Add label rendering support to NetworkModule

mesa_viz_tornado/templates/js/NetworkModule_d3.js

@@ -38,6 +38,8 @@ const NetworkModule = function (svg_width, svg_height) {
 
   const nodes = g.append("g").attr("class", "nodes");
 
+  const labels = g.append("g").attr("class", "labels");
+
   this.render = (data) => {
     const graph = JSON.parse(JSON.stringify(data));
 
@@ -51,10 +53,10 @@ const NetworkModule = function (svg_width, svg_height) {
 
     for (
       let i = 0,
-        n = Math.ceil(
-          Math.log(simulation.alphaMin()) /
-            Math.log(1 - simulation.alphaDecay())
-        );
+      n = Math.ceil(
+        Math.log(simulation.alphaMin()) /
+        Math.log(1 - simulation.alphaDecay())
+      );
       i < n;
       ++i
     ) {
@@ -120,7 +122,33 @@ const NetworkModule = function (svg_width, svg_height) {
       });
 
     nodes.selectAll("circle").data(graph.nodes).exit().remove();
+
+    // Create and update text labels
+    labels.selectAll("text").data(graph.nodes).enter().append("text");
+
+    labels
+      .selectAll("text")
+      .data(graph.nodes)
+      .attr("x", function (d) {
+        return d.x;
+      })
+      .attr("y", function (d) {
+        return d.y;
+      })
+      .attr("text-anchor", "middle")
+      .attr("dominant-baseline", "middle")
+      .attr("font-size", function (d) {
+        return (d.size * 1.5) + "px";
+      })
+      .attr("fill", function (d) {
+        return d.label_color || "#000000";
+      })
+      .text(function (d) {
+        return d.label || "";
+      });
+
+    labels.selectAll("text").data(graph.nodes).exit().remove();
   };
 
-  this.reset = () => {};
+  this.reset = () => { };
 };