This patch forward the "stateChanged" signal emitted from the private kinetic scroll animation all the way to Plasma::ScrollWidget, which then forwards this signal to its childs. This enables an object which derives from Plasma::ScrollWidget to know the kinetic scrolling animation state.

Patch by Bruno Abinader

svn path=/trunk/KDE/kdelibs/; revision=1064768

animator.h

@@ -23,6 +23,7 @@
 
 #include <QtGui/QImage>
 #include <QtCore/QObject>
+#include <QtCore/QAbstractAnimation>
 
 #include <plasma/plasma_export.h>
 
@@ -201,6 +202,8 @@ Q_SIGNALS:
     void movementFinished(QGraphicsItem *item);
     void elementAnimationFinished(int id);
     void customAnimationFinished(int id);
+    void scrollStateChanged(QGraphicsWidget *widget, QAbstractAnimation::State newState,
+            QAbstractAnimation::State oldState);
 
 protected:
     void timerEvent(QTimerEvent *event);
@@ -214,7 +217,10 @@ private:
     Q_PRIVATE_SLOT(d, void movingItemDestroyed(QObject*))
     Q_PRIVATE_SLOT(d, void animatedElementDestroyed(QObject*))
     Q_PRIVATE_SLOT(d, void customAnimReceiverDestroyed(QObject*))
+    Q_PRIVATE_SLOT(d, void scrollStateChanged(QAbstractAnimation::State,
+                QAbstractAnimation::State))
 
+    friend class AnimatorPrivate;
     AnimatorPrivate * const d;
 };
 

deprecated/animator.cpp

@@ -40,8 +40,9 @@ namespace Plasma
 static const int MIN_TICK_RATE_INT = 10;
 static const qreal MIN_TICK_RATE = 10;
 
-AnimatorPrivate::AnimatorPrivate()
-    : driver(0),
+AnimatorPrivate::AnimatorPrivate(Animator *parent)
+    : q(parent),
+      driver(0),
       animId(0),
       timerId(0)
 {
@@ -117,6 +118,18 @@ void AnimatorPrivate::performMovement(qreal amount, const MovementState *state)
     }
 }
 
+void AnimatorPrivate::scrollStateChanged(QAbstractAnimation::State newState,
+        QAbstractAnimation::State oldState)
+{
+    KineticScrolling *scroll = qobject_cast<KineticScrolling*>(q->sender());
+    if (!scroll) {
+        kDebug() << "Could not find KineticScrolling object";
+        return;
+    }
+
+    emit q->scrollStateChanged(scrollingManagers.key(scroll), newState, oldState);
+}
+
 class AnimatorSingleton
 {
     public:
@@ -132,7 +145,7 @@ Animator *Animator::self()
 
 Animator::Animator(QObject *parent)
     : QObject(parent),
-      d(new AnimatorPrivate)
+      d(new AnimatorPrivate(this))
 {
     d->init(this);
 }
@@ -752,12 +765,18 @@ void Animator::registerScrollingManager(QGraphicsWidget *widget)
     if (!d->scrollingManagers.contains(widget)) {
         KineticScrolling *scroll = new KineticScrolling(widget);
         d->scrollingManagers.insert(widget, scroll);
+        connect(scroll,
+                SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)), this,
+                SLOT(scrollStateChanged(QAbstractAnimation::State, QAbstractAnimation::State)));
     }
 }
 
 void Animator::unregisterScrollingManager(QGraphicsWidget *widget)
 {
     if (d->scrollingManagers.contains(widget)) {
+        disconnect(d->scrollingManagers.value(widget),
+                SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)), this,
+                SLOT(scrollStateChanged(QAbstractAnimation::State, QAbstractAnimation::State)));
         d->scrollingManagers.value(widget)->deleteLater();
         d->scrollingManagers.remove(widget);
     }

private/animator_p.h

@@ -90,10 +90,12 @@ struct CustomAnimationState
     char *slot;
 };
 
+class Animator;
+
 class AnimatorPrivate
 {
     public:
-        AnimatorPrivate();
+        AnimatorPrivate(Animator *parent);
         ~AnimatorPrivate();
 
         qreal calculateProgress(int time, int duration, Animator::CurveShape curve);
@@ -107,6 +109,10 @@ class AnimatorPrivate
         void animatedElementDestroyed(QObject*);
         void customAnimReceiverDestroyed(QObject*);
 
+        void scrollStateChanged(QAbstractAnimation::State newState,
+                QAbstractAnimation::State oldState);
+
+        Animator *q;
         AnimationDriver *driver;
         int animId;
         int timerId;

private/kineticscroll.cpp

@@ -349,6 +349,9 @@ void KineticScrolling::setWidget(QGraphicsWidget *parent)
     if (d->parent) {
         d->parent->removeEventFilter(this);
         disconnect(d->scrollAnimation, SIGNAL(finished()), this, SLOT(overshoot()));
+        disconnect(d->scrollAnimation,
+                SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)), this,
+                SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)));
         delete d->scrollAnimation;
     }
 
@@ -358,6 +361,9 @@ void KineticScrolling::setWidget(QGraphicsWidget *parent)
 
     d->scrollAnimation = new QPropertyAnimation(parent, "scrollPosition", parent);
     connect(d->scrollAnimation, SIGNAL(finished()), this, SLOT(overshoot()));
+    connect(d->scrollAnimation,
+            SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)), this,
+            SIGNAL(stateChanged(QAbstractAnimation::State, QAbstractAnimation::State)));
     d->scrollAnimation->setEasingCurve(QEasingCurve::OutCirc);
 
     if (parent) {

private/kineticscroll_p.h

@@ -28,6 +28,7 @@ class QGraphicsSceneWheelEvent;
 class QKeyEvent;
 #include <QObject>
 #include <QPointF>
+#include <QtCore/QAbstractAnimation>
 
 
 namespace Plasma
@@ -43,6 +44,10 @@ public:
     ~KineticScrolling();
     void setWidget(QGraphicsWidget *parent);
 
+Q_SIGNALS:
+    void stateChanged(QAbstractAnimation::State newState,
+            QAbstractAnimation::State oldState);
+
 protected:
     void mouseMoveEvent(QGraphicsSceneMouseEvent *event);
     void mousePressEvent(QGraphicsSceneMouseEvent *event);

widgets/scrollwidget.cpp

@@ -285,6 +285,14 @@ public:
         dragHandles.remove(static_cast<QGraphicsWidget *>(destroyed));
     }
 
+    void scrollStateChanged(QGraphicsWidget *widget, QAbstractAnimation::State newState,
+            QAbstractAnimation::State oldState)
+    {
+        if (widget == q) {
+            emit q->scrollStateChanged(newState, oldState);
+        }
+    }
+
     ScrollWidget *q;
     QGraphicsWidget *scrollingWidget;
     QWeakPointer<QGraphicsWidget> widget;
@@ -338,6 +346,11 @@ void ScrollWidget::setWidget(QGraphicsWidget *widget)
 
     d->widget = widget;
     Plasma::Animator::self()->registerScrollingManager(this);
+    connect(Plasma::Animator::self(),
+            SIGNAL(scrollStateChanged(QGraphicsWidget *, QAbstractAnimation::State,
+                    QAbstractAnimation::State)), this,
+            SLOT(scrollStateChanged(QGraphicsWidget *, QAbstractAnimation::State,
+                    QAbstractAnimation::State)));
     //it's not good it's setting a size policy here, but it's done to be retrocompatible with older applications
 
     if (widget) {

widgets/scrollwidget.h

@@ -20,6 +20,7 @@
 #ifndef PLASMA_SCROLLWIDGET_H
 #define PLASMA_SCROLLWIDGET_H
 
+#include <QtCore/QAbstractAnimation>
 #include <QtGui/QGraphicsWidget>
 
 #include <plasma/plasma_export.h>
@@ -181,6 +182,10 @@ public:
      */
     QWidget *nativeWidget() const;
 
+Q_SIGNALS:
+    void scrollStateChanged(QAbstractAnimation::State newState,
+            QAbstractAnimation::State oldState);
+
 protected:
 
     void resizeEvent(QGraphicsSceneResizeEvent *event);
@@ -202,6 +207,10 @@ private:
     Q_PRIVATE_SLOT(d, void makeItemVisible())
     Q_PRIVATE_SLOT(d, void cleanupDragHandles(QObject *destroyed))
     Q_PRIVATE_SLOT(d, void adjustScrollbars())
+    Q_PRIVATE_SLOT(d, void scrollStateChanged(QGraphicsWidget *, QAbstractAnimation::State,
+                QAbstractAnimation::State))
+
+    friend class ScrollWidgetPrivate;
 };
 
 } // namespace Plasma