diff options
Diffstat (limited to 'src/quick/items/qquickflickable.cpp')
| -rw-r--r-- | src/quick/items/qquickflickable.cpp | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/src/quick/items/qquickflickable.cpp b/src/quick/items/qquickflickable.cpp index d892e3b490..5a3db5e1eb 100644 --- a/src/quick/items/qquickflickable.cpp +++ b/src/quick/items/qquickflickable.cpp @@ -248,6 +248,7 @@ QQuickFlickablePrivate::QQuickFlickablePrivate() , stealMouse(false), pressed(false) , scrollingPhase(false), interactive(true), calcVelocity(false) , pixelAligned(false) + , syncDrag(false) , lastPosTime(-1) , lastPressTime(0) , deceleration(QML_FLICK_DEFAULTDECELERATION) @@ -959,6 +960,33 @@ void QQuickFlickable::setPixelAligned(bool align) } } +/*! + \qmlproperty bool QtQuick::Flickable::synchronousDrag + \since 5.12 + + If this property is set to true, then when the mouse or touchpoint moves + far enough to begin dragging the content, the content will jump, such that + the content pixel which was under the cursor or touchpoint when pressed + remains under that point. + + The default is \c false, which provides a smoother experience (no jump) + at the cost that some of the drag distance is "lost" at the beginning. +*/ +bool QQuickFlickable::synchronousDrag() const +{ + Q_D(const QQuickFlickable); + return d->syncDrag; +} + +void QQuickFlickable::setSynchronousDrag(bool v) +{ + Q_D(QQuickFlickable); + if (v != d->syncDrag) { + d->syncDrag = v; + emit synchronousDragChanged(); + } +} + qint64 QQuickFlickablePrivate::computeCurrentTime(QInputEvent *event) const { if (0 != event->timestamp()) @@ -1075,7 +1103,7 @@ void QQuickFlickablePrivate::drag(qint64 currentTimestamp, QEvent::Type eventTyp if (overThreshold || elapsedSincePress > 200) { if (!vMoved) vData.dragStartOffset = dy; - qreal newY = dy + vData.pressPos - vData.dragStartOffset; + qreal newY = dy + vData.pressPos - (syncDrag ? 0 : vData.dragStartOffset); // Recalculate bounds in case margins have changed, but use the content // size estimate taken at the start of the drag in case the drag causes // the estimate to be altered @@ -1151,7 +1179,7 @@ void QQuickFlickablePrivate::drag(qint64 currentTimestamp, QEvent::Type eventTyp if (overThreshold || elapsedSincePress > 200) { if (!hMoved) hData.dragStartOffset = dx; - qreal newX = dx + hData.pressPos - hData.dragStartOffset; + qreal newX = dx + hData.pressPos - (syncDrag ? 0 : hData.dragStartOffset); const qreal minX = hData.dragMinBound + hData.startMargin; const qreal maxX = hData.dragMaxBound - hData.endMargin; if (!(boundsBehavior & QQuickFlickable::DragOverBounds)) { |