Add moving and flicking properties to PathView

PathView handles its own mouse interaction, but lacked properties
similar to those in Flickable to determine when it is stationary.
This made it impossible to start an animation when the view stops moving,
for example.

Task-number: QTBUG-12497
Reviewed-by: Warwick Allison

3 files changed, 124 insertions, 10 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativepathview.cpp b/src/declarative/graphicsitems/qdeclarativepathview.cpp
index acf9827..002ae21 100644
--- a/src/declarative/graphicsitems/qdeclarativepathview.cpp
+++ b/src/declarative/graphicsitems/qdeclarativepathview.cpp
@@ -90,6 +90,26 @@ void QDeclarativePathViewAttached::setValue(const QByteArray &name, const QVaria
     m_metaobject->setValue(name, val);
 }
 
+
+void QDeclarativePathViewPrivate::init()
+{
+    Q_Q(QDeclarativePathView);
+    offset = 0;
+    q->setAcceptedMouseButtons(Qt::LeftButton);
+    q->setFlag(QGraphicsItem::ItemIsFocusScope);
+    q->setFiltersChildEvents(true);
+    q->connect(&tl, SIGNAL(updated()), q, SLOT(ticked()));
+    lastPosTime.invalidate();
+    static int timelineCompletedIdx = -1;
+    static int movementEndingIdx = -1;
+    if (timelineCompletedIdx == -1) {
+        timelineCompletedIdx = QDeclarativeTimeLine::staticMetaObject.indexOfSignal("completed()");
+        movementEndingIdx = QDeclarativePathView::staticMetaObject.indexOfSlot("movementEnding()");
+    }
+    QMetaObject::connect(&tl, timelineCompletedIdx,
+                         q, movementEndingIdx, Qt::DirectConnection);
+}
+
 QDeclarativeItem *QDeclarativePathViewPrivate::getItem(int modelIndex)
 {
     Q_Q(QDeclarativePathView);
@@ -848,6 +868,61 @@ void QDeclarativePathView::setInteractive(bool interactive)
 }
 
 /*!
+    \qmlproperty bool PathView::moving
+
+    This property holds whether the view is currently moving
+    due to the user either dragging or flicking the view.
+*/
+bool QDeclarativePathView::isMoving() const
+{
+    Q_D(const QDeclarativePathView);
+    return d->moving;
+}
+
+/*!
+    \qmlproperty bool PathView::flicking
+
+    This property holds whether the view is currently moving
+    due to the user flicking the view.
+*/
+bool QDeclarativePathView::isFlicking() const
+{
+    Q_D(const QDeclarativePathView);
+    return d->flicking;
+}
+
+/*!
+    \qmlsignal PathView::onMovementStarted()
+
+    This handler is called when the view begins moving due to user
+    interaction.
+*/
+
+/*!
+    \qmlsignal PathView::onMovementEnded()
+
+    This handler is called when the view stops moving due to user
+    interaction.  If a flick was generated, this handler will
+    be triggered once the flick stops.  If a flick was not
+    generated, the handler will be triggered when the
+    user stops dragging - i.e. a mouse or touch release.
+*/
+
+/*!
+    \qmlsignal PathView::onFlickStarted()
+
+    This handler is called when the view is flicked.  A flick
+    starts from the point that the mouse or touch is released,
+    while still in motion.
+*/
+
+/*!
+    \qmlsignal PathView::onFlickEnded()
+
+    This handler is called when the view stops moving due to a flick.
+*/
+
+/*!
     \qmlproperty Component PathView::delegate
 
     The delegate provides a template defining each item instantiated by the view.
@@ -964,7 +1039,11 @@ void QDeclarativePathView::mousePressEvent(QGraphicsSceneMouseEvent *event)
             return;
     }
 
-    d->stealMouse = false;
+    if (d->tl.isActive() && d->flicking)
+        d->stealMouse = true; // If we've been flicked then steal the click.
+    else
+        d->stealMouse = false;
+
     d->lastElapsed = 0;
     d->lastDist = 0;
     QDeclarativeItemPrivate::start(d->lastPosTime);
@@ -1000,6 +1079,11 @@ void QDeclarativePathView::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
             d->lastDist = diff;
             d->startPc = newPc;
         }
+        if (!d->moving) {
+            d->moving = true;
+            emit movingChanged();
+            emit movementStarted();
+        }
     }
 }
 
@@ -1039,12 +1123,19 @@ void QDeclarativePathView::mouseReleaseEvent(QGraphicsSceneMouseEvent *)
         d->moveOffset.setValue(d->offset);
         d->tl.accel(d->moveOffset, velocity, accel, dist);
         d->tl.callback(QDeclarativeTimeLineCallback(&d->moveOffset, d->fixOffsetCallback, d));
+        if (!d->flicking) {
+            d->flicking = true;
+            emit flickingChanged();
+            emit flickStarted();
+        }
     } else {
         d->fixOffset();
     }
 
     d->lastPosTime.invalidate();
     ungrabMouse();
+    if (!d->tl.isActive())
+        movementEnding();
 }
 
 bool QDeclarativePathView::sendMouseEvent(QGraphicsSceneMouseEvent *event)
@@ -1372,6 +1463,21 @@ void QDeclarativePathView::ticked()
     d->updateCurrent();
 }
 
+void QDeclarativePathView::movementEnding()
+{
+    Q_D(QDeclarativePathView);
+    if (d->flicking) {
+        d->flicking = false;
+        emit flickingChanged();
+        emit flickEnded();
+    }
+    if (d->moving && !d->stealMouse) {
+        d->moving = false;
+        emit movingChanged();
+        emit movementEnded();
+    }
+}
+
 // find the item closest to the snap position
 int QDeclarativePathViewPrivate::calcCurrentIndex()
 {
diff --git a/src/declarative/graphicsitems/qdeclarativepathview_p.h b/src/declarative/graphicsitems/qdeclarativepathview_p.h
index d2980c6..035a64b 100644
--- a/src/declarative/graphicsitems/qdeclarativepathview_p.h
+++ b/src/declarative/graphicsitems/qdeclarativepathview_p.h
@@ -74,6 +74,9 @@ class Q_AUTOTEST_EXPORT QDeclarativePathView : public QDeclarativeItem
     Q_PROPERTY(qreal flickDeceleration READ flickDeceleration WRITE setFlickDeceleration NOTIFY flickDecelerationChanged)
     Q_PROPERTY(bool interactive READ isInteractive WRITE setInteractive NOTIFY interactiveChanged)
 
+    Q_PROPERTY(bool moving READ isMoving NOTIFY movingChanged)
+    Q_PROPERTY(bool flicking READ isFlicking NOTIFY flickingChanged)
+
     Q_PROPERTY(int count READ count NOTIFY countChanged)
     Q_PROPERTY(QDeclarativeComponent *delegate READ delegate WRITE setDelegate NOTIFY delegateChanged)
     Q_PROPERTY(int pathItemCount READ pathItemCount WRITE setPathItemCount NOTIFY pathItemCountChanged)
@@ -122,6 +125,9 @@ public:
     bool isInteractive() const;
     void setInteractive(bool);
 
+    bool isMoving() const;
+    bool isFlicking() const;
+
     int count() const;
 
     QDeclarativeComponent *delegate() const;
@@ -151,9 +157,15 @@ Q_SIGNALS:
     void pathItemCountChanged();
     void flickDecelerationChanged();
     void interactiveChanged();
+    void movingChanged();
+    void flickingChanged();
     void highlightChanged();
     void highlightItemChanged();
     void highlightMoveDurationChanged();
+    void movementStarted();
+    void movementEnded();
+    void flickStarted();
+    void flickEnded();
 
 protected:
     void mousePressEvent(QGraphicsSceneMouseEvent *event);
@@ -167,6 +179,7 @@ protected:
 private Q_SLOTS:
     void refill();
     void ticked();
+    void movementEnding();
     void itemsInserted(int index, int count);
     void itemsRemoved(int index, int count);
     void itemsMoved(int,int,int);
diff --git a/src/declarative/graphicsitems/qdeclarativepathview_p_p.h b/src/declarative/graphicsitems/qdeclarativepathview_p_p.h
index a0d2610..9abec2e 100644
--- a/src/declarative/graphicsitems/qdeclarativepathview_p_p.h
+++ b/src/declarative/graphicsitems/qdeclarativepathview_p_p.h
@@ -78,6 +78,7 @@ public:
         , lastElapsed(0), mappedRange(1.0)
         , stealMouse(false), ownModel(false), interactive(true), haveHighlightRange(true)
         , autoHighlight(true), highlightUp(false), layoutScheduled(false)
+        , moving(false), flicking(false)
         , dragMargin(0), deceleration(100)
         , moveOffset(this, &QDeclarativePathViewPrivate::setOffset)
         , firstIndex(-1), pathItems(-1), requestedIndex(-1)
@@ -90,15 +91,7 @@ public:
     {
     }
 
-    void init() {
-        Q_Q(QDeclarativePathView);
-        offset = 0;
-        q->setAcceptedMouseButtons(Qt::LeftButton);
-        q->setFlag(QGraphicsItem::ItemIsFocusScope);
-        q->setFiltersChildEvents(true);
-        q->connect(&tl, SIGNAL(updated()), q, SLOT(ticked()));
-        lastPosTime.invalidate();
-    }
+    void init();
 
     void itemGeometryChanged(QDeclarativeItem *item, const QRectF &newGeometry, const QRectF &oldGeometry) {
         if ((newGeometry.size() != oldGeometry.size())
@@ -155,6 +148,8 @@ public:
     bool autoHighlight : 1;
     bool highlightUp : 1;
     bool layoutScheduled : 1;
+    bool moving : 1;
+    bool flicking : 1;
     QElapsedTimer lastPosTime;
     QPointF lastPos;
     qreal dragMargin;