After implementing a function to add a magnifying glass (.img-magnifier-glass) on button click, I am now looking to remove the glass by clicking the "cancel" button. However, I am unsure of how to write this function to interact with the "magnify" function.
I attempted to create a function that adds a class which sets the display property to none on ".img-magnifier-glass".
function magnify(imgID, zoom)
{
var img, glass, w, h, bw;
img = document.getElementById(imgID);
/*create magnifier glass:*/
glass = document.createElement("DIV");
glass.setAttribute("class", "img-magnifier-glass");
/*insert magnifier glass:*/
img.parentElement.insertBefore(glass, img);
/*set background properties for the magnifier glass:*/
glass.style.backgroundImage = "url('" + img.src + "')";
glass.style.backgroundRepeat = "no-repeat";
glass.style.backgroundSize = (img.width * zoom) + "px " + (img.height * zoom) + "px";
bw = 3;
w = glass.offsetWidth / 2;
h = glass.offsetHeight / 2;
/*execute a function when someone moves the magnifier glass over the image:*/
glass.addEventListener("mousemove", moveMagnifier);
img.addEventListener("mousemove", moveMagnifier);
/*and also for touch screens:*/
glass.addEventListener("touchmove", moveMagnifier);
img.addEventListener("touchmove", moveMagnifier);
function moveMagnifier(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);
x = pos.x;
y = pos.y;
/*prevent the magnifier glass from being positioned outside the image:*/
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; }
/*set the position of the magnifier glass:*/
glass.style.left = (x - w) + "px";
glass.style.top = (y - h) + "px";
/*display what the magnifier glass "sees":*/
glass.style.backgroundPosition = "-" + ((x * zoom) - w + bw) + "px -" + ((y * zoom) - h + bw) + "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};
}
}
function onClick()
{
magnify("img1", 1.5);
magnify("img2", 1.5);
magnify("img4", 1.5);
}<div>
<div class="slideshow-container">
<button onclick = "onClick()" id="btn1" type="button" class="btn"> Zoom In</button>
<button onclick = "zoomOut()" id= "btn2" type= "button" class="btn" >Cancel</button>
<div class="img-magnifier-container mySlides">
<img id = "img1" src="img1.jpg" width="800" height="600">
</div>
<div class="img-magnifier-container mySlides">
<img id = "img2" src="img2.jpg" width="800" height="600" >
</div>
<div class="img-magnifier-container mySlides">
<img id = "img4" src="img4.jpg" width="800" height="600">
</div>
</div>