Files
shoelace/docs/components/carousel.md
Alessandro c6a6a77bbd feat: add carousel component
feat: add nav indicators

wip

wip

wip

fix: minor fixes

fix: minor fixes

fix: some refactor

chore: update docs

chore: update docs

fix: remove slide component

feat: create sl-carousel-item

feat: code refactoring and improvements

chore: update docs with more examples

chore: fix docs

feat: add autoplay

feat: implement accessibility

fix: change icons for rtl

chore: minor change

feat: improve accessibility

fix: minor regression

fix: minor regression

chore: fix docs

fix: improve accessibility and minor fixes

fix: remove heading and refactor component

chore: add custom style exmaple

fix: address review commnets

* Removed header from carousel
* Added `ArrowUp` and `ArrowDown` in keyboard navigation
* Added `--scroll-hint-margin` css property
* Added an example with customized carousel layout
* Fixed thumbnails navigation in demo
* Renamed show-controls to show-arrows and updated the corresponding parts/css accordingly
* Changed `activeSlideElement` getter to a private method
* Changed pagination colors
* Added `--slide-width` and `--slide-height` css properties

chore: update docs

fix: integrate latest repo changes

fix: add aspect ratio and rebase

chore: remove ignore path

feat: multiple slides per page

feat: multiple slide per page

fix: various improvements

chore: minor changes

chore: minor changes

chore: add bit of documentation

chore: improve documentation

fix: add unit tests and fix minor issues

chore: update documentation and unit tests

chore: update tests
2023-01-08 12:24:24 +01:00

19 KiB

Carousel

[component-header:sl-carousel]

Carousels consist of optional navigation arrows to go backwards and forwards, as well as optional pagination indicators.

<sl-carousel loop pagination navigation autoplay mouse-dragging>
  <sl-carousel-item>
    <img
      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </sl-carousel-item>
</sl-carousel>
<sl-divider></sl-divider>
<div class="carousel-options">
  <div class="carousel-options">
    <sl-switch checked name="loop"> Loop </sl-switch>
    <sl-switch checked name="navigation"> Show navigation </sl-switch>
    <sl-switch checked name="pagination"> Show pagination </sl-switch>
    <sl-switch checked name="autoplay"> Autoplay (3s) </sl-switch>
    <sl-switch checked name="mouseDragging"> Mouse dragging </sl-switch>
  </div>
  <div class="carousel-options">
    <sl-input type="number" label="Slides per page" name="slidesPerPage" value="1"></sl-input>
    <sl-input type="number" label="Slides per move" name="slidesPerMove" value="1"></sl-input>
    <sl-select label="Orientation" name="orientation" value="horizontal">
      <sl-menu-item value="horizontal">Horizontal</sl-menu-item>
      <sl-menu-item value="vertical">Vertical</sl-menu-item>
    </sl-select>
  </div>
</div>

<style>
  sl-carousel {
    --aspect-ratio: 3 / 2;
  }

  .carousel-options {
    display: flex;
    flex-wrap: wrap;
    align-items: end;
    gap: 1rem;
  }
</style>
<script>
  (() => {
    const options = document.querySelector('.carousel-options');
    const carousel = document.querySelector('sl-carousel');
    const loop = options.querySelector('sl-switch[name="loop"]');
    const navigation = options.querySelector('sl-switch[name="navigation"]');
    const pagination = options.querySelector('sl-switch[name="pagination"]');
    const autoplay = options.querySelector('sl-switch[name="autoplay"]');
    const mouseDragging = options.querySelector('sl-switch[name="mouseDragging"]');
    const slidesPerMove = options.querySelector('sl-input[name="slidesPerMove"]');
    const slidesPerPage = options.querySelector('sl-input[name="slidesPerPage"]');
    const orientation = options.querySelector('sl-select[name="orientation"]');

    loop.addEventListener('sl-change', () => (carousel.loop = loop.checked));
    navigation.addEventListener('sl-change', () => (carousel.navigation = navigation.checked));
    pagination.addEventListener('sl-change', () => (carousel.pagination = pagination.checked));
    autoplay.addEventListener('sl-change', () => (carousel.autoplay = autoplay.checked));
    slidesPerMove.addEventListener('sl-change', () => (carousel.slidesPerMove = slidesPerMove.valueAsNumber));
    slidesPerPage.addEventListener('sl-change', () => (carousel.slidesPerPage = slidesPerPage.valueAsNumber));
    orientation.addEventListener('sl-change', () => (carousel.orientation = orientation.value));
    mouseDragging.addEventListener('sl-change', () => (carousel.mouseDragging = mouseDragging.checked));

    document.addEventListener('sl-slide-change', e => {
      console.log('Slide changed:', e.detail);
    });
  })();
</script>

Examples

Multiple slides per view

Setting the attribute slides-per-view is it possible to specify how many items are shown at a given time. Using this feature, it may be also useful to advance multiple slides at once, even though not strictly necessary. This can be done by using the slides-per-move attribute.

<sl-carousel class="multi-carousel" loop navigation pagination slides-per-page="3" slides-per-move="3">
  <sl-carousel-item style="background: #204ed8;">Slide 1</sl-carousel-item>
  <sl-carousel-item style="background: #be133d;">Slide 2</sl-carousel-item>
  <sl-carousel-item style="background: #6e28d9;">Slide 3</sl-carousel-item>
  <sl-carousel-item style="background: #c2420d;">Slide 4</sl-carousel-item>
  <sl-carousel-item style="background: #4d7c0f;">Slide 5</sl-carousel-item>
  <sl-carousel-item style="background: #4338cb;">Slide 6</sl-carousel-item>
</sl-carousel>

Adding/removing slides

The content of the carousel can be changed by either appending or removing items, the carousel will update itself automatically.

<sl-carousel class="dynamic-carousel" pagination navigation>
  <sl-carousel-item style="background: #204ed8;">Slide 1</sl-carousel-item>
  <sl-carousel-item style="background: #be133d;">Slide 2</sl-carousel-item>
  <sl-carousel-item style="background: #6e28d9;">Slide 3</sl-carousel-item>
</sl-carousel>
<sl-divider></sl-divider>
<div class="carousel-options">
  <sl-button id="dynamic-add">Add slide</sl-button>
  <sl-button id="dynamic-remove">Remove slide</sl-button>
</div>
<style>
  .dynamic-carousel {
    --aspect-ratio: 3 / 2;
  }

  .dynamic-carousel sl-carousel-item {
    flex: 0 0 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: var(--sl-font-size-2x-large);
  }
</style>
<script>
  (() => {
    const dynamicCarousel = document.querySelector('.dynamic-carousel');
    const dynamicAdd = document.querySelector('#dynamic-add');
    const dynamicRemove = document.querySelector('#dynamic-remove');

    const rnd = (min, max) => Math.round(Math.random() * (max - min)) + min;

    const getRandomColor = () => `rgb(${rnd(50, 150)}, ${rnd(50, 150)}, ${rnd(50, 150)})`;

    const addSlide = () => {
      const slide = document.createElement('sl-carousel-item');
      slide.innerText = `Slide ${dynamicCarousel.children.length + 1}`;
      slide.style.setProperty('background', getRandomColor());

      dynamicCarousel.appendChild(slide);
    };

    const removeSlide = () => {
      const slide = dynamicCarousel.children[dynamicCarousel.children.length - 1];
      slide.remove();
    };

    dynamicAdd.addEventListener('click', addSlide);
    dynamicRemove.addEventListener('click', removeSlide);
  })();
</script>

Vertical scrolling

Setting the orientation attribute to vertical, will make the carousel laying out vertically, making it possible for the user to scroll it up and down. In case of heterogeneous content, for example images of different sizes, it's important to specify a predefined height to the carousel through CSS.

<sl-carousel class="vertical" loop pagination orientation="vertical">
  <sl-carousel-item>
    <img
      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </sl-carousel-item>
</sl-carousel>
<style>
  .vertical {
    max-height: 400px;
  }

  .vertical::part(base) {
    grid-template-areas: 'slides slides pagination';
  }

  .vertical::part(pagination) {
    flex-direction: column;
  }

  .vertical::part(navigation) {
    transform: rotate(90deg);
    display: flex;
  }
</style>

Aspect ratio

Use the --aspect-ratio custom property to customize the size of viewport in order to make it match a particular aspect ratio.

<sl-carousel class="aspect-ratio" navigation pagination style="--aspect-ratio: 3 / 2">
  <sl-carousel-item>
    <img
      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </sl-carousel-item>
</sl-carousel>

<sl-divider></sl-divider>
<sl-select label="Aspect ratio" name="aspect" value="3 / 2">
  <sl-menu-item value="1 / 1">1 / 1</sl-menu-item>
  <sl-menu-item value="3 / 2">3 / 2</sl-menu-item>
  <sl-menu-item value="16 / 9">16 / 9</sl-menu-item>
</sl-select>

<script>
  (() => {
    const carousel = document.querySelector('sl-carousel.aspect-ratio');
    const aspect = document.querySelector('sl-select[name="aspect"]');

    aspect.addEventListener('sl-change', () => {
      carousel.style.setProperty('--aspect-ratio', aspect.value);
    });
  })();
</script>

Scroll hint

Use --scroll-padding to add inline padding in horizontal carousels and block padding in vertical carousels. Setting a padding, will make the closest slides visible, suggesting to the user that there are items that can be scrolled.

<sl-carousel class="scroll-hint" navigation pagination style="--scroll-padding: calc(var(--slide-gap) + 10%);">
  <sl-carousel-item>
    <img
      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </sl-carousel-item>
</sl-carousel>

<sl-divider></sl-divider>
<sl-range label="Size (%)" name="scroll-hint" value="5" min="0" max="15"></sl-range>

<script>
  (() => {
    const carousel = document.querySelector('sl-carousel.scroll-hint');
    const scrollHint = document.querySelector('sl-range[name="scroll-hint"]');

    scrollHint.addEventListener('sl-input', () => {
      carousel.style.setProperty('--scroll-padding', `calc(var(--slide-gap) + ${scrollHint.value}%)`);
    });
  })();
</script>

Custom layout

The appereance of the carousel can be easly customized through its slots or part attributes.

<sl-carousel class="custom-layout" navigation pagination>
  <sl-carousel-item>
    <img
      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </sl-carousel-item>

  <sl-icon name="arrow-right" slot="next-icon"></sl-icon>
  <sl-icon name="arrow-left" slot="previous-icon"></sl-icon>
</sl-carousel>

<style>
  .custom-layout::part(base) {
    grid-template-areas:
      'slides slides slides'
      'slides slides slides';
  }

  .custom-layout::part(pagination) {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: var(--sl-spacing-large);
    background: linear-gradient(0deg, rgba(0, 0, 0, 0.8) 5%, rgba(0, 0, 0, 0.2) 75%, rgba(0, 0, 0, 0) 100%);
  }

  .custom-layout::part(pagination-item) {
    height: 5px;
    width: var(--sl-spacing-large);
    border-radius: var(--sl-border-radius-pill);
    background-color: #fff;
  }

  .custom-layout::part(pagination-item--active) {
    background-color: var(--sl-color-primary-400);
    width: var(--sl-spacing-x-large);
  }

  .custom-layout::part(navigation-button) {
    margin: var(--sl-spacing-large);
    border-radius: var(--sl-border-radius-circle);
    font-weight: var(--sl-font-weight-bold);
    color: var(--sl-color-neutral-1000);
    background: var(--sl-color-neutral-0);
    opacity: 0.6;
    transition: var(--sl-transition-medium) opacity;
  }

  .custom-layout::part(navigation-button):focus,
  .custom-layout::part(navigation-button):hover {
    opacity: 1;
  }
</style>

The carousel has a set of API with which is possible to interact programmatically, for example it is possible to use next() or previous() to go respectively to the next or the previous slide.

When the active slide is changed, the sl-slide-change event is emitted providing the index of the slide.

Using the API is possible to extend the carousel, for exmaple by syncing the active slide with a set of thumbnails, like in the example below.

<sl-carousel class="carousel-thumbnails" navigation loop>
  <sl-carousel-item>
    <img
      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
  </sl-carousel-item>
  <sl-carousel-item>
    <img
      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </sl-carousel-item>
</sl-carousel>
<div class="thumbnails">
  <div class="thumbnails__scroller">
    <img
      alt="Thumbnail Photo by 1"
      class="thumbnails__image active"
      src="/assets/examples/carousel/adam-kool-ndN00KmbJ1c-unsplash.jpg"
    />
    <img
      alt="Thumbnail Photo by 2"
      class="thumbnails__image"
      Jeff
      King
      on
      Unsplash
      src="/assets/examples/carousel/thomas-kelley-JoH60FhTp50-unsplash.jpg"
    />
    <img
      alt="Thumbnail Photo by 3"
      class="thumbnails__image"
      Leonard
      Cotte
      on
      Unsplash
      src="/assets/examples/carousel/leonard-cotte-c1Jp-fo53U8-unsplash.jpg"
    />
    <img
      alt="Thumbnail Photo by 4"
      class="thumbnails__image"
      Lukasz
      Szmigiel
      on
      Unsplash
      src="/assets/examples/carousel/sapan-patel-i9Q9bc-WgfE-unsplash.jpg"
    />
    <img
      alt="Thumbnail Photo by 5"
      class="thumbnails__image"
      V2osk
      on
      Unsplash
      src="/assets/examples/carousel/v2osk-1Z2niiBPg5A-unsplash.jpg"
    />
  </div>
</div>
<style>
  .carousel-thumbnails {
    --slide-aspect-ratio: 3 / 2;
  }

  .thumbnails {
    display: flex;
    justify-content: center;
  }

  .thumbnails__scroller {
    display: flex;
    gap: var(--sl-spacing-small);
    overflow-x: auto;
    scrollbar-width: none;
    scroll-behavior: smooth;
    scroll-padding: var(--sl-spacing-small);
  }

  .thumbnails__scroller::-webkit-scrollbar {
    display: none;
  }

  .thumbnails__image {
    width: 64px;
    height: 64px;
    object-fit: cover;

    opacity: 0.3;
    will-change: opacity;
    transition: 250ms opacity;

    cursor: pointer;
  }

  .thumbnails__image.active {
    opacity: 1;
  }
</style>
<script>
  {
    const carousel = document.querySelector('.carousel-thumbnails');
    const scroller = document.querySelector('.thumbnails__scroller');
    const thumbnails = document.querySelectorAll('.thumbnails__image');

    scroller.addEventListener('click', e => {
      const target = e.target;

      if (target.matches('.thumbnails__image')) {
        const index = [...thumbnails].indexOf(target);
        carousel.goToSlide(index);
      }
    });

    carousel.addEventListener('sl-slide-change', e => {
      const slideIndex = e.detail.index;

      [...thumbnails].forEach((thumb, i) => {
        thumb.classList.toggle('active', i === slideIndex);
        if (i === slideIndex) {
          thumb.scrollIntoView({
            block: 'nearest'
          });
        }
      });
    });
  }
</script>

[component-metadata:sl-carousel]