https://geo.stat.gov.lv/stage2/lib/leaflet-draw/edit/handler/Edit.Circle.js

1L.Edit = L.Edit || {};
2/**
3 * @class L.Edit.Circle
4 * @aka Edit.Circle
5 * @inherits L.Edit.SimpleShape
6 */
7L.Edit.Circle = L.Edit.SimpleShape.extend({
8	_createMoveMarker: function () {
9		var center = this._shape.getLatLng();
10
11		this._moveMarker = this._createMarker(center, this.options.moveIcon);
12	},
13
14	_createResizeMarker: function () {
15		var center = this._shape.getLatLng(),
16			resizemarkerPoint = this._getResizeMarkerPoint(center);
17
18		this._resizeMarkers = [];
19		this._resizeMarkers.push(this._createMarker(resizemarkerPoint, this.options.resizeIcon));
20	},
21
22	_getResizeMarkerPoint: function (latlng) {
23		// From L.shape.getBounds()
24		var delta = this._shape._radius * Math.cos(Math.PI / 4),
25			point = this._map.project(latlng);
26		return this._map.unproject([point.x + delta, point.y - delta]);
27	},
28
29	_move: function (latlng) {
30		var resizemarkerPoint = this._getResizeMarkerPoint(latlng);
31
32		// Move the resize marker
33		this._resizeMarkers[0].setLatLng(resizemarkerPoint);
34
35		// Move the circle
36		this._shape.setLatLng(latlng);
37
38		this._map.fire(L.Draw.Event.EDITMOVE, { layer: this._shape });
39	},
40
41	_resize: function (latlng) {
42		var moveLatLng = this._moveMarker.getLatLng(),
43			radius = moveLatLng.distanceTo(latlng);
44
45		this._shape.setRadius(radius);
46
47		this._map.fire(L.Draw.Event.EDITRESIZE, { layer: this._shape });
48	}
49});
50
51L.Circle.addInitHook(function () {
52	if (L.Edit.Circle) {
53		this.editing = new L.Edit.Circle(this);
54
55		if (this.options.editable) {
56			this.editing.enable();
57		}
58	}
59
60	this.on('add', function () {
61		if (this.editing && this.editing.enabled()) {
62			this.editing.addHooks();
63		}
64	});
65
66	this.on('remove', function () {
67		if (this.editing && this.editing.enabled()) {
68			this.editing.removeHooks();
69		}
70	});
71});