From c61e1b9139e89c7b95b498d228d90436dbb1303d Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Tue, 27 Jun 2023 19:40:45 +0400
Subject: [PATCH] Don't scroll through from chats list to stories.

---
 .../SourceFiles/dialogs/dialogs_widget.cpp    | 28 +++++++++++++++++++
 Telegram/SourceFiles/dialogs/dialogs_widget.h |  2 ++
 Telegram/lib_ui                               |  2 +-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/Telegram/SourceFiles/dialogs/dialogs_widget.cpp b/Telegram/SourceFiles/dialogs/dialogs_widget.cpp
index 03679cfb8..9268b4fcd 100644
--- a/Telegram/SourceFiles/dialogs/dialogs_widget.cpp
+++ b/Telegram/SourceFiles/dialogs/dialogs_widget.cpp
@@ -73,11 +73,13 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/qt/qt_common_adapters.h"
 
 #include <QtCore/QMimeData>
+#include <QtWidgets/QScrollBar>
 
 namespace Dialogs {
 namespace {
 
 constexpr auto kSearchPerPage = 50;
+constexpr auto kWaitTillAllowStoriesExpand = crl::time(200);
 
 } // namespace
 
@@ -208,6 +210,9 @@ Widget::Widget(
 , _cancelSearch(_searchControls, st::dialogsCancelSearch)
 , _lockUnlock(_searchControls, st::dialogsLock)
 , _scroll(this)
+, _allowStoriesExpandTimer([=] {
+	_scroll->verticalScrollBar()->setMinimum(0);
+})
 , _scrollToTop(_scroll, st::dialogsToUp)
 , _searchTimer([=] { searchMessages(); })
 , _singleMessageSearch(&controller->session()) {
@@ -319,6 +324,9 @@ Widget::Widget(
 	) | rpl::start_with_next([=] {
 		listScrollUpdated();
 	}, lifetime());
+	_scroll->setCustomWheelProcess([=](not_null<QWheelEvent*> e) {
+		return customWheelProcess(e);
+	});
 
 	session().data().chatsListChanges(
 	) | rpl::filter([=](Data::Folder *folder) {
@@ -1122,6 +1130,9 @@ void Widget::jumpToTop(bool belowPinned) {
 }
 
 void Widget::scrollToDefault(bool verytop) {
+	if (verytop) {
+		_scroll->verticalScrollBar()->setMinimum(0);
+	}
 	_scrollToAnimation.stop();
 	auto scrollTop = _scroll->scrollTop();
 	const auto scrollTo = verytop ? 0 : _inner->defaultScrollTop();
@@ -2365,6 +2376,23 @@ void Widget::completeHashtag(QString tag) {
 	applyFilterUpdate(true);
 }
 
+bool Widget::customWheelProcess(not_null<QWheelEvent*> e) {
+	const auto now = _scroll->scrollTop();
+	const auto def = _inner->defaultScrollTop();
+	const auto bar = _scroll->verticalScrollBar();
+	const auto allow = (def <= 0)
+		|| (now < def)
+		|| (now == def && !_allowStoriesExpandTimer.isActive());
+	if (allow) {
+		_scroll->verticalScrollBar()->setMinimum(0);
+		_allowStoriesExpandTimer.cancel();
+	} else {
+		bar->setMinimum(def);
+		_allowStoriesExpandTimer.callOnce(kWaitTillAllowStoriesExpand);
+	}
+	return false;
+}
+
 void Widget::resizeEvent(QResizeEvent *e) {
 	updateControlsGeometry();
 }
diff --git a/Telegram/SourceFiles/dialogs/dialogs_widget.h b/Telegram/SourceFiles/dialogs/dialogs_widget.h
index 891afef3a..11a9e4648 100644
--- a/Telegram/SourceFiles/dialogs/dialogs_widget.h
+++ b/Telegram/SourceFiles/dialogs/dialogs_widget.h
@@ -136,6 +136,7 @@ private:
 	void cancelSearchInChat();
 	void filterCursorMoved();
 	void completeHashtag(QString tag);
+	bool customWheelProcess(not_null<QWheelEvent*> e);
 
 	[[nodiscard]] QString currentSearchQuery() const;
 	void clearSearchField();
@@ -245,6 +246,7 @@ private:
 	std::unique_ptr<HistoryView::ContactStatus> _forumReportBar;
 
 	object_ptr<Ui::ScrollArea> _scroll;
+	base::Timer _allowStoriesExpandTimer;
 	QPointer<InnerWidget> _inner;
 	class BottomButton;
 	object_ptr<BottomButton> _updateTelegram = { nullptr };
diff --git a/Telegram/lib_ui b/Telegram/lib_ui
index fc8d4d25d..8908c9b5c 160000
--- a/Telegram/lib_ui
+++ b/Telegram/lib_ui
@@ -1 +1 @@
-Subproject commit fc8d4d25dee6e3ded99749c06fd870e6df4615f8
+Subproject commit 8908c9b5c041f51176383a55e0b324588b28b68d