- const int numSteps = numDegrees / 15;
- smoothScroller->scrollTo(scrollBar->value() - numSteps * scrollBar->pageStep() / 4);
+ const int numSteps = qApp->wheelScrollLines() * numDegrees / 15;
+ if (event->modifiers().testFlag(Qt::ShiftModifier)) {
+ const int scrollingDirection = numSteps > 0 ? 1 : -1;
+ smoothScroller->scrollTo(scrollBar->value() - scrollBar->pageStep() * scrollingDirection);
+ } else {
+ smoothScroller->scrollTo(scrollBar->value() - numSteps * scrollBar->pageStep() / 12);
+ }