QScrollBar: clean up wheelEvent() implementation

This code was moved from the general event() handler.
Remove comments and casting that were necessary there.

Task-number: QTBUG-27308
Reported-by: chenjiexin
Task-number: QTBUG-21534
Reported-by: Martin Koller
Change-Id: I14ef4c6363002032895f6840a7c68c1f5f665384
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

1 files changed, 12 insertions, 14 deletions

diff --git a/src/widgets/widgets/qscrollbar.cpp b/src/widgets/widgets/qscrollbar.cpp
index 9ef56b7f95..aa45b4f54e 100644
--- a/src/widgets/widgets/qscrollbar.cpp
+++ b/src/widgets/widgets/qscrollbar.cpp
@@ -488,20 +488,18 @@ bool QScrollBar::event(QEvent *event)
 #ifndef QT_NO_WHEELEVENT
 void QScrollBar::wheelEvent(QWheelEvent *event)
 {
-        event->ignore();
-        // override wheel event without adding virtual function override
-        QWheelEvent *ev = static_cast<QWheelEvent *>(event);
-        int delta = ev->delta();
-        // scrollbar is a special case - in vertical mode it reaches minimum
-        // value in the upper position, however QSlider's minimum value is on
-        // the bottom. So we need to invert a value, but since the scrollbar is
-        // inverted by default, we need to inverse the delta value for the
-        // horizontal orientation.
-        if (ev->orientation() == Qt::Horizontal)
-            delta = -delta;
-        Q_D(QScrollBar);
-        if (d->scrollByDelta(ev->orientation(), ev->modifiers(), delta))
-            event->accept();
+    event->ignore();
+    int delta = event->delta();
+    // scrollbar is a special case - in vertical mode it reaches minimum
+    // value in the upper position, however QSlider's minimum value is on
+    // the bottom. So we need to invert a value, but since the scrollbar is
+    // inverted by default, we need to inverse the delta value for the
+    // horizontal orientation.
+    if (event->orientation() == Qt::Horizontal)
+        delta = -delta;
+    Q_D(QScrollBar);
+    if (d->scrollByDelta(event->orientation(), event->modifiers(), delta))
+        event->accept();
 }
 #endif