added overshoot resistance

3 files changed, 28 insertions, 5 deletions

diff --git a/qkineticscroller.cpp b/qkineticscroller.cpp
index 005abb8..46d1bc8 100644
--- a/qkineticscroller.cpp
+++ b/qkineticscroller.cpp
@@ -172,6 +172,7 @@ void QKineticScroller::resetScrollMetrics()
     metrics.insert(DragVelocitySmoothingFactor, qreal(0.15));
     metrics.insert(FrictionCoefficent, qreal(0.85));
     metrics.insert(OvershootSpringConstant, qreal(0.1));
+    metrics.insert(OvershootDragResistanceFactor, qreal(1));
     metrics.insert(OvershootMaximumDistance, QPointF(qreal(150), qreal(150)));
     metrics.insert(OvershootMaximumVelocity, qreal(2600));
     metrics.insert(DragStartDistance, qreal(25));
@@ -188,8 +189,9 @@ void QKineticScroller::resetScrollMetrics()
 #else
     metrics.insert(DragVelocitySmoothingFactor, qreal(0.02));
     metrics.insert(FrictionCoefficent, qreal(0.05));
-    metrics.insert(OvershootSpringConstant, qreal(2.0));
-    metrics.insert(OvershootMaximumDistance, QPointF(qreal(14.25 / 1000), qreal(14.25 / 1000)));
+    metrics.insert(OvershootSpringConstant, qreal(15.0));
+    metrics.insert(OvershootDragResistanceFactor, qreal(0.5));
+    metrics.insert(OvershootMaximumDistance, QPointF(0,0)); // QPointF(qreal(14.25 / 1000), qreal(14.25 / 1000)));
     metrics.insert(OvershootMaximumVelocity, qreal(247.0 / 1000));
     metrics.insert(DragStartDistance, qreal(2.5 / 1000));
     metrics.insert(DragStartDirectionErrorMargin, qreal(1.0 / 1000));
@@ -268,7 +270,7 @@ void QKineticScrollerPrivate::timerEvent(QTimerEvent *e)
             return;
         }
     }
- 
+
     if (timerId) {
         qWarning() << "Unhandled timer event, while in state " << stateName(state);
         killTimer(timerId);
@@ -361,6 +363,7 @@ QVariant QKineticScroller::scrollMetric(ScrollMetric metric) const
     case DragVelocitySmoothingFactor:   return d->dragVelocitySmoothingFactor;
     case FrictionCoefficent:            return d->frictionCoefficent;
     case OvershootSpringConstant:       return d->overshootSpringConstant;
+    case OvershootDragResistanceFactor: return d->overshootDragResistanceFactor;
     case OvershootMaximumDistance:      return d->overshootMaximumDistance;
     case DragStartDistance:             return d->dragStartDistance;
     case DragStartDirectionErrorMargin: return d->dragStartDirectionErrorMargin;
@@ -388,6 +391,7 @@ void QKineticScroller::setScrollMetric(ScrollMetric metric, const QVariant &valu
     case DragVelocitySmoothingFactor:   d->dragVelocitySmoothingFactor = qBound(qreal(0), value.toReal(), qreal(1)); break;
     case FrictionCoefficent:            d->frictionCoefficent = qBound(qreal(0), value.toReal(), qreal(1)); break;
     case OvershootSpringConstant:       d->overshootSpringConstant = value.toReal(); break;
+    case OvershootDragResistanceFactor: d->overshootDragResistanceFactor = value.toReal(); break;
     case OvershootMaximumDistance:      d->overshootMaximumDistance = value.toPointF(); break;
     case DragStartDistance:             d->dragStartDistance = value.toReal(); break;
     case DragStartDirectionErrorMargin: d->dragStartDirectionErrorMargin = value.toReal(); break;
@@ -704,7 +708,7 @@ void QKineticScrollerPrivate::timerEventWhileScrolling(qint64 time)
     // -- move (convert from [m/s] to [pix/frame]
     setContentPositionHelper(q->contentPosition() + overshootDistance + velocity * qreal(time) / 1000 * pixelPerMeter);
 
-   
+
     // --- (de)accelerate overshooting axis using spring constant or friction
     // actually we would need to calculate a root and not just divide
     qreal forcePerFrame = overshootSpringConstant * qreal(time) / 1000;
@@ -773,6 +777,15 @@ void QKineticScrollerPrivate::setState(QKineticScroller::State newstate)
 
     qWarning() << "Switching to state " << stateName(newstate);
 
+    switch (state) {
+    case QKineticScroller::StateDragging:
+        overshootDistance *= overshootDragResistanceFactor;
+        break;
+    default:
+        break;
+    }
+
+
     switch (newstate) {
     case QKineticScroller::StateInactive:
         if (state == QKineticScroller::StateScrolling) {
@@ -936,7 +949,15 @@ void QKineticScrollerPrivate::setContentPositionHelper(const QPointF &pos)
     }
 
     qKSDebug() << "setPosition raw: " << pos << ", clamped: " << clampedPos << ", overshoot: " << overshootDistance;
-    q->setContentPosition(clampedPos, overshootPolicy == QKineticScroller::OvershootAlwaysOff ? QPointF() : overshootDistance);
+
+    QPointF realOvershootDistance;
+    if (overshootPolicy != QKineticScroller::OvershootAlwaysOff) {
+        realOvershootDistance = overshootDistance;
+        if (state == QKineticScroller::StateDragging)
+            realOvershootDistance *= overshootDragResistanceFactor;
+    }
+
+    q->setContentPosition(clampedPos, realOvershootDistance);
 }
 
 
diff --git a/qkineticscroller.h b/qkineticscroller.h
index 8e9336c..3429d79 100644
--- a/qkineticscroller.h
+++ b/qkineticscroller.h
@@ -89,6 +89,7 @@ public:
         DragVelocitySmoothingFactor,             // qreal [0..1/s]  (complex calculation involving time) v = v_new* DASF + v_old * (1-DASF)
         FrictionCoefficent,                      // qreal [0..1]
         OvershootSpringConstant,                 // qreal [0..1]
+        OvershootDragResistanceFactor,           // qreal [0..1]
         OvershootMaximumDistance,                // QPointF([m], [m])
         OvershootMaximumVelocity,                // qreal [m/s]
 
diff --git a/qkineticscroller_p.h b/qkineticscroller_p.h
index d2012de..14188ce 100644
--- a/qkineticscroller_p.h
+++ b/qkineticscroller_p.h
@@ -94,6 +94,7 @@ public:
     qreal dragVelocitySmoothingFactor;
     qreal frictionCoefficent;
     qreal overshootSpringConstant;
+    qreal overshootDragResistanceFactor;
     QPointF overshootMaximumDistance;
     qreal overshootMaximumVelocity;
     qreal dragStartDistance;