ui: fixed autocompletion issues

* click in autocompletions list causes search
* right arrow for autocompletion
* changed query operator has from '>' to '.' and operator sub from '.' to '+'
* fixed autocompletions to fit to query
and
* fixed spectral layouting endless looping on unconnected node

src/lib/component/controller/GraphLayouter.cpp

@@ -76,6 +76,17 @@ void GraphLayouter::layoutSpectralPrototype(std::vector<DummyNode>& nodes, const
 
 	MatrixDynamicBase<int> laplacian = buildLaplacianMatrix(nodes, edges);
 
+	// If the laplacian matrix has a zero value in it's diagonal, that means there are unconnected nodes and the spectral
+	// layouting fails for some reason. In this case we switch to raster layout.
+	for (unsigned int i = 0; i < laplacian.getColumnsCount(); i++)
+	{
+		if (laplacian.getValue(i, i) == 0)
+		{
+			layoutSimpleRaster(nodes);
+			return;
+		}
+	}
+
 	Eigen::MatrixXd degreeMatrix = Eigen::MatrixXd::Zero(laplacian.getColumnsCount(), laplacian.getRowsCount());
 	Eigen::MatrixXd eigenMatrix = Eigen::MatrixXd::Zero(laplacian.getColumnsCount(), laplacian.getRowsCount());