Collapse and Expand DevTools Tree Nodes

packages/lexical-devtools/src/panel/components/Chevron/index.css

@@ -0,0 +1,9 @@
+.chevron-button {
+  background: #222;
+  border: none;
+  color: #fff;
+  cursor: pointer;
+  margin: 0;
+  padding: 0;
+  text-decoration: none;
+}

packages/lexical-devtools/src/panel/components/Chevron/index.tsx

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ */
+import './index.css';
+
+import * as React from 'react';
+
+function Chevron({
+  handleClick,
+  isExpanded,
+}: {
+  handleClick: React.MouseEventHandler;
+  isExpanded: boolean;
+}): JSX.Element {
+  return (
+    <button className="chevron-button" onClick={handleClick}>
+      {isExpanded ? <>&#x25BC;</> : <>&#9654;</>}
+    </button>
+  );
+}
+
+export default Chevron;

packages/lexical-devtools/src/panel/components/TreeNode/index.css

@@ -0,0 +1,18 @@
+.indentation {
+  background: #222;
+  border: none;
+  color: #222;
+  margin: 0;
+  padding: 0;
+  text-decoration: none;
+  user-select: none;
+}
+
+.tree-node {
+  padding-left: 1em;
+  width: 100%;
+}
+
+.tree-node-wrapper {
+  width: 100%;
+}

packages/lexical-devtools/src/panel/components/TreeNode/index.tsx

@@ -5,33 +5,52 @@
  * LICENSE file in the root directory of this source tree.
  *
  */
+import './index.css';
+
 import {DevToolsNode} from 'packages/lexical-devtools/types';
 import * as React from 'react';
+import {useState} from 'react';
+
+import Chevron from '../Chevron';
 
 function TreeNode({
-  lexicalKey,
   __text,
   __type,
   children,
-}: {
-  children: Array<DevToolsNode>;
-  lexicalKey: string;
-  __text?: string;
-  __type: string;
-}): JSX.Element {
+  depth,
+  lexicalKey,
+}: DevToolsNode): JSX.Element {
+  const [isExpanded, setIsExpanded] = useState(true);
+
+  const handleChevronClick = () => {
+    setIsExpanded(!isExpanded);
+  };
+
+  const nodeString = ` (${lexicalKey}) ${__type} ${
+    __text ? '"' + __text + '"' : ''
+  }`;
+  const childNodes =
+    children.length > 0 ? (
+      <>
+        {children.map((child) => (
+          <TreeNode {...child} />
+        ))}
+      </>
+    ) : (
+      ''
+    );
+
   return (
-    <li key={lexicalKey}>
-      ({lexicalKey}) {__type} {__text ? '"' + __text + '"' : ''}
+    <div className="tree-node" key={lexicalKey}>
       {children.length > 0 ? (
-        <ul>
-          {children.map((child) => (
-            <TreeNode {...child} />
-          ))}
-        </ul>
+        <Chevron handleClick={handleChevronClick} isExpanded={isExpanded} />
       ) : (
-        ''
+        <button className="indentation">&#9654;</button>
       )}
-    </li>
+      {nodeString}
+      {<br />}
+      {isExpanded ? childNodes : ''}
+    </div>
   );
 }
 

packages/lexical-devtools/src/panel/components/TreeView/index.css

@@ -4,14 +4,10 @@
   color: #fff;
   margin: 0;
   padding: 1em;
-  font-size: 1em;
+  font-size: 1.2em;
   overflow: auto;
   text-align: left;
   -moz-osx-font-smoothing: grayscale;
   font-weight: 400;
-}
-
-.tree-view-output ul li {
-  font-family: monospace;
-  padding-left: 0.5em;
+  --indentation-size: 1em;
 }

packages/lexical-devtools/src/panel/components/TreeView/index.tsx

@@ -19,29 +19,36 @@ function TreeView({
   viewClassName: string;
   nodeMap: DevToolsTree;
 }): JSX.Element {
-  const depthFirstSearch = (node: DevToolsNode): DevToolsNode => {
+  // takes flat JSON structure, nests child comments inside parents
+  const depthFirstSearch = (
+    map: DevToolsTree = nodeMap,
+    nodeKey = 'root',
+    depth = 0,
+  ): DevToolsNode => {
+    const node = map[nodeKey];
     const children: Array<DevToolsNode> = [];
 
     if (Object.prototype.hasOwnProperty.call(node, '__children')) {
       node.__children.forEach((childKey: string) => {
-        const child = nodeMap[childKey];
-        children.push(depthFirstSearch(child));
+        children.push(depthFirstSearch(map, childKey, depth + 1));
       });
     }
 
-    return {...node, __type: node.__type, children, lexicalKey: node.__key};
+    return {
+      ...node,
+      __type: node.__type,
+      children,
+      depth,
+      lexicalKey: node.__key,
+    };
   };
 
   const generateTree = (map: DevToolsTree): JSX.Element => {
-    const root = depthFirstSearch(map.root);
+    const root = depthFirstSearch(nodeMap, 'root', 0);
     return <TreeNode {...root} />;
   };
 
-  return (
-    <div className={viewClassName}>
-      <ul>{generateTree(nodeMap)}</ul>
-    </div>
-  );
+  return <div className={viewClassName}>{generateTree(nodeMap)}</div>;
 }
 
 export default TreeView;

packages/lexical-devtools/types.ts

@@ -12,8 +12,9 @@ export interface DevToolsTree {
 export interface DevToolsNode {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   [x: string]: any;
-  children: Array<DevToolsNode>;
   __text?: string;
   __type: string;
+  children: Array<DevToolsNode>;
+  depth: number;
   lexicalKey: string;
 }