feat(ui): add type filter toggles

node_modules/dagre/lib/order/init-order.js

@@ -0,0 +1,38 @@
+"use strict";
+
+var _ = require("../lodash");
+
+module.exports = initOrder;
+
+/*
+ * Assigns an initial order value for each node by performing a DFS search
+ * starting from nodes in the first rank. Nodes are assigned an order in their
+ * rank as they are first visited.
+ *
+ * This approach comes from Gansner, et al., "A Technique for Drawing Directed
+ * Graphs."
+ *
+ * Returns a layering matrix with an array per layer and each layer sorted by
+ * the order of its nodes.
+ */
+function initOrder(g) {
+  var visited = {};
+  var simpleNodes = _.filter(g.nodes(), function(v) {
+    return !g.children(v).length;
+  });
+  var maxRank = _.max(_.map(simpleNodes, function(v) { return g.node(v).rank; }));
+  var layers = _.map(_.range(maxRank + 1), function() { return []; });
+
+  function dfs(v) {
+    if (_.has(visited, v)) return;
+    visited[v] = true;
+    var node = g.node(v);
+    layers[node.rank].push(v);
+    _.forEach(g.successors(v), dfs);
+  }
+
+  var orderedVs = _.sortBy(simpleNodes, function(v) { return g.node(v).rank; });
+  _.forEach(orderedVs, dfs);
+
+  return layers;
+}