interactjs

JavaScript drag and drop, resizing and multi-touch gestures with inertia and snapping for modern browsers (and also IE9+).

Features include:

- inertia and snapping
- multi-touch, simultaneous interactions
- cross browser and device, supporting the desktop and mobile versions of
Chrome, Firefox and Opera as well as Internet Explorer 9+
- interaction with SVG elements
- being standalone and customizable
- not modifying the DOM except to change the cursor (but you can disable
that)

Installation

- npm: npm install interactjs
- jsDelivr CDN:
- unpkg CDN:
- Rails 5.1+:
1. yarn add interactjs
2. //= require interactjs/interact
- Webjars SBT/Play 2: libraryDependencies ++= Seq("org.webjars.npm" % "interactjs" % version)

$3

The project is written in Typescript and the npm package includes the type
definitions, but if you need the typings alone, you can install them with:

``
npm install --save-dev @interactjs/types
`

Documentation

http://interactjs.io/docs

Example

`javascript
var pixelSize = 16;

interact('.rainbow-pixel-canvas')
.origin('self')
.draggable({
modifiers: [
interact.modifiers.snap({
// snap to the corners of a grid
targets: [
interact.snappers.grid({ x: pixelSize, y: pixelSize }),
],
})
],
listeners: {
// draw colored squares on move
move: function (event) {
var context = event.target.getContext('2d'),
// calculate the angle of the drag direction
dragAngle = 180 * Math.atan2(event.dx, event.dy) / Math.PI;

// set color based on drag angle and speed
context.fillStyle = 'hsl(' + dragAngle + ', 86%, '
+ (30 + Math.min(event.speed / 1000, 1) * 50) + '%)';

// draw squares
context.fillRect(event.pageX - pixelSize / 2, event.pageY - pixelSize / 2,
pixelSize, pixelSize);
}
}
})
// clear the canvas on doubletap
.on('doubletap', function (event) {
var context = event.target.getContext('2d');

context.clearRect(0, 0, context.canvas.width, context.canvas.height);
});

function resizeCanvases () {
[].forEach.call(document.querySelectorAll('.rainbow-pixel-canvas'), function (canvas) {
canvas.width = document.body.clientWidth;
canvas.height = window.innerHeight * 0.7;
});
}

// interact.js can also add DOM event listeners
interact(document).on('DOMContentLoaded', resizeCanvases);
interact(window).on('resize', resizeCanvases);
``

See the above code in action at https://codepen.io/taye/pen/tCKAm

License

interact.js is released under the MIT License.

[ijs-twitter]: https://twitter.com/interactjs
[upcoming-changes]: https://github.com/taye/interact.js/blob/main/CHANGELOG.md#upcoming-changes