Viewfinder on Leaflet map adapter in the Consumer Portal. This extension creates a button in the toolbar, which activates "viewfinder" mode when clicked. When the map is clicked in the "viewfinder" mode, the "viewfinder" mode is disactivated. A viewfinder mode displays map with a hole in the topmost layer (technically it's a little different, see the implementation ), so it is possible to see what is in the layer underneath.
It will NOT WORK ON Internet Explorer due to lack of CSS clip-path support.
This extension uses private API and leaflet API.
Add the script with the following source code to your page.