Create an Image Zoom
Step 1: Create index.html file and implement below code in it.
<div class="img-zoom-container " style="display: flex"> <img id="image" src="../image/demo4.jpg" width="300" height="240"> <div id="result" class="img-zoom-result"></div> </div>
Step 2:Now we create css code to display zoomed image so implement below code in index.html file
The container must have a "relative" positioning.
<style> h1 { color: red; } * {box-sizing: border-box;} .img-zoom-container { position: relative; } .img-zoom-lens { position: absolute; border: 1px solid #d4d4d4; /*set the size of the lens:*/ width: 40px; height: 40px; } .img-zoom-result { border: 1px solid #d4d4d4; /*set the size of the result div:*/ width: 300px; height: 241px; } </style>
Step 3:Now we implement javascript to zoom image.
<script> function imageZoom(imgID, resultID) { var img, lens, result, cx, cy; img = document.getElementById(imgID); result = document.getElementById(resultID); /*create lens:*/ lens = document.createElement("DIV"); lens.setAttribute("class", "img-zoom-lens"); /*insert lens:*/ img.parentElement.insertBefore(lens, img); /*calculate the ratio between result DIV and lens:*/ cx = result.offsetWidth / lens.offsetWidth; cy = result.offsetHeight / lens.offsetHeight; /*set background properties for the result DIV:*/ result.style.backgroundImage = "url('" + img.src + "')"; result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px"; /*execute a function when someone moves the cursor over the image, or the lens:*/ lens.addEventListener("mousemove", moveLens); img.addEventListener("mousemove", moveLens); /*and also for touch screens:*/ lens.addEventListener("touchmove", moveLens); img.addEventListener("touchmove", moveLens); function moveLens(e) { var pos, x, y; /*prevent any other actions that may occur when moving over the image:*/ e.preventDefault(); /*get the cursor's x and y positions:*/ pos = getCursorPos(e); /*calculate the position of the lens:*/ x = pos.x - (lens.offsetWidth / 2); y = pos.y - (lens.offsetHeight / 2); /*prevent the lens from being positioned outside the image:*/ if (x > img.width - lens.offsetWidth) {x = img.width - lens.offsetWidth;} if (x < 0) {x = 0;} if (y > img.height - lens.offsetHeight) {y = img.height - lens.offsetHeight;} if (y < 0) {y = 0;} /*set the position of the lens:*/ lens.style.left = x + "px"; lens.style.top = y + "px"; /*display what the lens "sees":*/ result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "px"; } function getCursorPos(e) { var a, x = 0, y = 0; e = e || window.event; /*get the x and y positions of the image:*/ a = img.getBoundingClientRect(); /*calculate the cursor's x and y coordinates, relative to the image:*/ x = e.pageX - a.left; y = e.pageY - a.top; /*consider any page scrolling:*/ x = x - window.pageXOffset; y = y - window.pageYOffset; return {x : x, y : y}; } } </script>
<script> // Initiate zoom effect: imageZoom("image", "result"); </script>
<!DOCTYPE html> <html> <head> <title>How To Zoom An Image On Mouse Over Using JavaScript</title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css"> </head> <style> h1 { color: red; } * { box-sizing: border-box; } .img-zoom-container { position: relative; } .img-zoom-lens { position: absolute; border: 1px solid #d4d4d4; /*set the size of the lens:*/ width: 40px; height: 40px; } .img-zoom-result { border: 1px solid #d4d4d4; /*set the size of the result div:*/ width: 300px; height: 241px; } </style> <script> function imageZoom(imgID, resultID) { var img, lens, result, cx, cy; img = document.getElementById(imgID); result = document.getElementById(resultID); /*create lens:*/ lens = document.createElement("DIV"); lens.setAttribute("class", "img-zoom-lens"); /*insert lens:*/ img.parentElement.insertBefore(lens, img); /*calculate the ratio between result DIV and lens:*/ cx = result.offsetWidth / lens.offsetWidth; cy = result.offsetHeight / lens.offsetHeight; /*set background properties for the result DIV:*/ result.style.backgroundImage = "url('" + img.src + "')"; result.style.backgroundSize = (img.width * cx) + "px " + (img.height * cy) + "px"; /*execute a function when someone moves the cursor over the image, or the lens:*/ lens.addEventListener("mousemove", moveLens); img.addEventListener("mousemove", moveLens); /*and also for touch screens:*/ lens.addEventListener("touchmove", moveLens); img.addEventListener("touchmove", moveLens); function moveLens(e) { var pos, x, y; /*prevent any other actions that may occur when moving over the image:*/ e.preventDefault(); /*get the cursor's x and y positions:*/ pos = getCursorPos(e); /*calculate the position of the lens:*/ x = pos.x - (lens.offsetWidth / 2); y = pos.y - (lens.offsetHeight / 2); /*prevent the lens from being positioned outside the image:*/ if (x > img.width - lens.offsetWidth) { x = img.width - lens.offsetWidth; } if (x < 0) { x = 0; } if (y > img.height - lens.offsetHeight) { y = img.height - lens.offsetHeight; } if (y < 0) { y = 0; } /*set the position of the lens:*/ lens.style.left = x + "px"; lens.style.top = y + "px"; /*display what the lens "sees":*/ result.style.backgroundPosition = "-" + (x * cx) + "px -" + (y * cy) + "px"; } function getCursorPos(e) { var a, x = 0, y = 0; e = e || window.event; /*get the x and y positions of the image:*/ a = img.getBoundingClientRect(); /*calculate the cursor's x and y coordinates, relative to the image:*/ x = e.pageX - a.left; y = e.pageY - a.top; /*consider any page scrolling:*/ x = x - window.pageXOffset; y = y - window.pageYOffset; return {x: x, y: y}; } } </script> <body> <div class="container"> <br> <br> <div class="text-center"> <h1>How To Zoom An Image On Mouse Over Using JavaScript</h1> </div> <br> <div class="well"> <h1>Image Zoom</h1> <p>Mouse over the image:</p> <div class="img-zoom-container " style="display: flex"> <img id="image" src="../image/demo4.jpg" width="300" height="240"> <div id="result" class="img-zoom-result"></div> </div> <p>The image must be placed inside a container with relative positioning.</p> <p>The result can be put anywhere on the page, but must have the class name "img-zoom-result".</p> <p>Make sure both the image and the result have IDs. These IDs are used when a javaScript initiates the zoom effect.</p> <script> // Initiate zoom effect: imageZoom("image", "result"); </script> </div> <div> </body> </html>