Demo Backdrop Filters

8 - demo-backdrop-filters.markdown

Demo Backdrop Filters

A Pen by Jordan on CodePen.

License.

index.html

<header class="Header">
  <div>
    <input id="FilterBlur" name="FilterBlur" type="checkbox" data-filter-name="blur" checked/>
    <label for="FilterBlur">Blur</label>
  </div>
  <div>
    <input id="FilterBrightness" name="FilterBrightness" type="checkbox" data-filter-name="brightness"/>
    <label for="FilterBrightness">Brightness</label>
  </div>
  <div>
    <input id="FilterContrast" name="FilterContrast" type="checkbox" data-filter-name="contrast"/>
    <label for="FilterContrast">Contrast</label>
  </div>
  <div>
    <input id="FilterGrayscale" name="FilterGrayscale" type="checkbox" data-filter-name="grayscale"/>
    <label for="FilterGrayscale">Grayscale</label>
  </div>
  <div>
    <input id="FilterHueRotate" name="FilterHueRotate" type="checkbox" data-filter-name="hue-rotate"/>
    <label for="FilterHueRotate">Hue-rotate</label>
  </div>
  <div>
    <input id="FilterSaturate" name="FilterSaturate" type="checkbox" data-filter-name="saturate"/>
    <label for="FilterSaturate">Saturate</label>
  </div>
  <div>
    <input id="FilterInvert" name="FilterInvert" type="checkbox" data-filter-name="invert"/>
    <label for="FilterInvert">Invert</label>
  </div>
</header>
<main>
<div class="Container">
  <div class="Filter" data-filter-name="blur">
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="blur">Blur</label>
      <input type="range" id="blur" name="blur"
         value="10" min="0" max="100" />
    </div>
  </div>
  <div class="Filter" data-filter-name="brightness" hidden>
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="brightness">Brightness</label>
      <input type="range" id="brightness" name="brightness"
         value="60" min="0" max="200" />
    </div>
  </div>
  <div class="Filter" data-filter-name="contrast" hidden>
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="contrast">Contrast</label>
      <input type="range" id="contrast" name="contrast"
         value="60" min="0" max="200" />
    </div>
  </div>
  <div class="Filter" data-filter-name="grayscale" hidden>
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="grayscale">Grayscale</label>
      <input type="range" id="grayscale" name="grayscale"
         value="30" min="0" max="100" />
    </div>
  </div>
  <div class="Filter" data-filter-name="hue-rotate" hidden>
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="hue-rotate">Hue-rotate</label>
      <input type="range" id="hue-rotate" name="hue-rotate"
         value="30" min="0" max="360" />
    </div>
  </div>
  <div class="Filter" data-filter-name="saturate" hidden>
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="saturate">Saturate</label>
      <input type="range" id="saturate" name="saturate"
         value="30" min="0" max="100" />
    </div>
  </div>
  <div class="Filter" data-filter-name="invert" hidden>
    <div class="Filter-lens"></div>
    <div class="Filter-content">
      <label class="Filter-name" for="invert">Invert</label>
      <input type="range" id="invert" name="invert"
         value="100" min="0" max="100" />
    </div>
  </div>
</div>
<a class="Me" href="https://twitter.com/DeyJordan" target="_top">Pen by Dey Jordan</a>
</main>

script.js

const rootElement = document.querySelector(':root');
const filters = document.querySelectorAll('.Filter');
const filterTrigger = document.querySelectorAll('.Header input');
let filterZIndex = 0;
let previousTouch = undefined;

function updateElementPosition(element, event) {
  let movementX, movementY;

  if (event.type === 'touchmove') {
    const touch = event.touches[0];
    movementX = previousTouch ? touch.clientX - previousTouch.clientX : 0;
    movementY = previousTouch ? touch.clientY - previousTouch.clientY : 0;
    console.log('touch', { movementX: movementX, newX: touch.clientX, oldX: previousTouch && previousTouch.clientX });
    previousTouch = touch;
  } else {
    movementX = event.movementX;
    movementY = event.movementY;
  }
  
  const elementY = parseInt(element.style.top || 0) + movementY;
  const elementX = parseInt(element.style.left|| 0) + movementX;

  element.style.top = elementY + "px";
  element.style.left = elementX + "px";
}

function startDrag(element, event) {
  updateZIndex(element);
  const updateFunction = (event) => updateElementPosition(element, event);
  const stopFunction = () => stopDrag({update: updateFunction, stop: stopFunction});
  document.addEventListener("mousemove", updateFunction);
  document.addEventListener("touchmove", updateFunction);
  document.addEventListener("mouseup", stopFunction);
  document.addEventListener("touchend", stopFunction);
}

function stopDrag(functions) {
  previousTouch = undefined;
  document.removeEventListener("mousemove", functions.update);
  document.removeEventListener("touchmove", functions.update);
  document.removeEventListener("mouseup", functions.stop);
  document.removeEventListener("touchend", functions.stop);
}

function updateZIndex(element) {
  element.style.zIndex = filterZIndex;
  filterZIndex++;
}

function inputHandler(event) {
  const unit = event.target.name === 'blur' ? 'px' :
               event.target.name === 'hue-rotate' ? 'deg' : '%';
  const value = `${event.target.value}${unit}`;
  rootElement.style.setProperty(`--filter-${event.target.name}`, value);
}

filterTrigger.forEach(trigger => {
  trigger.addEventListener('change', (event) => {
    const filter = document.querySelector(`.Filter[data-filter-name="${event.target.dataset.filterName}"]`);
    if (event.currentTarget.checked) {
      filter.removeAttribute("hidden");
      updateZIndex(filter);
    } else {
      filter.setAttribute("hidden", "");
    }
  })
});

filters.forEach(filter => {
  const inputElement = filter.querySelector('input');
  const lensElement = filter.querySelector('.Filter-lens');
  const startFunction = (event) => startDrag(filter, event);
  
  filter.style.top = `0px`;
  filter.style.left = `0px`;
  
  lensElement.addEventListener("mousedown", startFunction);
  lensElement.addEventListener("touchstart", startFunction);
  inputElement.addEventListener('input', inputHandler);
});

style.css

/* --------------------- */
/* Filters ✨✨✨        */
/* --------------------- */

:root {
  --filter-blur: 10px;
  --filter-brightness: 60%;
  --filter-contrast: 60%;
  --filter-grayscale: 30%;
  --filter-hue-rotate: 30%;
  --filter-saturate: 30%;
  --filter-invert: 100%;
}

.Filter[data-filter-name="blur"] .Filter-lens {
  backdrop-filter: blur(var(--filter-blur));
}

.Filter[data-filter-name="brightness"] .Filter-lens {
  backdrop-filter: brightness(var(--filter-brightness));
}

.Filter[data-filter-name="contrast"] .Filter-lens {
  backdrop-filter: contrast(var(--filter-contrast));
}

.Filter[data-filter-name="grayscale"] .Filter-lens {
  backdrop-filter: grayscale(var(--filter-grayscale));
}

.Filter[data-filter-name="hue-rotate"] .Filter-lens {
  backdrop-filter: hue-rotate(var(--filter-hue-rotate));
}

.Filter[data-filter-name="saturate"] .Filter-lens {
  backdrop-filter: saturate(var(--filter-saturate));
}

.Filter[data-filter-name="invert"] .Filter-lens {
  backdrop-filter: invert(var(--filter-invert));
}

/* --------------------- */
/* Global style          */
/* --------------------- */

body::before {
  content: "";
  position: fixed;
  z-index: -1;
  inset: 0;
  background-image: url('https://cdn.pixabay.com/photo/2023/05/03/11/20/bird-7967356_1280.jpg');
  background-size: cover;
  background-position: center center;
}

.Header {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  padding: 12px 24px;
  border-bottom: 1px solid #fff;
  font-weight: 700;
  color: #fff;
  backdrop-filter: blur(10px) brightness(60%);
}

.Container {
  position: absolute;
  top: 50%;
  left: 50%;
}

.Filter {
  display: inline-block;
  position: absolute;
  top: 0;
  left: 0;
  border: 5px solid #fff;
  border-radius: 3px;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.3);
  transform: translate(-50%, -50%);
  user-select: none;
}

.Filter[hidden] {
  display: none;
}

.Filter-lens {
  content: "";
  display: block;
  width: 100%;
  aspect-ratio: 1/1;
  cursor: pointer;
}

.Filter-content {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  width: 300px;
  height: 70px;
  padding: 12px 24px;
  background: #fff;
  font-size: 1.5rem;
  text-align: center;
}

.Filter-name {
  position: absolute;
  top: 0;
  left: 5px;
  border-radius: 5px;
  padding: 2px 8px;
  background: linear-gradient(-25deg, #4affd3, #4a00d3);
  color: #fff;
  font-size: 1rem;
  font-weight: 700;
  transform: translateY(-50%);
}

.Filter input {
  width: 100%;
  cursor: pointer;
}

/* --------------------- */
/* Other styles          */
/* --------------------- */

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Poppins', sans-serif;
  overflow: hidden;
}

.Me {
  position: fixed;
  z-index: 10;
  bottom: 20px;
  left: 50%;
  color: #000;
  transform: translateX(-50%);
  font-weight: 700;
  opacity: .5;
}