From fb1716c91f80baf482a51b86a9a92cb1df2819b0 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Tue, 12 Mar 2024 17:05:17 +0400
Subject: [PATCH] Add fast Ctrl/Shift scroll to ElasticScroll.

---
 ui/widgets/elastic_scroll.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/ui/widgets/elastic_scroll.cpp b/ui/widgets/elastic_scroll.cpp
index 506b200..ec5c2a0 100644
--- a/ui/widgets/elastic_scroll.cpp
+++ b/ui/widgets/elastic_scroll.cpp
@@ -660,7 +660,14 @@ bool ElasticScroll::handleWheelEvent(not_null<QWheelEvent*> e, bool touch) {
 	const auto guard = gsl::finally([&] {
 		_lastScroll = now;
 	});
-	const auto pixels = ScrollDelta(e, touch);
+	const auto unmultiplied = ScrollDelta(e, touch);
+	const auto multiply = e->modifiers()
+		& (Qt::ControlModifier | Qt::ShiftModifier);
+	const auto pixels = multiply
+		? QPoint(
+			(unmultiplied.x() * std::max(width(), 120) / 120.),
+			(unmultiplied.y() * std::max(height(), 120) / 120.))
+		: unmultiplied;
 	auto delta = _vertical ? -pixels.y() : pixels.x();
 	if (std::abs(_vertical ? pixels.x() : pixels.y()) >= std::abs(delta)) {
 		delta = 0;
@@ -1030,7 +1037,7 @@ void ElasticScroll::sendWheelEvent(Qt::ScrollPhase phase, QPoint delta) {
 		delta,
 		delta,
 		Qt::NoButton,
-		QGuiApplication::keyboardModifiers(),
+		Qt::KeyboardModifiers(), // Ignore Ctrl/Shift fast scroll on touch.
 		phase,
 		false,
 		Qt::MouseEventSynthesizedByApplication);