From 2d22ffda49c0e06e28175c403baea2833bf0dc9f Mon Sep 17 00:00:00 2001
From: David Luzar <luzar.david@gmail.com>
Date: Sun, 16 Feb 2020 16:23:56 +0100
Subject: [PATCH] fix wheel zoom step (#771)

---
 src/index.tsx | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/index.tsx b/src/index.tsx
index 7c6fdade..0fe4dd72 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1985,8 +1985,15 @@ export class App extends React.Component<any, AppState> {
     const { deltaX, deltaY } = e;
 
     if (e[KEYS.META]) {
+      const sign = Math.sign(deltaY);
+      const MAX_STEP = 10;
+      let delta = Math.abs(deltaY);
+      if (delta > MAX_STEP) {
+        delta = MAX_STEP;
+      }
+      delta *= sign;
       this.setState(({ zoom }) => ({
-        zoom: getNormalizedZoom(zoom - deltaY / 100),
+        zoom: getNormalizedZoom(zoom - delta / 100),
       }));
       return;
     }