KvadrantPage, which is. The type size of a row is this project's: the toolkit's ListPickerPage.xaml is a separate file from the Generic.xaml this repository has, so the one number that decides how the page looks was not available to read — it ships as itemStyle rather than as a constant, and it is the first thing to fix if that file ever turns up.

DatePicker and TimePicker are the same shape and are also unbuilt; research §1.11 records them as "real frame navigation with zeroed transitions, not a popup". This composable is the answer for those too.