Added Cia Scenario Viewer

src/components/useLayout.js

@@ -0,0 +1,56 @@
+import dagre from '@dagrejs/dagre'
+import { Position, useVueFlow } from '@vue-flow/core'
+import { ref } from 'vue'
+
+/**
+ * Composable to run the layout algorithm on the graph.
+ * It uses the `dagre` library to calculate the layout of the nodes and edges.
+ */
+export function useLayout() {
+  const { findNode } = useVueFlow()
+
+  const graph = ref(new dagre.graphlib.Graph())
+
+  const previousDirection = ref('LR')
+
+  function layout(nodes, edges, direction) {
+    // we create a new graph instance, in case some nodes/edges were removed, otherwise dagre would act as if they were still there
+    const dagreGraph = new dagre.graphlib.Graph()
+
+    graph.value = dagreGraph
+
+    dagreGraph.setDefaultEdgeLabel(() => ({}))
+
+    const isHorizontal = direction === 'LR'
+    dagreGraph.setGraph({ rankdir: direction })
+
+    previousDirection.value = direction
+
+    for (const node of nodes) {
+      // if you need width+height of nodes for your layout, you can use the dimensions property of the internal node (`GraphNode` type)
+      const graphNode = findNode(node.id)
+
+      dagreGraph.setNode(node.id, { width: graphNode.dimensions.width || 150, height: graphNode.dimensions.height || 50 })
+    }
+
+    for (const edge of edges) {
+      dagreGraph.setEdge(edge.source, edge.target)
+    }
+
+    dagre.layout(dagreGraph)
+
+    // set nodes with updated positions
+    return nodes.map((node) => {
+      const nodeWithPosition = dagreGraph.node(node.id)
+
+      return {
+        ...node,
+        targetPosition: isHorizontal ? Position.Left : Position.Top,
+        sourcePosition: isHorizontal ? Position.Right : Position.Bottom,
+        position: { x: nodeWithPosition.x, y: nodeWithPosition.y },
+      }
+    })
+  }
+
+  return { graph, layout, previousDirection }
+}