Layers

Layers in a Felt map hold geospatial data, but also configure how the data is rendered both on the map and in the legend. The data can be vector data such as Points, Lines, or Polygons, or raster data such as satellite images.

Each Layer can be grouped under a LayerGroup, and has associated LegendItems that represent how the layer is rendered in the legend.

You can control the visibility of layers, layer groups, and legend items using the`setLayerVisibility`, `setLayerGroupVisibility`, and `setLegendItemVisibility` methods.

When a Layer is styled to as categorical data or "classed" numeric data, there will be a LegendItem for each category or class. Each LegendItem can be controlled for visibility independently of the Layer, so you can turn on and off each category or class individually.