diff --git a/src/axis/qabstractaxis.cpp b/src/axis/qabstractaxis.cpp
index 4d4e685..a96a08a 100644
--- a/src/axis/qabstractaxis.cpp
+++ b/src/axis/qabstractaxis.cpp
@@ -561,15 +561,15 @@ void QAbstractAxis::hide()
 }
 
 
-void QAbstractAxis::setMin(const QVariant& min)
+void QAbstractAxis::setMin(const qreal min)
 {
     d_ptr->setMin(min);
 }
-void QAbstractAxis::setMax(const QVariant& max)
+void QAbstractAxis::setMax(const qreal max)
 {
     d_ptr->setMax(max);
 }
-void QAbstractAxis::setRange(const QVariant& min, const QVariant& max)
+void QAbstractAxis::setRange(const qreal min, const qreal max)
 {
     d_ptr->setRange(min,max);
 }
@@ -585,7 +585,10 @@ QAbstractAxisPrivate::QAbstractAxisPrivate(QAbstractAxis* q):
     m_shadesVisible(false),
     m_shadesBrush(Qt::SolidPattern),
     m_shadesOpacity(1.0),
-    m_orientation(Qt::Orientation(0))
+    m_orientation(Qt::Orientation(0)),
+    m_min(0),
+    m_max(0),
+    m_ticksCount(5)
 {
 
 }
diff --git a/src/axis/qabstractaxis.h b/src/axis/qabstractaxis.h
index 51c9cd1..56b07d6 100644
--- a/src/axis/qabstractaxis.h
+++ b/src/axis/qabstractaxis.h
@@ -101,9 +101,9 @@ public:
     QColor shadesBorderColor() const;
 
     //range handling
-    void setMin(const QVariant& min);
-    void setMax(const QVariant& max);
-    void setRange(const QVariant& min, const QVariant& max);
+    void setMin(const qreal min);
+    void setMax(const qreal max);
+    void setRange(const qreal min, const qreal max);
 
     void show();
     void hide();
diff --git a/src/axis/qabstractaxis_p.h b/src/axis/qabstractaxis_p.h
index c94c67d..631e92e 100644
--- a/src/axis/qabstractaxis_p.h
+++ b/src/axis/qabstractaxis_p.h
@@ -51,9 +51,9 @@ public:
     virtual ChartAxis* createGraphics(ChartPresenter* presenter) = 0;
 
 protected:
-    virtual void setMin(const QVariant& min) = 0;
-    virtual void setMax(const QVariant& max) = 0;
-    virtual void setRange(const QVariant& min, const QVariant& max) = 0;
+    virtual void setMin(const qreal min) = 0;
+    virtual void setMax(const qreal max) = 0;
+    virtual void setRange(const qreal min, const qreal max) = 0;
     virtual int ticksCount() const = 0;
 
 public:
@@ -79,6 +79,11 @@ public:
 
     Qt::Orientation m_orientation;
 
+    // range
+    qreal m_min;
+    qreal m_max;
+    int m_ticksCount;
+
     friend class QAbstractAxis;
 };
 
diff --git a/src/axis/qcategoriesaxis.cpp b/src/axis/qcategoriesaxis.cpp
index 7562a0e..d1bb3f6 100644
--- a/src/axis/qcategoriesaxis.cpp
+++ b/src/axis/qcategoriesaxis.cpp
@@ -130,11 +130,7 @@ QString QCategoriesAxis::at(int index) const
 void QCategoriesAxis::setMin(const QString& minCategory)
 {
     Q_D(QCategoriesAxis);
-    int minIndex = d->m_categories.indexOf(minCategory);
-    if (minIndex == -1)
-        return;
-//    else
-//        QAbstractAxis::setMin(minIndex);
+    d->setMinCategory(minCategory);
 }
 
 /*!
@@ -143,11 +139,7 @@ void QCategoriesAxis::setMin(const QString& minCategory)
 void QCategoriesAxis::setMax(const QString& maxCategory)
 {
     Q_D(QCategoriesAxis);
-    int maxIndex = d->m_categories.indexOf(maxCategory);
-    if (maxIndex == -1)
-        return;
-//    else
-//        QAbstractAxis::setMax(maxIndex);
+    d->setMaxCategory(maxCategory);
 }
 
 /*!
@@ -155,9 +147,8 @@ void QCategoriesAxis::setMax(const QString& maxCategory)
 */
 void QCategoriesAxis::setRange(const QString& minCategory, const QString& maxCategory)
 {
-    // TODO: what if maxCategory < minCategory?
-    setMin(minCategory);
-    setMax(maxCategory);
+    Q_D(QCategoriesAxis);
+    d->setRangeCategory(minCategory,maxCategory);
 }
 
 /*!
@@ -181,23 +172,68 @@ QCategoriesAxisPrivate::~QCategoriesAxisPrivate()
 
 }
 
+void QCategoriesAxisPrivate::setMinCategory(const QString& minCategory)
+{
+    // Convert the category to value
+    int minIndex = m_categories.indexOf(minCategory);
+    if (minIndex == -1) {
+        return;
+    }
+    setRange(minIndex,m_max);
+}
 
-void QCategoriesAxisPrivate::setMin(const QVariant& min)
+void QCategoriesAxisPrivate::setMaxCategory(const QString& maxCategory)
 {
-    Q_Q(QCategoriesAxis);
-    q->setMin(min.toString());
+    // Convert the category to value
+    int maxIndex = m_categories.indexOf(maxCategory);
+    if (maxIndex == -1) {
+        return;
+    }
+    setRange(m_min,maxIndex);
 }
 
-void QCategoriesAxisPrivate::setMax(const QVariant& max)
+void QCategoriesAxisPrivate::setRangeCategory(const QString& minCategory, const QString& maxCategory)
 {
-    Q_Q(QCategoriesAxis);
-    q->setMax(max.toString());
+    // TODO:
+    int minIndex = m_categories.indexOf(minCategory);
+    if (minIndex == -1) {
+        return;
+    }
+    int maxIndex = m_categories.indexOf(maxCategory);
+    if (maxIndex == -1) {
+        return;
+    }
+    setRange(minIndex,maxIndex);
 }
 
-void QCategoriesAxisPrivate::setRange(const QVariant& min, const QVariant& max)
+void QCategoriesAxisPrivate::setMin(const qreal min)
 {
-   Q_Q(QCategoriesAxis);
-   q->setRange(min.toString(),max.toString());
+    setRange(min,m_max);
+}
+
+void QCategoriesAxisPrivate::setMax(const qreal max)
+{
+    setRange(m_min,max);
+}
+
+void QCategoriesAxisPrivate::setRange(const qreal min, const qreal max)
+{
+    Q_Q(QCategoriesAxis);
+    bool changed = false;
+    if (!qFuzzyIsNull(m_min - min)) {
+        m_min = min;
+        changed = true;
+    }
+
+    if (!qFuzzyIsNull(m_max - max)) {
+        m_max = max;
+        changed = true;
+    }
+
+    if (changed) {
+        emit this->changed(m_min, m_max, m_ticksCount, false);
+        emit q->categoriesChanged();
+    }
 }
 
 int QCategoriesAxisPrivate::ticksCount() const
@@ -205,6 +241,19 @@ int QCategoriesAxisPrivate::ticksCount() const
     return m_categories.count()+1;
 }
 
+void QCategoriesAxisPrivate::handleAxisRangeChanged(qreal min, qreal max,int count)
+{
+//   Q_Q(QCategoriesAxis);
+//   q->setRange(min,max);
+//   q->setTicksCount(count);
+    m_min = min;
+    m_max = max;
+    m_ticksCount = count;
+
+    // TODO?:
+    //emit updated();
+}
+
 ChartAxis* QCategoriesAxisPrivate::createGraphics(ChartPresenter* presenter)
 {
     Q_Q( QCategoriesAxis);
@@ -213,7 +262,6 @@ ChartAxis* QCategoriesAxisPrivate::createGraphics(ChartPresenter* presenter)
     }else{
         return new ChartCategoriesAxisX(q,presenter);
     }
-
 }
 
 #include "moc_qcategoriesaxis.cpp"
diff --git a/src/axis/qcategoriesaxis_p.h b/src/axis/qcategoriesaxis_p.h
index b9eb367..332c8c6 100644
--- a/src/axis/qcategoriesaxis_p.h
+++ b/src/axis/qcategoriesaxis_p.h
@@ -47,19 +47,29 @@ public:
     ChartAxis* createGraphics(ChartPresenter* presenter);
 
 private:
+    void setMinCategory(const QString& minCategory);
+    void setMaxCategory(const QString& maxCategory);
+    void setRangeCategory(const QString& minCategory, const QString& maxCategory);
+
     //range handling
-    void setMin(const QVariant& min);
-    void setMax(const QVariant& max);
-    void setRange(const QVariant& min, const QVariant& max);
+    void setMin(const qreal min);
+    void setMax(const qreal max);
+    void setRange(const qreal min, const qreal max);
     int ticksCount() const;
 
+Q_SIGNALS:
+    void changed(qreal min, qreal max, int tickCount,bool niceNumbers);
+
+public Q_SLOTS:
+    void handleAxisRangeChanged(qreal min, qreal max,int count);
+
 private:
     QStringList m_categories;
     QString m_minCategory;
     QString m_maxCategory;
 
-Q_SIGNALS:
-    void updated();
+//    qreal m_rangeMin;
+//    qreal m_rangeMax;
 
 private:
     Q_DECLARE_PUBLIC(QCategoriesAxis)
diff --git a/src/axis/qvaluesaxis.cpp b/src/axis/qvaluesaxis.cpp
index 2c06431..a479b2a 100644
--- a/src/axis/qvaluesaxis.cpp
+++ b/src/axis/qvaluesaxis.cpp
@@ -131,23 +131,7 @@ qreal QValuesAxis::max() const
 void QValuesAxis::setRange(qreal min, qreal max)
 {
     Q_D(QValuesAxis);
-    bool changed = false;
-    if (!qFuzzyIsNull(d->m_min - min)) {
-        d->m_min = min;
-        changed = true;
-        emit minChanged(min);
-    }
-
-    if (!qFuzzyIsNull(d->m_max - max)) {
-        d->m_max = max;
-        changed = true;
-        emit maxChanged(max);
-    }
-
-    if (changed) {
-       emit rangeChanged(d->m_min,d->m_max);
-       emit d->changed(d->m_min, d->m_max, d->m_ticksCount, d->m_niceNumbers);
-    }
+    d->setRange(min,max);
 }
 
 /*!
@@ -196,10 +180,7 @@ QAbstractAxis::AxisType QValuesAxis::type() const
 
 QValuesAxisPrivate::QValuesAxisPrivate(QValuesAxis* q):
     QAbstractAxisPrivate(q),
-    m_min(0),
-    m_max(0),
-    m_niceNumbers(false),
-    m_ticksCount(5)
+    m_niceNumbers(false)
 {
 
 }
@@ -217,30 +198,36 @@ void QValuesAxisPrivate::handleAxisRangeChanged(qreal min, qreal max,int count)
 }
 
 
-void QValuesAxisPrivate::setMin(const QVariant& min)
+void QValuesAxisPrivate::setMin(const qreal min)
 {
-    Q_Q(QValuesAxis);
-    bool ok;
-    qreal value = min.toReal(&ok);
-    if(ok) q->setMin(value);
+    setRange(min,m_max);
 }
 
-void QValuesAxisPrivate::setMax(const QVariant& max)
+void QValuesAxisPrivate::setMax(const qreal max)
 {
-    Q_Q(QValuesAxis);
-    bool ok;
-    qreal value = max.toReal(&ok);
-    if(ok) q->setMax(value);
+    setRange(m_min,max);
 }
 
-void QValuesAxisPrivate::setRange(const QVariant& min, const QVariant& max)
+void QValuesAxisPrivate::setRange(const qreal min, const qreal max)
 {
     Q_Q(QValuesAxis);
-    bool ok1;
-    bool ok2;
-    qreal value1 = min.toReal(&ok1);
-    qreal value2 = max.toReal(&ok2);
-    if(ok1&&ok2) q->setRange(value1,value2);
+    bool changed = false;
+    if (!qFuzzyIsNull(m_min - min)) {
+        m_min = min;
+        changed = true;
+        emit q->minChanged(min);
+    }
+
+    if (!qFuzzyIsNull(m_max - max)) {
+        m_max = max;
+        changed = true;
+        emit q->maxChanged(max);
+    }
+
+    if (changed) {
+       emit q->rangeChanged(m_min,m_max);
+       emit this->changed(m_min, m_max, m_ticksCount, m_niceNumbers);
+    }
 }
 
 int QValuesAxisPrivate::ticksCount() const
diff --git a/src/axis/qvaluesaxis_p.h b/src/axis/qvaluesaxis_p.h
index ccd870c..fb4e39a 100644
--- a/src/axis/qvaluesaxis_p.h
+++ b/src/axis/qvaluesaxis_p.h
@@ -52,16 +52,13 @@ public:
     ChartAxis* createGraphics(ChartPresenter* presenter);
 
 protected:
-    void setMin(const QVariant& min);
-    void setMax(const QVariant& max);
-    void setRange(const QVariant& min, const QVariant& max);
+    void setMin(const qreal min);
+    void setMax(const qreal max);
+    void setRange(const qreal min, const qreal max);
     int ticksCount() const;
 
 private:
-    qreal m_min;
-    qreal m_max;
     bool m_niceNumbers;
-    int m_ticksCount;
     Q_DECLARE_PUBLIC(QValuesAxis)
 };
 
diff --git a/src/barchart/qbarseries.cpp b/src/barchart/qbarseries.cpp
index 970e96a..0b29cb2 100644
--- a/src/barchart/qbarseries.cpp
+++ b/src/barchart/qbarseries.cpp
@@ -28,6 +28,7 @@
 #include "charttheme_p.h"
 #include "chartanimator_p.h"
 #include "qvaluesaxis.h"
+#include "qcategoriesaxis.h"
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
@@ -610,7 +611,7 @@ QList<LegendMarker*> QBarSeriesPrivate::createLegendMarker(QLegend* legend)
 
 QAbstractAxis* QBarSeriesPrivate::createAxisX(QObject* parent)
 {
-    return new QValuesAxis(parent);
+    return new QCategoriesAxis(parent);
 }
 
 QAbstractAxis* QBarSeriesPrivate::createAxisY(QObject* parent)