Contextual Zoom Source Code
index.js
import React, { useState, useCallback } from 'react';
import ReactFlow, {
removeElements,
addEdge,
MiniMap,
Controls,
} from 'react-flow-renderer';
import ZoomNode from './ZoomNode';
import './index.css';
const snapGrid = [20, 20];
const nodeTypes = {
zoom: ZoomNode,
};
const initialElements = [
{
id: '1',
type: 'zoom',
data: {
content: <>Zoom to toggle content and placeholder</>,
},
position: { x: 0, y: 50 },
},
{
id: '2',
type: 'zoom',
data: { content: <>this is a node with some lines of text in it.</> },
position: { x: 300, y: 50 },
},
{
id: '3',
type: 'zoom',
data: { content: <>this is another node with some more text.</> },
position: { x: 650, y: 50 },
},
{
id: 'e1-2',
source: '1',
target: '2',
animated: true,
},
{
id: 'e2-3',
source: '2',
target: '3',
animated: true,
},
];
const CustomNodeFlow = () => {
const [elements, setElements] = useState(initialElements);
const onElementsRemove = useCallback(
(elementsToRemove) =>
setElements((els) => removeElements(elementsToRemove, els)),
[]
);
const onConnect = useCallback(
(params) =>
setElements((els) => addEdge({ ...params, animated: true }, els)),
[]
);
return (
<ReactFlow
elements={elements}
onElementsRemove={onElementsRemove}
onConnect={onConnect}
nodeTypes={nodeTypes}
snapToGrid={true}
snapGrid={snapGrid}
defaultZoom={1.5}
>
<MiniMap />
<Controls />
</ReactFlow>
);
};
export default CustomNodeFlow;
ZoomNode.js
import React, { memo } from 'react';
import { Handle, useStoreState } from 'react-flow-renderer';
const Placeholder = () => (
<div className="placeholder">
<div />
<div />
<div />
</div>
);
export default memo(({ data }) => {
const [, , zoom] = useStoreState((state) => state.transform);
const showContent = zoom >= 1.5;
return (
<>
<Handle type="target" position="left" />
{showContent ? data.content : <Placeholder />}
<Handle type="source" position="right" />
</>
);
});