PW Viewer

Image viewer with the following features:

• Follows the progressive enhancement strategy: if javascript fails, the web page keeps working
• CSS powered:
  • High performance: Use css transform to scale, rotate, translate elements
  • No styles or themes are provided with this package. You decide how the viewer must look.
• Responsive:
  • Suport for touch devices
  • Works with <picture> element
  • Light and fast
• Modern
  • Build with ES6 and modern tools (webpack, babel, etc)
  • Easy to extend and adapt to your needs
  • Support for all modern browsers. IE10+ should work

Install

Requirements:

• NPM to install the package and the dependencies
• Webpack (or any other javascript loader)

npm install pw-viewer

Usage

Html

Let's say we have the following html code:

<button class="viewer-zoom">Zoom</button>
<button class="viewer-reset">Reset</button>

<figure class="viewer">
    <picture>
        <source srcset="http://placehold.it/2000x1200" media="(min-width:2000px)">
        <source srcset="http://placehold.it/1500x900" media="(min-width:1500px)">
        <source srcset="http://placehold.it/1000x600" media="(min-width:1000px)">
        <source srcset="http://placehold.it/500x300" media="(min-width:500px)">
        <img srcset="http://placehold.it/500x300" data-viewer-src="http://placehold.it/2000x1200">
    </picture>
</figure>

Note the data-viewer-src attribute in the image. It's used to load a full quality image on zoom.

CSS

The following css code is optional (but recommended):

.viewer {
    overflow: hidden;
    margin: 0;
}
.viewer img {
    max-width: 100%;
    display: block;
    margin: 0 auto;
    transition: transform .5s;
}

JS

And finally the javascript to build the viewer:

import Viewer from 'pw-viewer';

//Init the viewer
var myViewer = new Viewer(document.querySelector('.viewer img'));

//Zoom on click the button
document.querySelector('.viewer-zoom').addEventListener('click', event => {
    myViewer.transform({ scale: 1.5 }); //zoom
    myViewer.drag(true); //enable dragging
});

document.querySelector('.viewer-reset').addEventListener('click', event => {
    myViewer.reset(); //Reset transforms
    myViewer.drag(false); //disable dragging
});

Demo

To run the demo, just clone this repository enter in the directory and execute:

npm install
npm start

You should see something in http://localhost:8080/