PathView was missing the maximumFlickVelocity property

Change-Id: I0ed4ff0fe169187f7a8e03597be7407e9896100d
Reviewed-by: Bea Lam <bea.lam@nokia.com>

3 files changed, 69 insertions, 24 deletions

diff --git a/src/quick/items/qquickpathview.cpp b/src/quick/items/qquickpathview.cpp
index b85a449c51..962dddafc9 100644
--- a/src/quick/items/qquickpathview.cpp
+++ b/src/quick/items/qquickpathview.cpp
@@ -67,8 +67,16 @@
 #define QML_FLICK_DISCARDSAMPLES 1
 #endif
 
+// The default maximum velocity of a flick.
+#ifndef QML_FLICK_DEFAULTMAXVELOCITY
+#define QML_FLICK_DEFAULTMAXVELOCITY 2500
+#endif
+
+
 QT_BEGIN_NAMESPACE
 
+const qreal MinimumFlickVelocity = 75.0;
+
 inline qreal qmlMod(qreal x, qreal y)
 {
 #ifdef QT_USE_MATH_H_FLOATS
@@ -105,6 +113,23 @@ void QQuickPathViewAttached::setValue(const QByteArray &name, const QVariant &va
     m_metaobject->setValue(name, val);
 }
 
+QQuickPathViewPrivate::QQuickPathViewPrivate()
+  : path(0), currentIndex(0), currentItemOffset(0.0), startPc(0), lastDist(0)
+    , lastElapsed(0), offset(0.0), offsetAdj(0.0), mappedRange(1.0)
+    , stealMouse(false), ownModel(false), interactive(true), haveHighlightRange(true)
+    , autoHighlight(true), highlightUp(false), layoutScheduled(false)
+    , moving(false), flicking(false), requestedOnPath(false), inRequest(false)
+    , dragMargin(0), deceleration(100), maximumFlickVelocity(QML_FLICK_DEFAULTMAXVELOCITY)
+    , moveOffset(this, &QQuickPathViewPrivate::setAdjustedOffset), flickDuration(0)
+    , firstIndex(-1), pathItems(-1), requestedIndex(-1), requestedZ(0)
+    , moveReason(Other), moveDirection(Shortest), attType(0), highlightComponent(0), highlightItem(0)
+    , moveHighlight(this, &QQuickPathViewPrivate::setHighlightPosition)
+    , highlightPosition(0)
+    , highlightRangeStart(0), highlightRangeEnd(0)
+    , highlightRangeMode(QQuickPathView::StrictlyEnforceRange)
+    , highlightMoveDuration(300), modelCount(0)
+{
+}
 
 void QQuickPathViewPrivate::init()
 {
@@ -975,6 +1000,28 @@ void QQuickPathView::setFlickDeceleration(qreal dec)
 }
 
 /*!
+    \qmlproperty real QtQuick2::PathView::maximumFlickVelocity
+    This property holds the approximate maximum velocity that the user can flick the view in pixels/second.
+
+    The default value is platform dependent.
+*/
+qreal QQuickPathView::maximumFlickVelocity() const
+{
+    Q_D(const QQuickPathView);
+    return d->maximumFlickVelocity;
+}
+
+void QQuickPathView::setMaximumFlickVelocity(qreal vel)
+{
+    Q_D(QQuickPathView);
+    if (vel == d->maximumFlickVelocity)
+        return;
+    d->maximumFlickVelocity = vel;
+    emit maximumFlickVelocityChanged();
+}
+
+
+/*!
     \qmlproperty bool QtQuick2::PathView::interactive
 
     A user cannot drag or flick a PathView that is not interactive.
@@ -1203,7 +1250,7 @@ void QQuickPathView::mousePressEvent(QMouseEvent *event)
 void QQuickPathViewPrivate::handleMousePressEvent(QMouseEvent *event)
 {
     Q_Q(QQuickPathView);
-    if (!interactive || !items.count())
+    if (!interactive || !items.count() || !model || !modelCount)
         return;
     velocityBuffer.clear();
     QPointF scenePoint = q->mapToScene(event->localPos());
@@ -1252,7 +1299,7 @@ void QQuickPathView::mouseMoveEvent(QMouseEvent *event)
 void QQuickPathViewPrivate::handleMouseMoveEvent(QMouseEvent *event)
 {
     Q_Q(QQuickPathView);
-    if (!interactive || !lastPosTime.isValid())
+    if (!interactive || !lastPosTime.isValid() || !model || !modelCount)
         return;
 
     qreal newPc;
@@ -1306,14 +1353,22 @@ void QQuickPathViewPrivate::handleMouseReleaseEvent(QMouseEvent *)
     Q_Q(QQuickPathView);
     stealMouse = false;
     q->setKeepMouseGrab(false);
-    if (!interactive || !lastPosTime.isValid())
+    if (!interactive || !lastPosTime.isValid() || !model || !modelCount) {
+        lastPosTime.invalidate();
+        if (!tl.isActive())
+            q->movementEnding();
         return;
+    }
 
     qreal velocity = calcVelocity();
-    if (model && modelCount && qAbs(velocity) > 0.5) {
-        qreal count = pathItems == -1 ? modelCount : pathItems;
-        if (qAbs(velocity) > count * 2) // limit velocity
-            velocity = (velocity > 0 ? count : -count) * 2;
+    qreal count = modelCount*mappedRange;
+    qreal pixelVelocity = (path->path().length()/count) * velocity;
+    if (qAbs(pixelVelocity) > MinimumFlickVelocity) {
+        if (qAbs(pixelVelocity) > maximumFlickVelocity) {
+            // limit velocity
+            qreal maxVel = velocity < 0 ? -maximumFlickVelocity : maximumFlickVelocity;
+            velocity = maxVel / (path->path().length()/count);
+        }
         // Calculate the distance to be travelled
         qreal v2 = velocity*velocity;
         qreal accel = deceleration/10;
diff --git a/src/quick/items/qquickpathview_p.h b/src/quick/items/qquickpathview_p.h
index 8f1ecd6caf..8b15e85b8a 100644
--- a/src/quick/items/qquickpathview_p.h
+++ b/src/quick/items/qquickpathview_p.h
@@ -73,6 +73,7 @@ class Q_AUTOTEST_EXPORT QQuickPathView : public QQuickItem
     Q_PROPERTY(int highlightMoveDuration READ highlightMoveDuration WRITE setHighlightMoveDuration NOTIFY highlightMoveDurationChanged)
 
     Q_PROPERTY(qreal dragMargin READ dragMargin WRITE setDragMargin NOTIFY dragMarginChanged)
+    Q_PROPERTY(qreal maximumFlickVelocity READ maximumFlickVelocity WRITE setMaximumFlickVelocity NOTIFY maximumFlickVelocityChanged)
     Q_PROPERTY(qreal flickDeceleration READ flickDeceleration WRITE setFlickDeceleration NOTIFY flickDecelerationChanged)
     Q_PROPERTY(bool interactive READ isInteractive WRITE setInteractive NOTIFY interactiveChanged)
 
@@ -126,6 +127,9 @@ public:
     qreal flickDeceleration() const;
     void setFlickDeceleration(qreal dec);
 
+    qreal maximumFlickVelocity() const;
+    void setMaximumFlickVelocity(qreal);
+
     bool isInteractive() const;
     void setInteractive(bool);
 
@@ -160,6 +164,7 @@ Q_SIGNALS:
     void snapPositionChanged();
     void delegateChanged();
     void pathItemCountChanged();
+    void maximumFlickVelocityChanged();
     void flickDecelerationChanged();
     void interactiveChanged();
     void movingChanged();
diff --git a/src/quick/items/qquickpathview_p_p.h b/src/quick/items/qquickpathview_p_p.h
index 412caa6d2b..ac74e9a568 100644
--- a/src/quick/items/qquickpathview_p_p.h
+++ b/src/quick/items/qquickpathview_p_p.h
@@ -74,23 +74,7 @@ class QQuickPathViewPrivate : public QQuickItemPrivate, public QQuickItemChangeL
     Q_DECLARE_PUBLIC(QQuickPathView)
 
 public:
-    QQuickPathViewPrivate()
-      : path(0), currentIndex(0), currentItemOffset(0.0), startPc(0), lastDist(0)
-        , lastElapsed(0), offset(0.0), offsetAdj(0.0), mappedRange(1.0)
-        , stealMouse(false), ownModel(false), interactive(true), haveHighlightRange(true)
-        , autoHighlight(true), highlightUp(false), layoutScheduled(false)
-        , moving(false), flicking(false), requestedOnPath(false), inRequest(false)
-        , dragMargin(0), deceleration(100)
-        , moveOffset(this, &QQuickPathViewPrivate::setAdjustedOffset), flickDuration(0)
-        , firstIndex(-1), pathItems(-1), requestedIndex(-1), requestedZ(0)
-        , moveReason(Other), moveDirection(Shortest), attType(0), highlightComponent(0), highlightItem(0)
-        , moveHighlight(this, &QQuickPathViewPrivate::setHighlightPosition)
-        , highlightPosition(0)
-        , highlightRangeStart(0), highlightRangeEnd(0)
-        , highlightRangeMode(QQuickPathView::StrictlyEnforceRange)
-        , highlightMoveDuration(300), modelCount(0)
-    {
-    }
+    QQuickPathViewPrivate();
 
     void init();
 
@@ -169,6 +153,7 @@ public:
     QPointF lastPos;
     qreal dragMargin;
     qreal deceleration;
+    qreal maximumFlickVelocity;
     QQuickTimeLine tl;
     QQuickTimeLineValueProxy<QQuickPathViewPrivate> moveOffset;
     int flickDuration;