feat(example): add example with floating edge and whole node as handle

example/src/NodeAsHandle/CustomEdge.tsx

@@ -0,0 +1,163 @@
+import { FC, useMemo } from 'react';
+import cc from 'classcat';
+import {
+  EdgeProps,
+  getMarkerEnd,
+  useStoreState,
+  Position,
+  getBezierPath,
+  ConnectionLineComponentProps,
+} from 'react-flow-renderer';
+
+function getNodeIntersection(source: any, target: any) {
+  // https://math.stackexchange.com/questions/1724792/an-algorithm-for-finding-the-intersection-point-between-a-center-of-vision-and-a
+  const w = source.__rf.width / 2;
+  const h = source.__rf.height / 2;
+
+  const x2 = source.__rf.position.x + w;
+  const y2 = source.__rf.position.y + h;
+  const x1 = target.__rf.position.x;
+  const y1 = target.__rf.position.y;
+
+  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];
+}
+
+function getEdgePosition(node: any, x: number, y: number) {
+  const n = { ...node.__rf.position, ...node.__rf };
+  const nx = Math.round(n.x);
+  const ny = Math.round(n.y);
+  const px = Math.round(x);
+  const py = Math.round(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;
+}
+
+function getArrow(source: any, target: any) {
+  const [sx, sy] = getNodeIntersection(source, target);
+  const [tx, ty] = getNodeIntersection(target, source);
+
+  const sourcePos = getEdgePosition(source, sx, sy);
+  const targetPos = getEdgePosition(target, tx, ty);
+
+  return {
+    sx,
+    sy,
+    tx,
+    ty,
+    label: null,
+    sourcePos,
+    targetPos,
+  };
+}
+
+const CustomEdge: FC<EdgeProps> = ({
+  id,
+  source,
+  target,
+  sourceX,
+  sourceY,
+  targetX,
+  targetY,
+  sourcePosition,
+  targetPosition,
+  data,
+  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, label, sourcePos, targetPos } = getArrow(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={cc(['react-flow__edge-path'])}
+          d={d}
+          markerEnd={markerEnd}
+          // opacity={style?.opacity}
+          style={style}
+        />
+      </g>
+      {label && (
+        <text>
+          <textPath href={`#${id}`} style={{ fontSize: '12px' }} startOffset="50%" textAnchor="middle">
+            {label}
+          </textPath>
+        </text>
+      )}
+    </>
+  );
+};
+
+export const ConnectionLine: FC<ConnectionLineComponentProps> = ({
+  sourceX,
+  sourceY,
+  targetX,
+  targetY,
+  sourceNode,
+}) => {
+  if (!sourceNode) {
+    return null;
+  }
+
+  const targetNode = { __rf: { width: 100, height: 100, position: { x: targetX, y: targetY - 50 } } };
+  const { sx, sy, tx, ty, label, sourcePos, targetPos } = getArrow(sourceNode, targetNode);
+  const d = getBezierPath({
+    sourceX: sx,
+    sourceY: sy,
+    sourcePosition: sourcePos,
+    targetPosition: targetPos,
+    targetX: tx,
+    targetY: ty,
+  });
+
+  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 CustomEdge;

example/src/NodeAsHandle/CustomNode.tsx

@@ -0,0 +1,16 @@
+import { Handle, Position, NodeProps } from 'react-flow-renderer';
+
+const CustomNode = ({ data }: NodeProps) => {
+  const handleType = data?.isTarget ? 'target' : 'source';
+
+  return (
+    <div className="customnode">
+      This is a node
+      <div className="handlewrapper">
+        <Handle type={handleType} position={Position.Top} />
+      </div>
+    </div>
+  );
+};
+
+export default CustomNode;

example/src/NodeAsHandle/index.tsx

@@ -0,0 +1,92 @@
+import React, { useState } from 'react';
+
+import ReactFlow, {
+  removeElements,
+  addEdge,
+  MiniMap,
+  Controls,
+  Background,
+  OnLoadParams,
+  EdgeTypesType,
+  Elements,
+  Connection,
+  Edge,
+  ArrowHeadType,
+  NodeTypesType,
+} from 'react-flow-renderer';
+
+import CustomEdge, { ConnectionLine } from './CustomEdge';
+import CustomNode from './CustomNode';
+
+import './style.css';
+
+const onLoad = (reactFlowInstance: OnLoadParams) => reactFlowInstance.fitView();
+
+const getCustomEdge = (props: any) => ({
+  type: 'custom',
+  arrowHeadType: ArrowHeadType.Arrow,
+  ...props,
+});
+
+function createElements() {
+  const elements = [];
+  const center = { x: window.innerWidth / 2, y: window.innerHeight / 2 };
+
+  elements.push({ type: 'custom', id: 'source', data: { label: 'Source', isTarget: false }, 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({ type: 'custom', id: `${i}`, data: { label: 'Target', isTarget: true }, position: { x, y } });
+
+    if (i % 2 === 0) {
+      elements.push(
+        getCustomEdge({
+          id: `source-${i}`,
+          source: 'source',
+          target: `${i}`,
+        })
+      );
+    }
+  }
+
+  return elements;
+}
+
+const initialElements: Elements = createElements();
+
+const edgeTypes: EdgeTypesType = {
+  custom: CustomEdge,
+};
+
+const nodeTypes: NodeTypesType = {
+  custom: CustomNode,
+};
+
+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(getCustomEdge(params), els));
+
+  return (
+    <ReactFlow
+      elements={elements}
+      onElementsRemove={onElementsRemove}
+      onConnect={onConnect}
+      onLoad={onLoad}
+      edgeTypes={edgeTypes}
+      nodeTypes={nodeTypes}
+      connectionLineComponent={ConnectionLine}
+    >
+      <MiniMap />
+      <Controls />
+      <Background />
+    </ReactFlow>
+  );
+};
+
+export default NodeAsHandleFlow;

example/src/NodeAsHandle/style.css

@@ -0,0 +1,24 @@
+.customnode {
+  padding: 10px;
+  border: 1px solid #ddd;
+  position: relative;
+}
+
+.handlewrapper {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+}
+
+.react-flow__handle {
+  background-color: red;
+  opacity: 0.5;
+  height: 100%;
+  width: 100%;
+  border-radius: 0;
+  left: 0;
+  top: 0;
+  transform: none;
+}

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 NodeAsHandle from './NodeAsHandle';
 import NodeTypeChange from './NodeTypeChange';
 import NodeTypesObjectChange from './NodeTypesObjectChange';
 import UpdatableEdge from './UpdatableEdge';
@@ -79,6 +80,10 @@ const routes = [
     path: '/custom-connectionline',
     component: CustomConnectionLine,
   },
+  {
+    path: '/node-as-handle',
+    component: NodeAsHandle,
+  },
   {
     path: '/nodetype-change',
     component: NodeTypeChange,