Custom anchor point

src/Path.Transform.js

@@ -48,6 +48,7 @@ L.PathTransform.RotateHandle = L.PathTransform.Handle.extend({
 L.Handler.PathTransform = L.Handler.extend({
   options: {
     rotation: true,
+    rotationAnchor: null,
     scaling: true,
     uniformScaling: true,
     maxZoom: 22,
@@ -360,12 +361,29 @@ L.Handler.PathTransform = L.Handler.extend({
     this._path._transform(null);
     this._rect._transform(null);
 
-    this._transformPoints(this._path);
-    this._transformPoints(this._rect);
-
     if (this.options.rotation) {
       this._handleLine._transform(null);
-      this._transformPoints(this._handleLine, this._angle, null, this._origin);
+      this._transformPoints(
+        this._path,
+        this._angle,
+        null,
+        this.options.rotationAnchor
+      );
+      this._transformPoints(
+        this._rect,
+        this._angle,
+        null,
+        this.options.rotationAnchor
+      );
+      this._transformPoints(
+        this._handleLine,
+        this._angle,
+        null,
+        this.options.rotationAnchor
+      );
+    } else {
+      this._transformPoints(this._path);
+      this._transformPoints(this._rect);
     }
   },
 
@@ -506,7 +524,9 @@ L.Handler.PathTransform = L.Handler.extend({
 
     // move handlers to the top of all other layers; prevents handlers from
     // being blocked by other layers
-    this._handlersGroup.getLayers().forEach(function(layer) { layer.bringToFront(); });
+    this._handlersGroup.getLayers().forEach(function (layer) {
+      layer.bringToFront();
+    });
   },
 
   /**
@@ -558,6 +578,14 @@ L.Handler.PathTransform = L.Handler.extend({
    * @return {L.LatLng}
    */
   _getRotationOrigin: function () {
+    if (this.options.rotationAnchor) {
+      var anchor = this.options.rotationAnchor;
+      if (Array.isArray(anchor) && anchor.length >= 2) {
+        return new L.LatLng(anchor[0], anchor[1]);
+      } else if (anchor instanceof L.LatLng) {
+        return anchor;
+      }
+    }
     var latlngs = this._rect._latlngs[0];
     var lb = latlngs[0];
     var rt = latlngs[2];