lemon3 / slick-image-compare

before-after image slider

slick image compare

Is a modern image comparison slider written in vanilla JavaScript and has no dependencies on other libraries. Best for comparing images, image retouching, color adjustments, renderings, etc...

DOCUMENTARY (API) AND DEMOS >>

(Started as a jQuery-Plugin back in the days (2013) and was used for a custom WordPress-Plugin)

tl;dr

module:

npm install slick-image-compare

<div id="my-div"></div>

import SlickImageCompare from '@/slick-image-compare';
// import SlickImageCompare from "./node_modules/slick-image-compare/index.js";
const options = {
  beforeImage: 'before.jpg',
  afterImage: 'after.jpg',
}; // options (see below)
const sic = new SlickImageCompare('#my-div', options);

classic:

<link rel="stylesheet" href="https://unpkg.com/slick-image-compare/dist/style.css">
<script src="https://unpkg.com/slick-image-compare"></script>

<div id="my-div" style="max-width=640px">
  <img src="before.jpg" alt="before image" />
  <img src="after.jpg" alt="after image" />
</div>

<script>
  const sic = new SlickImageCompare('#my-div');
</script>

Default Settings

use it with the default settings

javascript

<div id="my-div">
  <img src="01_before.jpg" alt="before" />
  <img src="01_after.jpg" alt="after" />
</div>

const sic = new SlickImageCompare('#my-div');

you can also use the data-api (data-sic must be used) like so. Btw.: The preferred method is the javascript approach!

data api

<div data-sic>
  <img src="01_before.jpg" alt="before" />
  <img src="01_after.jpg" alt="after" />
</div>

Start Position and Labels

we use a custom start position and labels here.

javascript

<div id="my-div">
  <img src="01_before.jpg" alt="before" />
  <img src="01_after.jpg" alt="after" />
</div>

// for more options see Options section below.
const options = {
  startPos: 20,
  afterLabel: 'after',
  beforeLabel: 'before'
};
const sic = new SlickImageCompare('#my-div', options);

the same using the data-sic attribute

data api

<div data-sic="{
  startPos: 20,
  afterLabel: 'after',
  beforeLabel: 'before'
}">
  <img src="01_before.jpg" alt="before" />
  <img src="01_after.jpg" alt="after" />
</div>

Events

you can listen to all kind of events, to extend the functionality of the image compare slider. List of available events

name	called ...
init	after initialization
drag	on interaction (drag, mousemove)
update	on every handle position change
beforeshown	if the before image is shown (70% or more)
aftershown	if the after image is shown (70% or more)
interactionstart	user begins interaction
interactionend	user ends interaction
viewchange	changed form before image shown to after image shown (and vice versa)

example

using viewchange event

<div id="my-div">
  <img src="01_before.jpg" alt="before" />
  <img src="01_after.jpg" alt="after" />
</div>
<div id="my-text-box"></div>

// create an instance
const sic = new SlickImageCompare('#my-div');

const myTextBox = document.getElementById('my-text-box');
const changeText = (evt) => {
  const afterShown = evt.detail.afterShown;
  myTextBox.innerHTML = afterShown ? 'After' : 'Before';
}

// listen for events
sic.addEventListener('viewchange', changeText);

Options

list of the available options:

options = {
  // if the app should automatically initialize
  // possible values: true, false
  // default: true
  autoInit: true,

  // the initial start position in percent (from the left)
  // possible values: 0 - 100
  // default: 50
  startPos: 50,

  // the image src of the first image
  // leave it at null if there are images in the DOM
  // possible values: all regular image urls
  // default: null
  beforeImage: null,

  // the image src of the first image
  // leave it at null if there are images in the DOM
  // possible values: all regular image urls
  // default: null
  afterImage: null,

  // defines the orientation of the slider
  // true: horizontal, false: vertical
  // possible values: true, false
  // default: true
  horizontal: true,

  // defines the direction of the slider
  // ltr: true,
  // means the "after" images is shown, when the slider is on
  // the right side (100%)
  // ltr: false,
  // means the "after" images is shown, when the slider is on
  // the left side (0%)
  // possible values: true, false
  // default: true
  ltr: true,

  // if the slider should smoothly follow the interaction
  // possible values: true, false
  // default: false
  smooth: false,

  // the smoothness amount
  // possible values: 100 - 500 (are good values)
  // default: 250
  smoothAmount: 250,

  // animate to the clicked/tapped position
  // if true it animates to, if false it jumps to the position
  // possible values: true, false
  // default: true
  animateOnClick: true,

  // for desktop devices
  // follow the mouse movement instead click-and-drag
  // possible values: true, false
  // default: false
  followMouse: false,

  // possible values: true, false
  // default: false
  onlyHandleDraggable: false,

  // only works if onlyHandleDraggable is set to true
  // possible values: true, false
  // default: false
  clickable: false,

  // if the handle should snap back to the start position
  // after user-interaction ends
  // possible values: true, false
  // default: false
  snapToStart: false,

  // the delay
  // possible values: 0 - 10000 (in ms)
  // default: 1000 (1 sec)
  snapToStartDelay: 1000,

  // the animation duration for snapping back to start position
  // possible values: 0 - 10000 (in ms)
  // default: 1250
  snapToStartDuration: 1250,

  // the easing function used
  snapToStartEasing: easing.Elastic.easeOut,

  // min distance to left and right border
  handleMinDistance: 0,

  // animate in
  animateIn: false,
  animateInDuration: 1250, // ms
  animateInEasing: easing.Elastic.easeOut,
  animateInDelay: 100, // in ms
  animateInStartPos: 40, // % from left

  // the default animation duration im ms
  animateDuration: 250, // ms
  animateEasing: easing.Cubic.easeOut,

  // the label for the before image
  // possible values: 'Strings'
  // default: ''
  beforeLabel: '',

  // the label for the after image
  // possible values: 'Strings'
  // default: ''
  afterLabel: '',
};

todo's

• add more test
• update this document ...