diff options
| -rw-r--r-- | src/quick/items/qquickflickablebehavior_p.h | 5 | ||||
| -rw-r--r-- | src/quick/items/qquickpathview.cpp | 11 |
2 files changed, 15 insertions, 1 deletions
diff --git a/src/quick/items/qquickflickablebehavior_p.h b/src/quick/items/qquickflickablebehavior_p.h index ae7fe71359..fbce62f075 100644 --- a/src/quick/items/qquickflickablebehavior_p.h +++ b/src/quick/items/qquickflickablebehavior_p.h @@ -93,6 +93,11 @@ #define QML_FLICK_MULTIFLICK_THRESHOLD 1250 #endif +// If the time (ms) between the last move and the release exceeds this, then velocity will be zero. +#ifndef QML_FLICK_VELOCITY_DECAY_TIME +#define QML_FLICK_VELOCITY_DECAY_TIME 50 +#endif + // Multiflick acceleration minimum contentSize/viewSize ratio #ifndef QML_FLICK_MULTIFLICK_RATIO #define QML_FLICK_MULTIFLICK_RATIO 10 diff --git a/src/quick/items/qquickpathview.cpp b/src/quick/items/qquickpathview.cpp index 4e81573356..35b8a872ec 100644 --- a/src/quick/items/qquickpathview.cpp +++ b/src/quick/items/qquickpathview.cpp @@ -60,6 +60,7 @@ QT_BEGIN_NAMESPACE Q_DECLARE_LOGGING_CATEGORY(lcItemViewDelegateLifecycle) +Q_LOGGING_CATEGORY(lcPathView, "qt.quick.pathview") const qreal MinimumFlickVelocity = 75.0; @@ -1623,6 +1624,7 @@ void QQuickPathViewPrivate::addVelocitySample(qreal v) velocityBuffer.append(v); if (velocityBuffer.count() > QML_FLICK_SAMPLEBUFFER) velocityBuffer.remove(0); + qCDebug(lcPathView) << "instantaneous velocity" << v; } qreal QQuickPathViewPrivate::calcVelocity() const @@ -1635,6 +1637,7 @@ qreal QQuickPathViewPrivate::calcVelocity() const velocity += v; } velocity /= count; + qCDebug(lcPathView) << "average velocity" << velocity << "based on" << count << "samples"; } return velocity; } @@ -1765,7 +1768,7 @@ void QQuickPathView::mouseReleaseEvent(QMouseEvent *event) } } -void QQuickPathViewPrivate::handleMouseReleaseEvent(QMouseEvent *) +void QQuickPathViewPrivate::handleMouseReleaseEvent(QMouseEvent *event) { Q_Q(QQuickPathView); stealMouse = false; @@ -1779,6 +1782,12 @@ void QQuickPathViewPrivate::handleMouseReleaseEvent(QMouseEvent *) } qreal velocity = calcVelocity(); + qint64 elapsed = computeCurrentTime(event) - lastPosTime; + // Let the velocity linearly decay such that it becomes 0 if elapsed time > QML_FLICK_VELOCITY_DECAY_TIME + // The intention is that if you are flicking at some speed, then stop in one place for some time before releasing, + // the previous velocity is lost. (QTBUG-77173, QTBUG-59052) + velocity *= qreal(qMax(0LL, QML_FLICK_VELOCITY_DECAY_TIME - elapsed)) / QML_FLICK_VELOCITY_DECAY_TIME; + qCDebug(lcPathView) << "after elapsed time" << elapsed << "velocity decayed to" << velocity; qreal count = pathItems == -1 ? modelCount : qMin(pathItems, modelCount); const auto averageItemLength = path->path().length() / count; qreal pixelVelocity = averageItemLength * velocity; |