From bc31679267b0d478f95884cbbc47f5bd9b14c7cc Mon Sep 17 00:00:00 2001
From: Deception666 <29422981+Deception666@users.noreply.github.com>
Date: Mon, 13 Jul 2026 23:45:14 -0500
Subject: [PATCH] Make Auto Hide Side Bar React Correctly To Scroll Events

- the scroll wheel operation only worked between the tabbed buttons and
  not when the mouse was on the auto hide tab button.  since the auto
  hide side bar already had event filters applied to the auto hide tab
  buttons, a filtered event of the mouse wheel is redirected to be
  handled by the auto hide side bar class itself.

- the auto hide side bar class now handles the wheel event to correctly
  handle the direction the auto scroll should take.  previously, when
  the scroll operation was performed on a vertical auto hide side bar,
  the scroll operation with no keyboard modifiers would scroll
  vertically as expected.  when a scroll operation was performed on a
  horizontal auto hide side bar, the scroll operation would still move
  the viewport vertically.  this change now detects the orientation of
  the auto hide side bar to correctly apply the mouse wheel operation.

- the alt key will no longer have any effect.  when the alt key was held
  during the scroll operation, the opposite scroll operation was
  performed.  if alt is detected, the x and y angle deltas are just
  swapped to perform the correct scroll operation.

- validated the following combinations:
  * Windows 11 Qt6 x86_64
  * Windows 11 Qt5 x86_64
  * Kubuntu 25.10 Qt6 Wayland x86_64
---
 src/AutoHideSideBar.cpp | 43 +++++++++++++++++++++++++++++++++++++++++
 src/AutoHideSideBar.h   | 10 ++++++++++
 2 files changed, 53 insertions(+)

diff --git a/src/AutoHideSideBar.cpp b/src/AutoHideSideBar.cpp
index 7dea2fe3e..7e32b46be 100644
--- a/src/AutoHideSideBar.cpp
+++ b/src/AutoHideSideBar.cpp
@@ -34,6 +34,7 @@
 #include <QStyleOption>
 #include <QPainter>
 #include <QXmlStreamWriter>
+#include <QWheelEvent>
 
 #include "DockContainerWidget.h"
 #include "DockWidgetTab.h"
@@ -300,6 +301,13 @@ bool CAutoHideSideBar::eventFilter(QObject *watched, QEvent *event)
 		 }
 		 break;
 
+#if QT_CONFIG(wheelevent)
+	case QEvent::Wheel:
+		// the button received the event so pass to the scroll area
+		wheelEvent(static_cast<QWheelEvent*>(event));
+		break;
+#endif
+
 	default:
 		break;
 	}
@@ -433,6 +441,41 @@ QSize CAutoHideSideBar::sizeHint() const
 }
 
 
+//===========================================================================
+#if QT_CONFIG(wheelevent)
+void CAutoHideSideBar::wheelEvent(QWheelEvent* e)
+{
+	QPoint AngleDelta = e->angleDelta();
+
+	// completely ignore the effects if the alt key is being held
+	// if alt is held on a vertical scroll area, cancel the applied horizontal scroll by forcing a vertical scroll
+	// if alt is held on a horizontal scroll area, cancel the applied vertical scroll by forcing a horizontal scroll
+	if (!d->isHorizontal() && (e->modifiers() & Qt::KeyboardModifier::AltModifier) ||
+		 d->isHorizontal() && (~e->modifiers() & Qt::KeyboardModifier::AltModifier))
+	{
+		AngleDelta = e->angleDelta().transposed();
+	}
+
+	QWheelEvent WheelEvent {
+		e->position(),
+		e->globalPosition(),
+		e->pixelDelta(),
+		AngleDelta,
+		e->buttons(),
+		e->modifiers(),
+		e->phase(),
+		e->inverted(),
+		e->source()
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+		,e->pointingDevice()
+#endif
+	};
+
+	Super::wheelEvent(&WheelEvent);
+}
+#endif
+
+
 //===========================================================================
 int CAutoHideSideBar::spacing() const
 {
diff --git a/src/AutoHideSideBar.h b/src/AutoHideSideBar.h
index 350568253..f10aa20d1 100644
--- a/src/AutoHideSideBar.h
+++ b/src/AutoHideSideBar.h
@@ -185,6 +185,16 @@ class ADS_EXPORT CAutoHideSideBar : public QScrollArea
 	 */
 	virtual QSize sizeHint() const override;
 
+#if QT_CONFIG(wheelevent)
+	/**
+	 * This function handles scroll wheel events and will ignore the
+	 * alt key modifier if applied by the user to make sure vertical
+	 * auto-hide side bars will always scroll vertically and that
+	 * horizontal ones will always scroll horizontally.
+	 */
+	virtual void wheelEvent(QWheelEvent* e) override;
+#endif
+
 	/**
 	 * Getter for spacing property - returns the spacing of the tabs
 	 */