{"id":56240,"date":"2022-09-11T03:01:59","date_gmt":"2022-09-10T17:01:59","guid":{"rendered":"http:\/\/www.rjmprogramming.com.au\/ITblog\/?p=56240"},"modified":"2022-09-11T08:54:48","modified_gmt":"2022-09-10T22:54:48","slug":"mouse-wheel-event-primer-tutorial","status":"publish","type":"post","link":"https:\/\/www.rjmprogramming.com.au\/ITblog\/mouse-wheel-event-primer-tutorial\/","title":{"rendered":"Mouse Wheel Event Primer Tutorial"},"content":{"rendered":"<div style=\"width: 230px\" class=\"wp-caption alignnone\"><a target=_blank href=\"http:\/\/www.rjmprogramming.com.au\/HTMLCSS\/wheel_zoom.html\"><img decoding=\"async\" style=\"border: 15px solid pink;\" alt=\"Mouse Wheel Event Primer Tutorial\" src=\"http:\/\/www.rjmprogramming.com.au\/HTMLCSS\/wheel_zoom.jpg\" title=\"Mouse Wheel Event Primer Tutorial\"  style=\"float:left;\" \/><\/a><p class=\"wp-caption-text\">Mouse Wheel Event Primer Tutorial<\/p><\/div>\n<p>If your pointing device of choice is a mouse and it has a wheel, there&#8217;s an event to hone in on the use you make of that mouse wheel &#8230;<\/p>\n<ul>\n<li>normally used for <i>scrolling in Y<\/i> &#8230; but, today, thanks to <a target=_blank title='https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event' href='\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event'>https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event<\/a>, reimagined as &#8230;<\/li>\n<li>a scaling and rotating and skewering mechanism for our lightblue div element<\/li>\n<\/ul>\n<p>It&#8217;s a simple <a target=_blank href=\"http:\/\/www.rjmprogramming.com.au\/HTMLCSS\/wheel_zoom.html_GETME\">&#8220;proof of concept&#8221;<\/a> &#8230;<\/p>\n<p><code><br \/>\n&lt;html&gt;<br \/>\n&lt;head&gt;<br \/>\n&lt;title&gt;Mouse Wheel Event - RJM Programming - June, 2022 ... Thanks to https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event&lt;\/title&gt;<br \/>\n<br \/>\n&lt;style&gt;<br \/>\n div {<br \/>\n   width:150px;<br \/>\n   height:150px;<br \/>\n   background-color: lightblue;<br \/>\n   text-align: center;<br \/>\n   margin-left: 35%;<br \/>\n   margin-top: 35vh;<br \/>\n }<br \/>\n&lt;\/style&gt;<br \/>\n&lt;script type='text\/javascript'&gt;<br \/>\nvar scale = 1;<br \/>\nvar rotate = 0;<br \/>\nvar skew = 0;<br \/>\nvar el=null;<br \/>\n<br \/>\nfunction zoom(event) {<br \/>\n  event.preventDefault();<br \/>\n<br \/>\n  scale -= event.deltaY * 0.01;<br \/>\n  rotate -= event.deltaY * 0.01 * 90;<br \/>\n  skew -= event.deltaY * 0.01 * 30;<br \/>\n<br \/>\n  \/\/ Restrict scale<br \/>\n  scale = Math.min(Math.max(.125, scale), 4);<br \/>\n  rotate = Math.min(Math.max(-180.0, rotate), 180.0);<br \/>\n<br \/>\n  \/\/ Apply scale transform<br \/>\n  el.style.transform = 'scale(' + scale + ') rotate(' + rotate + 'deg) skew(' + skew + 'deg)';<br \/>\n}<br \/>\n<br \/>\nfunction onl() {<br \/>\n  el = document.querySelector('div');<br \/>\n  el.addEventListener('wheel', zoom); \/\/el.onwheel = zoom;<br \/>\n}<br \/>\n&lt;\/script&gt;<br \/>\n&lt;\/head&gt;<br \/>\n&lt;body onload=onl();&gt;<br \/>\n&lt;h1&gt;Mouse Wheel Event&lt;\/h1&gt;<br \/>\n&lt;h3&gt;RJM Programming - June, 2022&lt;\/h3&gt;<br \/>\n&lt;h4&gt;Thanks to &lt;a target=_blank title='https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event' href='\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event'&gt;https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/Element\/wheel_event&lt;\/a&gt;&lt;\/h4&gt;<br \/>\n&lt;div&gt;&lt;br&gt;&lt;br&gt;Scale and&lt;br&gt;<br \/>\nrotate and&lt;br&gt;<br \/>\nskew me&lt;br&gt;<br \/>\nwith your &lt;br&gt;<br \/>\nmouse wheel.&lt;br&gt;&lt;\/div&gt;<br \/>\n&lt;\/body&gt;<br \/>\n&lt;\/html&gt;<br \/>\n<\/code><\/p>\n<p> &#8230; <a target=_blank href=\"http:\/\/www.rjmprogramming.com.au\/HTMLCSS\/wheel_zoom.html\">web application<\/a> &#8230;<\/p>\n<p><iframe src=\"http:\/\/www.rjmprogramming.com.au\/HTMLCSS\/wheel_zoom.html\" style=\"width:95%;height:900px;\"><\/iframe><\/p>\n<p>If this was interesting you may be interested in <a title='Click here to see topics in which you might be interested' href='#d56240' onclick='var dv=document.getElementById(\"d56240\"); dv.innerHTML = \"&lt;iframe width=670 height=600 src=\" + \"https:\/\/www.rjmprogramming.com.au\/ITblog\/tag\/mouse\" + \"&gt;&lt;\/iframe&gt;\"; dv.style.display = \"block\";'>this<\/a> too.<\/p>\n<div id='d56240' style='display: none; border-left: 2px solid green; border-top: 2px solid green;'><\/div>\n","protected":false},"excerpt":{"rendered":"<p>If your pointing device of choice is a mouse and it has a wheel, there&#8217;s an event to hone in on the use you make of that mouse wheel &#8230; normally used for scrolling in Y &#8230; but, today, thanks &hellip; <a href=\"https:\/\/www.rjmprogramming.com.au\/ITblog\/mouse-wheel-event-primer-tutorial\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,14,37],"tags":[281,400,576,652,812,2949,997,1071,1094,1917,1147,1298,1319,3020],"class_list":["post-56240","post","type-post","status-publish","format-standard","hentry","category-elearning","category-event-driven-programming","category-tutorials","tag-css","tag-event","tag-html","tag-javascript","tag-mouse","tag-onwheel","tag-programming","tag-rotate","tag-scale","tag-scroll","tag-skew","tag-transform","tag-tutorial","tag-wheel"],"_links":{"self":[{"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/posts\/56240"}],"collection":[{"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/comments?post=56240"}],"version-history":[{"count":3,"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/posts\/56240\/revisions"}],"predecessor-version":[{"id":56814,"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/posts\/56240\/revisions\/56814"}],"wp:attachment":[{"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/media?parent=56240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/categories?post=56240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rjmprogramming.com.au\/ITblog\/wp-json\/wp\/v2\/tags?post=56240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}