Add PhotoPicker helper

[adityadaniel]

Hi @mbrandonw @stephencelis,

with iOS 16.0 Apple introduces .photoPicker view modifier that let us show Photos picker.

Since it's possible to drive showing photos picker from state, I create this following extension on one of my project.

extension View {
    @available(iOS 16, *)
    public func photosPicker<Value>(
        unwrapping value: Binding<Value?>,
        selection: Binding<[PhotosPickerItem]>,
        maxSelectionCount: Int? = nil,
        selectionBehaviour: PhotosPickerSelectionBehavior = .default,
        matching: PHPickerFilter? = nil,
        preferredItemEncoding: PhotosPickerItem.EncodingDisambiguationPolicy = .automatic,
        photoLibrary: PHPhotoLibrary = .shared()
    ) -> some View {
        self.photosPicker(
            isPresented: value.isPresent(),
            selection: selection,
            maxSelectionCount: maxSelectionCount,
            selectionBehavior: selectionBehaviour,
            matching: matching,
            preferredItemEncoding: preferredItemEncoding,
            photoLibrary: photoLibrary
        )
    }
    
    @available(iOS 16, *)
    public func photosPicker<Enum, Case>(
        unwrapping enum: Binding<Enum?>,
        case casePath: CasePath<Enum, Case>,
        selection: Binding<[PhotosPickerItem]>,
        maxSelectionCount: Int? = nil,
        selectionBehaviour: PhotosPickerSelectionBehavior = .default,
        matching: PHPickerFilter? = nil,
        preferredItemEncoding: PhotosPickerItem.EncodingDisambiguationPolicy = .automatic,
        photoLibrary: PHPhotoLibrary = .shared()
    ) -> some View {
        self.photosPicker(
            unwrapping: `enum`.case(casePath),
            selection: selection,
            maxSelectionCount: maxSelectionCount,
            selectionBehaviour: selectionBehaviour,
            matching: matching,
            preferredItemEncoding: preferredItemEncoding,
            photoLibrary: photoLibrary
        )
    }
}

Do you think this will be useful addition to the library? If so, I'd glad to open a PR.
Thanks and let me know if you have any feedbacks.

[mbrandonw]

Hi @adityadaniel, it appears that only a Binding<Bool> version of this API is provided by Apple, so I'm not sure we need dedicated support for it in this library. I think this is clear due to the fact that although your API takes a Binding<Value?>, the Value is never actually used anywhere in the API.

So I would recommend just using the isPresented and case helpers that come with this library directly when using photosPicker:

.photosPicker(isPresented: $model.photos.isPresent(), …)

…or:

.photosPicker(isPresented: $model.$destination.case(/Destination.photos).isPresent(), …)