Close #206 | replace layoutRandom() with silent layoutRandomInMemory() in Eades

layoutRandom() emits setNodePos per vertex and owns a progress dialog —
inappropriate for internal initialisation inside another layout algorithm.
Add layoutRandomInMemory() which sets vertex positions silently (no signals,
no progress dialog) for use as an initial condition before the Eades
iteration loop begins.

Author: oxy86

src/graph.h

@@ -1079,6 +1079,8 @@ public slots:
 
     void layoutRandom();
 
+    void layoutRandomInMemory();
+
     void layoutRadialRandom(const bool &guides = true);
 
     void layoutCircular(const double &x0,

src/graph/layouts/graph_layouts_basic.cpp

@@ -121,6 +121,30 @@ void Graph::layoutRadialRandom(const bool &guides)
     setModStatus(ModStatus::VertexPositions);
 }
 
+
+/**
+ * @brief Repositions all vertices at random coordinates without emitting any signals.
+ *
+ * Used internally by force-directed layout algorithms (Eades, FR) to set up
+ * initial particle positions before the iteration loop begins. Since the iteration
+ * loop will immediately overwrite these positions and emits a bulk setNodePos pass
+ * at the end, there is no need to signal the graphics scene here.
+ *
+ * For the standalone random layout action (with progress dialog and scene update),
+ * use layoutRandom() instead.
+ */
+void Graph::layoutRandomInMemory()
+{
+    qDebug() << "Graph::layoutRandomInMemory()";
+    VList::const_iterator it;
+    for (it = m_graph.cbegin(); it != m_graph.cend(); ++it)
+    {
+        (*it)->setX(canvasRandomX());
+        (*it)->setY(canvasRandomY());
+    }
+}
+
+
 /**
  * @brief Repositions all nodes on the periphery of a circle with given radius
  * @param x0

src/graph/layouts/graph_layouts_force.cpp

@@ -57,8 +57,7 @@ void Graph::layoutForceDirectedSpringEmbedder(const int maxIterations)
              << " naturalLength " << naturalLength;
 
     /* apply an initial random layout */
-    // layoutCircular(canvasWidth/2.0, canvasHeight/2.0, naturalLength/2.0 ,false);
-    layoutRandom();
+    layoutRandomInMemory();
 
     QString pMsg = tr("Embedding Eades Spring-Gravitational model. \n"
                       "Please wait ....");