Pinch-zoom

Pinch an image or div for zoom.

Visit Demo with your phone.

Features

Pinch to zoom, tested on ios > 9.2 and android 4.0
Scale back with animation when exceed maximun scale level ( default 5).
Drag element with animation and sceen edge limitation.
Support tap to reset transform status with animation.
Reset transform status when scale level below zero.
Restore to sane position when insane padding exists.
Emit tap and swipe event when reasonable.
No interrapt with touchmove event when not scaled and move left/right.
Use 3d transform when possible and requestAnimationFrame to improve performance.
Built with reusable & lightweight components, no sucks jquery.

Installation

npm install pinch-zoom

Example

#viewport {
  width: 100vw;
  height: 100vh;
  position: relative;
  background-color: #000;
  overflow: hidden;
}
.wrapper {
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  margin-top: -80px;
}
.wrapper > img {
  width: 100%;
  display: block;
  height: auto;
}

<div id="viewport">
  <div class="wrapper">
    <img src="./one.jpg" alt="">
  </div>
</div>

var pinchZoom = require('pinch-zoom')
var el = document.querySelector('.wrapper')
var pzoom = pinchZoom(el, {
  draggable: true,
  maxScale: 4
})

Events

tap emitted when double tap or scale level is 1.
swipe emitted with direction left or right when fast swipe detected.
scale emitted with current transform properties (x, y , scale) after pinch or reset.
end emitted on pinch end.
start emitted on pinch start.

API

PinchZoom(el , [opt])

Init PinchZoom with element and optional opt, el should not have transform and transition style.

opt.tapreset reset transoform if scale is not 1 and not double tap.
opt.maxScale maximun scale for element, default 5.
opt.draggable make element draggable with one finger, default false.
opt.threshold threshold for fast swipe event in ms, default 200
opt.fastThreshold minimal moved distance for fast swipe in pixel, default 40

.animate(o, duration, [ease])

Animation base element with options.

o.x translateX.
o.y translateY.
o.scale value for scale() or scale3d().
duration animation duration in ms.
ease ease function name, default out-circ

.reset()

Reset to initial state with animation.

.unbind()

Reset trasform style and unbind all events.

LICENSE

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

NorthFred/pinch-zoom