Change volume by wheel events on volume icon.

Telegram/SourceFiles/media/player/media_player_volume_controller.cpp

@@ -57,6 +57,10 @@ void VolumeController::setIsVertical(bool vertical) {
 	_slider->setAlwaysDisplayMarker(vertical);
 }
 
+void VolumeController::outerWheelEvent(not_null<QWheelEvent*> e) {
+	QGuiApplication::sendEvent(_slider.data(), e);
+}
+
 void VolumeController::resizeEvent(QResizeEvent *e) {
 	_slider->setGeometry(rect());
 }
@@ -78,7 +82,8 @@ void VolumeController::applyVolumeChange(float64 volume) {
 
 void PrepareVolumeDropdown(
 		not_null<Dropdown*> dropdown,
-		not_null<Window::SessionController*> controller) {
+		not_null<Window::SessionController*> controller,
+		rpl::producer<not_null<QWheelEvent*>> outerWheelEvents) {
 	const auto volume = Ui::CreateChild<VolumeController>(
 		dropdown.get(),
 		controller);
@@ -98,6 +103,12 @@ void PrepareVolumeDropdown(
 				- ((st::mediaPlayerVolumeSize.width()
 					- st::mediaPlayerPanelPlayback.width) / 2)));
 	}, volume->lifetime());
+
+	std::move(
+		outerWheelEvents
+	) | rpl::start_with_next([=](not_null<QWheelEvent*> e) {
+		volume->outerWheelEvent(e);
+	}, volume->lifetime());
 }
 
 } // namespace Media::Player

Telegram/SourceFiles/media/player/media_player_volume_controller.h

@@ -10,6 +10,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/rp_widget.h"
 #include "base/object_ptr.h"
 
+class QWheelEvent;
+
 namespace Ui {
 class MediaSlider;
 } // namespace Ui
@@ -29,6 +31,7 @@ public:
 		not_null<Window::SessionController*> controller);
 
 	void setIsVertical(bool vertical);
+	void outerWheelEvent(not_null<QWheelEvent*> e);
 
 protected:
 	void resizeEvent(QResizeEvent *e) override;
@@ -43,6 +46,7 @@ private:
 
 void PrepareVolumeDropdown(
 	not_null<Dropdown*> dropdown,
-	not_null<Window::SessionController*> controller);
+	not_null<Window::SessionController*> controller,
+	rpl::producer<not_null<QWheelEvent*>> outerWheelEvents);
 
 } // namespace Media::Player

Telegram/SourceFiles/media/player/media_player_widget.cpp

@@ -515,7 +515,12 @@ Widget::Widget(
 		handleSongUpdate(state);
 	}, lifetime());
 
-	PrepareVolumeDropdown(_volume.get(), controller);
+	PrepareVolumeDropdown(_volume.get(), controller, _volumeToggle->events(
+	) | rpl::filter([=](not_null<QEvent*> e) {
+		return (e->type() == QEvent::Wheel);
+	}) | rpl::map([=](not_null<QEvent*> e) {
+		return not_null{ static_cast<QWheelEvent*>(e.get()) };
+	}));
 	_volumeToggle->installEventFilter(_volume.get());
 	_volume->events(
 	) | rpl::start_with_next([=](not_null<QEvent*> e) {