Fix control by props, add control test example

packages/dev/src/app.tsx

@@ -1,6 +1,7 @@
 import * as React from 'react'
-import Editor from './components/editor'
+import Controlled from './controlled'
+import Basic from './basic'
 
 export default function App(): JSX.Element {
-  return <Editor />
+  return <Controlled />
 }

packages/dev/src/basic.tsx

@@ -0,0 +1,6 @@
+import * as React from 'react'
+import Editor from './components/editor'
+
+export default function BasicUsage(): JSX.Element {
+  return <Editor />
+}

packages/dev/src/controlled.tsx

@@ -0,0 +1,93 @@
+import * as React from 'react'
+import {
+  TLDraw,
+  ColorStyle,
+  DashStyle,
+  SizeStyle,
+  TLDrawDocument,
+  TLDrawShapeType,
+} from '@tldraw/tldraw'
+
+export default function Controlled() {
+  const [doc, setDoc] = React.useState<TLDrawDocument>({
+    id: 'doc',
+    pages: {
+      page1: {
+        id: 'page1',
+        shapes: {
+          rect1: {
+            id: 'rect1',
+            type: TLDrawShapeType.Rectangle,
+            parentId: 'page1',
+            name: 'Rectangle',
+            childIndex: 1,
+            point: [100, 100],
+            size: [100, 100],
+            style: {
+              dash: DashStyle.Draw,
+              size: SizeStyle.Medium,
+              color: ColorStyle.Blue,
+            },
+          },
+          rect2: {
+            id: 'rect2',
+            parentId: 'page1',
+            name: 'Rectangle',
+            childIndex: 2,
+            type: TLDrawShapeType.Rectangle,
+            point: [150, 250],
+            size: [150, 150],
+            style: {
+              dash: DashStyle.Draw,
+              size: SizeStyle.Medium,
+              color: ColorStyle.Blue,
+            },
+          },
+        },
+        bindings: {},
+      },
+    },
+    pageStates: {
+      page1: {
+        id: 'page1',
+        selectedIds: ['rect1'],
+        camera: {
+          point: [0, 0],
+          zoom: 1,
+        },
+      },
+    },
+  })
+
+  React.useEffect(() => {
+    const timeout = setTimeout(
+      () =>
+        setDoc({
+          ...doc,
+          pages: {
+            ...doc.pages,
+            page1: {
+              ...doc.pages.page1,
+              shapes: {
+                ...doc.pages.page1.shapes,
+                rect2: {
+                  ...doc.pages.page1.shapes.rect2,
+                  style: {
+                    ...doc.pages.page1.shapes.rect2.style,
+                    color: ColorStyle.Orange,
+                  },
+                },
+              },
+            },
+          },
+        }),
+      1000
+    )
+
+    return () => {
+      clearTimeout(timeout)
+    }
+  }, [])
+
+  return <TLDraw document={doc} />
+}

packages/tldraw/src/components/tldraw/tldraw.tsx

@@ -61,30 +61,26 @@ export function TLDraw({ id, document, currentPageId, onMount, onChange }: TLDra
     return { tlstate, useSelector: tlstate.useStore }
   })
 
-  React.useEffect(() => {
-    if (!document) return
-    tlstate.loadDocument(document)
-  }, [document, tlstate])
-
-  React.useEffect(() => {
-    if (!currentPageId) return
-    tlstate.changePage(currentPageId)
-  }, [currentPageId, tlstate])
-
   return (
     <TLDrawContext.Provider value={context}>
       <IdProvider>
-        <InnerTldraw />
+        <InnerTldraw currentPageId={currentPageId} document={document} />
       </IdProvider>
     </TLDrawContext.Provider>
   )
 }
 
-function InnerTldraw() {
-  useCustomFonts()
-
+function InnerTldraw({
+  currentPageId,
+  document,
+}: {
+  currentPageId?: string
+  document?: TLDrawDocument
+}) {
   const { tlstate, useSelector } = useTLDrawContext()
 
+  useCustomFonts()
+
   useKeyboardShortcuts()
 
   const page = useSelector(pageSelector)
@@ -128,6 +124,20 @@ function InnerTldraw() {
     return {}
   }, [isDarkMode])
 
+  React.useEffect(() => {
+    if (!document) return
+    if (document.id === tlstate.document.id) {
+      tlstate.updateDocument(document)
+    } else {
+      tlstate.loadDocument(document)
+    }
+  }, [document, tlstate])
+
+  React.useEffect(() => {
+    if (!currentPageId) return
+    tlstate.changePage(currentPageId)
+  }, [currentPageId, tlstate])
+
   return (
     <Layout>
       <ContextMenu>

packages/tldraw/src/state/tlstate.ts

@@ -67,7 +67,7 @@ const defaultDocument: TLDrawDocument = {
   },
 }
 
-const initialData: Data = {
+const defaultState: Data = {
   settings: {
     isPenMode: false,
     isDarkMode: false,
@@ -120,11 +120,11 @@ export class TLDrawState extends StateManager<Data> {
   selectedGroupId?: string
 
   constructor(
-    id = Utils.uniqueId(),
+    id?: string,
     onChange?: (tlstate: TLDrawState, data: Data, reason: string) => void,
     onMount?: (tlstate: TLDrawState) => void
   ) {
-    super(initialData, id, 2, (prev, next, prevVersion) => {
+    super(defaultState, id, 2, (prev, next, prevVersion) => {
       const state = { ...prev }
       if (prevVersion === 1)
         state.settings = {
@@ -478,56 +478,79 @@ export class TLDrawState extends StateManager<Data> {
   }
 
   /**
-   * Load a new document.
-   * @param document The document to load
+   * Update the current document.
+   * @param document
    */
-  loadDocument = (document: TLDrawDocument): this => {
-    this.deselectAll()
-    this.resetHistory()
-    this.clearSelectHistory()
-    this.session = undefined
-    this.selectedGroupId = undefined
+  updateDocument = (document: TLDrawDocument, reason = 'updated_document'): this => {
+    console.log(reason)
+
+    const state = this.state
 
-    return this.replaceState(
+    const currentPageId = document.pages[this.currentPageId]
+      ? this.currentPageId
+      : Object.keys(document.pages)[0]
+
+    this.replaceState(
       {
         ...this.state,
         appState: {
           ...this.appState,
-          currentPageId: Object.keys(document.pages)[0],
+          currentPageId,
         },
         document: {
           ...document,
           pages: Object.fromEntries(
             Object.entries(document.pages)
               .sort((a, b) => (a[1].childIndex || 0) - (b[1].childIndex || 0))
-              .map(([id, page], i) => {
-                return [
-                  id,
-                  {
-                    ...page,
-                    name: page.name ? page.name : `Page ${i++}`,
-                  },
-                ]
+              .map(([pageId, page], i) => {
+                const nextPage = { ...page }
+                if (!nextPage.name) nextPage.name = `Page ${i + 1}`
+                return [pageId, nextPage]
               })
           ),
           pageStates: Object.fromEntries(
-            Object.entries(document.pageStates).map(([id, pageState]) => {
-              return [
-                id,
-                {
-                  ...pageState,
-                  bindingId: undefined,
-                  editingId: undefined,
-                  hoveredId: undefined,
-                  pointedId: undefined,
-                },
-              ]
+            Object.entries(document.pageStates).map(([pageId, pageState]) => {
+              const page = document.pages[pageId]
+              const nextPageState = { ...pageState }
+              const keysToCheck = ['bindingId', 'editingId', 'hoveredId', 'pointedId'] as const
+
+              for (const key of keysToCheck) {
+                if (!page.shapes[key]) {
+                  nextPageState[key] = undefined
+                }
+              }
+
+              nextPageState.selectedIds = pageState.selectedIds.filter(
+                (id) => !!document.pages[pageId].shapes[id]
+              )
+
+              return [pageId, nextPageState]
             })
           ),
         },
       },
-      `loaded_document:${document.id}`
+      `${reason}:${document.id}`
     )
+
+    console.log(
+      'did page change?',
+      this.state.document.pages['page1'] !== state.document.pages['page1']
+    )
+
+    return this
+  }
+
+  /**
+   * Load a new document.
+   * @param document The document to load
+   */
+  loadDocument = (document: TLDrawDocument): this => {
+    this.deselectAll()
+    this.resetHistory()
+    this.clearSelectHistory()
+    this.session = undefined
+    this.selectedGroupId = undefined
+    return this.updateDocument(document, 'loaded_document')
   }
 
   /**