SolidPolygonLayer

lonboard.SolidPolygonLayer

Bases: BaseArrowLayer

The SolidPolygonLayer renders filled and/or extruded polygons.

Note

This layer is similar to the PolygonLayer but will not render an outline around polygons. In most cases, you'll want to use the PolygonLayer directly, but for very large datasets not drawing the outline can significantly improve performance, in which case you may want to use this layer.

Example:

From GeoPandas:

import geopandas as gpd
from lonboard import Map, SolidPolygonLayer

# A GeoDataFrame with Polygon or MultiPolygon geometries
gdf = gpd.GeoDataFrame()
layer = SolidPolygonLayer.from_geopandas(
    gdf,
    get_fill_color=[255, 0, 0],
)
m = Map(layer)

From geoarrow-rust:

from geoarrow.rust.core import read_parquet
from lonboard import Map, SolidPolygonLayer

# Example: A GeoParquet file with Polygon or MultiPolygon geometries
table = read_parquet("path/to/file.parquet")
layer = SolidPolygonLayer(
    table=table,
    get_fill_color=[255, 0, 0],
)
m = Map(layer)

auto_highlight class-attribute instance-attribute

auto_highlight = tag(sync=True)

When true, the current object pointed to by the mouse pointer (when hovered over) is highlighted with highlightColor.

Requires pickable to be True.

• Type: bool
• Default: False

elevation_scale class-attribute instance-attribute

elevation_scale = tag(sync=True)

Elevation multiplier. The final elevation is calculated by elevation_scale * get_elevation(d). elevation_scale is a handy property to scale all elevation without updating the data.

• Type: float, optional
• Default: 1

extensions class-attribute instance-attribute

extensions = tag(sync=True, **widget_serialization)

A list of layer extension objects to add additional features to a layer.

extruded class-attribute instance-attribute

extruded = tag(sync=True)

Whether to extrude the polygons (based on the elevations provided by the get_elevation accessor'). If set to False, all polygons will be flat, this generates less geometry and is faster than simply returning 0 from get_elevation.

• Type: bool, optional
• Default: False

filled class-attribute instance-attribute

filled = tag(sync=True)

Whether to fill the polygons (based on the color provided by the get_fill_color accessor).

• Type: bool, optional
• Default: True

get_elevation class-attribute instance-attribute

get_elevation = FloatAccessor(None, allow_none=True)

The elevation to extrude each polygon with, in meters.

Only applies if extruded=True.

• Type: FloatAccessor, optional
  • If a number is provided, it is used as the width for all polygons.
  • If an array is provided, each value in the array will be used as the width for the polygon at the same row index.
• Default: 1000.

get_fill_color class-attribute instance-attribute

get_fill_color = ColorAccessor(None, allow_none=True)

The fill color of each polygon in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

• Type: ColorAccessor, optional
  • If a single list or tuple is provided, it is used as the fill color for all polygons.
  • If a numpy or pyarrow array is provided, each value in the array will be used as the fill color for the polygon at the same row index.
• Default: [0, 0, 0, 255].

get_line_color class-attribute instance-attribute

get_line_color = ColorAccessor(None, allow_none=True)

The line color of each polygon in the format of [r, g, b, [a]]. Each channel is a number between 0-255 and a is 255 if not supplied.

Only applies if extruded=True.

• Type: ColorAccessor, optional
  • If a single list or tuple is provided, it is used as the line color for all polygons.
  • If a numpy or pyarrow array is provided, each value in the array will be used as the line color for the polygon at the same row index.
• Default: [0, 0, 0, 255].

opacity class-attribute instance-attribute

opacity = tag(sync=True)

The opacity of the layer.

• Type: float. Must range between 0 and 1.
• Default: 1

pickable class-attribute instance-attribute

pickable = tag(sync=True)

Whether the layer responds to mouse pointer picking events.

This must be set to True for tooltips and other interactive elements to be available. This can also be used to only allow picking on specific layers within a map instance.

Note that picking has some performance overhead in rendering. To get the absolute best rendering performance with large data (at the cost of removing interactivity), set this to False.

• Type: bool
• Default: True

selected_index class-attribute instance-attribute

selected_index = tag(sync=True)

The positional index of the most-recently clicked on row of data.

You can use this to access the full row of data from a GeoDataFrame

gdf.iloc[layer.selected_index]

Setting a value here from Python will do nothing. This attribute only exists to be updated from JavaScript on a map click. Note that pickable must be True (the default) on this layer for the JavaScript onClick handler to work; if pickable is set to False, selected_index will never update.

Note that you can use observe to call a function whenever a new value is received from JavaScript. Refer here for an example.

table class-attribute instance-attribute

table = PyarrowTableTrait(allowed_geometry_types={POLYGON, MULTIPOLYGON})

A GeoArrow table with a Polygon or MultiPolygon column.

This is the fastest way to plot data from an existing GeoArrow source, such as geoarrow-rust or geoarrow-pyarrow.

If you have a GeoPandas GeoDataFrame, use [from_geopandas][lonboard.SolidPolygonLayer.from_geopandas] instead.

visible class-attribute instance-attribute

visible = tag(sync=True)

Whether the layer is visible.

Under most circumstances, using the visible attribute to control the visibility of layers is recommended over removing/adding the layer from the Map.layers list.

In particular, toggling the visible attribute will persist the layer on the JavaScript side, while removing/adding the layer from the Map.layers list will re-download and re-render from scratch.

• Type: bool
• Default: True

wireframe class-attribute instance-attribute

wireframe = tag(sync=True)

Whether to generate a line wireframe of the polygon. The outline will have "horizontal" lines closing the top and bottom polygons and a vertical line (a "strut") for each vertex on the polygon.

• Type: bool, optional
• Default: False

Remarks:

• These lines are rendered with GL.LINE and will thus always be 1 pixel wide.
• Wireframe and solid extrusions are exclusive, you'll need to create two layers with the same data if you want a combined rendering effect.