Merge pull request #1584 from wbkd/node-as-handle-example

chore(examples): add floating edge example

example/package-lock.json

@@ -27,7 +27,7 @@
     },
     "..": {
       "name": "react-flow-renderer",
-      "version": "9.6.7",
+      "version": "9.6.8",
       "license": "MIT",
       "dependencies": {
         "@babel/runtime": "^7.15.4",

example/src/FloatingEdges/FloatingConnectionLine.tsx

@@ -0,0 +1,40 @@
+import { FC } from 'react';
+import { getBezierPath, ConnectionLineComponentProps, Node } from 'react-flow-renderer';
+
+import { getEdgeParams } from './utils';
+
+const FloatingConnectionLine: FC<ConnectionLineComponentProps> = ({
+  targetX,
+  targetY,
+  sourcePosition,
+  targetPosition,
+  sourceNode,
+}) => {
+  if (!sourceNode) {
+    return null;
+  }
+
+  const targetNode = {
+    id: 'connection-target',
+    __rf: { width: 1, height: 1, position: { x: targetX, y: targetY } },
+  } as Node;
+
+  const { sx, sy } = getEdgeParams(sourceNode, targetNode);
+  const d = getBezierPath({
+    sourceX: sx,
+    sourceY: sy,
+    sourcePosition,
+    targetPosition,
+    targetX,
+    targetY,
+  });
+
+  return (
+    <g>
+      <path fill="none" stroke="#222" strokeWidth={1.5} className="animated" d={d} />
+      <circle cx={targetX} cy={targetY} fill="#fff" r={3} stroke="#222" strokeWidth={1.5} />
+    </g>
+  );
+};
+
+export default FloatingConnectionLine;

example/src/FloatingEdges/FloatingEdge.tsx

@@ -0,0 +1,35 @@
+import { FC, useMemo, CSSProperties } from 'react';
+import { EdgeProps, getMarkerEnd, useStoreState, getBezierPath } from 'react-flow-renderer';
+
+import { getEdgeParams } from './utils';
+
+const FloatingEdge: FC<EdgeProps> = ({ id, source, target, arrowHeadType, markerEndId, style }) => {
+  const nodes = useStoreState((state) => state.nodes);
+  const markerEnd = getMarkerEnd(arrowHeadType, markerEndId);
+
+  const sourceNode = useMemo(() => nodes.find((n) => n.id === source), [source, nodes]);
+  const targetNode = useMemo(() => nodes.find((n) => n.id === target), [target, nodes]);
+
+  if (!sourceNode || !targetNode) {
+    return null;
+  }
+
+  const { sx, sy, tx, ty, sourcePos, targetPos } = getEdgeParams(sourceNode, targetNode);
+
+  const d = getBezierPath({
+    sourceX: sx,
+    sourceY: sy,
+    sourcePosition: sourcePos,
+    targetPosition: targetPos,
+    targetX: tx,
+    targetY: ty,
+  });
+
+  return (
+    <g className="react-flow__connection">
+      <path id={id} className="react-flow__edge-path" d={d} markerEnd={markerEnd} style={style as CSSProperties} />
+    </g>
+  );
+};
+
+export default FloatingEdge;

example/src/FloatingEdges/index.tsx

@@ -0,0 +1,53 @@
+import React, { useState } from 'react';
+
+import ReactFlow, {
+  removeElements,
+  addEdge,
+  Background,
+  OnLoadParams,
+  EdgeTypesType,
+  Elements,
+  Connection,
+  Edge,
+  ArrowHeadType,
+} from 'react-flow-renderer';
+
+import './style.css';
+
+import FloatingEdge from './FloatingEdge';
+import FloatingConnectionLine from './FloatingConnectionLine';
+import { createElements } from './utils';
+
+const onLoad = (reactFlowInstance: OnLoadParams) => reactFlowInstance.fitView();
+
+const initialElements: Elements = createElements();
+
+const edgeTypes: EdgeTypesType = {
+  floating: FloatingEdge,
+};
+
+const NodeAsHandleFlow = () => {
+  const [elements, setElements] = useState<Elements>(initialElements);
+
+  const onElementsRemove = (elementsToRemove: Elements) => setElements((els) => removeElements(elementsToRemove, els));
+
+  const onConnect = (params: Connection | Edge) =>
+    setElements((els) => addEdge({ ...params, type: 'floating', arrowHeadType: ArrowHeadType.Arrow }, els));
+
+  return (
+    <div className="floatingedges">
+      <ReactFlow
+        elements={elements}
+        onElementsRemove={onElementsRemove}
+        onConnect={onConnect}
+        onLoad={onLoad}
+        edgeTypes={edgeTypes}
+        connectionLineComponent={FloatingConnectionLine}
+      >
+        <Background />
+      </ReactFlow>
+    </div>
+  );
+};
+
+export default NodeAsHandleFlow;

example/src/FloatingEdges/style.css

@@ -0,0 +1,9 @@
+.floatingedges {
+  flex-direction: column;
+  display: flex;
+  height: 100%;
+}
+
+.floatingedges .react-flow__handle {
+  opacity: 0;
+}

example/src/FloatingEdges/utils.ts

@@ -0,0 +1,99 @@
+import { Position, ArrowHeadType, Node, XYPosition } from 'react-flow-renderer';
+
+// this helper function returns the intersection point
+// of the line between the center of the intersectionNode and the target node
+function getNodeIntersection(intersectionNode: Node, targetNode: Node): XYPosition {
+  // https://math.stackexchange.com/questions/1724792/an-algorithm-for-finding-the-intersection-point-between-a-center-of-vision-and-a
+  const {
+    width: intersectionNodeWidth,
+    height: intersectionNodeHeight,
+    position: intersectionNodePosition,
+  } = intersectionNode.__rf;
+  const targetPosition = targetNode.__rf.position;
+
+  const w = intersectionNodeWidth / 2;
+  const h = intersectionNodeHeight / 2;
+
+  const x2 = intersectionNodePosition.x + w;
+  const y2 = intersectionNodePosition.y + h;
+  const x1 = targetPosition.x + w;
+  const y1 = targetPosition.y + h;
+
+  const xx1 = (x1 - x2) / (2 * w) - (y1 - y2) / (2 * h);
+  const yy1 = (x1 - x2) / (2 * w) + (y1 - y2) / (2 * h);
+  const a = 1 / (Math.abs(xx1) + Math.abs(yy1));
+  const xx3 = a * xx1;
+  const yy3 = a * yy1;
+  const x = w * (xx3 + yy3) + x2;
+  const y = h * (-xx3 + yy3) + y2;
+
+  return { x, y };
+}
+
+// returns the position (top,right,bottom or right) passed node compared to the intersection point
+function getEdgePosition(node: Node, intersectionPoint: XYPosition) {
+  const n = { ...node.__rf.position, ...node.__rf };
+  const nx = Math.round(n.x);
+  const ny = Math.round(n.y);
+  const px = Math.round(intersectionPoint.x);
+  const py = Math.round(intersectionPoint.y);
+
+  if (px <= nx + 1) {
+    return Position.Left;
+  }
+  if (px >= nx + n.width - 1) {
+    return Position.Right;
+  }
+  if (py <= ny + 1) {
+    return Position.Top;
+  }
+  if (py >= n.y + n.height - 1) {
+    return Position.Bottom;
+  }
+
+  return Position.Top;
+}
+
+// returns the parameters (sx, sy, tx, ty, sourcePos, targetPos) you need to create an edge
+export function getEdgeParams(source: Node, target: Node) {
+  const sourceIntersectionPoint = getNodeIntersection(source, target);
+  const targetIntersectionPoint = getNodeIntersection(target, source);
+
+  const sourcePos = getEdgePosition(source, sourceIntersectionPoint);
+  const targetPos = getEdgePosition(target, targetIntersectionPoint);
+
+  return {
+    sx: sourceIntersectionPoint.x,
+    sy: sourceIntersectionPoint.y,
+    tx: targetIntersectionPoint.x,
+    ty: targetIntersectionPoint.y,
+    sourcePos,
+    targetPos,
+  };
+}
+
+export function createElements() {
+  const elements = [];
+  const center = { x: window.innerWidth / 2, y: window.innerHeight / 2 };
+
+  elements.push({ id: 'target', data: { label: 'Target' }, position: center });
+
+  for (let i = 0; i < 8; i++) {
+    const degrees = i * (360 / 8);
+    const radians = degrees * (Math.PI / 180);
+    const x = 250 * Math.cos(radians) + center.x;
+    const y = 250 * Math.sin(radians) + center.y;
+
+    elements.push({ id: `${i}`, data: { label: 'Source' }, position: { x, y } });
+
+    elements.push({
+      id: `edge-${i}`,
+      target: 'target',
+      source: `${i}`,
+      type: 'floating',
+      arrowHeadType: ArrowHeadType.Arrow,
+    });
+  }
+
+  return elements;
+}

example/src/index.tsx

@@ -14,6 +14,7 @@ import Provider from './Provider';
 import Hidden from './Hidden';
 import EdgeTypes from './EdgeTypes';
 import CustomConnectionLine from './CustomConnectionLine';
+import FloatingEdges from './FloatingEdges';
 import NodeTypeChange from './NodeTypeChange';
 import NodeTypesObjectChange from './NodeTypesObjectChange';
 import UpdatableEdge from './UpdatableEdge';
@@ -79,6 +80,10 @@ const routes = [
     path: '/custom-connectionline',
     component: CustomConnectionLine,
   },
+  {
+    path: '/floating-edges',
+    component: FloatingEdges,
+  },
   {
     path: '/nodetype-change',
     component: NodeTypeChange,