This page shows a prototype of a context frame around a web map. Depending on the zoom level, the frame shows countries and cities that are outside of the map, with an approximate distance in kilometers. This helps the user understand where the map is located relative to known places, in a similar spirit to an overview map. Clicking on a label moves the map to the target place. To explore, click on the random place button, or use the search bar to find places.

Author and contact: Andrea Ballatore, andrea [dot] ballatore [at] gmail [dot] com

How to cite: A. Ballatore (2019) A Context Frame for Interactive Maps, AGILE Conference on Geographical Information Science, Short papers [PDF]

GitHub repo: github.com/andrea-ballatore/map-context-frame

Acknowledgements: This prototype relies on a variety of open-source tools and datasets. The base maps are by ESRI and OpenStreetMap. The web mapping is powered by Leaflet and plugins (leaflet-overview and leaflet-search). The spatial computing is delegated to Turf, while the website template is based on BootLeaf. The cities dataset simplemaps-worldcities-basic-20K.geojson is from SimpleMaps, and and the country boundaries countries.geojson are from world.geo.json.