case QEvent::Wheel:
handleWheelEvent(static_cast<QWheelEvent*>(event));
- break;
+ return true; // eat event so that QScrollBar does not scroll one step more by itself
default:
break;
void KItemListSmoothScroller::handleWheelEvent(QWheelEvent* event)
{
- const int numDegrees = event->delta() / 8;
- const int numSteps = numDegrees / 15;
-
const bool previous = m_smoothScrolling;
m_smoothScrolling = true;
- const int value = m_scrollBar->value();
- const int pageStep = m_scrollBar->pageStep();
- m_scrollBar->setValue(value - numSteps * pageStep);
+ int numPixels;
+ if (!event->pixelDelta().isNull()) {
+ numPixels = event->pixelDelta().y();
+ } else {
+ const int numDegrees = event->angleDelta().y() / 8;
+ const int numSteps = numDegrees / 15;
+ numPixels = numSteps * m_scrollBar->pageStep() / 4;
+ }
+ int value = m_scrollBar->value();
+ if (event->modifiers().testFlag(Qt::ShiftModifier)) {
+ const int scrollingDirection = numPixels > 0 ? 1 : -1;
+ value -= m_scrollBar->pageStep() * scrollingDirection;
+ } else {
+ value -= numPixels;
+ }
+ m_scrollBar->setValue(value);
m_smoothScrolling = previous;