wip: Define models for Views, Basemap

[kylebarron]

@vgeorge @felixpalmer this is progress on the Python side to be able to serialize

In particular, #906 passes a bare projection="globe" parameter through. I think this is too simplistic because there are too many other things to consider when switching to globe view.

This PR defines all the data models for deck.gl views and maplibre basemap information so that on the JS side we should be able to precisely map the input into deck.gl calls.

This PR also sets the stage for non-geospatial map rendering and for multi-view support.

With this PR, to generate a map with globe view, someone would call

from lonboard import Map
from lonboard.view import GlobeView
from lonboard.basemap import MaplibreBasemap

lonboard.Map(
	layer,
	view=GlobeView(),
	basemap=MaplibreBasemap(mode="interleaved"),
)

Perhaps we could add something like projection="globe" to viz to permit a less-verbose way for users to define a map with a globe, but that would call the above code internally on the Python side.

Relates to

• composable maps based on ipywidgets #905 (multi-views),
• Support Maplibre GlobeView #886 (globe view),
• Linked maps side by side #718 (multi-view),
• Enable repeating map view #658 (repeating map view),
• Multiple linked plots #637 (multiple linked plots),
• Basemap refactor #494 (basemap refactor),
• Swipe and sync between two maps #404 (swipe between two maps),
• Add support for OrthographicView #375 (orthographic view)

TODO:

• update view state validation to permit multiple views
• Add before_id attribute to layers

[kylebarron]

This is a small separate refactor to make it easier to read _map.py by removing the HTML export functionality

[kylebarron]

This diff is from moving view_state lower so that it's immediately after the new views attribute; nothing was changed except for adding views

[kylebarron]

This allows users to customize the basemap, and to turn off the basemap altogether by passing None.

Before merging we may keep basemap_style around to not break backwards compatibility, but I think documenting that the new API is

Map(basemap=MaplibreBasemap(basemap_style=basemap_style))

isn't too bad

[kylebarron]

Here the user can explicitly choose a rendering mode between interleaved (mapbox overlay set to interleaved), overlaid (mapbox overlay not using interleaved), or reverse-controlled, the existing behavior, which doesn't use mapbox overlay

[kylebarron]

This file implements Python models for deck.gl Views, allowing a definition of a globe view and of non-geospatial views.

[kylebarron]

This defines the TS/JS side of the view models, with the ability to create deck View objects

[vgeorge]

@kylebarron The general approach seems quite comprehensive. I’d suggest implementing the different modes more progressively, as this will likely require some refactoring on the JS side. In hindsight, adding XState wasn’t the best choice on my part, it makes state management a bit harder to evolve. I’ll open a ticket to propose an alternative. I think we can still address this technical debt while it’s not too complex, but not on this PR.

[kylebarron]

I think despite what are a bunch of changes here on the Python side, the JS side only needs to change to support two modes: One with mapbox overlay and one without.

We can also merge this PR or something similar without exposing the classes to users, so we can keep developing on the JS side

[vgeorge]

@kylebarron sounds good. Now that we merged the Playwright PR we can add specs to ensure JS features continue to work as expected.