Bookmarks - Add binding selection init parameter

[dfeinzimer]

Update:
See discussion below

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Original:
As an alternate to using a viewpoint, the bookmarks component can potentially take advantage of the setBookmark(_:) method on a map or scene view proxy.

[philium]

Alternatively, it could be simplified by taking a binding to the selected bookmark as an initializer parameter, giving the caller flexibility to do whatever they want when the selected bookmark is updated (onChange(of selectedBookmark) { … }). I think that would be better than taking a binding to a viewpoint.

[dfeinzimer]

Closing; onSelectionChanged(perform:) is provided

[philium]

@dfeinzimer Was there any consideration given to taking a binding to the selection? While there is the modifier that you pointed out, taking a binding to the selected bookmark would be simpler and more idiomatic in SwiftUI. Many SwiftUI-provided modifiers take a selection binding instead of providing a separate modifier to inform when the selection has changed.

[dfeinzimer]

Yes - I still think we should do it and I thought we had an issue for it but I'm not seeing it so I'll reopen and re-characterize this issue instead.

[dfeinzimer]

Some additional API considerations:

The current initializers are:

init(isPresented: Binding<Bool>, bookmarks: [Bookmark], viewpoint: Binding<Viewpoint?>?)
&
init(isPresented: Binding<Bool>, bookmarks: [Bookmark], viewpoint: Binding<Viewpoint?>?)

Would we want to add 2 new initializers:
init(isPresented: Binding<Bool>, bookmarks: [Bookmark], selection: Binding<Bookmark?>?)
&
init(isPresented: Binding<Bool>, geoModel: GeoModel, selection: Binding<Bookmark?>?)

brining us to a total of 4? 4 seems like it would be a lot to me.

[philium]

The selection parameter should be non-optional because those initializers should only be used with a selection binding. In my opinion, having four initializers isn't a big deal. Several SwiftUI views have much more than four initializers.