Split classes out of Graph.js

GraphGroup.js

@@ -0,0 +1,42 @@
+class GraphGroup {
+  constructor() {
+    this.nodes = [];
+  }
+
+  resolve(nodesByLabel) {
+    for (let label of this.nodeLabels.values()) {
+      for (let node of nodesByLabel.get(label)) {
+        this.nodes.push(node);
+        node.groups.add(this);
+      }
+    }
+  }
+
+  setPageRank() {
+    // All members of a group get the rank of the maximum member, so the
+    // initial positions will put them all near each other
+    let maxRank = 0;
+    for (let node of this.nodes) {
+      maxRank = Math.max(maxRank, node.pageRank);
+    }
+    for (let node of this.nodes) {
+      node.pageRank = maxRank;
+    }
+  }
+
+  static process(item) {
+    let group = new GraphGroup();
+    group.label = item.label;
+    group.nodeLabels = new Set();
+    for (let member of item.members) {
+      if (member.label == '') {
+        continue;
+      }
+      group.nodeLabels.add(member.label);
+    }
+    if (group.nodeLabels.size == 0) {
+      return null;
+    }
+    return group;
+  }
+}