Allow render service to specify handle location

src/lib/editor/editor.component.ts

@@ -346,10 +346,6 @@ export class EditorComponent implements OnInit, OnDestroy {
   }
 
   createHandle(element: dia.CellView, kind: string, action: () => void, location: dia.Point): dia.Element {
-    if (!location) {
-      let bbox: any = (<any>element.model).getBBox();
-      location = bbox.origin().offset(bbox.width / 2, bbox.height / 2);
-    }
     let handle = Shapes.Factory.createHandle({
       renderer: this.renderer,
       paper: this.paper,

src/lib/shared/shapes.ts

@@ -687,9 +687,6 @@ export namespace Shapes {
       let graph = params.graph || (params.paper ? params.paper.model : undefined);
 
       let handle: dia.Element;
-      if (!location) {
-        location = {x: 0, y: 0};
-      }
       if (renderer && _.isFunction(renderer.createHandle)) {
         handle = renderer.createHandle(kind, parent);
       } else {
@@ -703,7 +700,9 @@ export namespace Shapes {
         });
       }
       handle.set('type', joint.shapes.flo.HANDLE_TYPE);
-      handle.set('position', location);
+      if (location) {
+        handle.set('position', location);
+      }
       if ((isChrome || isFF) && parent && typeof parent.get('z') === 'number') {
         handle.set('z', parent.get('z') + 1);
       }