1 files changed, 40 insertions, 29 deletions

diff --git a/src/gui/widgets/qabstractslider.cpp b/src/gui/widgets/qabstractslider.cpp
index 2874647b36..73c17dba8e 100644
--- a/src/gui/widgets/qabstractslider.cpp
+++ b/src/gui/widgets/qabstractslider.cpp
@@ -214,8 +214,8 @@ QT_BEGIN_NAMESPACE
 */
 
 QAbstractSliderPrivate::QAbstractSliderPrivate()
-    : minimum(0), maximum(99), singleStep(1), pageStep(10),
-      value(0), position(0), pressValue(-1), offset_accumulated(0), tracking(true),
+    : minimum(0), maximum(99), pageStep(10), value(0), position(0), pressValue(-1),
+      singleStep(1), offset_accumulated(0), tracking(true),
       blocktracking(false), pressed(false),
       invertedAppearance(false), invertedControls(false),
       orientation(Qt::Horizontal), repeatAction(QAbstractSlider::SliderNoAction)
@@ -688,51 +688,62 @@ void QAbstractSlider::sliderChange(SliderChange)
     update();
 }
 
-
-/*!
-    \reimp
-*/
-#ifndef QT_NO_WHEELEVENT
-void QAbstractSlider::wheelEvent(QWheelEvent * e)
+bool QAbstractSliderPrivate::scrollByDelta(Qt::Orientation orientation, Qt::KeyboardModifiers modifiers, int delta)
 {
-    Q_D(QAbstractSlider);
-    e->ignore();
-
+    Q_Q(QAbstractSlider);
     int stepsToScroll = 0;
-    qreal offset = qreal(e->delta()) / 120;
+    // in Qt scrolling to the right gives negative values.
+    if (orientation == Qt::Horizontal)
+        delta = -delta;
+    qreal offset = qreal(delta) / 120;
 
-    if ((e->modifiers() & Qt::ControlModifier) || (e->modifiers() & Qt::ShiftModifier)) {
+    if ((modifiers & Qt::ControlModifier) || (modifiers & Qt::ShiftModifier)) {
         // Scroll one page regardless of delta:
-        stepsToScroll = qBound(-d->pageStep, int(offset * d->pageStep), d->pageStep);
-        d->offset_accumulated = 0;
+        stepsToScroll = qBound(-pageStep, int(offset * pageStep), pageStep);
+        offset_accumulated = 0;
     } else {
         // 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->effectiveSingleStep();
+        qreal stepsToScrollF = offset * QApplication::wheelScrollLines() * effectiveSingleStep();
         // Check if wheel changed direction since last event:
-        if (d->offset_accumulated != 0 && (offset / d->offset_accumulated) < 0)
-            d->offset_accumulated = 0;
+        if (offset_accumulated != 0 && (offset / offset_accumulated) < 0)
+            offset_accumulated = 0;
 
-        d->offset_accumulated += stepsToScrollF;
-        stepsToScroll = qBound(-d->pageStep, int(d->offset_accumulated), d->pageStep);
-        d->offset_accumulated -= int(d->offset_accumulated);
+        offset_accumulated += stepsToScrollF;
+        stepsToScroll = qBound(-pageStep, int(offset_accumulated), pageStep);
+        offset_accumulated -= int(offset_accumulated);
         if (stepsToScroll == 0)
-            return;
+            return false;
     }
 
-    if (d->invertedControls)
+    if (invertedControls)
         stepsToScroll = -stepsToScroll;
 
-    int prevValue = d->value;
-    d->position = d->overflowSafeAdd(stepsToScroll); // value will be updated by triggerAction()
-    triggerAction(SliderMove);
+    int prevValue = value;
+    position = overflowSafeAdd(stepsToScroll); // value will be updated by triggerAction()
+    q->triggerAction(QAbstractSlider::SliderMove);
+
+    if (prevValue == value) {
+        offset_accumulated = 0;
+        return false;
+    }
+    return true;
+}
 
-    if (prevValue == d->value)
-        d->offset_accumulated = 0;
-    else
+/*!
+    \reimp
+*/
+#ifndef QT_NO_WHEELEVENT
+void QAbstractSlider::wheelEvent(QWheelEvent * e)
+{
+    Q_D(QAbstractSlider);
+    e->ignore();
+    int delta = e->delta();
+    if (d->scrollByDelta(e->orientation(), e->modifiers(), delta))
         e->accept();
 }
+
 #endif
 #ifdef QT_KEYPAD_NAVIGATION
 /*!