feat: introduce leaflet-geoman as an alternative to leaflet-draw

[iisakkirotko]

This replaces the old leaflet-draw implementation with a leaflet-geoman based one, in accordance with #1165. The change should be backwards compatible in that even though leaflet-draw is no longer used on the front end, the functionality is available identically from the python side.

[iisakkirotko]

The remaining visual test failure seems unrelated, see the reported diffs:

[maartenbreddels]

@giswqs do you use DrawControls a lot? I wonder if you are willing to test this PR. We have to break things.

[giswqs]

Yes, I can give it a try. Do I Just pip install from the branch? Anything else I need to do to make sure the JS part is included?

[maartenbreddels]

I think that should work fine.
Installation instructions have changed a bit btw https://github.com/jupyter-widgets/ipyleaflet?tab=readme-ov-file#installation-from-sources

[giswqs]

It seems the position of the draw control is not working properly. In the example below, the DrawControl is supposed to be placed beneath the LayersControl, but instead it is being added above the ZoomControl. Same thing happens when adding the draw control to other position, e.g., topright. In other words, the draw control will always be placed at the top or bottom corner, ignoring other controls that have already been placed in the corner.

from ipyleaflet import Map, LayersControl, FullScreenControl, DrawControl, GeomanDrawControl

m = Map(center=[40, -100], zoom=4)
m.layout.height='600px'
m.scroll_wheel_zoom=True
m.add(FullScreenControl())
m.add(LayersControl(position='topleft'))
draw_control = DrawControl(position='topleft')
m.add(draw_control)
m

New DrawControl

GeomanDrawControl

Old DrawControl

The UI tests also has the same issue.

[giswqs]

When a drawn polygon has no more than four vertices, it returns a polygon type. When it has more than four vertices, it returns a Polygon type. The old draw control returns a Polygon type no matter how many vertices the polygon has.

New DrawControl

Old DrawControl

[giswqs]

Can't enter text when the text layer is initially created. Need to click on the edit layer button in order to add text.

The JavaScript version can add enter text when the layer is added. No need to click on the edit layer button.

https://www.geoman.io/docs/text-layer

from ipyleaflet import Map, GeomanDrawControl

m = Map(center=(50, 354), zoom=5)

draw_control = GeomanDrawControl()
draw_control.text = {
    "textOptions": {
        "text":  "Geoman is fantastic! 🚀"
    }
}

m.add(draw_control)
m.layout.height = '600px'
m.scroll_wheel_zoom = True
m

[giswqs]

How to add the marker tool to the draw control? The following code does not work.

from ipyleaflet import Map, GeomanDrawControl

m = Map(center=(50, 354), zoom=5)
draw_control = GeomanDrawControl()
draw_control.marker = {
    "markerStyle": {
        "draggable": True
    }}
draw_control.polyline =  {
    "pathOptions": {
        "color": "#6bc2e5",
        "weight": 8,
        "opacity": 1.0
    }
}
m.add(draw_control)
m.layout.height = '600px'
m.scroll_wheel_zoom = True
m

[iisakkirotko]

Thanks a lot for your feedback @giswqs! I'll take a look at the issues later this week.

[iisakkirotko]

Hey @giswqs!

b8863cc should address all of your comments, with the exception of the issue with the differing capitalisation of "polygon". The type you mention there is consistent, but admittedly confusingly named - one instance is under "feature.geometry.type", while the other is under "feature.properties.type". The second one is used, among other things, to differentiate between different types of Marker layers (TextMarker, CircleMarker, etc). Maybe renaming this one is in order to avoid confusion. I'd love to hear your thoughts on what you think a suitable name would be!

[maartenbreddels]

Hi all,

first of all, some credits, and thank you's:
Thanks to @mangecoeur from Planeto SA for sponsoring this feature. Planeto develops geospatial solutions for district energy planning (planeto-energy.ch) and use ipyleaflet a lot. It's great to see companies funding open source projects which they use, kudos to them.

Iisakki: Thank you for the hard work you put into building this feature. A lot of energy went into it.

@giswqs Thank you for the thorough review, it has improved the quality and backwards compatibility a lot.

I talked to @martinRenou privately and expressed my concerns about breaking backward compatibility despite my best efforts to avoid that.
Given that leaflet.draw is still working, there is no strong reason to get rid (e.g. a security issue, or strong maintenance issue), we thought it would be better for now to:

1. Keep the old DrawControl, nothing changes or breaks for existing users.
2. Introduce the new GeomanDrawControl (this is done in this PR) and DrawControlCompat (rename what is now DrawControl in this PR).

In the future, when needed, if we do a major release, we can then:

1. remove the old DrawControl
2. rename DrawControlCompat to DrawControl and add DrawControlCompat as an alias for backward compatibility.

I hope everyone agrees that's a safe and frictionless path forward.

cheers,

Maarten

[martinRenou]

Thanks a lot for that work! ipyleaflet is really missing contributors right now. I personally don't have time/energy to continue any maintenance on it, but I'm happy to make releases from time to time.

Is the PR ready? Happy to give it a final review/merge.

[iisakkirotko]

Hi @martinRenou!

I'll make this PR reflect the approach @maartenbreddels outlined in #1181 (comment) today, and open a draft PR for the future breaking change. So I expect this to be fully ready for review later today!

[iisakkirotko]

@martinRenou PR should be ready for final review! The installation errors seem to be due to an upgrade to @types/leaflet@1.9.9, which should be fixed in #1186

[martinRenou]

Thanks! I just rebased from the UI, you'll need to pull again

[martinRenou]

Thanks!

[maartenbreddels]

Just a few small issues.
Btw, I love how the compatibility part is only on the Python side.

[maartenbreddels]

@martinRenou do you think we can merge this?

[martinRenou]

Thanks!