From 332ae408a4faef1cbbf348e17bdfbc01f6123bfe Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Wed, 5 Jul 2023 13:16:28 +0200
Subject: [PATCH] Middle Column: Fixing the keyboard hiding issue on iOs
 (#3488)

---
 src/components/middle/MiddleColumn.tsx | 10 +++++++++-
 src/util/windowSize.ts                 | 10 ++++++++--
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/components/middle/MiddleColumn.tsx b/src/components/middle/MiddleColumn.tsx
index 9ad7cdc5c..1971a8c9e 100644
--- a/src/components/middle/MiddleColumn.tsx
+++ b/src/components/middle/MiddleColumn.tsx
@@ -1,7 +1,7 @@
 import React, {
   useEffect, useState, memo, useMemo,
 } from '../../lib/teact/teact';
-import { requestMutation } from '../../lib/fasterdom/fasterdom';
+import { requestMeasure, requestMutation } from '../../lib/fasterdom/fasterdom';
 import { getActions, withGlobal } from '../../global';
 
 import type { ApiChat, ApiChatBannedRights } from '../../api/types';
@@ -304,6 +304,14 @@ function MiddleColumn({
 
       requestMutation(() => {
         document.body.classList.toggle('keyboard-visible', isFixNeeded);
+
+        requestMeasure(() => {
+          if (!isFixNeeded && visualViewport.offsetTop) {
+            requestMutation(() => {
+              window.scrollTo({ top: 0 });
+            });
+          }
+        });
       });
     };
 
diff --git a/src/util/windowSize.ts b/src/util/windowSize.ts
index a76075b8d..e65896e9b 100644
--- a/src/util/windowSize.ts
+++ b/src/util/windowSize.ts
@@ -7,16 +7,22 @@ type IDimensions = {
   height: number;
 };
 
+const WINDOW_ORIENTATION_CHANGE_THROTTLE_MS = 100;
 const WINDOW_RESIZE_THROTTLE_MS = 250;
 
-const initialHeight = window.innerHeight;
+let initialHeight = window.innerHeight;
 let currentWindowSize = updateSizes();
 
 const handleResize = throttle(() => {
   currentWindowSize = updateSizes();
 }, WINDOW_RESIZE_THROTTLE_MS, true);
 
-window.addEventListener('orientationchange', handleResize);
+const handleOrientationChange = throttle(() => {
+  initialHeight = window.innerHeight;
+  handleResize();
+}, WINDOW_ORIENTATION_CHANGE_THROTTLE_MS, false);
+
+window.addEventListener('orientationchange', handleOrientationChange);
 if (IS_IOS) {
   window.visualViewport!.addEventListener('resize', handleResize);
 } else {