From 30b9378d2cbf140816c185b8649489bc8cb6fb8a Mon Sep 17 00:00:00 2001
From: tophf <tophf@gmx.com>
Date: Mon, 9 Nov 2020 22:59:42 +0300
Subject: [PATCH] use mousewheel to change a focused input[type=range]

---
 js/dom.js | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/js/dom.js b/js/dom.js
index 2babfac6..d8bafda8 100644
--- a/js/dom.js
+++ b/js/dom.js
@@ -97,10 +97,13 @@ document.on('wheel', event => {
   if (!el || el !== event.target && !el.contains(event.target)) {
     return;
   }
-  if (el.tagName === 'SELECT') {
-    const old = el.selectedIndex;
-    el.selectedIndex = Math.max(0, Math.min(el.length - 1, old + Math.sign(event.deltaY)));
-    if (el.selectedIndex !== old) {
+  const isSelect = el.tagName === 'SELECT';
+  if (isSelect || el.tagName === 'INPUT' && el.type === 'range') {
+    const key = isSelect ? 'selectedIndex' : 'valueAsNumber';
+    const old = el[key];
+    const rawVal = old + Math.sign(event.deltaY) * (el.step || 1);
+    el[key] = Math.max(el.min || 0, Math.min(el.max || el.length - 1, rawVal));
+    if (el[key] !== old) {
       el.dispatchEvent(new Event('change', {bubbles: true}));
     }
     event.preventDefault();