implemented new fitView logic

packages/react/src/hooks/useOnSelectionChange.ts

@@ -1,20 +1,53 @@
 import { useEffect } from 'react';
 
 import { useStoreApi } from './useStore';
-import type { OnSelectionChangeFunc } from '../types';
+import type { OnSelectionChangeFunc, Node, Edge } from '../types';
 
-export type UseOnSelectionChangeOptions = {
-  onChange: OnSelectionChangeFunc;
+export type UseOnSelectionChangeOptions<NodeType extends Node = Node, EdgeType extends Edge = Edge> = {
+  /** The handler to register. */
+  onChange: OnSelectionChangeFunc<NodeType, EdgeType>;
 };
 
 /**
- * Hook for registering an onSelectionChange handler.
+ * This hook lets you listen for changes to both node and edge selection. As the
+ *name implies, the callback you provide will be called whenever the selection of
+ *_either_ nodes or edges changes.
  *
  * @public
- * @param params.onChange - The handler to register
+ * @example
+ * ```jsx
+ *import { useState } from 'react';
+ *import { ReactFlow, useOnSelectionChange } from '@xyflow/react';
+ *
+ *function SelectionDisplay() {
+ *  const [selectedNodes, setSelectedNodes] = useState([]);
+ *  const [selectedEdges, setSelectedEdges] = useState([]);
+ *
+ *  // the passed handler has to be memoized, otherwise the hook will not work correctly
+ *  const onChange = useCallback(({ nodes, edges }) => {
+ *    setSelectedNodes(nodes.map((node) => node.id));
+ *    setSelectedEdges(edges.map((edge) => edge.id));
+ *  }, []);
+ *
+ *  useOnSelectionChange({
+ *    onChange,
+ *  });
+ *
+ *  return (
+ *    <div>
+ *      <p>Selected nodes: {selectedNodes.join(', ')}</p>
+ *      <p>Selected edges: {selectedEdges.join(', ')}</p>
+ *    </div>
+ *  );
+ *}
+ *```
+ *
+ * @remarks You need to memoize the passed `onChange` handler, otherwise the hook will not work correctly.
  */
-export function useOnSelectionChange({ onChange }: UseOnSelectionChangeOptions) {
-  const store = useStoreApi();
+export function useOnSelectionChange<NodeType extends Node = Node, EdgeType extends Edge = Edge>({
+  onChange,
+}: UseOnSelectionChangeOptions<NodeType, EdgeType>) {
+  const store = useStoreApi<NodeType, EdgeType>();
 
   useEffect(() => {
     const nextOnSelectionChangeHandlers = [...store.getState().onSelectionChangeHandlers, onChange];