Ignore horizontal wheel scrolling in workarea

We do not know what to do with horizontal scrolling events, so we ignore them.

Note that the code has to be different between Qt4 and Qt5.

Fixes bug #11257.

diff --git a/src/frontends/qt4/GuiWorkArea.cpp b/src/frontends/qt4/GuiWorkArea.cpp
index 45c4469e61e13e7d0bce1872ddbdae53feddbbd9..2df9342c5a5823d0917c6d06c3a071f7ca2f675d 100644 (file)
--- a/src/frontends/qt4/GuiWorkArea.cpp
+++ b/src/frontends/qt4/GuiWorkArea.cpp
@@ -900,7 +900,23 @@ void GuiWorkArea::wheelEvent(QWheelEvent * ev)
 {
        // Wheel rotation by one notch results in a delta() of 120 (see
        // documentation of QWheelEvent)
+       // But first we have to ignore horizontal scroll events.
+#if QT_VERSION < 0x050000
+       if (ev->orientation() == Qt::Horizontal) {
+               ev->accept();
+               return;
+       }
        double const delta = ev->delta() / 120.0;
+#else
+       QPoint const aDelta = ev->angleDelta();
+       // skip horizontal wheel event
+       if (abs(aDelta.x()) > abs(aDelta.y())) {
+               ev->accept();
+               return;
+       }
+       double const delta = aDelta.y() / 120.0;
+#endif
+
        bool zoom = false;
        switch (lyxrc.scroll_wheel_zoom) {
        case LyXRC::SCROLL_WHEEL_ZOOM_CTRL: