Memoise selection of nodes

Summary:
For the visualiser we use the same trick as with the hover state. We subscribe to selection changes and only render if the prev or new state concerns us.

For the tree we change from object identity to the node id + and indent guide are added to the memoisation equal check.

Depending on teh change this tree memoisation can vary in effectiveness. If you go from nothing selecting to selecting the top element nothing is memoised since react needs to render every element to draw the indent guide. If you have somethign selected and select a nearby element the memoisation works well.

There are ways to improve this more down the road

changelog: UIDebugger improve performance of selecting nodes

Reviewed By: lblasa

Differential Revision: D43305979

fbshipit-source-id: 5d90e806ed7b6a8401e9968be398d4a67ed0c294

desktop/plugins/public/ui-debugger/components/Tree.tsx

@@ -29,7 +29,7 @@ import {
 } from 'flipper-plugin';
 import {plugin} from '../index';
 import {Glyph} from 'flipper';
-import {groupBy, head, last} from 'lodash';
+import {groupBy, head, isEqual, last} from 'lodash';
 import {reverse} from 'lodash/fp';
 import {Dropdown, Menu, Typography} from 'antd';
 import {UIDebuggerMenuItem} from './util/UIDebuggerMenuItem';
@@ -50,21 +50,12 @@ export type TreeNode = UINode & {
   indentGuide: NodeIndentGuide | null;
 };
 
-export function Tree2({
-  nodes,
-  rootId,
-  selectedNode,
-  onSelectNode,
-}: {
-  nodes: Map<Id, UINode>;
-  rootId: Id;
-  selectedNode?: Id;
-  onSelectNode: (node?: Id) => void;
-}) {
+export function Tree2({nodes, rootId}: {nodes: Map<Id, UINode>; rootId: Id}) {
   const instance = usePlugin(plugin);
   const focusedNode = useValue(instance.uiState.focusedNode);
   const expandedNodes = useValue(instance.uiState.expandedNodes);
   const searchTerm = useValue(instance.uiState.searchTerm);
+  const selectedNode = useValue(instance.uiState.selectedNode);
   const isContextMenuOpen = useValue(instance.uiState.isContextMenuOpen);
   const hoveredNode = head(useValue(instance.uiState.hoveredNodes));
 
@@ -96,7 +87,7 @@ export function Tree2({
     refs,
     selectedNode,
     hoveredNode,
-    onSelectNode,
+    instance.uiActions.onSelectNode,
     instance.uiActions.onExpandNode,
     instance.uiActions.onCollapseNode,
     isUsingKBToScroll,
@@ -140,7 +131,7 @@ export function Tree2({
               hoveredNode={hoveredNode}
               isUsingKBToScroll={isUsingKBToScroll}
               isContextMenuOpen={isContextMenuOpen}
-              onSelectNode={onSelectNode}
+              onSelectNode={instance.uiActions.onSelectNode}
               onExpandNode={instance.uiActions.onExpandNode}
               onCollapseNode={instance.uiActions.onCollapseNode}
               onHoverNode={instance.uiActions.onHoverNode}
@@ -157,7 +148,7 @@ const MemoTreeItemContainer = React.memo(
   (prevProps, nextProps) => {
     const id = nextProps.treeNode.id;
     return (
-      prevProps.treeNode === nextProps.treeNode &&
+      prevProps.treeNode.id === nextProps.treeNode.id &&
       prevProps.isContextMenuOpen === nextProps.isContextMenuOpen &&
       prevProps.frameworkEvents === nextProps.frameworkEvents &&
       prevProps.highlightedNodes === nextProps.highlightedNodes &&
@@ -166,7 +157,8 @@ const MemoTreeItemContainer = React.memo(
       prevProps.hoveredNode !== id && //make sure that prev or next hover/selected node doesnt concern this tree node
       nextProps.hoveredNode !== id &&
       prevProps.selectedNode !== id &&
-      nextProps.selectedNode !== id
+      nextProps.selectedNode !== id &&
+      isEqual(prevProps.treeNode.indentGuide, nextProps.treeNode.indentGuide)
     );
   },
 );