Disable certain mouse wheel events in Options dialog

The mouse wheel events for QComboBox & QSpinBox widgets in Options
dialog are filtered out.

src/gui/advancedsettings.cpp

@@ -485,10 +485,6 @@ void AdvancedSettings::loadAdvancedSettings()
 template <typename T>
 void AdvancedSettings::addRow(int row, const QString &rowText, T* widget)
 {
-    // ignore mouse wheel event
-    static WheelEventEater filter;
-    widget->installEventFilter(&filter);
-
     setItem(row, PROPERTY, new QTableWidgetItem(rowText));
     setCellWidget(row, VALUE, widget);
 

src/gui/advancedsettings.h

@@ -31,28 +31,11 @@
 
 #include <QCheckBox>
 #include <QComboBox>
-#include <QEvent>
 #include <QLabel>
 #include <QLineEdit>
 #include <QSpinBox>
 #include <QTableWidget>
 
-class WheelEventEater: public QObject
-{
-    Q_OBJECT
-
-private:
-    bool eventFilter(QObject *obj, QEvent *event)
-    {
-        switch (event->type()) {
-        case QEvent::Wheel:
-            return true;
-        default:
-            return QObject::eventFilter(obj, event);
-        }
-    }
-};
-
 class AdvancedSettings: public QTableWidget
 {
     Q_OBJECT

src/gui/optionsdlg.cpp

@@ -38,6 +38,7 @@
 #include <QDesktopServices>
 #include <QDesktopWidget>
 #include <QDialogButtonBox>
+#include <QEvent>
 #include <QFileDialog>
 #include <QMessageBox>
 #include <QSystemTrayIcon>
@@ -50,6 +51,7 @@
 
 #include "app/application.h"
 #include "base/bittorrent/session.h"
+#include "base/global.h"
 #include "base/net/dnsupdater.h"
 #include "base/net/portforwarder.h"
 #include "base/net/proxyconfigurationmanager.h"
@@ -72,6 +74,18 @@
 
 #include "ui_optionsdlg.h"
 
+class WheelEventEater : public QObject
+{
+public:
+    using QObject::QObject;
+
+private:
+    bool eventFilter(QObject *, QEvent *event) override
+    {
+        return (event->type() == QEvent::Wheel);
+    }
+};
+
 // Constructor
 OptionsDialog::OptionsDialog(QWidget *parent)
     : QDialog(parent)
@@ -425,6 +439,13 @@ OptionsDialog::OptionsDialog(QWidget *parent)
     m_ui->textTempPath->setDialogCaption(tr("Choose a save directory"));
     m_ui->textTempPath->setMode(FileSystemPathEdit::Mode::DirectorySave);
 
+    // disable mouse wheel event on widgets to avoid mis-selection
+    WheelEventEater *wheelEventEater = new WheelEventEater(this);
+    for (QComboBox *widget : copyAsConst(findChildren<QComboBox *>()))
+        widget->installEventFilter(wheelEventEater);
+    for (QSpinBox *widget : copyAsConst(findChildren<QSpinBox *>()))
+        widget->installEventFilter(wheelEventEater);
+
     loadWindowState();
     show();
     // Have to be called after show(), because splitter width needed