Add experimental code in QtListController for animated per-item scrolling.

3 files changed, 61 insertions, 3 deletions

diff --git a/src/qlistcontroller.cpp b/src/qlistcontroller.cpp
index c6101eb..cd3e57e 100644
--- a/src/qlistcontroller.cpp
+++ b/src/qlistcontroller.cpp
@@ -30,6 +30,7 @@
 #include <qtransform.h>
 #include <qevent.h>
 #include <qgraphicssceneevent.h>
+#include <qpropertyanimation.h>
 #include <qdebug.h>
 
 QT_BEGIN_NAMESPACE
@@ -44,6 +45,8 @@ QtListControllerPrivate::QtListControllerPrivate()
     model(0),
     selectionManager(0),
     view(0),
+    animation(0),
+    firstIndex(0),
     scrollPerItem(true)
 {
 }
@@ -99,6 +102,44 @@ void QtListControllerPrivate::_q_offsetChanged(qreal offset)
         emit q->scrollValueChanged(offset);
 }
 
+/*!
+ \internal
+*/
+void QtListControllerPrivate::_q_animationFinished()
+{
+    view->setOffset(0);
+    view->setFirstIndex(firstIndex);
+}
+
+/*!
+  \internal
+*/
+void QtListControllerPrivate::animateFirstIndex(int index)
+{
+    // animate the offset when scrolling per item
+    int previous = view->firstIndex();
+    if (animation && index != previous) {
+        animation->stop();
+        if (index > previous) { // scrolling down
+            qreal offset = 0;
+            for (int i = previous; i < index; ++i)
+                offset += view->itemGeometry(i).height();
+            animation->setStartValue(view->offset());
+            animation->setEndValue(offset);
+        } else { // scrolling up
+            qreal offset = view->offset();
+            view->setFirstIndex(index);
+            for (int i = index; i < previous; ++i)
+                offset += view->itemGeometry(i).height();
+            view->setOffset(offset);
+            animation->setStartValue(offset);
+            animation->setEndValue(0);
+        }
+        firstIndex = index;
+        animation->start();
+    }
+}
+
 // QtListController
 
 /*!
@@ -250,6 +291,13 @@ void QtListController::setView(QtGraphicsListView *view)
 
     QtGraphicsListView *old = d->view;
 
+    if (!d->animation) {
+        d->animation = new QPropertyAnimation(0, "offset", this);
+        d->animation->setDuration(100);
+        connect(d->animation, SIGNAL(finished()), this, SLOT(_q_animationFinished()));
+    }
+    d->animation->setTargetObject(view);
+
     if (d->view) {
         disconnect(d->view, SIGNAL(destroyed()), this, SLOT(_q_viewDestroyed()));
         disconnect(d->view, SIGNAL(firstIndexChanged(int)), this, SLOT(_q_firstIndexChanged(int)));
@@ -300,6 +348,7 @@ void QtListController::setScrollValue(qreal value)
     if (!d->view)
         return;
     if (d->scrollPerItem)
+        //d->animateFirstIndex(value);
         d->view->setFirstIndex(static_cast<int>(value));
     else
         d->view->setOffset(value);
@@ -554,9 +603,11 @@ bool QtListController::wheelEvent(QGraphicsSceneWheelEvent *event, const QTransf
     if (d->scrollPerItem) {
         const int index = d->view->firstIndex() - event->delta() / 120;
         d->view->setFirstIndex(qBound(0, index, d->view->maximumFirstIndex()));
-        return true;
-    } // ### FIXME: set offset
-    return false;
+    } else {
+        const qreal offset = d->view->offset() - event->delta() / 120;
+        d->view->setOffset(qBound(.0, offset, d->view->maximumOffset()));
+    }
+    return true;
 }
 
 /*!
diff --git a/src/qlistcontroller.h b/src/qlistcontroller.h
index 1c3232c..ad7f7c6 100644
--- a/src/qlistcontroller.h
+++ b/src/qlistcontroller.h
@@ -117,6 +117,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_selectionsDestroyed())
     Q_PRIVATE_SLOT(d_func(), void _q_firstIndexChanged(int index))
     Q_PRIVATE_SLOT(d_func(), void _q_offsetChanged(qreal offset))
+    Q_PRIVATE_SLOT(d_func(), void _q_animationFinished())
 };
 
 QT_END_NAMESPACE
diff --git a/src/qlistcontroller_p.h b/src/qlistcontroller_p.h
index d8b396d..13825e0 100644
--- a/src/qlistcontroller_p.h
+++ b/src/qlistcontroller_p.h
@@ -44,6 +44,7 @@ QT_BEGIN_NAMESPACE
 class QtListController;
 class QtListSelectionManager;
 class QtGraphicsListView;
+class QPropertyAnimation;
 
 class QtListControllerPrivate
 {
@@ -57,7 +58,9 @@ public:
     void _q_selectionsDestroyed();
     void _q_firstIndexChanged(int index);
     void _q_offsetChanged(qreal offset);
+    void _q_animationFinished();
 
+    void animateFirstIndex(int index);
     // ### hack - not implemented in Qt
     QVariant inputMethodQueryHelper(Qt::InputMethodQuery query) const { Q_UNUSED(query); return QVariant(); }
 
@@ -67,6 +70,9 @@ public:
     QPointer<QtListSelectionManager> selectionManager;
     QtGraphicsListView *view;
 
+    QPropertyAnimation *animation;
+    int firstIndex;
+
     bool scrollPerItem;
 };