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authorRichard Moe Gustavsen <richard.gustavsen@nokia.com>2009-10-27 08:14:28 (GMT)
committerRichard Moe Gustavsen <richard.gustavsen@nokia.com>2009-10-27 09:25:49 (GMT)
commit0fd6390800969d174dba819c54c4183a99e8f83c (patch)
tree79e6d0a1d2beb61d0afa988607db018f92447503 /src/gui/widgets/qabstractslider.cpp
parent5a4909d9f87b9abf471908a085c0e9f31b7e0a50 (diff)
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Implement support for wheel delta with finer resolution than 15 deg.
At the moment, Qt, in many places, does not really understand that a mouse wheel, or touch pad, might operate on a much higher granularity than 15 degrees (that is, a delta of 120). This is clear disadvantage on mac, since the mighty mouse, and track pad, got a resolution that is close to 1 degree. This is called pixel scrolling. This patch first and formost changes the implementation of QAbstractSlider::wheelEvent to _really_ understand what to do when delta is less than 120. Rather than accumulate delta until 120 is reached, then scroll with a value equal to: offset * step * QApplication::wheelScrollLines (default = 3), we multiply offset directly, before waiting for 120. This means that event tough offset is below 120, multiplying it with wheelScrollLines and step will very often give a value over 120, menaing we can scroll much earlier and _much more_ fined grained. This also fixes some auto tests that was ifdeffed out because of specialised mac code written inside this function from before. (NB: we still plan to introduce a new event for pixel scrolling, perhaps for Qt-4.7) Rev-By: Andreas Rev-By: denis
Diffstat (limited to 'src/gui/widgets/qabstractslider.cpp')
-rw-r--r--src/gui/widgets/qabstractslider.cpp44
1 files changed, 20 insertions, 24 deletions
diff --git a/src/gui/widgets/qabstractslider.cpp b/src/gui/widgets/qabstractslider.cpp
index 588a48e..fec9fab 100644
--- a/src/gui/widgets/qabstractslider.cpp
+++ b/src/gui/widgets/qabstractslider.cpp
@@ -693,29 +693,27 @@ void QAbstractSlider::wheelEvent(QWheelEvent * e)
if (e->orientation() != d->orientation && !rect().contains(e->pos()))
return;
- qreal currentOffset = qreal(e->delta()) / 120;
- d->offset_accumulated += currentOffset;
- if (int(d->offset_accumulated) == 0) {
- // QAbstractSlider works on integer values. So if the accumulated
- // offset is less than +/- 1, we need to wait until we get more
- // wheel events (this means that the wheel resolution is higher than
- // 15 degrees, e.g. when using mac mighty mouse/trackpad):
- return;
- }
+ int stepsToScroll = 0;
+ qreal offset = qreal(e->delta()) / 120;
- int stepsToScroll;
if ((e->modifiers() & Qt::ControlModifier) || (e->modifiers() & Qt::ShiftModifier)) {
- stepsToScroll = currentOffset > 0 ? d->pageStep : -d->pageStep;
+ // Scroll one page regardless of delta:
+ stepsToScroll = qBound(-d->pageStep, int(offset * d->pageStep), d->pageStep);
+ d->offset_accumulated = 0;
} else {
- // Calculate the number of steps to scroll (per 15 degrees of rotate):
-#ifdef Q_OS_MAC
- // On mac, since mouse wheel scrolling is accelerated and
- // fine tuned by the OS, we skip applying acceleration:
- stepsToScroll = int(d->offset_accumulated);
-#else
- stepsToScroll = int(d->offset_accumulated) * QApplication::wheelScrollLines() * d->singleStep;
-#endif
- stepsToScroll = qBound(-d->pageStep, stepsToScroll, d->pageStep);
+ // Calculate how many lines to scroll. Depending on what delta is (and
+ // offset), we might end up with a fraction (e.g. scroll 1.3 lines). We can
+ // only scroll whole lines, so we keep the reminder until next event.
+ qreal stepsToScrollF = offset * QApplication::wheelScrollLines() * d->singleStep;
+ // Check if wheel changed direction since last event:
+ if (d->offset_accumulated != 0 && (offset / d->offset_accumulated) < 0)
+ d->offset_accumulated = 0;
+
+ d->offset_accumulated += stepsToScrollF;
+ stepsToScroll = qBound(-d->pageStep, int(d->offset_accumulated), d->pageStep);
+ d->offset_accumulated -= int(d->offset_accumulated);
+ if (stepsToScroll == 0)
+ return;
}
if (d->invertedControls)
@@ -725,12 +723,10 @@ void QAbstractSlider::wheelEvent(QWheelEvent * e)
d->position = d->overflowSafeAdd(stepsToScroll); // value will be updated by triggerAction()
triggerAction(SliderMove);
- if (prevValue == d->value) {
+ if (prevValue == d->value)
d->offset_accumulated = 0;
- } else {
- d->offset_accumulated -= int(d->offset_accumulated);
+ else
e->accept();
- }
}
#endif
#ifdef QT_KEYPAD_NAVIGATION