Manage map tiles dark mode with leaflet-osm plugin

[AntonKhorev]

I guess #4769 meant "how about we use dark tile variants when available". If Transport Dark is approved to be used on the osm website, we can switch to it in dark mode when "Transport Map" is selected.

Here's how it can work together with prefers-color-scheme switching from #4761:

Layers without alternative dark tiles get dimmed, layers with switch to their alternative tiles.

I modified leaflet-osm in this repository directly. Is https://github.com/openstreetmap/leaflet-osm maintained? Its npm package was last updated years ago.

[AntonKhorev]

Added context menu options similar to "Map Brightness" dropdown in https://userstyles.world/style/15596/openstreetmap-dark-theme

[AntonKhorev]

• There's a bug when switching to a layer that comes earlier in the list because I assumed that "add" event happens after "remove" event.
• Context menu is not translated.
• Context menu selection is not remembered
• No context menus on other maps like dashboard map, but maybe that's not needed if the selection is remembered
• Selected filter doesn't affect map key

[pnorman]

I modified leaflet-osm in this repository directly. Is https://github.com/openstreetmap/leaflet-osm maintained

Yes. It's had updates in the last 8 months, when we added or removed featured layers.

[tomhughes]

Specifically I have maintainer access there ;-)

[AntonKhorev]

Yes. It's had updates in the last 8 months, when we added or removed featured layers.

Supposedly not when layers are removed because L.OSM.OPNVKarte is still there. And it would be odd for this layer to disappear for anyone who is using leaflet-osm independently from the osm website.