Slider: add wheel support

Change-Id: I413d8c853bfe3cc748584dfebd28172ead89d638
Task-number: QTBUG-50221
Reviewed-by: Mitch Curtis <mitch.curtis@theqtcompany.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/src/templates/qquickslider.cpp b/src/templates/qquickslider.cpp
index 261c1577..395725eb 100644
--- a/src/templates/qquickslider.cpp
+++ b/src/templates/qquickslider.cpp
@@ -565,6 +565,20 @@ void QQuickSlider::mouseUngrabEvent()
     setPressed(false);
 }
 
+void QQuickSlider::wheelEvent(QWheelEvent *event)
+{
+    Q_D(QQuickSlider);
+    QQuickControl::wheelEvent(event);
+    if (d->wheelEnabled) {
+        const qreal oldValue = d->value;
+        const QPointF angle = event->angleDelta();
+        const qreal delta = (qFuzzyIsNull(angle.y()) ? angle.x() : angle.y()) / QWheelEvent::DefaultDeltasPerStep;
+        const qreal step = qFuzzyIsNull(d->stepSize) ? 0.1 : d->stepSize;
+        setValue(oldValue + step * delta);
+        event->setAccepted(!qFuzzyCompare(d->value, oldValue));
+    }
+}
+
 void QQuickSlider::mirrorChange()
 {
     QQuickControl::mirrorChange();
diff --git a/src/templates/qquickslider_p.h b/src/templates/qquickslider_p.h
index b348baa9..a6231d09 100644
--- a/src/templates/qquickslider_p.h
+++ b/src/templates/qquickslider_p.h
@@ -133,6 +133,8 @@ protected:
     void mouseMoveEvent(QMouseEvent *event) override;
     void mouseReleaseEvent(QMouseEvent *event) override;
     void mouseUngrabEvent() override;
+    void wheelEvent(QWheelEvent *event) override;
+
     void mirrorChange() override;
     void componentComplete() override;