react-svg-pan-zoom

react-svg-pan-zoom

react-svg-pan-zoom is a React component that adds pan and zoom features to the SVG images. It helps to display big SVG images in a small space.

Live Demo

available at http://chrvadala.github.io/react-svg-pan-zoom/

Features

This component can work in three different modes depending on the selected tool:

• With the tool pan the user can move the image and drag it around within the viewer
• With the tool zoom the user can scale the image either with a point click or selecting a region to zoom the specified area
• With the tool none the user can interact with the SVG content and trigger browser events

Additional Features

• Zoom detection performed through pinch and scroll (optional)
• Autopan when the mouse is close to the edge of the viewer (optional)
• Each callback function receives (x,y) coords mapped to the real size of the SVG
• Programmatically controllable
• Event info managed lazily to ensure high performance
• ES6 syntax

Usage

npm install --save react-svg-pan-zoom

Sample code available here

import React from 'react';
import ReactDOM from 'react-dom';
import {ReactSVGPanZoom} from 'react-svg-pan-zoom';

class Demo extends React.Component {
  constructor(props, context) {
    super(props, context);
    this.Viewer = null;
  }
  componentDidMount() {
    this.Viewer.fitToViewer();
  }
  render() {
    return (
      <div>
        <button onClick={event => this.Viewer.zoomOnViewerCenter(1.1)}>Zoom in</button>
        <button onClick={event => this.Viewer.fitSelection(40, 40, 200, 200)}>Zoom area</button>
        <button onClick={event => this.Viewer.fitToViewer()}>Fit</button>

        <hr/>

        <ReactSVGPanZoom
          style={{border: "1px solid black"}}
          width={500} height={500} ref={Viewer => this.Viewer = Viewer}
          onClick={event => console.log('click', event.x, event.y, event.originalEvent)}
          onMouseUp={event => console.log('up', event.x, event.y)}
          onMouseMove={event => console.log('move', event.x, event.y)}
          onMouseDown={event => console.log('down', event.x, event.y)}>

          <svg width={900} height={800}>
              <-- put here your SVG content -->
          </svg>
        </ReactSVGPanZoom>
      </div>
    );
  }
}

Props

• width – required – width of the viewer displayed on screen (if you want to omit this see Autosize)
• height – required – height of the viewer displayed on screen (if you want to omit this see Autosize)
• background – background of the viewer (default color: dark grey)
• style - CSS style of the viewer
• detectWheel - detect zoom operation performed through pinch gesture or mouse scroll
• detectAutoPan - perform PAN if the mouse is on the border of the viewer
• toolbarPosition - toolbar position (one of none, top, right, bottom, left)
• SVGBackground - background of the SVG (default color: white)
• onClick - handler for click fn(viewerEvent: ViewerEvent) (available with the tool none)
• onMouseUp - handler for mouseup fn(viewerEvent: ViewerEvent) (available with the tool none)
• onMouseMove - handler for mousemove fn(viewerEvent: ViewerEvent) (available with the tool none)
• onMouseDown - handler for mousedown fn(viewerEvent: ViewerEvent) (available with the tool none)
• value - inject and lock the viewer to a specific value
• onChangeValue - callback called when the viewer changes its value fn(value)
• tool - inject and lock the viewer to a specific tool ( one of none, pan, zoom-in, zoom-out )
• onChangeTool - callback called when the viewer changes the used tool fn(tool)

Methods

• pan( SVGDeltaX, SVGDeltaY ) - Apply a pan
• zoom(SVGPointX, SVGPointY, scaleFactor) - Zoom in or out the SVG
• fitSelection(selectionSVGPointX, selectionSVGPointY, selectionWidth, selectionHeight) - Fit an SVG area to viewer
• fitToViewer() - Fit all SVG to Viewer
• zoomOnViewerCenter(scaleFactor) - Zoom SVG on center
• getValue() - Get current viewer value
• setValue(value) - Through this method you can set a new value
• getTool() - Get current tool
• setTool(tool) - Set a tool (one of none,pan,zoom-in,zoom-out)

ViewerEvent attributes

Your event handlers will be passed instances of ViewerEvent. It has some useful attributes (See below). If, for your purpose, you need the original React event instance (SyntheticEvent), you can get it through event.originalEvent.

• originalEvent: SyntheticEvent - The original React event
• SVGViewer: SVGSVGElement - Reference to SVGViewer
• point: object - coordinates (x,y) of the event mapped to SVG coordinates
• x: number - x coordinate of the event mapped to SVG coordinates
• y: number - y coordinate of the event mapped to SVG coordinates
• scaleFactor: number - zoom level
• translationX: number - x delta from the viewer origin
• translationY: number - y delta from the viewer origin

Examples

Example	Description
Basic	This project show how to use the component in a scenario when is not required a full control on the internal state. This is the easist React SVG Pan Zoom usage.
Controlled state	This advanced project show a scenario in which the parent component has a full control of the svg viewer. The state is owned by the parent and injected on the viewer throught props. Any state change request is performed by two callbacks onChangeValue(value) and onChangeTool(tool). This demo apply the same pattern of an <input> tag (React Controlled Components).
Redux	This advanced project show a scenario in which a redux store handle the state. Each component can dispatch a Redux action and edit the current view of the viewer.
React Planner	This is a React project that use this component.

Autosize

React SVG Pan Zoom requires the properties width and height to be set in order to work properly. If you need an autosized component you can use ReactDimension to get the dimensions of a wrapper element and pass them as properties to its child element.

Start local demo

git clone https://github.com/chrvadala/react-svg-pan-zoom.git
cd react-svg-pan-zoom
npm install && npm start

Changelog

V	Changes
2.0	Project refactor. Follow this guide for migration instructions.

Contributing

Your contributions (issues and pull request) are very appreciated!

Author

• chrvadala

License

MIT