AreaSelect is a leaflet plugin for letting users select a square area (bounding box), using a resizable centered box on top of the map.
Another similar plugin is leaflet-locationfilter, which solves the same problem but provides a rectangle that is movable and not fixed to the center, but doesn't support keeping the aspect ratio.
// Add it to the map
var areaSelect = L.areaSelect({width:200, height:300, minWidth:40, minHeight:40, minHorizontalSpacing:40, minVerticalSpacing:100, keepAspectRatio:false});
areaSelect.addTo(map);
// Read the bounding box
var bounds = areaSelect.getBounds();
// Get a callback when the bounds change
areaSelect.on("change", function() {
console.log("Bounds:", this.getBounds());
});
// Set the dimensions of the box
areaSelect.setDimensions({width: 500, height: 500})
// And to remove it do:
//areaSelect.remove();
var areaSelect = L.areaSelect({width:200, height:300, keepAspectRatio:true});
areaSelect.setBounds([{lat:59.2272559, lng:17.7606917}, {lat:59.4402838, lng:18.2000673}]);
Check out the bundled example.
AreaSelect is developed by Jonatan Heyman.
MIT License