svg-pan-zoom-container

A vanilla-js module for adding zoom-on-wheel and pan-on-drag behavior to inline SVG elements.
No need to write scripts. Just markup.

Demo

Usage

1. Load this module.
2. Diddle the parent element of the inline SVG element:
   • Add data-zoom-on-wheel attribute to add zoom-on-wheel behavior.
   • Add data-pan-on-drag attribute to add pan-on-drag behavior.
   • Make sure that the container's height is not "auto". The container's height must not be calculated from its content.

That's it!

<script src="https://cdn.jsdelivr.net/npm/[email protected]"></script>

<div
  data-zoom-on-wheel
  data-pan-on-drag
  style="height: 80vh;"
>
  <svg viewBox="0 0 100 100">
    <circle cx="50" cy="50" r="50" />
  </svg>
</div>

Run on CodePen

Installation

via npm (with a module bundler)

$ npm i svg-pan-zoom-container

import 'svg-pan-zoom-container'

via CDN (jsDelivr)

<script src="https://cdn.jsdelivr.net/npm/[email protected]"></script>

Options

Some options can be specified as data-zoom-on-wheel and data-pan-on-drag attribute value.
Option name and value should be separated by colon (:).
Multiple options should be separated by semicolon (;).

Example

<div
  data-zoom-on-wheel="zoom-amount: 0.01; min-scale: 0.3; max-scale: 20;"
  data-pan-on-drag="button: right;"
  style="height: 80vh;"
>
  <svg viewBox="0 0 100 100">
    <circle cx="50" cy="50" r="50" />
  </svg>
</div>

Run on CodePen

Options for data-zoom-on-wheel

Name	Type	Default	Description
zoom-amount	number	0.002	Zoom amount per deltaY of wheel events.
min-scale	number	1	Minimum scale.
max-scale	number	10	Maximum scale.

Options for data-pan-on-drag

Name	Type	Default	Description
button	"left" | "right"	"left"	Mouse button to drag to pan.
modifier	"" | "Alt" | "Control" | "Meta" | "Shift"	""	Drag to pan only when this modifier key is pressed.

Observation

Observe the transform attribute of the SVG element using MutationObserver.

const container = document.getElementById('my-svg-container')

const observer = new MutationObserver(function (mutations) {
  mutations.forEach(function (mutation) {
    console.log('scale:', getScale(container));
  });
});

observer.observe(container.firstElementChild, {
  attributes: true,
  attributeFilter: ['transform'],
});

API

This module provides some functions for scripting to control pan and zoom behavior.

API usage

When installing via npm

import { pan, zoom, getScale, setScale, resetScale } from 'svg-pan-zoom-container';

When installing via CDN

<script src="https://cdn.jsdelivr.net/npm/[email protected]"></script>
<script>
  const { pan, zoom, getScale, setScale, resetScale } = svgPanZoomContainer;
</script>

pan(container, deltaX, deltaY)

Pans.

getScale(container[, options])

Returns current scale.
The return value is a 1-based fraction, not a percentage.

setScale(container, value[, options])

Sets scale.
The value is considered as 1-based fraction, not as percentage.

The options can be specified as part of the following object (following values are the default):

const options = {
  origin: {
    clientX: 0,
    clientY: 0,
  },
  minScale: 1,
  maxScale: 10,
};

resetScale(container)

Resets scale and scroll position.

zoom(container, ratio[, options])

Equivalents to setScale(container, getScale(container) * ratio, options).

License

WTFPL