fix graph passing to fromGraphLib

Author: zbynekstara

packages/joint-layout-directed-graph/DirectedGraph.d.ts

@@ -41,9 +41,14 @@ export namespace DirectedGraph {
         [key: string]: any;
     }
 
+    interface fromGraphLibOptions {
+        graph?: dia.Graph;
+        [key: string]: any;
+    }
+
     export function layout(graph: dia.Graph | dia.Cell[], opt?: LayoutOptions): g.Rect;
 
     export function toGraphLib(graph: dia.Graph, opt?: toGraphLibOptions): any;
 
-    export function fromGraphLib(glGraph: any, opt?: { [key: string]: any }): dia.Graph;
+    export function fromGraphLib(glGraph: any, opt?: fromGraphLibOptions): dia.Graph;
 }

packages/joint-layout-directed-graph/DirectedGraph.mjs

@@ -173,6 +173,7 @@ export const DirectedGraph = {
         graph.startBatch('layout');
 
         DirectedGraph.fromGraphLib(glGraph, {
+            graph,
             importNode: opt.importNode,
             importEdge: opt.importEdge,
             setPosition: opt.setPosition,
@@ -217,7 +218,7 @@ export const DirectedGraph = {
 
         var importNode = opt.importNode || util.noop;
         var importEdge = opt.importEdge || util.noop;
-        var graph = new dia.Graph();
+        var graph = opt.graph || new dia.Graph();
 
         // Import all nodes.
         glGraph.nodes().forEach(function(node) {