Decrease flickering in Dact OS X

gistfile1.diff

diff --git a/src/PopupItem.cpp b/src/PopupItem.cpp
index 7f656be..808868c 100644
--- a/src/PopupItem.cpp
+++ b/src/PopupItem.cpp
@@ -24,7 +24,7 @@ QRectF PopupItem::boundingRect() const
 QRectF PopupItem::rect() const
 {
     QSizeF popup = size();
-    return QRectF(QPointF(-popup.width() / 2.0, -34.0), popup);
+    return QRectF(QPointF(-popup.width() / 2.0, -popup.height() / 2.0), popup);
 }
 
 QFont PopupItem::font() const
diff --git a/src/TreeNode.cpp b/src/TreeNode.cpp
index 39d2188..7bcbaa9 100644
--- a/src/TreeNode.cpp
+++ b/src/TreeNode.cpp
@@ -74,14 +74,25 @@ void TreeNode::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
 
 void TreeNode::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
 {
-    if (d_popupItem && d_popupItem->isVisible())
+    if (d_popupItem && d_popupItem->isVisible()) {
         d_popupItem->setVisible(false);
+        event->accept();
+    }
 }
 
 void TreeNode::hoverMoveEvent(QGraphicsSceneHoverEvent *event)
 {
-    if (d_popupItem && d_popupItem->isVisible())
-        d_popupItem->setPos(event->scenePos());
+    if (d_popupItem && d_popupItem->isVisible()) {
+        if (event->screenPos() == event->lastScreenPos())
+        {
+            QRectF oldRect = d_popupItem->sceneBoundingRect();
+            d_popupItem->setPos(event->scenePos());
+            d_popupItem->scene()->invalidate(oldRect);
+        }
+        else
+            d_popupItem->setPos(event->scenePos());
+        event->accept();
+}
 }
 
 void TreeNode::setAttribute(QString const &name, QString const &value)