feat(react/svelte): controlled viewport (#3461)

* feat(react): controlled viewport

* refactor(react): cleanup viewport

* feat(svelte): two way data binding for viewport, cleanup transform <> viewport stuff

* refactor(svelte): viewport stuff

examples/react/src/App/index.tsx

@@ -4,6 +4,7 @@ import { BrowserRouter, Route, Routes, useLocation, useNavigate } from 'react-ro
 import Basic from '../examples/Basic';
 import Backgrounds from '../examples/Backgrounds';
 import ControlledUncontrolled from '../examples/ControlledUncontrolled';
+import ControlledViewport from '../examples/ControlledViewport';
 import CustomConnectionLine from '../examples/CustomConnectionLine';
 import CustomMiniMapNode from '../examples/CustomMiniMapNode';
 import CustomNode from '../examples/CustomNode';
@@ -74,6 +75,11 @@ const routes: IRoute[] = [
     path: '/controlled-uncontrolled',
     component: ControlledUncontrolled,
   },
+  {
+    name: 'Controlled Viewport',
+    path: '/controlled-viewport',
+    component: ControlledViewport,
+  },
   {
     name: 'Custom Connection Line',
     path: '/custom-connectionline',

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

@@ -0,0 +1,88 @@
+import { MouseEvent, useCallback, useState } from 'react';
+import {
+  ReactFlow,
+  addEdge,
+  Node,
+  Connection,
+  Edge,
+  useNodesState,
+  useEdgesState,
+  Viewport,
+  Panel,
+  MiniMap,
+  Background,
+  ReactFlowProvider,
+  useReactFlow,
+  Controls,
+} from '@xyflow/react';
+
+const initNodes: Node[] = [
+  {
+    id: '1a',
+    type: 'input',
+    data: { label: 'Node 1' },
+    position: { x: 250, y: 5 },
+    className: 'light',
+    ariaLabel: 'Input Node 1',
+  },
+  {
+    id: '2a',
+    data: { label: 'Node 2' },
+    position: { x: 100, y: 100 },
+    className: 'light',
+    ariaLabel: 'Default Node 2',
+  },
+  {
+    id: '3a',
+    data: { label: 'Node 3' },
+    position: { x: 400, y: 100 },
+    className: 'light',
+  },
+  {
+    id: '4a',
+    data: { label: 'Node 4' },
+    position: { x: 400, y: 200 },
+    className: 'light',
+  },
+];
+
+const initEdges: Edge[] = [
+  { id: 'e1-2', source: '1a', target: '2a', ariaLabel: undefined },
+  { id: 'e1-3', source: '1a', target: '3a' },
+];
+
+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 { fitView } = useReactFlow();
+
+  const onConnect = useCallback((params: Connection | Edge) => setEdges((eds) => addEdge(params, eds)), [setEdges]);
+
+  return (
+    <ReactFlow
+      nodes={nodes}
+      edges={edges}
+      onNodesChange={onNodesChange}
+      onEdgesChange={onEdgesChange}
+      onConnect={onConnect}
+      viewport={viewport}
+      onViewportChange={setViewport}
+    >
+      <Panel position="top-left">
+        <button onClick={() => setViewport((vp) => ({ ...vp, y: vp.y + 10 }))}>update viewport</button>
+        <button onClick={() => fitView()}>fitView</button>
+      </Panel>
+
+      <MiniMap />
+      <Background />
+      <Controls />
+    </ReactFlow>
+  );
+};
+
+export default () => (
+  <ReactFlowProvider>
+    <Flow />
+  </ReactFlowProvider>
+);