Hands-On GUI Programming with C++ and Qt5

Displaying shapes on a map

Besides adding markers to the map, we can also draw different types of shapes on the map to indicate an area of interest or serve as geofences, which give out warnings whenever a target is entering or leaving the area covered by the shape. A geofence is a polygonal shape that defines an area of interest or virtual geographic boundary on a map for location-based services. Usually, geofences are used to trigger an alarm when a device is entering and/or exiting a geofence. A good example of using a geofence is when you need a shopping reminder, you can draw a geofence around the supermarket and attach a shopping list along with the geofence. When you (and your phone) are entering the area of the geofence, you will ...