Fix spin box with fine grained wheel events

Only step the value in the spin box when we have accumulated one wheel
tick worth of wheel delta.

Also fixes the obsolete contructors of QWheelEvent so they set the non
obsolete properties.

Change-Id: Ic6ea4b37afa8eec85a6ca7bdc0d919bf8fb02608
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

src/gui/kernel/qevent.cpp

@@ -642,6 +642,10 @@ QWheelEvent::QWheelEvent(const QPointF &pos, int delta,
     : QInputEvent(Wheel, modifiers), p(pos), qt4D(delta), qt4O(orient), mouseState(buttons)
 {
     g = QCursor::pos();
+    if (orient == Qt::Vertical)
+        angleD = QPoint(0, delta);
+    else
+        angleD = QPoint(delta, 0);
 }
 
 /*!
@@ -670,7 +674,12 @@ QWheelEvent::QWheelEvent(const QPointF &pos, const QPointF& globalPos, int delta
                          Qt::MouseButtons buttons, Qt::KeyboardModifiers modifiers,
                          Qt::Orientation orient)
     : QInputEvent(Wheel, modifiers), p(pos), g(globalPos), qt4D(delta), qt4O(orient), mouseState(buttons)
-{}
+{
+    if (orient == Qt::Vertical)
+        angleD = QPoint(0, delta);
+    else
+        angleD = QPoint(delta, 0);
+}
 
 /*!
     Constructs a wheel event object.

src/widgets/widgets/qabstractspinbox.cpp

@@ -1100,7 +1100,10 @@ void QAbstractSpinBox::keyReleaseEvent(QKeyEvent *event)
 #ifndef QT_NO_WHEELEVENT
 void QAbstractSpinBox::wheelEvent(QWheelEvent *event)
 {
-    const int steps = (event->delta() > 0 ? 1 : -1);
+    Q_D(QAbstractSpinBox);
+    d->wheelDeltaRemainder += event->angleDelta().y();
+    const int steps = d->wheelDeltaRemainder / 120;
+    d->wheelDeltaRemainder -= steps * 120;
     if (stepEnabled() & (steps > 0 ? StepUpEnabled : StepDownEnabled))
         stepBy(event->modifiers() & Qt::ControlModifier ? steps * 10 : steps);
     event->accept();
@@ -1344,7 +1347,7 @@ QAbstractSpinBoxPrivate::QAbstractSpinBoxPrivate()
       ignoreCursorPositionChanged(false), frame(true), accelerate(false), keyboardTracking(true),
       cleared(false), ignoreUpdateEdit(false), correctionMode(QAbstractSpinBox::CorrectToPreviousValue),
       acceleration(0), hoverControl(QStyle::SC_None), buttonSymbols(QAbstractSpinBox::UpDownArrows), validator(0),
-      showGroupSeparator(0)
+      showGroupSeparator(0), wheelDeltaRemainder(0)
 {
 }
 

src/widgets/widgets/qabstractspinbox_p.h

@@ -151,6 +151,7 @@ public:
     QAbstractSpinBox::ButtonSymbols buttonSymbols;
     QSpinBoxValidator *validator;
     uint showGroupSeparator : 1;
+    int wheelDeltaRemainder;
 };
 
 class QSpinBoxValidator : public QValidator

tests/auto/widgets/widgets/qspinbox/tst_qspinbox.cpp

@@ -82,6 +82,12 @@ public:
     {
         return QSpinBox::valueFromText(text);
     }
+#ifndef QT_NO_WHEELEVENT
+    void wheelEvent(QWheelEvent *event)
+    {
+        QSpinBox::wheelEvent(event);
+    }
+#endif
 
     QLineEdit *lineEdit() const { return QSpinBox::lineEdit(); }
 };
@@ -148,6 +154,8 @@ private slots:
     void setGroupSeparatorShown_data();
     void setGroupSeparatorShown();
 
+    void wheelEvents();
+
 public slots:
     void valueChangedHelper(const QString &);
     void valueChangedHelper(int);
@@ -1190,5 +1198,29 @@ void tst_QSpinBox::setGroupSeparatorShown()
     QCOMPARE(spinBox.value()+1000, 33000);
 }
 
+void tst_QSpinBox::wheelEvents()
+{
+#ifndef QT_NO_WHEELEVENT
+    SpinBox spinBox;
+    spinBox.setRange(-20, 20);
+    spinBox.setValue(0);
+
+    QWheelEvent wheelUp(QPointF(), QPointF(), QPoint(), QPoint(0, 120), 120, Qt::Vertical, Qt::NoButton, Qt::NoModifier);
+    spinBox.wheelEvent(&wheelUp);
+    QCOMPARE(spinBox.value(), 1);
+
+    QWheelEvent wheelDown(QPointF(), QPointF(), QPoint(), QPoint(0, -120), -120, Qt::Vertical, Qt::NoButton, Qt::NoModifier);
+    spinBox.wheelEvent(&wheelDown);
+    spinBox.wheelEvent(&wheelDown);
+    QCOMPARE(spinBox.value(), -1);
+
+    QWheelEvent wheelHalfUp(QPointF(), QPointF(), QPoint(), QPoint(0, 60), 60,  Qt::Vertical, Qt::NoButton, Qt::NoModifier);
+    spinBox.wheelEvent(&wheelHalfUp);
+    QCOMPARE(spinBox.value(), -1);
+    spinBox.wheelEvent(&wheelHalfUp);
+    QCOMPARE(spinBox.value(), 0);
+#endif
+}
+
 QTEST_MAIN(tst_QSpinBox)
 #include "tst_qspinbox.moc"