I'm wondering if there's any way to force the UIViewController presented by a Share Extension to use the UISheetPresentationController introduced in iOS 15?
Right now, the only way they're presented is modally, occupying almost the entire screen. Most share extensions don't need that much space and would allow you to have more context from where you shared (the originating app).
Technically share extensions are presented with UISheetPresentationController, just a UISheetPresentationController where detents only contains the large detent, so the sheet appears full height on iPhone, and as a form-sized sheet on iPad.
Are you asking if there is a way to customize the detents on the UISheetPresentationController instance used to present your extension? If so, unfortunately the answer is no, but as always we welcome feedback on our APIs, and I encourage you to file a feedback report!
Alternatively, you can specify NSExtensionActionWantsFullScreenPresentation in your extension's Info.plist, which will present your extension over the full screen with no additional chrome (e.g. the shadow, dimming, or corner radius provided by UISheetPresentationController). Then you can size your extension however you want within that full screen view. However, this is not recommended, as this approach loses the standard look and pull to dismiss behavior of UISheetPresentationController.
