1 files changed, 26 insertions, 7 deletions

diff --git a/src/client/views/collections/TreeView.tsx b/src/client/views/collections/TreeView.tsx
index 2398d8f58..0d2968ba1 100644
--- a/src/client/views/collections/TreeView.tsx
+++ b/src/client/views/collections/TreeView.tsx
@@ -32,6 +32,7 @@ import { CollectionTreeView, TreeViewType } from './CollectionTreeView';
 import { CollectionView } from './CollectionView';
 import './TreeView.scss';
 import React = require('react');
+import { render } from 'react-dom';
 
 export interface TreeViewProps {
     treeView: CollectionTreeView;
@@ -95,7 +96,7 @@ export class TreeView extends React.Component<TreeViewProps> {
     private _header: React.RefObject<HTMLDivElement> = React.createRef();
     private _tref = React.createRef<HTMLDivElement>();
     @observable _docRef: Opt<DocumentView>;
-    private _selDisposer: Opt<IReactionDisposer>;
+    private _disposers: { [name: string]: IReactionDisposer } = {};
     private _editTitleScript: (() => ScriptField) | undefined;
     private _openScript: (() => ScriptField) | undefined;
     private _treedropDisposer?: DragManager.DragDropDisposer;
@@ -212,14 +213,14 @@ export class TreeView extends React.Component<TreeViewProps> {
     };
 
     @action setEditTitle = (docView?: DocumentView) => {
-        this._selDisposer?.();
+        this._disposers.selection?.();
         if (!docView) {
             this._editTitle = false;
         } else if (docView.isSelected()) {
             const doc = docView.Document;
             SelectionManager.SelectSchemaViewDoc(doc);
             this._editTitle = true;
-            this._selDisposer = reaction(
+            this._disposers.selection = reaction(
                 () => SelectionManager.SelectedSchemaDoc(),
                 seldoc => seldoc !== doc && this.setEditTitle(undefined)
             );
@@ -259,7 +260,8 @@ export class TreeView extends React.Component<TreeViewProps> {
     };
 
     componentWillUnmount() {
-        this._selDisposer?.();
+        this._renderTimer && clearTimeout(this._renderTimer);
+        Object.values(this._disposers).forEach(disposer => disposer?.());
         this._treeEle && this.props.unobserveHeight(this._treeEle);
         document.removeEventListener('pointermove', this.onDragMove, true);
         document.removeEventListener('pointermove', this.onDragUp, true);
@@ -268,6 +270,10 @@ export class TreeView extends React.Component<TreeViewProps> {
     }
 
     componentDidUpdate() {
+        this._disposers.opening = reaction(
+            () => this.treeViewOpen,
+            open => !open && (this._renderCount = 20)
+        );
         this.props.hierarchyIndex !== undefined && this.props.AddToMap?.(this.doc, this.props.hierarchyIndex);
     }
 
@@ -512,6 +518,8 @@ export class TreeView extends React.Component<TreeViewProps> {
         return rows;
     }
 
+    _renderTimer: any;
+    @observable _renderCount = 1;
     @computed get renderContent() {
         TraceMobx();
         const expandKey = this.treeViewExpandedView;
@@ -543,6 +551,14 @@ export class TreeView extends React.Component<TreeViewProps> {
             const docs = expandKey === 'aliases' ? this.childAliases : expandKey === 'links' ? this.childLinks : expandKey === 'annotations' ? this.childAnnos : this.childDocs;
             let downX = 0,
                 downY = 0;
+            if (docs?.length && this._renderCount < docs?.length) {
+                this._renderTimer && clearTimeout(this._renderTimer);
+                this._renderTimer = setTimeout(
+                    action(() => {
+                        this._renderCount = Math.min(docs!.length, this._renderCount + 20);
+                    })
+                );
+            }
             return (
                 <>
                     {!docs?.length || this.props.AddToMap /* hack to identify pres box trees */ ? null : (
@@ -599,7 +615,8 @@ export class TreeView extends React.Component<TreeViewProps> {
                                   // TODO: [AL] add these
                                   this.props.AddToMap,
                                   this.props.RemFromMap,
-                                  this.props.hierarchyIndex
+                                  this.props.hierarchyIndex,
+                                  this._renderCount
                               )}
                     </ul>
                 </>
@@ -651,7 +668,7 @@ export class TreeView extends React.Component<TreeViewProps> {
         return (
             <div
                 className={`bullet${this.props.treeView.outlineMode ? '-outline' : ''}`}
-                key={'bullet'}
+                key="bullet"
                 title={this.childDocs?.length ? `click to see ${this.childDocs?.length} items` : 'view fields'}
                 onClick={this.bulletClick}
                 style={
@@ -1131,7 +1148,8 @@ export class TreeView extends React.Component<TreeViewProps> {
         // TODO: [AL] add these
         AddToMap?: (treeViewDoc: Doc, index: number[]) => Doc[],
         RemFromMap?: (treeViewDoc: Doc, index: number[]) => Doc[],
-        hierarchyIndex?: number[]
+        hierarchyIndex?: number[],
+        renderCount?: number
     ) {
         const viewSpecScript = Cast(containerCollection.viewSpecScript, ScriptField);
         if (viewSpecScript) {
@@ -1144,6 +1162,7 @@ export class TreeView extends React.Component<TreeViewProps> {
         return docs
             .filter(child => child instanceof Doc)
             .map((child, i) => {
+                if (renderCount && i > renderCount) return null;
                 const pair = Doc.GetLayoutDataDocPair(containerCollection, dataDoc, child);
                 if (!pair.layout || pair.data instanceof Promise) {
                     return null;