08-27-周三_17-09-29

node_modules/dagre-layout/lib/normalize.js

@@ -0,0 +1,93 @@
+import _ from 'lodash'
+
+import util from './util'
+
+/*
+ * Breaks any long edges in the graph into short segments that span 1 layer
+ * each. This operation is undoable with the denormalize function.
+ *
+ * Pre-conditions:
+ *
+ *    1. The input graph is a DAG.
+ *    2. Each node in the graph has a "rank" property.
+ *
+ * Post-condition:
+ *
+ *    1. All edges in the graph have a length of 1.
+ *    2. Dummy nodes are added where edges have been split into segments.
+ *    3. The graph is augmented with a "dummyChains" attribute which contains
+ *       the first dummy in each chain of dummy nodes produced.
+ */
+function run (g) {
+  g.graph().dummyChains = []
+  _.forEach(g.edges(), function (edge) { normalizeEdge(g, edge) })
+}
+
+function normalizeEdge (g, e) {
+  let v = e.v
+  let vRank = g.node(v).rank
+  const w = e.w
+  const wRank = g.node(w).rank
+  const name = e.name
+  const edgeLabel = g.edge(e)
+  const labelRank = edgeLabel.labelRank
+
+  if (wRank === vRank + 1) return
+
+  g.removeEdge(e)
+
+  let dummy
+  let attrs
+  let i
+  for (i = 0, ++vRank; vRank < wRank; ++i, ++vRank) {
+    edgeLabel.points = []
+    attrs = {
+      width: 0,
+      height: 0,
+      edgeLabel: edgeLabel,
+      edgeObj: e,
+      rank: vRank
+    }
+    dummy = util.addDummyNode(g, 'edge', attrs, '_d')
+    if (vRank === labelRank) {
+      attrs.width = edgeLabel.width
+      attrs.height = edgeLabel.height
+      attrs.dummy = 'edge-label'
+      attrs.labelpos = edgeLabel.labelpos
+    }
+    g.setEdge(v, dummy, { weight: edgeLabel.weight }, name)
+    if (i === 0) {
+      g.graph().dummyChains.push(dummy)
+    }
+    v = dummy
+  }
+
+  g.setEdge(v, w, { weight: edgeLabel.weight }, name)
+}
+
+function undo (g) {
+  _.forEach(g.graph().dummyChains, function (v) {
+    let node = g.node(v)
+    const origLabel = node.edgeLabel
+    let w = null
+    g.setEdge(node.edgeObj, origLabel)
+    while (node.dummy) {
+      w = g.successors(v)[0]
+      g.removeNode(v)
+      origLabel.points.push({ x: node.x, y: node.y })
+      if (node.dummy === 'edge-label') {
+        origLabel.x = node.x
+        origLabel.y = node.y
+        origLabel.width = node.width
+        origLabel.height = node.height
+      }
+      v = w
+      node = g.node(v)
+    }
+  })
+}
+
+export default {
+  run,
+  undo
+}