Improve touchscreen chats list stories physics.

Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp

@@ -479,6 +479,10 @@ rpl::producer<bool> InnerWidget::storiesExpandedRequests() const {
 		_storiesExpandedRequests.events());
 }
 
+void InnerWidget::setTouchScrollActive(bool active) {
+	_stories->setTouchScrollActive(active);
+}
+
 int InnerWidget::defaultScrollTop() const {
 	return storiesShown()
 		? std::max(_stories->height() - st::dialogsStories.height, 0)

Telegram/SourceFiles/dialogs/dialogs_inner_widget.h

@@ -104,6 +104,7 @@ public:
 		const QVector<MTPPeer> &my,
 		const QVector<MTPPeer> &result);
 
+	void setTouchScrollActive(bool active);
 	[[nodiscard]] rpl::producer<bool> storiesExpandedRequests() const;
 	[[nodiscard]] int defaultScrollTop() const;
 	void setViewportHeight(int viewportHeight);

Telegram/SourceFiles/dialogs/dialogs_widget.cpp

@@ -327,6 +327,9 @@ Widget::Widget(
 	_scroll->setCustomWheelProcess([=](not_null<QWheelEvent*> e) {
 		return customWheelProcess(e);
 	});
+	_scroll->setCustomTouchProcess([=](not_null<QTouchEvent*> e) {
+		return customTouchProcess(e);
+	});
 
 	session().data().chatsListChanges(
 	) | rpl::filter([=](Data::Folder *folder) {
@@ -856,6 +859,7 @@ void Widget::changeOpenedSubsection(
 		}
 		oldContentCache = grabForFolderSlideAnimation();
 	}
+	_scroll->verticalScrollBar()->setMinimum(0);
 	_showAnimation = nullptr;
 	destroyChildListCanvas();
 	change();
@@ -2394,6 +2398,27 @@ bool Widget::customWheelProcess(not_null<QWheelEvent*> e) {
 	return false;
 }
 
+bool Widget::customTouchProcess(not_null<QTouchEvent*> e) {
+	const auto type = e->type();
+	const auto now = _scroll->scrollTop();
+	const auto def = _inner->defaultScrollTop();
+	const auto bar = _scroll->verticalScrollBar();
+	_allowStoriesExpandTimer.cancel();
+	if (type == QEvent::TouchBegin
+		|| type == QEvent::TouchUpdate) {
+		_inner->setTouchScrollActive(true);
+		bar->setMinimum(0);
+	} else if (type == QEvent::TouchEnd || type == QEvent::TouchCancel) {
+		_inner->setTouchScrollActive(false);
+		if (def > 0 && now >= def) {
+			bar->setMinimum(def);
+		} else {
+			bar->setMinimum(0);
+		}
+	}
+	return false;
+}
+
 void Widget::resizeEvent(QResizeEvent *e) {
 	updateControlsGeometry();
 }

Telegram/SourceFiles/dialogs/dialogs_widget.h

@@ -137,6 +137,7 @@ private:
 	void filterCursorMoved();
 	void completeHashtag(QString tag);
 	bool customWheelProcess(not_null<QWheelEvent*> e);
+	bool customTouchProcess(not_null<QTouchEvent*> e);
 
 	[[nodiscard]] QString currentSearchQuery() const;
 	void clearSearchField();

Telegram/SourceFiles/dialogs/ui/dialogs_stories_list.cpp

@@ -306,7 +306,7 @@ List::Layout List::computeLayout() {
 		_lastHeight = shownHeight;
 		if (_lastHeight == st.height || _lastHeight == full.height) {
 			_snapExpandedTimer.cancel();
-		} else {
+		} else if (!_touchScrollActive) {
 			_snapExpandedTimer.callOnce(kSnapExpandedTimeout);
 		}
 	}
@@ -831,6 +831,17 @@ void List::setBgOverride(QBrush brush) {
 	_bgOverride = std::move(brush);
 }
 
+void List::setTouchScrollActive(bool active) {
+	if (_touchScrollActive != active) {
+		_touchScrollActive = active;
+		if (active) {
+			_snapExpandedTimer.cancel();
+		} else {
+			requestExpanded(_expanded);
+		}
+	}
+}
+
 void List::contextMenuEvent(QContextMenuEvent *e) {
 	_menu = nullptr;
 

Telegram/SourceFiles/dialogs/ui/dialogs_stories_list.h

@@ -69,6 +69,7 @@ public:
 		Fn<int()> shownHeight);
 
 	void setBgOverride(QBrush brush);
+	void setTouchScrollActive(bool active);
 
 	[[nodiscard]] rpl::producer<uint64> clicks() const;
 	[[nodiscard]] rpl::producer<uint64> showProfileRequests() const;
@@ -189,6 +190,7 @@ private:
 	float64 _lastRatio = 0.;
 	int _lastHeight = 0;
 	bool _expanded = false;
+	bool _touchScrollActive = false;
 
 	int _selected = -1;
 	int _pressed = -1;

Telegram/lib_ui

@@ -1 +1 @@
-Subproject commit 8908c9b5c041f51176383a55e0b324588b28b68d
+Subproject commit 6fe9e0838685b0a799057a9218c4beca0cd7c52e