Allow for zoom on photo with mouse wheel

assets/css/photos.css

@@ -100,12 +100,14 @@
     margin: 0;
     padding: 0;
     position: fixed;
-    max-width: 100%;
-    max-height: 100%;
     z-index: 6;
     left: 50%;
     top: 50%;
+    max-width: none;
+    max-height: none;
     transform: translate(-50%, -50%);
+    cursor: move;
+    box-shadow: 0 0 5px #000;
 }
 
 #close, #right, #left, #fullscreen, #download {
@@ -234,7 +236,7 @@
     position: fixed;
     width: 100%;
     height: 100%;
-    background-color: #212121;
+    background-color: #212121aa;
     z-index: 5;
 }
 

assets/scripts/jquery.mousewheel.min.js

@@ -0,0 +1,8 @@
+/*!
+ * jQuery Mousewheel 3.1.13
+ *
+ * Copyright 2015 jQuery Foundation and other contributors
+ * Released under the MIT license.
+ * http://jquery.org/license
+ */
+!function(a){"function"==typeof define&&define.amd?define(["jquery"],a):"object"==typeof exports?module.exports=a:a(jQuery)}(function(a){function b(b){var g=b||window.event,h=i.call(arguments,1),j=0,l=0,m=0,n=0,o=0,p=0;if(b=a.event.fix(g),b.type="mousewheel","detail"in g&&(m=-1*g.detail),"wheelDelta"in g&&(m=g.wheelDelta),"wheelDeltaY"in g&&(m=g.wheelDeltaY),"wheelDeltaX"in g&&(l=-1*g.wheelDeltaX),"axis"in g&&g.axis===g.HORIZONTAL_AXIS&&(l=-1*m,m=0),j=0===m?l:m,"deltaY"in g&&(m=-1*g.deltaY,j=m),"deltaX"in g&&(l=g.deltaX,0===m&&(j=-1*l)),0!==m||0!==l){if(1===g.deltaMode){var q=a.data(this,"mousewheel-line-height");j*=q,m*=q,l*=q}else if(2===g.deltaMode){var r=a.data(this,"mousewheel-page-height");j*=r,m*=r,l*=r}if(n=Math.max(Math.abs(m),Math.abs(l)),(!f||f>n)&&(f=n,d(g,n)&&(f/=40)),d(g,n)&&(j/=40,l/=40,m/=40),j=Math[j>=1?"floor":"ceil"](j/f),l=Math[l>=1?"floor":"ceil"](l/f),m=Math[m>=1?"floor":"ceil"](m/f),k.settings.normalizeOffset&&this.getBoundingClientRect){var s=this.getBoundingClientRect();o=b.clientX-s.left,p=b.clientY-s.top}return b.deltaX=l,b.deltaY=m,b.deltaFactor=f,b.offsetX=o,b.offsetY=p,b.deltaMode=0,h.unshift(b,j,l,m),e&&clearTimeout(e),e=setTimeout(c,200),(a.event.dispatch||a.event.handle).apply(this,h)}}function c(){f=null}function d(a,b){return k.settings.adjustOldDeltas&&"mousewheel"===a.type&&b%120===0}var e,f,g=["wheel","mousewheel","DOMMouseScroll","MozMousePixelScroll"],h="onwheel"in document||document.documentMode>=9?["wheel"]:["mousewheel","DomMouseScroll","MozMousePixelScroll"],i=Array.prototype.slice;if(a.event.fixHooks)for(var j=g.length;j;)a.event.fixHooks[g[--j]]=a.event.mouseHooks;var k=a.event.special.mousewheel={version:"3.1.12",setup:function(){if(this.addEventListener)for(var c=h.length;c;)this.addEventListener(h[--c],b,!1);else this.onmousewheel=b;a.data(this,"mousewheel-line-height",k.getLineHeight(this)),a.data(this,"mousewheel-page-height",k.getPageHeight(this))},teardown:function(){if(this.removeEventListener)for(var c=h.length;c;)this.removeEventListener(h[--c],b,!1);else this.onmousewheel=null;a.removeData(this,"mousewheel-line-height"),a.removeData(this,"mousewheel-page-height")},getLineHeight:function(b){var c=a(b),d=c["offsetParent"in a.fn?"offsetParent":"parent"]();return d.length||(d=a("body")),parseInt(d.css("fontSize"),10)||parseInt(c.css("fontSize"),10)||16},getPageHeight:function(b){return a(b).height()},settings:{adjustOldDeltas:!0,normalizeOffset:!0}};a.fn.extend({mousewheel:function(a){return a?this.bind("mousewheel",a):this.trigger("mousewheel")},unmousewheel:function(a){return this.unbind("mousewheel",a)}})});

assets/scripts/photosScript.js

@@ -1,11 +1,56 @@
-var showcase = $("#img-big");
+let showcase = $("#img-big");
-var showcaseButton = $("#photo-buttons");
+let showcaseButton = $("#photo-buttons");
-var showcaseLink = $("#img_big_link");
+let showcaseLink = $("#img_big_link");
-var showcaseDownload = $("#img_big_download");
+let showcaseDownload = $("#img_big_download");
-var photoOverlay = $("#photo-overlay");
+let photoOverlay = $("#photo-overlay");
-var headerTop = $("#header-top");
+let headerTop = $("#header-top");
-var sideNav = $("#menuSidenav");
+let sideNav = $("#menuSidenav");
-var loading = $("#loading");
+let loading = $("#loading");
+
+$(document).ready(
+    function () {
+        showcase.bind("mousewheel", function(event, delta) {
+            let min_width = $(window).width() / 5;
+            let min_height = $(window).height() / 5;
+            let max_width = $(window).width() * 5;
+            let max_height = $(window).height() * 5;
+
+            let scale = 150 / 100;
+            if (delta < 0)
+               scale = 1/scale;
+            let cursorY = event.pageY - $(window).scrollTop();
+            let offsetX = event.pageX - (showcase.position().left + showcase.width()/2);
+            let offsetY = cursorY - (showcase.position().top + showcase.height()/2);
+
+            let new_width = showcase.width() * scale;
+            let new_height = showcase.height() * scale;
+            if (new_width > max_width || new_width < min_width)
+                new_width = 0;
+            if (new_height > max_height || new_height < min_height)
+                new_height = 0;
+
+            if (new_width !== 0 && new_height !== 0){
+                let new_left = event.pageX - (offsetX * scale);
+                let new_top = cursorY - (offsetY * scale);
+
+                showcase.width(new_width);
+                showcase.height(new_height);
+
+                if (new_height > $(window).height() || new_width > $(window).width()){
+                    showcase.css('left', new_left +'px');
+                    showcase.css('top', new_top +'px');
+                }
+                else{
+                    showcase.css('left', $(window).width()/2 +'px');
+                    showcase.css('top', $(window).height()/2 +'px');
+                }
+
+
+            }
+            return false;
+        });
+    }
+);
 
 /*
  * Display selected image in showcase
@@ -35,7 +80,7 @@ function closeBig() {
  * Toggle display of buttons/header
  */
 function toggleFullscreen() {
-    if (showcaseButton.css("display") == "none")
+    if (showcaseButton.css("display") === "none")
         disableFullscreen();
     else
         enableFullscreen();
@@ -59,7 +104,7 @@ function showTopBar() {
     sideNav.fadeIn(500);
 }
 
-$(document).ready(function() {
+$(document).ready(function () {
     document.getElementById("photos_title").scrollIntoView();
 });
 
@@ -67,8 +112,8 @@ $(document).ready(function() {
 /*
  * Control images with keyboard arrows
  */
-$(document).keydown(function(e) {
+$(document).keydown(function (e) {
-    switch(e.which) {
+    switch (e.which) {
         case 37: // left
             displayNext(-1);
             break;
@@ -77,7 +122,8 @@ $(document).keydown(function(e) {
             displayNext(1);
             break;
 
-        default: return; // exit this handler for other keys
+        default:
+            return; // exit this handler for other keys
     }
     e.preventDefault(); // prevent the default action (scroll / move caret)
 });
@@ -94,19 +140,16 @@ var Swipe = new Hammer.Swipe();
 manager.add(Swipe);
 
 // Subscribe to the swipe event
-manager.on('swipe', function(e) {
+manager.on('swipe', function (e) {
     var direction = e.offsetDirection;
     if (direction === 4) { // right
         displayNext(-1);
-    } else if (direction === 2){ // left
+    } else if (direction === 2) { // left
         displayNext(1);
     }
 });
 
 
-
-
-
 /*
  * Display next/last image in showcase. When reaching end/start, loop back to start/end
  */
@@ -138,11 +181,15 @@ function displayNext(direction) {
  */
 function changeImage(thumb) {
     displayLoading();
-    showcase.on('load', function() {
+    showcase.on('load', function () {
         hideLoading();
     });
     var source = getSourceFromThumbnail(thumb);
     showcase.attr("src", source);
+    showcase.css({
+        width: 'auto',
+        height: '90%'
+    });
     showcaseLink.attr("href", source);
     showcaseDownload.attr("href", source);
 }

photos.php

@@ -220,7 +220,8 @@ function generatePath($path)
 ?>
 <div id="photo-overlay" style="display:none">
 
-    <img src="" id="img-big" onclick="toggleFullscreen()">
+    <img src="" id="img-big">
+
     <div id="close-back" onclick="closeBig()"></div>
     <div id="loading" onclick="closeBig()">
         <i class="fas fa-spinner fa-spin"></i>
@@ -284,6 +285,7 @@ $pageTitle = "Photos";
 ob_start(); // Start reading html
 ?>
 <link rel="stylesheet" type="text/css" media="screen" href="assets/css/photos.css">
+<script type="text/javascript" src="assets/scripts/jquery.mousewheel.min.js"></script>
 <?php
 $pageMeta = ob_get_clean(); // Store html content in variable
 include("template.php"); // Display template with variable content