vanilla-js-wheel-zoom

Image resizing using mouse wheel (pinch to zoom) + drag scrollable image (as well as any HTML content)

Usage no npm install needed!

<script type="module">
  import vanillaJsWheelZoom from 'https://cdn.skypack.dev/vanilla-js-wheel-zoom';
</script>

README

vanilla-js-wheel-zoom

Image resizing using mouse wheel (pinch to zoom) + drag scrollable image (as well as any HTML content)

GitHub tag (latest by date) GitHub stars GitHub issues GitHub forks

Advantages:

  • the ability to fit the image into a container of any proportion
  • the ability to scale any HTML content
  • touch screen devices support

Starting with version 5, the plugin switched to using style transform. To use the plugin in older browsers, switch to earlier versions.

You need to center the image (or any HTML content) in the "window" in which scaling will take place. The "window" is taken automatically as the parent of the image in DOM.

HTML content can be of any structure, but the topmost child element in the β€œwindow” must be one. In the example with "badge" below, it will be more clear what is meant.

πŸ– If you find my plugin helpful, please donate me 🀝

Demo (only one image)

Demo (html)

Demo (multi images with custom align)

Playground... Have some fun πŸ€Έβ€β™‚οΈ

Install

npm i vanilla-js-wheel-zoom

or

yarn add vanilla-js-wheel-zoom

Get started

#myWindow {
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: #999;
}

#myContent {
    position: relative;
    display: flex;
    align-items: center;
}
<div id="myWindow" style="width:600px;height:600px;">
    <img id="myContent" src="https://placehold.it/2400x1400" alt="image" />
</div>
WZoom.create('#myContent');

Supported "hotswap" src of image (when type = image). You can do document.getElementById('myContent').src = "_new_path_" after initializing the plugin.

Syntax & Parameters

/**
 * Create WZoom instance
 * @param {string|HTMLElement} selectorOrHTMLElement
 * @param {Object} [options]
 * @returns {WZoom}
 */
const wzoom = WZoom.create(selectorOrHTMLElement[, options]);

Default options

const defaults = {
    // type content: `image` - only one image, `html` - any HTML content
    type: 'image',
    // for type `image` computed auto (if width set null), for type `html` need set real html content width, else computed auto
    width: null,
    // for type `image` computed auto (if height set null), for type `html` need set real html content height, else computed auto
    height: null,
    // drag scrollable image
    dragScrollable: true,
    // options for the DragScrollable module
    dragScrollableOptions: {
        // smooth extinction (value in seconds)
        smoothExtinction: .25,
        // callback triggered when grabbing an element
        onGrab: null,
        // callback triggered when moving an element
        onMove: null,
        // callback triggered when dropping an element
        onDrop: null
    },
    // minimum allowed proportion of scale (computed auto if null)
    minScale: null,
    // maximum allowed proportion of scale (1 = 100% content size)
    maxScale: 1,
    // image resizing speed
    speed: 10,
    // zoom to maximum (minimum) size on click
    zoomOnClick: true,
    // if is true, then when the source image changes, the plugin will automatically restart init function (used with type = image)
    // attention: if false, it will work correctly only if the images are of the same size
    watchImageChange: true,
    // smooth extinction (value in seconds)
    smoothExtinction: .3,
    // align content `center`, `left`, `top`, `right`, `bottom` 
    alignContent: 'center',
    /********************/
    disableWheelZoom: false
};

Badge on the image

#myWindow {
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: aqua;
}

#myContent {
    position: relative;
    display: flex;
    align-items: center;
}

#myBadge {
    position: absolute;
    border: solid 2px red;
    font-size: 80px;
}

#myImage {
    display: block;
    width: auto;
    height: auto;
    margin: auto;
    align-self: center;
    flex-shrink: 0;
}
<div id="myWindow" style="width:600px;height:600px;">
    <div id="myContent">
        <div id="myBadge" style="left:900px;top:500px;">Badge</div>
        <img id="myImage" src="https://placehold.it/2500x1500" alt="image"/>
    </div>
</div>
WZoom.create('#myContent', {
    type: 'html',
    width: 2500,
    height: 1500
});

Control buttons

<button data-zoom-up>Zoom Up</button>
<button data-zoom-down>Zoom Down</button>
const wzoom = WZoom.create('img');

document.querySelector('[data-zoom-up]').addEventListener('click', () => {
    wzoom.zoomUp();
});

document.querySelector('[data-zoom-down]').addEventListener('click', () => {
    wzoom.zoomDown();
});

On window resize

const wzoom = WZoom.create('img');

window.addEventListener('resize', () => {
    wzoom.prepare();
});

How to rotate the image?

Try this πŸ˜‰ (and see demo)

Options

name type default note
type String image image - if you need to scale only one image. In this case, there is no need to pass the parameters width and height. html - if you need to scale the HTML code. It is advisable to specify the parameters width and height that correspond to the original full size of the HTML content.
width Number null For type image computed auto (if width set null), for type html need set real html content width, else computed auto.
height Number null For type image computed auto (if height set null), for type html need set real html content height, else computed auto.
dragScrollable Boolean true If true - scaled image can be dragged with the mouse to see parts of the image that are out of scale.
dragScrollableOptions.smoothExtinction Number .25 Time of smooth extinction. if 0 then no smooth extinction. (value in seconds)
dragScrollableOptions.onGrab Function undefined Called after grabbing an element.
dragScrollableOptions.onMove Function undefined Called on every tick when moving element.
dragScrollableOptions.onDrop Function undefined Called after dropping an element.
minScale Number null The minimum scale to which the image can be zoomed.
If falsy or greater than maxScale then computed auto.
maxScale Number 1 The maximum scale to which the image can be zoomed.
1 means that the image can be maximized to 100%, 2 - 200%, etc.
speed Number 10 Step with which the image will be scaled. Measured in relative units.
The larger the value, the smaller the step and vice versa.
zoomOnClick Boolean true Zoom to maximum (minimum) size on click.
watchImageChange Boolean true If is true, then when the source image changes, the plugin will automatically restart init function (used with type = image). Attention: if false, it will work correctly only if the images are of the same size.
prepare Function undefined Called after the script is initialized when the image is scaled and fit into the container.
rescale Function undefined Called on every change of scale.
alignContent String center Align content center, left, top, right, bottom
smoothExtinction Number .3 Time of smooth extinction. if 0 then no smooth extinction. (value in seconds)
disableWheelZoom Boolean false

API

name note
.prepare() Reinitialize script
.zoomUp() Zoom on one step (see option speed)
.maxZoomUp() Zoom to max scale
.zoomDown() Zoom out on one step (see option speed)
.maxZoomDown() Zoom to min scale
.destroy() Destroy object

LICENSE

vanilla-js-wheel-zoom is licensed under the GPLv3 license for all open source applications. A commercial license is required for all commercial applications (including sites, themes and apps you plan to sell).