.img-magnifier-container {
font-family: system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
position: relative;
width: 100%;
max-width: 400px;
margin: 0 auto;
}
#myimage {
width: 100%;
height: auto;
display: block;
border-radius: 8px;
cursor: crosshair;
}
.img-magnifier-glass {
position: absolute;
border: 3px solid #fff;
border-radius: 50%;
cursor: none;
width: 100px;
height: 100px;
box-shadow: 0 5px 15px rgba(0,0,0,0.3);
display: none;
background-repeat: no-repeat;
background-color: #fff;
pointer-events: none;
z-index: 10;
}
function magnify(imgID, zoom) {
const img = document.getElementById(imgID);
const glass = document.createElement("DIV");
glass.setAttribute("class", "img-magnifier-glass");
img.parentElement.insertBefore(glass, img);
const initMagnifier = () => {
// Using unquoted URL to prevent SQL escaping errors. Safe because img.src is URL encoded.
glass.style.backgroundImage = "url(" + img.src + ")";
glass.style.backgroundSize = (img.width * zoom) + "px " + (img.height * zoom) + "px";
const bw = 3;
const w = glass.offsetWidth / 2;
const h = glass.offsetHeight / 2;
// Mouse Events
glass.addEventListener("mousemove", moveMagnifier);
img.addEventListener("mousemove", moveMagnifier);
img.addEventListener("mouseenter", () => glass.style.display = "block");
img.addEventListener("mouseleave", () => glass.style.display = "none");
// Touch Events for Mobile
glass.addEventListener("touchmove", moveMagnifier);
img.addEventListener("touchmove", moveMagnifier);
img.addEventListener("touchstart", () => glass.style.display = "block");
img.addEventListener("touchend", () => glass.style.display = "none");
function moveMagnifier(e) {
e.preventDefault();
const pos = getCursorPos(e);
let x = pos.x;
let y = pos.y;
if (x > img.width - (w / zoom)) {x = img.width - (w / zoom);}
if (x < w / zoom) {x = w / zoom;}
if (y > img.height - (h / zoom)) {y = img.height - (h / zoom);}
if (y < h / zoom) {y = h / zoom;}
glass.style.left = (x - w) + "px";
glass.style.top = (y - h) + "px";
glass.style.backgroundPosition = "-" + ((x * zoom) - w + bw) + "px -" + ((y * zoom) - h + bw) + "px";
}
function getCursorPos(e) {
let a, x = 0, y = 0;
e = e || window.event;
a = img.getBoundingClientRect();
// Handle touch or mouse
const pageX = e.pageX || e.touches[0].pageX;
const pageY = e.pageY || e.touches[0].pageY;
// Calculate cursor position relative to the image
x = pageX - a.left - window.scrollX;
y = pageY - a.top - window.scrollY;
return {x : x, y : y};
}
};
if (img.complete) {
initMagnifier();
} else {
img.addEventListener("load", initMagnifier);
}
}
magnify("myimage", 2);