Slideshow Gallery

Slideshow 기능과 비슷한데 추가하면 각 이미지에 대한 alt text를 보여주고, 하단에 작은 이미지를 추가하여 하단 이미지 클릭 시 슬라이드 이동되는 기능이다.

HTML

<!-- Container for the image gallery -->
<div class="container">

    <!-- Full-width images with number text -->
    <div class="mySlides">
      <div class="numbertext">1 / 3</div>
        <img src="Slideshow_img/img1.jpg" style="width:100%">
    </div>
  
    <div class="mySlides">
      <div class="numbertext">2 / 3</div>
        <img src="Slideshow_img/img2.jpg" style="width:100%">
    </div>
  
    <div class="mySlides">
      <div class="numbertext">3 / 3</div>
        <img src="Slideshow_img/img3.jpg" style="width:100%">
    </div>
  
  
    <!-- Next and previous buttons -->
    <a class="prev" onclick="plusSlides(-1)">&#10094;</a>
    <a class="next" onclick="plusSlides(1)">&#10095;</a>
  
    <!-- Image text -->
    <div class="caption-container">
      <p id="caption"></p>
    </div>
  
    <!-- Thumbnail images -->
    <div class="row">
      <div class="column">
        <img class="demo cursor" src="Slideshow_img/img1.jpg" style="width:100%" onclick="currentSlide(1)" alt="The beach">
      </div>
      <div class="column">
        <img class="demo cursor" src="Slideshow_img/img2.jpg" style="width:100%" onclick="currentSlide(2)" alt="Ticket">
      </div>
      <div class="column">
        <img class="demo cursor" src="Slideshow_img/img3.jpg" style="width:100%" onclick="currentSlide(3)" alt="opera house">
      </div>
    </div>
  </div>

CSS

 * {
  box-sizing: border-box;
}

/* Position the image container (needed to position the left and right arrows) */
.container {
  position: relative;
}
/* Hide the images by default */
.mySlides {
  display: none;
}

/* Add a pointer when hovering over the thumbnail images */
.cursor {
  cursor: pointer;
}

/* Next & previous buttons */
.prev,
.next {
  cursor: pointer;
  position: absolute;
  top: 40%;
  width: auto;
  padding: 16px;
  margin-top: -50px;
  color: white;
  font-weight: bold;
  font-size: 20px;
  border-radius: 0 3px 3px 0;
  user-select: none;
  -webkit-user-select: none;
}

/* Position the "next button" to the right */
.next {
  right: 0;
  border-radius: 3px 0 0 3px;
}

/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
  background-color: rgba(0, 0, 0, 0.8);
}

/* Number text (1/3 etc) */
.numbertext {
  color: #f2f2f2;
  font-size: 12px;
  padding: 8px 12px;
  position: absolute;
  top: 0;
}

/* Container for image text */
.caption-container {
  text-align: center;
  background-color: #222;
  padding: 2px 16px;
  color: white;
}

.row:after {
  content: "";
  display: table;
  clear: both;
}

/* Six columns side by side */
.column {
  float: left;
  width: 16.66%;
}

/* Add a transparency effect for thumnbail images */
.demo {
  opacity: 0.6;
}

.active,
.demo:hover {
  opacity: 1;
}

• content: "";
  • 속성값에 삽입된 텍스트나 이미지 등을 화면에 출력

JS

let slideIndex = 1;
showSlides(slideIndex);

// Next/previous controls
function plusSlides(n) {
  showSlides(slideIndex += n);
}

// Thumbnail image controls
function currentSlide(n) {
  showSlides(slideIndex = n);
}

function showSlides(n) {
  let i;
  let slides = document.getElementsByClassName("mySlides");
  let dots = document.getElementsByClassName("demo");
  let captionText = document.getElementById("caption");
  if (n > slides.length) {slideIndex = 1}
  if (n < 1) {slideIndex = slides.length}
  for (i = 0; i < slides.length; i++) {
    slides[i].style.display = "none";
  }
  for (i = 0; i < dots.length; i++) {
    dots[i].className = dots[i].className.replace(" active", "");
  }
  slides[slideIndex-1].style.display = "block";
  dots[slideIndex-1].className += " active";
  captionText.innerHTML = dots[slideIndex-1].alt;
}

• captionText.innerHTML = dots[slideIndex-1].alt;
  • "caption" id를 가진 대상의 alt 내용을 innerHTML 메서드의 의해서 alt 텍스트가 화면에 출력된다.
• innerHTML
  • HTML 요소에 접근하려면 document.getElementById 메서드를 함께 사용
  • 요소(element) 내에 포함 된 HTML 또는 XML 마크업을 가져오거나 설정