diff --git a/src/axisitem.cpp b/src/axisitem.cpp
index 4b255a8..be588f6 100644
--- a/src/axisitem.cpp
+++ b/src/axisitem.cpp
@@ -43,7 +43,7 @@ void AxisItem::setPlotDomain(const PlotDomain& plotDomain)
     createItems();
 }
 
-void AxisItem::setSize(const QSize &size)
+void AxisItem::setSize(const QSizeF &size)
 {
     m_rect = QRectF(QPoint(0,0),size);
     createItems();
diff --git a/src/axisitem_p.h b/src/axisitem_p.h
index 0a01670..c0dc844 100644
--- a/src/axisitem_p.h
+++ b/src/axisitem_p.h
@@ -20,7 +20,7 @@ public:
     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){};
 
 public: // from ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
 public:
diff --git a/src/barchart/bar.cpp b/src/barchart/bar.cpp
index ed36d0e..374d5a6 100644
--- a/src/barchart/bar.cpp
+++ b/src/barchart/bar.cpp
@@ -9,7 +9,7 @@ Bar::Bar(QGraphicsItem *parent)
 {
 }
 
-void Bar::setSize(const QSize& size)
+void Bar::setSize(const QSizeF& size)
 {
     mWidth = size.width();
     mHeight = size.height();
diff --git a/src/barchart/bar.h b/src/barchart/bar.h
index 7a8e956..323cb4e 100644
--- a/src/barchart/bar.h
+++ b/src/barchart/bar.h
@@ -14,7 +14,7 @@ public:
     Bar(QGraphicsItem *parent=0);
 
 public: // from ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
     // Layout Stuff
diff --git a/src/barchart/bargroup.cpp b/src/barchart/bargroup.cpp
index ff270b4..dae8f8c 100644
--- a/src/barchart/bargroup.cpp
+++ b/src/barchart/bargroup.cpp
@@ -15,7 +15,7 @@ BarGroup::BarGroup(BarChartSeries& series, QGraphicsItem *parent) :
     dataChanged();
 }
 
-void BarGroup::setSize(const QSize& size)
+void BarGroup::setSize(const QSizeF& size)
 {
     qDebug() << "BarGroup::setSize";
     mWidth = size.width();
diff --git a/src/barchart/bargroup.h b/src/barchart/bargroup.h
index d509fa1..a30e9b7 100644
--- a/src/barchart/bargroup.h
+++ b/src/barchart/bargroup.h
@@ -14,7 +14,7 @@ public:
     explicit BarGroup(BarChartSeries& series, QGraphicsItem *parent = 0);
 
 public: // from ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
     // Layout "api"
diff --git a/src/barchart/percentbargroup.cpp b/src/barchart/percentbargroup.cpp
index f8d8a96..a8739d6 100644
--- a/src/barchart/percentbargroup.cpp
+++ b/src/barchart/percentbargroup.cpp
@@ -16,7 +16,7 @@ PercentBarGroup::PercentBarGroup(PercentBarChartSeries& series, QGraphicsItem *p
 }
 
 
-void PercentBarGroup::setSize(const QSize& size)
+void PercentBarGroup::setSize(const QSizeF& size)
 {
 //    qDebug() << "PercentBarGroup::setSize";
     mWidth = size.width();
diff --git a/src/barchart/percentbargroup.h b/src/barchart/percentbargroup.h
index 074a4bb..6427d34 100644
--- a/src/barchart/percentbargroup.h
+++ b/src/barchart/percentbargroup.h
@@ -14,7 +14,7 @@ public:
     PercentBarGroup(PercentBarChartSeries& series, QGraphicsItem *parent = 0);
 
 public: // From ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
 public:
diff --git a/src/barchart/stackedbargroup.cpp b/src/barchart/stackedbargroup.cpp
index f91978c..c01996a 100644
--- a/src/barchart/stackedbargroup.cpp
+++ b/src/barchart/stackedbargroup.cpp
@@ -17,7 +17,7 @@ StackedBarGroup::StackedBarGroup(StackedBarChartSeries& series, QGraphicsItem *p
 }
 
 
-void StackedBarGroup::setSize(const QSize& size)
+void StackedBarGroup::setSize(const QSizeF& size)
 {
 //    qDebug() << "StackedBarGroup::setSize";
     mWidth = size.width();
diff --git a/src/barchart/stackedbargroup.h b/src/barchart/stackedbargroup.h
index 6a6d909..c299698 100644
--- a/src/barchart/stackedbargroup.h
+++ b/src/barchart/stackedbargroup.h
@@ -17,7 +17,7 @@ public:
     StackedBarGroup(StackedBarChartSeries& series, QGraphicsItem *parent = 0);
 
 public: // From ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
     // From ChartThemeObserver
diff --git a/src/chartitem_p.h b/src/chartitem_p.h
index 88a4fdc..0bfd011 100644
--- a/src/chartitem_p.h
+++ b/src/chartitem_p.h
@@ -12,7 +12,7 @@ class ChartItem : public QGraphicsItem
 public:
     ChartItem(QGraphicsItem* parent = 0):QGraphicsItem(parent){};
     virtual ~ChartItem(){};
-    virtual void setSize(const QSize &size) = 0;
+    virtual void setSize(const QSizeF &size) = 0;
     virtual void setPlotDomain(const PlotDomain& data) = 0;
 };
 
diff --git a/src/plotdomain.cpp b/src/plotdomain.cpp
index 5e4bc84..b96574e 100644
--- a/src/plotdomain.cpp
+++ b/src/plotdomain.cpp
@@ -28,7 +28,7 @@ qreal PlotDomain::spanY() const
 	return m_maxY - m_minY;
 }
 
-PlotDomain PlotDomain::subDomain(const QRect& rect, qreal maxWidth,qreal maxHeight) const
+PlotDomain PlotDomain::subDomain(const QRectF& rect, qreal maxWidth,qreal maxHeight) const
 {
   PlotDomain domain;
 
diff --git a/src/plotdomain_p.h b/src/plotdomain_p.h
index 7681b62..e813dd1 100644
--- a/src/plotdomain_p.h
+++ b/src/plotdomain_p.h
@@ -13,7 +13,7 @@ public:
 	qreal spanX() const;
 	qreal spanY() const;
 
-	PlotDomain subDomain(const QRect& rect, qreal maxWidth, qreal maxHeight) const;
+	PlotDomain subDomain(const QRectF& rect, qreal maxWidth, qreal maxHeight) const;
 
 
 public:
diff --git a/src/qchart.cpp b/src/qchart.cpp
index 357bfaf..2394baa 100644
--- a/src/qchart.cpp
+++ b/src/qchart.cpp
@@ -19,11 +19,12 @@
 #include "plotdomain_p.h"
 #include "axisitem_p.h"
 #include <QGraphicsScene>
+#include <QGraphicsSceneResizeEvent>
 #include <QDebug>
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
-QChart::QChart(QGraphicsObject* parent) : QGraphicsObject(parent),
+QChart::QChart(QGraphicsItem *parent, Qt::WindowFlags wFlags) : QGraphicsWidget(parent,wFlags),
     m_backgroundItem(0),
     m_titleItem(0),
     m_axisXItem(new AxisItem(AxisItem::X_AXIS, this)),
@@ -226,36 +227,6 @@ QChartSeries* QChart::createSeries(QChartSeries::QChartSeriesType type)
     return series;
 }
 
-void QChart::setSize(const QSize& size)
-{
-    m_rect = QRect(QPoint(0,0),size);
-    QRect rect = m_rect.adjusted(margin(),margin(), -margin(), -margin());
-
-    // recalculate title position
-    if (m_titleItem) {
-        QPointF center = m_rect.center() -m_titleItem->boundingRect().center();
-        m_titleItem->setPos(center.x(),m_rect.top()/2 + margin()/2);
-    }
-
-    //recalculate background gradient
-    if (m_backgroundItem) {
-        m_backgroundItem->setRect(rect);
-        if (m_bacgroundOrinetation == HorizonatlGradientOrientation)
-            m_backgroundGradient.setFinalStop(m_backgroundItem->rect().width(), 0);
-        else
-            m_backgroundGradient.setFinalStop(0, m_backgroundItem->rect().height());
-        m_backgroundItem->setBrush(m_backgroundGradient);
-    }
-
-    // resize and reposition childs
-    foreach (ChartItem *item, m_chartItems) {
-        item->setPos(rect.topLeft());
-        item->setSize(rect.size());
-    }
-
-    update();
-}
-
 void QChart::setBackground(const QColor& startColor, const QColor& endColor, GradientOrientation orientation)
 {
 
@@ -319,14 +290,14 @@ void QChart::setTheme(QChart::ChartThemeId theme)
     update();
 }
 
-void QChart::zoomInToRect(const QRect& rectangle)
+void QChart::zoomInToRect(const QRectF& rectangle)
 {
 
     if(!rectangle.isValid()) return;
 
     qreal margin = this->margin();
 
-    QRect rect = rectangle.normalized();
+    QRectF rect = rectangle.normalized();
     rect.translate(-margin, -margin);
 
     PlotDomain& oldDomain = m_plotDomainList[m_plotDataIndex];
@@ -350,7 +321,7 @@ void QChart::zoomIn()
             item->setPlotDomain(m_plotDomainList[m_plotDataIndex]);
         update();
     } else {
-        QRect rect = m_rect.adjusted(margin(),margin(), -margin(), -margin());
+        QRectF rect = m_rect.adjusted(margin(),margin(), -margin(), -margin());
         rect.setWidth(rect.width()/2);
         rect.setHeight(rect.height()/2);
         rect.moveCenter(m_rect.center());
@@ -397,6 +368,39 @@ void QChart::setAxis(AxisItem *item, const QChartAxis& axis)
     item->setVisible(axis.isAxisVisible());
 }
 
+void QChart::resizeEvent(QGraphicsSceneResizeEvent *event)
+{
+
+    m_rect = QRectF(QPoint(0,0),event->newSize());
+    QRectF rect = m_rect.adjusted(margin(),margin(), -margin(), -margin());
+
+    // recalculate title position
+    if (m_titleItem) {
+        QPointF center = m_rect.center() -m_titleItem->boundingRect().center();
+        m_titleItem->setPos(center.x(),m_rect.top()/2 + margin()/2);
+    }
+
+    //recalculate background gradient
+    if (m_backgroundItem) {
+        m_backgroundItem->setRect(rect);
+        if (m_bacgroundOrinetation == HorizonatlGradientOrientation)
+        m_backgroundGradient.setFinalStop(m_backgroundItem->rect().width(), 0);
+        else
+        m_backgroundGradient.setFinalStop(0, m_backgroundItem->rect().height());
+        m_backgroundItem->setBrush(m_backgroundGradient);
+    }
+
+    // resize and reposition childs
+    foreach (ChartItem *item, m_chartItems) {
+        item->setPos(rect.topLeft());
+        item->setSize(rect.size());
+    }
+
+    update();
+}
+
+
+
 #include "moc_qchart.cpp"
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/qchart.h b/src/qchart.h
index 5dbcd76..ec79e11 100644
--- a/src/qchart.h
+++ b/src/qchart.h
@@ -3,10 +3,12 @@
 
 #include <qchartglobal.h>
 #include <qchartseries.h>
-#include <QGraphicsObject>
+#include <QGraphicsWidget>
 #include <QLinearGradient>
 #include <QFont>
 
+class QGraphicsSceneResizeEvent;
+
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
 class AxisItem;
@@ -25,7 +27,7 @@ class ChartItem;
 /*!
  * TODO: define the responsibilities
  */
-class QTCOMMERCIALCHART_EXPORT QChart : public QGraphicsObject
+class QTCOMMERCIALCHART_EXPORT QChart : public QGraphicsWidget
 {
     Q_OBJECT
 public:
@@ -45,7 +47,7 @@ public:
     };
 
 public:
-    QChart(QGraphicsObject* parent = 0);
+    QChart(QGraphicsItem *parent = 0, Qt::WindowFlags wFlags = 0);
     ~QChart();
 
     //from QGraphicsItem
@@ -57,7 +59,6 @@ public:
     // TODO: who owns the series now? maybe owned by chart and returned a reference instead...
     QChartSeries* createSeries(QChartSeries::QChartSeriesType type);
 
-    void setSize(const QSize& size);
     void setMargin(int margin);
     int margin() const;
     void setTheme(QChart::ChartThemeId theme);
@@ -65,7 +66,7 @@ public:
     void setTitle(const QString& title,const QFont& font = QFont());
     void setBackground(const QColor& startColor, const QColor& endColor = Qt::white, GradientOrientation orientation = VerticalGradientOrientation);
 
-    void zoomInToRect(const QRect& rectangle);
+    void zoomInToRect(const QRectF& rectangle);
     void zoomIn();
     void zoomOut();
     void zoomReset();
@@ -74,6 +75,9 @@ public:
     void setAxisY(const QChartAxis& axis);
     void setAxisY(const QList<QChartAxis>& axis);
 
+protected:
+    void resizeEvent(QGraphicsSceneResizeEvent *event);
+
 private:
     void setAxis(AxisItem *item, const QChartAxis& axis);
 
@@ -85,7 +89,7 @@ private:
     QGraphicsTextItem* m_titleItem;
     AxisItem* m_axisXItem;
     QList<AxisItem*> m_axisYItem;
-    QRect m_rect;
+    QRectF m_rect;
     QList<QChartSeries *> m_chartSeries;
     QList<ChartItem *> m_chartItems;
     QVector<PlotDomain> m_plotDomainList;
diff --git a/src/qchartview.cpp b/src/qchartview.cpp
index 0c2dbaf..426eb7f 100644
--- a/src/qchartview.cpp
+++ b/src/qchartview.cpp
@@ -28,7 +28,7 @@ QChartView::~QChartView()
 void QChartView::resizeEvent(QResizeEvent *event)
 {
     m_scene->setSceneRect(0,0,size().width(),size().height());
-    m_chart->setSize(size());
+    m_chart->resize(size());
     QWidget::resizeEvent(event);
 }
 
diff --git a/src/qchartwidget.cpp b/src/qchartwidget.cpp
index a3f7dd8..c13ebed 100644
--- a/src/qchartwidget.cpp
+++ b/src/qchartwidget.cpp
@@ -32,7 +32,7 @@ QChartWidget::~QChartWidget()
 void QChartWidget::resizeEvent(QResizeEvent *event)
 {
     m_scene->setSceneRect(0,0,size().width(),size().height());
-    m_chart->setSize(size());
+    m_chart->resize(size());
     QWidget::resizeEvent(event);
 }
 
diff --git a/src/qpieseries.cpp b/src/qpieseries.cpp
index 33e0df3..357ea6f 100644
--- a/src/qpieseries.cpp
+++ b/src/qpieseries.cpp
@@ -49,7 +49,7 @@ bool QPieSeriesPrivate::setData(QList<qreal> data)
     return true;
 }
 
-void QPieSeriesPrivate::setSize(const QSize &size)
+void QPieSeriesPrivate::setSize(const QSizeF &size)
 {
     // TODO: allow user setting the size?
     // TODO: allow user defining the margins?
diff --git a/src/qpieseries_p.h b/src/qpieseries_p.h
index da958be..4cdd5f1 100644
--- a/src/qpieseries_p.h
+++ b/src/qpieseries_p.h
@@ -19,7 +19,7 @@ public:
     ~QPieSeriesPrivate();
 
 public: // from ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
     // This is a dummy QGraphicsItem; dummy implementation
     QRectF boundingRect() const { return parentItem()->boundingRect(); }
diff --git a/src/qscatterseries.cpp b/src/qscatterseries.cpp
index 1300d51..b00367f 100644
--- a/src/qscatterseries.cpp
+++ b/src/qscatterseries.cpp
@@ -37,7 +37,7 @@ void QScatterSeriesPrivate::changeGeometry()
     }
 }
 
-void QScatterSeriesPrivate::setSize(const QSize &size)
+void QScatterSeriesPrivate::setSize(const QSizeF &size)
 {
 //    m_boundingRect = QRectF(pos().x(), pos().y(), size.width(), size.height());
     m_boundingRect = QRectF(0, 0, size.width(), size.height());
diff --git a/src/qscatterseries_p.h b/src/qscatterseries_p.h
index 0eeee39..99bcaa8 100644
--- a/src/qscatterseries_p.h
+++ b/src/qscatterseries_p.h
@@ -18,7 +18,7 @@ public:
     QScatterSeriesPrivate(QGraphicsItem *parent);
 
 public: // from ChartObjectInterface
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
 public: // from ChartThemeObserver
diff --git a/src/xylinechart/xylinechartitem.cpp b/src/xylinechart/xylinechartitem.cpp
index efdf70d..559a1f3 100644
--- a/src/xylinechart/xylinechartitem.cpp
+++ b/src/xylinechart/xylinechartitem.cpp
@@ -15,7 +15,7 @@ XYLineChartItem::XYLineChartItem(QXYChartSeries* series,QGraphicsItem *parent) :
     setFlags(QGraphicsItem::ItemClipsChildrenToShape);
 }
 
-void XYLineChartItem::setSize(const QSize &size)
+void XYLineChartItem::setSize(const QSizeF &size)
 {
     m_rect = QRect(0, 0, size.width(), size.height());
     prepareGeometryChange();
diff --git a/src/xylinechart/xylinechartitem_p.h b/src/xylinechart/xylinechartitem_p.h
index 55cc087..2ecc650 100644
--- a/src/xylinechart/xylinechartitem_p.h
+++ b/src/xylinechart/xylinechartitem_p.h
@@ -22,7 +22,7 @@ public:
    // virtual QPainterPath shape() const;
 
 public: // from ChartItem
-    void setSize(const QSize &size);
+    void setSize(const QSizeF &size);
     void setPlotDomain(const PlotDomain& data);
 
 private: