void QtViewportInteractionEngine::wheelEvent(QWheelEvent* ev)
{
if (scrollAnimationActive() || scaleAnimationActive() || pinchGestureActive())
return; // Ignore.
// A normal scroll-tick should have a delta of 120 (1/8) degrees. Convert this to
// local standard scroll step of 3 lines of 20 pixels.
static const int cDefaultQtScrollStep = 20;
static const int wheelScrollLines = 3;
const int wheelTick = wheelScrollLines * cDefaultQtScrollStep;
int pixelDelta = ev->delta() * (wheelTick / 120.f);
QPointF newPosition = m_viewport->contentPos();
if (ev->orientation() == Qt::Horizontal)
newPosition.rx() -= pixelDelta;
else
newPosition.ry() -= pixelDelta;
QRectF endPosRange = computePosRangeForItemAtScale(m_content->contentsScale());
QPointF currentPosition = m_viewport->contentPos();
newPosition = boundPosition(endPosRange.topLeft(), newPosition, endPosRange.bottomRight());
m_viewport->setContentPos(newPosition);
emit contentViewportChanged(currentPosition - newPosition);
}
void QtViewportInteractionEngine::wheelEvent(QWheelEvent* ev)
{
if (scrollAnimationActive() || scaleAnimationActive() || pinchGestureActive())
return; // Ignore.
int delta = ev->delta();
// A delta that is not mod 120 indicates a device that is sending
// fine-resolution scroll events, so use the delta as number of wheel ticks
// and number of pixels to scroll. See also webkit.org/b/29601
bool fullTick = !(delta % 120);
static const int cDefaultQtScrollStep = 20;
static const int wheelScrollLines = 3;
int scrollLines = (fullTick) ? wheelScrollLines * cDefaultQtScrollStep : 1;
delta = (fullTick) ? delta / 120.0f : delta;
delta *= scrollLines;
QPointF newPosition = m_viewport->contentPos();
if (ev->orientation() == Qt::Horizontal)
newPosition.rx() += delta;
else
newPosition.ry() += delta;
QRectF endPosRange = computePosRangeForItemAtScale(m_content->contentsScale());
QPointF currentPosition = m_viewport->contentPos();
newPosition = boundPosition(endPosRange.topLeft(), newPosition, endPosRange.bottomRight());
m_viewport->setContentPos(newPosition);
emit contentViewportChanged(currentPosition - newPosition);
}
