Nodes selection store, linking and unlinking nodes

src/App.tsx

@@ -1,7 +1,8 @@
-import React, { createContext, useState } from 'react';
+import React, { createContext, useEffectEvent, useState } from 'react';
 import { Layout, theme, Breadcrumb } from 'antd';
 import Graph, { GraphModel } from './components/Graph';
 import type { BreadcrumbItemType } from 'antd/es/breadcrumb/Breadcrumb';
+import { useKeysdownStore } from './stores/ArrayStore';
 
 const { Content } = Layout;
 
@@ -10,6 +11,20 @@ const App: React.FC = () => {
     token: { colorBgContainer, borderRadiusLG },
   } = theme.useToken();
   const [graphLevel, setGraphLevel] = useState<BreadcrumbItemType[]>([])
+  const addKey = useKeysdownStore(state => state.add);
+  const removeKey = useKeysdownStore(state => state.remove);
+  const onKeydown = useEffectEvent((key: string) => {
+    addKey(key);    
+  });
+  const onKeyUp = useEffectEvent((key: string) => {
+    removeKey(key);
+  })
+  document.addEventListener('keydown', (ev) => {    
+    onKeydown(ev.key)
+  });
+  document.addEventListener('keyup', (ev) =>  {
+    onKeyUp(ev.key);
+  })
 
   return (
     <Layout>

src/Graphviz.tsx

@@ -15,7 +15,9 @@ export function graphToDot(g) {
 
   // edges
   for (const e of g.edges) {
-    lines.push(`  \"${e.from}\" -> \"${e.to}\";`);
+    const attrs = [];
+    attrs.push(`id=\"${e.id}\"`)
+    lines.push(`  \"${e.from}\" -> \"${e.to}\" [${attrs.join(', ')}];`);
   }
 
   // close

src/components/Graph.tsx

@@ -6,7 +6,8 @@ import { graphToDot } from "../Graphviz";
 import type { BreadcrumbItemType } from "antd/es/breadcrumb/Breadcrumb";
 import NodeContextMenu from "./NodeContextMenu";
 import NodeRenameModal from "./NodeRenameModal";
-import { useGraphsStore } from "./GraphsCollection";
+import { useGraphsStore } from "../stores/GraphsStore";
+import { useKeysdownStore, useSelectedNodesStore } from "../stores/ArrayStore";
 
 
 export class GraphModel {
@@ -17,10 +18,12 @@ export class GraphModel {
 export class EdgeModel {
   from: string;
   to: string;
+  id: string;
 
-  constructor(from: string, to: string) {
+  constructor(from: string, to: string, id: string) {
     this.from = from;
     this.to = to;
+    this.id = id;
   }
 }
 
@@ -63,7 +66,7 @@ export default function Graph({ setGraphPath }: { setGraphPath: React.Dispatch<R
   const containerRef = useRef(null);
   const [graph, setGraph] = useState(defaultGraph());
   const [contextMenuOpened, openContextMenu] = useState(false);
-  const [renameModalOpened, openRenameModal] = useState(false);  
+  const [renameModalOpened, openRenameModal] = useState(false);
   const [graphId, selectGraphId] = useState('main');
   const [graphsPath, setGraphsPath] = useState([createPathSegment('main', 'Main')])
   const [nodeContext, openNodeContext] = useState<null | NodeContext>(null);
@@ -73,6 +76,12 @@ export default function Graph({ setGraphPath }: { setGraphPath: React.Dispatch<R
     graph: graph,
     setGraph: setGraph
   };
+  const isKeyPressed = useKeysdownStore(store => store.has);
+  const selectNode = useSelectedNodesStore(store => store.add);
+  const deselectNode = useSelectedNodesStore(store => store.remove);
+  const isNodeSelected = useSelectedNodesStore(store => store.has);
+  const anyNodeSelected = useSelectedNodesStore(store => store.hasAny);
+  const deselectAllNodes = useSelectedNodesStore(store => store.clear);
 
   useEffect(() => {
     setGraphPath(graphsPath);
@@ -119,12 +128,39 @@ export default function Graph({ setGraphPath }: { setGraphPath: React.Dispatch<R
 
   function attachInteractions(svgElement: SVGSVGElement) {
     const svg = d3.select(svgElement);
+    svg.selectAll('g.edge')
+      .style('cursor', 'not-allowed')
+      .on('click', function () {
+        const d3Node = d3.select(this);
+        const id = d3Node.attr('id');
+        setGraph(prev => ({ ...prev, edges: [...prev.edges.filter(e => e.id !== id)] }));
+      })
     svg.selectAll('g.node')
       .style('cursor', 'pointer')
-      .on('click', function (event) {
-        const id = d3.select(this).attr('id');
-        createChildNode(id);
-        renderGraph();
+      .on('click', function () {
+        const d3Node = d3.select(this);
+        const d3Rect = d3Node.select('g.node polygon');
+        const id = d3Node.attr('id');
+        if (isKeyPressed('Control')) {
+          if (isNodeSelected(id)) {
+            deselectNode(id);
+            d3Rect
+              .attr("stroke", "#000000");
+          } else {
+            selectNode(id);
+            d3Rect
+              .attr("stroke", "#1677ff")
+          }
+        } else {
+          if (anyNodeSelected()) {
+            linkSelectedNodesAsParents(id);
+            deselectAllNodes();
+            d3.selectAll('g.node polygon')
+              .attr("stroke", "#000000");
+          } else {
+            createChildNode(id);
+          }
+        }
       })
       .on('contextmenu', function (event) {
         const id = d3.select(this).attr('id');
@@ -143,9 +179,27 @@ export default function Graph({ setGraphPath }: { setGraphPath: React.Dispatch<R
       });
   }
 
+  function linkSelectedNodesAsParents(childNodeId: string) {
+    const selectedNodesIds = useSelectedNodesStore.getState().items;
+    setGraph(prev => ({ ...prev, edges: [...prev.edges, ...selectedNodesIds.map(parentId => ({ from: parentId, to: childNodeId, id: crypto.randomUUID() }))] }))
+  }
+
   function createChildNode(parentId: string) {
     const id = crypto.randomUUID();
-    setGraph(prev => ({ ...prev, nodes: [...prev.nodes, { id, label: 'New node' }], edges: [...prev.edges, { from: parentId, to: id }] }));
+    setGraph(prev => ({ ...prev, nodes: [...prev.nodes, { id, label: getRandomWords(1)[0] }], edges: [...prev.edges, { from: parentId, to: id, id: crypto.randomUUID() }] }));
+  }
+
+  function getRandomWords(count: number) {
+    const wordList = [
+      "apple", "river", "mountain", "sky", "storm", "ocean", "forest", "dream",
+      "stone", "flame", "shadow", "cloud", "leaf", "wind", "fire", "earth",
+      "flower", "bird", "light", "night", "sun", "rain", "snow", "tree",
+      "wolf", "star", "sand", "wave", "heart", "path"
+    ];
+
+    return wordList
+      .sort(() => Math.random() - 0.5)
+      .slice(0, count);
   }
 
   function createPathSegment(
@@ -199,11 +253,7 @@ export function defaultGraph(): GraphModel {
       { id: end, label: 'End' }
     ],
     edges: [
-      { from: start, to: end },
+      { from: start, to: end, id: crypto.randomUUID() },
     ]
   };
 }
-
-
-
-

src/components/NodeContextMenu.tsx

@@ -2,7 +2,7 @@ import { Dropdown, type MenuProps } from "antd";
 import { defaultGraph, graphContext, type EdgeModel, type NodeContext } from "./Graph";
 import { useContext } from "react";
 import { cloneDeep } from "lodash";
-import { useGraphsStore } from "./GraphsCollection";
+import { useGraphsStore } from "../stores/GraphsStore";
 
 const items: MenuProps['items'] = [
   {

src/stores/ArrayStore.tsx

@@ -0,0 +1,42 @@
+import { create } from 'zustand'
+
+export interface ArrayStore<T> {
+  items: T[];
+  add: (key: T) => void;
+  remove: (key: T) => void;
+  has: (key: T) => boolean;
+  hasAny: () => boolean;
+  clear: () => void;
+}
+
+export function createArrayStore<T>() {
+  return create<ArrayStore<T>>()((set, get) => ({
+    items: [],
+    add: (item) => set((state) => {
+      const newState = { items: [...state.items, item] };;
+      console.info(newState);
+      return newState;
+    }),
+    remove: (item) => set((state) => {
+      const newState = ({ items: [...state.items.filter(k => k !== item)] });
+      console.info(newState);
+      return newState;
+    }),
+    has: (key: T) => {
+      const state = get();
+      return state.items.indexOf(key) > -1;
+    },
+    hasAny: () => {
+      const state = get();
+      return state.items.length > 0;
+    },
+    clear: () => set(() => {
+      const newState = ({ items: [] });
+      console.info(newState);
+      return newState;
+    })
+  }));
+}
+
+export const useKeysdownStore = createArrayStore<string>();
+export const useSelectedNodesStore = createArrayStore<string>();

src/stores/GraphsStore.tsx

@@ -1,5 +1,5 @@
 import { create } from 'zustand'
-import type { GraphModel } from './Graph'
+import type { GraphModel } from '../components/Graph'
 
 export const useGraphsStore = create((set) => ({
   graphsById: new Map<string, GraphModel>(),