Zoom to Scale denominatorsΒΆ

The classes found in the org.geotools.styling.zoom package provide a way to convert zoom levels into scale denominators. In particular:

  • ZoomContextFactory is a factory class that provides a way to create a ZoomContext object for a given Tile Matrix Set, by name.

  • ZoomContext is an interface that provides a way to convert zoom levels into scale denominators.

  • ScalerRange is an interface that describe a range of scale denominators.

The WellKnownZoomContextFactory class provides way to create a ZoomContext object for well-known zoom Tile Matrix Sets such as WebMercatorQuad and WGS84. Other projects, such as GeoServer, can provide their own implementations of ZoomContextFinder that matches configured Tile Matrix Sets, e.g. GWCZoomContextFactory provides access to all Tile Matrix Sets defined in the GeoServer configuration.

Here is an example of how to use these facilities:

ZoomContextFactory zoomContextFactory = new WellKnownZoomContextFactory();
ZoomContext zoomContext = zoomContextFactory.createContext("WebMercatorQuad");
double scaleDenominator = zoomContext.getScaleDenominator(10);
ScaleRange scaleRange = zoomContext.getScaleRange(10, 12);