Automatically parse style properties if they exist.

[mattdreisbach]

There is no way to specify style within the geopapckage.

Can you parse the geopackage for style properties if they exist?

Perhaps you could use standard QGIS Styling names:

 "fill": "#ff0000",
 "fill-opacity": 0.5,
 "radius": 1.5,
 "stroke": "#000000",
 "stroke-width": 1,
 "stroke-opacity": 1.0

Example:

import geopandas as gpd
from shapely.geometry import Point, Polygon

# Define the coordinates for three points and one polygon
points = [
    {"geometry": Point(-85.50, 42.98), "name": "Detroit", "fill": "#ff0000", "radius": 100000},
    {"geometry": Point(-84.68, 42.70), "name": "Lansing", "fill": "#00ff00", "radius": 100000},
    {"geometry": Point(-87.98, 41.86), "name": "Chicago", "fill": "#0000ff", "radius": 100000}
]

polygon_coords = [
    (-84., 45.),
    (-87., 41.),
    (-81., 41.),
    (-84., 45.)
]

polygon = [{"geometry": Polygon(polygon_coords), "name": "Michigan", "fill": "#808080"}]

# Create GeoDataFrames
points_gdf = gpd.GeoDataFrame(points, crs="EPSG:4326")
polygon_gdf = gpd.GeoDataFrame(polygon, crs="EPSG:4326")

# Save to a GeoPackage
points_gdf.to_file("michigan_data.gpkg", layer='points', driver="GPKG")
polygon_gdf.to_file("michigan_data.gpkg", layer='polygon', driver="GPKG", mode='a')

Should yield something like this (colors incorrect for points)

gejson could also support this:

{
 "type": "FeatureCollection",
 "features": [
   {
     "type": "Feature",
     "geometry": {
       "type": "Polygon",
       "coordinates": [
         [
           [102.0, 0.0],
           [103.0, 1.0],
           [104.0, 0.0],
           [102.0, 0.0]
         ]
       ]
     },
     "properties": {
       "name": "Sample Polygon",
       "style": {
         "fill": "#ff0000",
         "fill-opacity": 0.5,
         "stroke": "#000000",
         "stroke-width": 1,
         "stroke-opacity": 1.0
       }
     }
   }
 ]
}

should yield something like this:

[mattdreisbach]

After working with QGIS for some more time it seems that the alpha channel can be included in the color for example:

 "fill": "#ff000000",  // patern is #aarrggbb so this is black with no opacity
 // "fill-opacity": 0.5,  // no longer needed
 "radius": 1.5,
 "stroke": "#800000ff",  // patern is #aarrggbb so this is blue with 50% opacity
 "stroke-width": 1,
 // "stroke-opacity": 1.0// no longer needed

[rmwiesenberg]

Partially done. I think we match QGIS now for color. The stroke/radius piece is a little more work as they aren't tied to a field yet.

Also, regardless of file type (gpkg, geojson, kml) if there is a field called fill or stroke they are also pulled by default to be the fill or stroke items.

[mattdreisbach]

Works like a champ! Playing around with this, seems you encoded the alpha bytes at the end: #rrggbbaa but the standard encoding puts the alpha bytes first: #aarrggbb

[rmwiesenberg]

Oh weird. I'm following the css standard https://developer.mozilla.org/en-US/docs/Web/CSS/hex-color

QGIS has "admitted" that the #aarrggbb is a mistake that they won't fix 😂

[rmwiesenberg]

(the three and four color hex codes won't work right now either, but imma PR that in a minute)

[mattdreisbach]

:fire: