fix(viewport): make onViewportChange prop dynamic #4579

examples/react/src/examples/ControlledViewport/index.tsx

@@ -1,4 +1,4 @@
-import { MouseEvent, useCallback, useState } from 'react';
+import { MouseEvent, useCallback, useRef, useState } from 'react';
 import {
   ReactFlow,
   addEdge,
@@ -55,10 +55,18 @@ const Flow = () => {
   const [nodes, setNodes, onNodesChange] = useNodesState(initNodes);
   const [edges, setEdges, onEdgesChange] = useEdgesState(initEdges);
   const [viewport, setViewport] = useState<Viewport>({ x: 0, y: 0, zoom: 1 });
+  const [viewport2, setViewport2] = useState<Viewport>({ x: 100, y: 100, zoom: 1.5 });
+  const [currentViewport, setCurrentViewport] = useState(0);
   const { fitView } = useReactFlow();
 
   const onConnect = useCallback((params: Connection | Edge) => setEdges((eds) => addEdge(params, eds)), [setEdges]);
 
+  const setter = currentViewport === 0 ? setViewport : setViewport2;
+
+  const toggleViewport = () => {
+    setCurrentViewport(currentViewport === 0 ? 1 : 0);
+  };
+
   return (
     <ReactFlow
       nodes={nodes}
@@ -66,12 +74,13 @@ const Flow = () => {
       onNodesChange={onNodesChange}
       onEdgesChange={onEdgesChange}
       onConnect={onConnect}
-      viewport={viewport}
-      onViewportChange={setViewport}
+      viewport={currentViewport === 0 ? viewport : viewport2}
+      onViewportChange={setter}
     >
       <Panel position="top-left">
-        <button onClick={() => setViewport((vp) => ({ ...vp, y: vp.y + 10 }))}>update viewport</button>
+        <button onClick={() => setter((vp) => ({ ...vp, y: vp.y + 10 }))}>update viewport</button>
         <button onClick={() => fitView()}>fitView</button>
+        <button onClick={() => toggleViewport()}>toggle viewport</button>
       </Panel>
 
       <MiniMap />

packages/react/src/container/ZoomPane/index.tsx

@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-import { useEffect, useRef } from 'react';
+import { useCallback, useEffect, useRef } from 'react';
 import { shallow } from 'zustand/shallow';
 import { XYPanZoom, PanOnScrollMode, type Transform, type PanZoomInstance } from '@xyflow/system';
 
@@ -57,6 +57,17 @@ export function ZoomPane({
 
   useResizeHandler(zoomPane);
 
+  const onTransformChange = useCallback(
+    (transform: Transform) => {
+      onViewportChange?.({ x: transform[0], y: transform[1], zoom: transform[2] });
+
+      if (!isControlledViewport) {
+        store.setState({ transform });
+      }
+    },
+    [onViewportChange, isControlledViewport]
+  );
+
   useEffect(() => {
     if (zoomPane.current) {
       panZoom.current = XYPanZoom({
@@ -66,13 +77,6 @@ export function ZoomPane({
         translateExtent,
         viewport: defaultViewport,
         paneClickDistance,
-        onTransformChange: (transform: Transform) => {
-          onViewportChange?.({ x: transform[0], y: transform[1], zoom: transform[2] });
-
-          if (!isControlledViewport) {
-            store.setState({ transform });
-          }
-        },
         onDraggingChange: (paneDragging: boolean) => store.setState({ paneDragging }),
         onPanZoomStart: (event, vp) => {
           const { onViewportChangeStart, onMoveStart } = store.getState();
@@ -121,6 +125,7 @@ export function ZoomPane({
       userSelectionActive,
       noWheelClassName,
       lib,
+      onTransformChange,
     });
   }, [
     onPaneContextMenu,
@@ -137,6 +142,7 @@ export function ZoomPane({
     userSelectionActive,
     noWheelClassName,
     lib,
+    onTransformChange,
   ]);
 
   return (

packages/svelte/src/lib/actions/zoom/index.ts

@@ -5,6 +5,7 @@ import {
   type CoordinateExtent,
   type OnPanZoom,
   type PanZoomInstance,
+  type Transform,
   type Viewport
 } from '@xyflow/system';
 
@@ -36,6 +37,7 @@ type ZoomParams = {
   userSelectionActive: boolean;
   lib: string;
   paneClickDistance: number;
+  onTransformChange: (transform: Transform) => void;
 };
 
 export default function zoom(domNode: Element, params: ZoomParams) {
@@ -57,8 +59,6 @@ export default function zoom(domNode: Element, params: ZoomParams) {
     translateExtent,
     viewport: initialViewport,
     paneClickDistance,
-    onTransformChange: (transform) =>
-      viewport.set({ x: transform[0], y: transform[1], zoom: transform[2] }),
     onDraggingChange: dragging.set
   });
   const currentViewport = panZoomInstance.getViewport();

packages/svelte/src/lib/container/Zoom/Zoom.svelte

@@ -1,10 +1,10 @@
 <script lang="ts">
-  import { PanOnScrollMode } from '@xyflow/system';
+  import { onMount } from 'svelte';
+  import { PanOnScrollMode, type Transform } from '@xyflow/system';
 
   import { useStore } from '$lib/store';
   import zoom from '$lib/actions/zoom';
   import type { ZoomProps } from './types';
-  import { onMount } from 'svelte';
 
   type $$Props = ZoomProps;
 
@@ -39,6 +39,9 @@
   $: _panOnDrag = $panActivationKeyPressed || panOnDrag;
   $: _panOnScroll = $panActivationKeyPressed || panOnScroll;
 
+  const onTransformChange = (transform: Transform) =>
+    viewport.set({ x: transform[0], y: transform[1], zoom: transform[2] });
+
   onMount(() => {
     $viewportInitialized = true;
   });
@@ -70,7 +73,8 @@
     userSelectionActive: !!$selectionRect,
     translateExtent: $translateExtent,
     lib: $lib,
-    paneClickDistance
+    paneClickDistance,
+    onTransformChange
   }}
 >
   <slot />

packages/system/src/types/panzoom.ts

@@ -12,7 +12,6 @@ export type PanZoomParams = {
   paneClickDistance: number;
   viewport: Viewport;
   translateExtent: CoordinateExtent;
-  onTransformChange: OnTransformChange;
   onDraggingChange: OnDraggingChange;
   onPanZoomStart?: OnPanZoom;
   onPanZoom?: OnPanZoom;
@@ -40,6 +39,7 @@ export type PanZoomUpdateOptions = {
   zoomOnDoubleClick: boolean;
   zoomActivationKeyPressed: boolean;
   lib: string;
+  onTransformChange: OnTransformChange;
 };
 
 export type PanZoomInstance = {

packages/system/src/xypanzoom/XYPanZoom.ts

@@ -40,7 +40,6 @@ export function XYPanZoom({
   onPanZoom,
   onPanZoomStart,
   onPanZoomEnd,
-  onTransformChange,
   onDraggingChange,
 }: PanZoomParams): PanZoomInstance {
   const zoomPanValues: ZoomPanValues = {
@@ -105,6 +104,7 @@ export function XYPanZoom({
     zoomOnDoubleClick,
     zoomActivationKeyPressed,
     lib,
+    onTransformChange,
   }: PanZoomUpdateOptions) {
     if (userSelectionActive && !zoomPanValues.isZoomingOrPanning) {
       destroy();