Break layout node into its own Wave Object (#21)

I am updating the layout node setup to write to its own wave object. 

The existing setup requires me to plumb the layout updates through every
time the tab gets updated, which produces a lot of annoying and
unintuitive design patterns. With this new setup, the tab object doesn't
get written to when the layout changes, only the layout object will get
written to. This prevents collisions when both the tab object and the
layout node object are getting updated, such as when a new block is
added or deleted.

db/migrations-wstore/000001_init.down.sql

@@ -5,4 +5,3 @@ DROP TABLE db_workspace;
 DROP TABLE db_tab;
 
 DROP TABLE db_block;
-

db/migrations-wstore/000001_init.up.sql

@@ -27,3 +27,4 @@ CREATE TABLE db_block (
     version int NOT NULL,
     data json NOT NULL
 );
+

db/migrations-wstore/000002_init.down.sql

@@ -0,0 +1 @@
+DROP TABLE db_layout;

db/migrations-wstore/000002_init.up.sql

@@ -0,0 +1,5 @@
+CREATE TABLE db_layout (
+    oid varchar(36) PRIMARY KEY,
+    version int NOT NULL,
+    data json NOT NULL
+);

frontend/app/store/wos.ts

@@ -3,7 +3,6 @@
 
 // WaveObjectStore
 
-import { LayoutNode } from "@/faraday/index";
 import { Call as $Call, Events } from "@wailsio/runtime";
 import * as jotai from "jotai";
 import * as React from "react";
@@ -297,7 +296,7 @@ function getObjectValue<T>(oref: string, getFn?: jotai.Getter): T {
 // sets the value of a WaveObject in the cache.
 // should provide setFn if it is available (e.g. inside of a jotai atom)
 // otherwise it will use the globalStore.set function
-function setObjectValue<T>(value: WaveObj, setFn?: jotai.Setter, pushToServer?: boolean) {
+function setObjectValue<T extends WaveObj>(value: T, setFn?: jotai.Setter, pushToServer?: boolean) {
     const oref = makeORef(value.otype, value.oid);
     let wov = waveObjectValueCache.get(oref);
     if (wov == null) {
@@ -309,7 +308,9 @@ function setObjectValue<T>(value: WaveObj, setFn?: jotai.Setter, pushToServer?:
     }
     console.log("Setting", oref, "to", value);
     setFn(wov.dataAtom, { value: value, loading: false });
+    console.log("Setting", oref, "to", value, "done");
     if (pushToServer) {
+        console.log("pushToServer", oref, value);
         UpdateObject(value, false);
     }
 }
@@ -326,8 +327,8 @@ export function CreateBlock(blockDef: BlockDef, rtOpts: RuntimeOpts): Promise<{
     return wrapObjectServiceCall("CreateBlock", blockDef, rtOpts);
 }
 
-export function DeleteBlock(blockId: string, newLayout?: LayoutNode<any>): Promise<void> {
+export function DeleteBlock(blockId: string): Promise<void> {
-    return wrapObjectServiceCall("DeleteBlock", blockId, newLayout);
+    return wrapObjectServiceCall("DeleteBlock", blockId);
 }
 
 export function CloseTab(tabId: string): Promise<void> {
@@ -339,9 +340,9 @@ export function UpdateObjectMeta(blockId: string, meta: MetadataType): Promise<v
 }
 
 export function UpdateObject(waveObj: WaveObj, returnUpdates: boolean): Promise<WaveObjUpdate[]> {
+    console.log("UpdateObject", waveObj, returnUpdates);
     return wrapObjectServiceCall("UpdateObject", waveObj, returnUpdates);
 }
-
 export {
     cleanWaveObjectCache,
     clearWaveObjectCache,

frontend/app/tab/tab.tsx

@@ -27,13 +27,10 @@ const TabContent = ({ tabId }: { tabId: string }) => {
         return <Block blockId={tabData.blockId} onClose={onClose} />;
     }, []);
 
-    const onNodeDelete = useCallback(
+    const onNodeDelete = useCallback((data: TabLayoutData) => {
-        (data: TabLayoutData) => {
+        console.log("onNodeDelete", data);
-            console.log("onNodeDelete", data, tabData);
+        return WOS.DeleteBlock(data.blockId);
-            WOS.DeleteBlock(data.blockId, tabData.layout);
+    }, []);
-        },
-        [tabData]
-    );
 
     if (tabLoading) {
         return <CenteredLoadingDiv />;

frontend/app/workspace/workspace.tsx

@@ -77,7 +77,7 @@ function Widgets() {
             };
             dispatchLayoutStateAction(insertNodeAction);
         },
-        [activeTabAtom]
+        [activeTabAtom, dispatchLayoutStateAction]
     );
 
     async function createBlock(blockDef: BlockDef) {

frontend/faraday/lib/TileLayout.tsx

@@ -22,7 +22,7 @@ import { setTransform as createTransform, debounce, determineDropDirection } fro
 export interface TileLayoutProps<T> {
     layoutTreeStateAtom: WritableLayoutTreeStateAtom<T>;
     renderContent: ContentRenderer<T>;
-    onNodeDelete?: (data: T) => void;
+    onNodeDelete?: (data: T) => Promise<void>;
     className?: string;
 }
 
@@ -120,7 +120,7 @@ export const TileLayout = <T,>({ layoutTreeStateAtom, className, renderContent,
                 );
             }
         }, 30),
-        [activeDrag, overlayContainerRef, displayContainerRef, layoutTreeState, nodeRefs]
+        [activeDrag, overlayContainerRef, displayContainerRef, layoutTreeState.leafs, nodeRefs]
     );
 
     // Update the transforms whenever we drag something and whenever the layout updates.
@@ -133,6 +133,7 @@ export const TileLayout = <T,>({ layoutTreeStateAtom, className, renderContent,
     // reattach the new callback.
     const [prevUpdateTransforms, setPrevUpdateTransforms] = useState<() => void>(undefined);
     useEffect(() => {
+        console.log("replace resize listener");
         if (prevUpdateTransforms) window.removeEventListener("resize", prevUpdateTransforms);
         window.addEventListener("resize", updateTransforms);
         setPrevUpdateTransforms(updateTransforms);
@@ -156,7 +157,7 @@ export const TileLayout = <T,>({ layoutTreeStateAtom, className, renderContent,
     }, []);
 
     const onLeafClose = useCallback(
-        (node: LayoutNode<T>) => {
+        async (node: LayoutNode<T>) => {
             console.log("onLeafClose", node);
             const deleteAction: LayoutTreeDeleteNodeAction = {
                 type: LayoutTreeActionType.DeleteNode,
@@ -165,7 +166,7 @@ export const TileLayout = <T,>({ layoutTreeStateAtom, className, renderContent,
             console.log("calling dispatch", deleteAction);
             dispatch(deleteAction);
             console.log("calling onNodeDelete", node);
-            onNodeDelete?.(node.data);
+            await onNodeDelete?.(node.data);
             console.log("node deleted");
         },
         [onNodeDelete, dispatch]

frontend/faraday/lib/layoutAtom.ts

@@ -1,11 +1,13 @@
 // Copyright 2024, Command Line Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-import { PrimitiveAtom, WritableAtom, atom, useAtom } from "jotai";
+import { WOS } from "@/app/store/global.js";
+import { Atom, Getter, PrimitiveAtom, WritableAtom, atom, useAtom } from "jotai";
 import { useCallback } from "react";
 import { layoutTreeStateReducer, newLayoutTreeState } from "./layoutState.js";
 import {
     LayoutNode,
+    LayoutNodeWaveObj,
     LayoutTreeAction,
     LayoutTreeState,
     WritableLayoutNodeAtom,
@@ -29,27 +31,16 @@ export function newLayoutTreeStateAtom<T>(rootNode: LayoutNode<T>): PrimitiveAto
  * @returns The derived WritableLayoutTreeStateAtom.
  */
 export function withLayoutTreeState<T>(layoutNodeAtom: WritableLayoutNodeAtom<T>): WritableLayoutTreeStateAtom<T> {
-    return atom(
+    const pendingActionAtom = atom<LayoutTreeAction>(null) as PrimitiveAtom<LayoutTreeAction>;
-        (get) => newLayoutTreeState(get(layoutNodeAtom)),
-        (_get, set, value) => set(layoutNodeAtom, value.rootNode)
-    );
-}
-
-export function withLayoutStateFromTab(
-    tabAtom: WritableAtom<Tab, [value: Tab], void>
-): WritableLayoutTreeStateAtom<TabLayoutData> {
     return atom(
         (get) => {
-            const tabData = get(tabAtom);
+            const layoutState = newLayoutTreeState(get(layoutNodeAtom));
-            console.log("get layout state from tab", tabData);
+            layoutState.pendingAction = get(pendingActionAtom);
-            return newLayoutTreeState(tabData?.layout);
+            return layoutState;
         },
-        (get, set, value) => {
+        (_get, set, value) => {
-            const tabValue = get(tabAtom);
+            set(pendingActionAtom, value.pendingAction);
-            const newTabValue = { ...tabValue };
+            set(layoutNodeAtom, value.rootNode);
-            newTabValue.layout = value.rootNode;
-            console.log("set tab", tabValue, value);
-            set(tabAtom, newTabValue);
         }
     );
 }
@@ -72,6 +63,38 @@ export function useLayoutTreeStateReducerAtom<T>(
 
 const tabLayoutAtomCache = new Map<string, WritableLayoutTreeStateAtom<TabLayoutData>>();
 
+function getLayoutNodeWaveObjAtomFromTab<T>(
+    tabAtom: Atom<Tab>,
+    get: Getter
+): WritableAtom<LayoutNodeWaveObj<T>, [value: LayoutNodeWaveObj<T>], void> {
+    const tabValue = get(tabAtom);
+    console.log("getLayoutNodeWaveObjAtomFromTab tabValue", tabValue);
+    if (!tabValue) return;
+    const layoutNodeOref = WOS.makeORef("layout", tabValue.layoutNode);
+    console.log("getLayoutNodeWaveObjAtomFromTab oref", layoutNodeOref);
+    return WOS.getWaveObjectAtom<LayoutNodeWaveObj<T>>(layoutNodeOref);
+}
+
+export function withLayoutNodeAtomFromTab<T>(tabAtom: Atom<Tab>): WritableLayoutNodeAtom<T> {
+    return atom(
+        (get) => {
+            console.log("get withLayoutNodeAtomFromTab", tabAtom);
+            const atom = getLayoutNodeWaveObjAtomFromTab<T>(tabAtom, get);
+            if (!atom) return null;
+            const retVal = get(atom)?.node;
+            console.log("get withLayoutNodeAtomFromTab end", retVal);
+            return get(atom)?.node;
+        },
+        (get, set, value) => {
+            console.log("set withLayoutNodeAtomFromTab", value);
+            const waveObjAtom = getLayoutNodeWaveObjAtomFromTab<T>(tabAtom, get);
+            if (!waveObjAtom) return;
+            const newWaveObjAtom = { ...get(waveObjAtom), node: value };
+            set(waveObjAtom, newWaveObjAtom);
+        }
+    );
+}
+
 export function getLayoutStateAtomForTab(
     tabId: string,
     tabAtom: WritableAtom<Tab, [value: Tab], void>
@@ -82,7 +105,7 @@ export function getLayoutStateAtomForTab(
         return atom;
     }
     console.log("Creating new atom for tab", tabId);
-    atom = withLayoutStateFromTab(tabAtom);
+    atom = withLayoutTreeState(withLayoutNodeAtomFromTab<TabLayoutData>(tabAtom));
     tabLayoutAtomCache.set(tabId, atom);
     return atom;
 }

frontend/faraday/lib/model.ts

@@ -131,3 +131,7 @@ export type WritableLayoutNodeAtom<T> = WritableAtom<LayoutNode<T>, [value: Layo
 export type WritableLayoutTreeStateAtom<T> = WritableAtom<LayoutTreeState<T>, [value: LayoutTreeState<T>], void>;
 
 export type ContentRenderer<T> = (data: T, ready: boolean, onClose?: () => void) => React.ReactNode;
+
+export interface LayoutNodeWaveObj<T> extends WaveObj {
+    node: LayoutNode<T>;
+}

frontend/types/custom.d.ts

@@ -1,8 +1,6 @@
 // Copyright 2024, Command Line Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-import { LayoutNode } from "../faraday";
-
 declare global {
     type UIContext = {
         windowid: string;
@@ -70,7 +68,7 @@ declare global {
         version: number;
         name: string;
         blockids: string[];
-        layout: LayoutNode<TabLayoutData>;
+        layoutNode: string;
     };
 
     type Point = {

pkg/filestore/blockstore_test.go

@@ -79,7 +79,7 @@ func TestCreate(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	err := WFS.MakeFile(ctx, zoneId, "testfile", nil, FileOptsType{})
 	if err != nil {
 		t.Fatalf("error creating file: %v", err)
@@ -153,7 +153,7 @@ func TestDelete(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	err := WFS.MakeFile(ctx, zoneId, "testfile", nil, FileOptsType{})
 	if err != nil {
 		t.Fatalf("error creating file: %v", err)
@@ -216,7 +216,7 @@ func TestSetMeta(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	err := WFS.MakeFile(ctx, zoneId, "testfile", nil, FileOptsType{})
 	if err != nil {
 		t.Fatalf("error creating file: %v", err)
@@ -319,7 +319,7 @@ func TestAppend(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	fileName := "t2"
 	err := WFS.MakeFile(ctx, zoneId, fileName, nil, FileOptsType{})
 	if err != nil {
@@ -347,7 +347,7 @@ func TestWriteFile(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	fileName := "t3"
 	err := WFS.MakeFile(ctx, zoneId, fileName, nil, FileOptsType{})
 	if err != nil {
@@ -391,7 +391,7 @@ func TestCircularWrites(t *testing.T) {
 	defer cleanupDb(t)
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	err := WFS.MakeFile(ctx, zoneId, "c1", nil, FileOptsType{Circular: true, MaxSize: 50})
 	if err != nil {
 		t.Fatalf("error creating file: %v", err)
@@ -478,7 +478,7 @@ func TestMultiPart(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	fileName := "m2"
 	data := makeText(80)
 	err := WFS.MakeFile(ctx, zoneId, fileName, nil, FileOptsType{})
@@ -554,7 +554,7 @@ func TestSimpleDBFlush(t *testing.T) {
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	fileName := "t1"
 	err := WFS.MakeFile(ctx, zoneId, fileName, nil, FileOptsType{})
 	if err != nil {
@@ -586,7 +586,7 @@ func TestConcurrentAppend(t *testing.T) {
 	defer cleanupDb(t)
 	ctx, cancelFn := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancelFn()
-	zoneId := uuid.New().String()
+	zoneId := uuid.NewString()
 	fileName := "t1"
 	err := WFS.MakeFile(ctx, zoneId, fileName, nil, FileOptsType{})
 	if err != nil {

pkg/service/objectservice/objectservice.go

@@ -147,11 +147,11 @@ func (svc *ObjectService) CreateBlock(uiContext wstore.UIContext, blockDef *wsto
 	return updatesRtn(ctx, rtn)
 }
 
-func (svc *ObjectService) DeleteBlock(uiContext wstore.UIContext, blockId string, newLayout any) (any, error) {
+func (svc *ObjectService) DeleteBlock(uiContext wstore.UIContext, blockId string) (any, error) {
 	ctx, cancelFn := context.WithTimeout(context.Background(), DefaultTimeout)
 	defer cancelFn()
 	ctx = wstore.ContextWithUpdates(ctx)
-	err := wstore.DeleteBlock(ctx, uiContext.ActiveTabId, blockId, newLayout)
+	err := wstore.DeleteBlock(ctx, uiContext.ActiveTabId, blockId)
 	if err != nil {
 		return nil, fmt.Errorf("error deleting block: %w", err)
 	}

pkg/wshrpc/rpc_client.go

@@ -199,7 +199,7 @@ func (c *RpcClient) removeReqInfo(rpcId string, clearSend bool) {
 }
 
 func (c *RpcClient) SimpleReq(ctx context.Context, command string, data any) (any, error) {
-	rpcId := uuid.New().String()
+	rpcId := uuid.NewString()
 	seqNum := c.NextSeqNum.Add(1)
 	var timeoutInfo *TimeoutInfo
 	deadline, ok := ctx.Deadline()
@@ -235,7 +235,7 @@ func (c *RpcClient) SimpleReq(ctx context.Context, command string, data any) (an
 }
 
 func (c *RpcClient) StreamReq(ctx context.Context, command string, data any, respTimeout time.Duration) (chan *RpcPacket, error) {
-	rpcId := uuid.New().String()
+	rpcId := uuid.NewString()
 	seqNum := c.NextSeqNum.Add(1)
 	var timeoutInfo *TimeoutInfo = &TimeoutInfo{RespPacketTimeout: respTimeout.Milliseconds()}
 	deadline, ok := ctx.Deadline()

pkg/wstore/wstore.go

@@ -140,13 +140,19 @@ func CreateTab(ctx context.Context, workspaceId string, name string) (*Tab, erro
 		if ws == nil {
 			return nil, fmt.Errorf("workspace not found: %q", workspaceId)
 		}
+		layoutNodeId := uuid.NewString()
 		tab := &Tab{
-			OID:      uuid.New().String(),
+			OID:        uuid.NewString(),
-			Name:     name,
+			Name:       name,
-			BlockIds: []string{},
+			BlockIds:   []string{},
+			LayoutNode: layoutNodeId,
+		}
+		layoutNode := &LayoutNode{
+			OID: layoutNodeId,
 		}
 		ws.TabIds = append(ws.TabIds, tab.OID)
 		DBInsert(tx.Context(), tab)
+		DBInsert(tx.Context(), layoutNode)
 		DBUpdate(tx.Context(), ws)
 		return tab, nil
 	})
@@ -154,7 +160,7 @@ func CreateTab(ctx context.Context, workspaceId string, name string) (*Tab, erro
 
 func CreateWorkspace(ctx context.Context) (*Workspace, error) {
 	ws := &Workspace{
-		OID:    uuid.New().String(),
+		OID:    uuid.NewString(),
 		TabIds: []string{},
 	}
 	DBInsert(ctx, ws)
@@ -185,7 +191,7 @@ func CreateBlock(ctx context.Context, tabId string, blockDef *BlockDef, rtOpts *
 		if tab == nil {
 			return nil, fmt.Errorf("tab not found: %q", tabId)
 		}
-		blockId := uuid.New().String()
+		blockId := uuid.NewString()
 		blockData := &Block{
 			OID:         blockId,
 			BlockDef:    blockDef,
@@ -210,7 +216,7 @@ func findStringInSlice(slice []string, val string) int {
 	return -1
 }
 
-func DeleteBlock(ctx context.Context, tabId string, blockId string, newLayout any) error {
+func DeleteBlock(ctx context.Context, tabId string, blockId string) error {
 	return WithTx(ctx, func(tx *TxWrap) error {
 		tab, _ := DBGet[*Tab](tx.Context(), tabId)
 		if tab == nil {
@@ -221,11 +227,8 @@ func DeleteBlock(ctx context.Context, tabId string, blockId string, newLayout an
 			return nil
 		}
 		tab.BlockIds = append(tab.BlockIds[:blockIdx], tab.BlockIds[blockIdx+1:]...)
-		if newLayout != nil {
-			tab.Layout = newLayout
-		}
 		DBUpdate(tx.Context(), tab)
-		DBDelete(tx.Context(), "block", blockId)
+		DBDelete(tx.Context(), OType_Block, blockId)
 		return nil
 	})
 }
@@ -246,9 +249,10 @@ func CloseTab(ctx context.Context, workspaceId string, tabId string) error {
 		}
 		ws.TabIds = append(ws.TabIds[:tabIdx], ws.TabIds[tabIdx+1:]...)
 		DBUpdate(tx.Context(), ws)
-		DBDelete(tx.Context(), "tab", tabId)
+		DBDelete(tx.Context(), OType_Tab, tabId)
+		DBDelete(tx.Context(), OType_LayoutNode, tab.LayoutNode)
 		for _, blockId := range tab.BlockIds {
-			DBDelete(tx.Context(), "block", blockId)
+			DBDelete(tx.Context(), OType_Block, blockId)
 		}
 		return nil
 	})
@@ -300,11 +304,12 @@ func EnsureInitialData() error {
 	if clientCount > 0 {
 		return nil
 	}
-	windowId := uuid.New().String()
+	windowId := uuid.NewString()
-	workspaceId := uuid.New().String()
+	workspaceId := uuid.NewString()
-	tabId := uuid.New().String()
+	tabId := uuid.NewString()
+	layoutNodeId := uuid.NewString()
 	client := &Client{
-		OID:          uuid.New().String(),
+		OID:          uuid.NewString(),
 		MainWindowId: windowId,
 	}
 	err = DBInsert(ctx, client)
@@ -339,13 +344,22 @@ func EnsureInitialData() error {
 		return fmt.Errorf("error inserting workspace: %w", err)
 	}
 	tab := &Tab{
-		OID:      tabId,
+		OID:        tabId,
-		Name:     "Tab-1",
+		Name:       "Tab-1",
-		BlockIds: []string{},
+		BlockIds:   []string{},
+		LayoutNode: layoutNodeId,
 	}
 	err = DBInsert(ctx, tab)
 	if err != nil {
 		return fmt.Errorf("error inserting tab: %w", err)
 	}
+
+	layoutNode := &LayoutNode{
+		OID: layoutNodeId,
+	}
+	err = DBInsert(ctx, layoutNode)
+	if err != nil {
+		return fmt.Errorf("error inserting layout node: %w", err)
+	}
 	return nil
 }

pkg/wstore/wstore_types.go

@@ -21,6 +21,15 @@ const (
 	UpdateType_Delete = "delete"
 )
 
+const (
+	OType_Client     = "client"
+	OType_Window     = "window"
+	OType_Workspace  = "workspace"
+	OType_Tab        = "tab"
+	OType_LayoutNode = "layout"
+	OType_Block      = "block"
+)
+
 type WaveObjUpdate struct {
 	UpdateType string          `json:"updatetype"`
 	OType      string          `json:"otype"`
@@ -51,7 +60,7 @@ type Client struct {
 }
 
 func (*Client) GetOType() string {
-	return "client"
+	return OType_Client
 }
 
 // stores the ui-context of the window
@@ -69,7 +78,7 @@ type Window struct {
 }
 
 func (*Window) GetOType() string {
-	return "window"
+	return OType_Window
 }
 
 type Workspace struct {
@@ -81,20 +90,31 @@ type Workspace struct {
 }
 
 func (*Workspace) GetOType() string {
-	return "workspace"
+	return OType_Workspace
 }
 
 type Tab struct {
-	OID      string         `json:"oid"`
+	OID        string         `json:"oid"`
-	Version  int            `json:"version"`
+	Version    int            `json:"version"`
-	Name     string         `json:"name"`
+	Name       string         `json:"name"`
-	Layout   any            `json:"layout,omitempty"`
+	LayoutNode string         `json:"layoutNode"`
-	BlockIds []string       `json:"blockids"`
+	BlockIds   []string       `json:"blockids"`
-	Meta     map[string]any `json:"meta"`
+	Meta       map[string]any `json:"meta"`
 }
 
 func (*Tab) GetOType() string {
-	return "tab"
+	return OType_Tab
+}
+
+type LayoutNode struct {
+	OID     string         `json:"oid"`
+	Version int            `json:"version"`
+	Node    any            `json:"node,omitempty"`
+	Meta    map[string]any `json:"meta,omitempty"`
+}
+
+func (*LayoutNode) GetOType() string {
+	return OType_LayoutNode
 }
 
 type FileDef struct {
@@ -138,7 +158,7 @@ type Block struct {
 }
 
 func (*Block) GetOType() string {
-	return "block"
+	return OType_Block
 }
 
 func AllWaveObjTypes() []reflect.Type {
@@ -148,5 +168,6 @@ func AllWaveObjTypes() []reflect.Type {
 		reflect.TypeOf(&Workspace{}),
 		reflect.TypeOf(&Tab{}),
 		reflect.TypeOf(&Block{}),
+		reflect.TypeOf(&LayoutNode{}),
 	}
 }