Disable combobox scroll hijacking, and only show one event by default (rather than all)

noscrollcombobox.cpp

@@ -0,0 +1,15 @@
+#include "noscrollcombobox.h"
+
+NoScrollComboBox::NoScrollComboBox(QWidget *parent)
+    : QComboBox(parent)
+{
+    // Don't let scrolling hijack focus.
+    setFocusPolicy(Qt::StrongFocus);
+}
+
+void NoScrollComboBox::wheelEvent(QWheelEvent *event)
+{
+    // Only allow scrolling to modify contents when it explicitly has focus.
+    if (hasFocus())
+        QComboBox::wheelEvent(event);
+}