Axis formatter customization example

Also refactored the formatter api somewhat:

- Removed virtual from allowNegatives and allowZero and added a
setter function for those. This will make it cleaner if we need to
add similar properties to the axis formatter in the future, as
no new virtual methods can be added without breaking BC.

- Changed the labelValues array to labelStrings list, as it makes
more sense to directly format the strings in recalculate.

Change-Id: I3ea005afa984bb756845ca356b999762e0807415
Reviewed-by: Tomi Korpipää <tomi.korpipaa@digia.com>

10 files changed, 98 insertions, 105 deletions

diff --git a/src/datavisualization/axis/qabstract3daxis.cpp b/src/datavisualization/axis/qabstract3daxis.cpp
index 3b60ff5d..94ff4283 100644
--- a/src/datavisualization/axis/qabstract3daxis.cpp
+++ b/src/datavisualization/axis/qabstract3daxis.cpp
@@ -288,7 +288,7 @@ void QAbstract3DAxisPrivate::updateLabels()
     // Default implementation does nothing
 }
 
-void QAbstract3DAxisPrivate::setRange(float min, float max)
+void QAbstract3DAxisPrivate::setRange(float min, float max, bool suppressWarnings)
 {
     bool adjusted = false;
     if (!allowNegatives()) {
@@ -332,7 +332,7 @@ void QAbstract3DAxisPrivate::setRange(float min, float max)
     }
 
     if (minDirty || maxDirty) {
-        if (adjusted) {
+        if (adjusted && !suppressWarnings) {
             qWarning() << "Warning: Tried to set invalid range for axis."
                           " Range automatically adjusted to a valid one:"
                        << min << "-" << max << "-->" << m_min << "-" << m_max;
diff --git a/src/datavisualization/axis/qabstract3daxis_p.h b/src/datavisualization/axis/qabstract3daxis_p.h
index 80f8f0b2..38d5361c 100644
--- a/src/datavisualization/axis/qabstract3daxis_p.h
+++ b/src/datavisualization/axis/qabstract3daxis_p.h
@@ -47,7 +47,7 @@ public:
     inline bool isDefaultAxis() { return m_isDefaultAxis; }
     inline void setDefaultAxis(bool isDefault) { m_isDefaultAxis = isDefault; }
 
-    virtual void setRange(float min, float max);
+    virtual void setRange(float min, float max, bool suppressWarnings = false);
     virtual void setMin(float min);
     virtual void setMax (float max);
 
diff --git a/src/datavisualization/axis/qlogvalue3daxisformatter.cpp b/src/datavisualization/axis/qlogvalue3daxisformatter.cpp
index e8c2fbad..128d784d 100644
--- a/src/datavisualization/axis/qlogvalue3daxisformatter.cpp
+++ b/src/datavisualization/axis/qlogvalue3daxisformatter.cpp
@@ -96,6 +96,8 @@ QLogValue3DAxisFormatter::QLogValue3DAxisFormatter(QLogValue3DAxisFormatterPriva
                                                    QObject *parent) :
     QValue3DAxisFormatter(d, parent)
 {
+    setAllowNegatives(false);
+    setAllowZero(false);
 }
 
 /*!
@@ -104,6 +106,8 @@ QLogValue3DAxisFormatter::QLogValue3DAxisFormatter(QLogValue3DAxisFormatterPriva
 QLogValue3DAxisFormatter::QLogValue3DAxisFormatter(QObject *parent) :
     QValue3DAxisFormatter(new QLogValue3DAxisFormatterPrivate(this), parent)
 {
+    setAllowNegatives(false);
+    setAllowZero(false);
 }
 
 /*!
@@ -200,22 +204,6 @@ bool QLogValue3DAxisFormatter::showEdgeLabels() const
 /*!
  * \internal
  */
-bool QLogValue3DAxisFormatter::allowNegatives() const
-{
-    return false;
-}
-
-/*!
- * \internal
- */
-bool QLogValue3DAxisFormatter::allowZero() const
-{
-    return false;
-}
-
-/*!
- * \internal
- */
 QValue3DAxisFormatter *QLogValue3DAxisFormatter::createNewInstance() const
 {
     return new QLogValue3DAxisFormatter();
@@ -257,14 +245,6 @@ void QLogValue3DAxisFormatter::populateCopy(QValue3DAxisFormatter &copy) const
 /*!
  * \internal
  */
-QString QLogValue3DAxisFormatter::labelForIndex(int index) const
-{
-    return dptrc()->labelForIndex(index);
-}
-
-/*!
- * \internal
- */
 QLogValue3DAxisFormatterPrivate *QLogValue3DAxisFormatter::dptr()
 {
     return static_cast<QLogValue3DAxisFormatterPrivate *>(d_ptr.data());
@@ -305,6 +285,7 @@ void QLogValue3DAxisFormatterPrivate::recalculate()
 
     int subGridCount = m_axis->subSegmentCount() - 1;
     int segmentCount = m_axis->segmentCount();
+    QString labelFormat =  m_axis->labelFormat();
     qreal segmentStep;
     if (m_base > 0.0) {
         // Update parent axis segment counts
@@ -336,36 +317,53 @@ void QLogValue3DAxisFormatterPrivate::recalculate()
         m_gridPositions.resize(segmentCount + 1);
         m_subGridPositions.resize(segmentCount * subGridCount);
         m_labelPositions.resize(segmentCount + 1);
-        m_labelValues.resize(segmentCount + 1);
+        m_labelStrings.clear();
+        m_labelStrings.reserve(segmentCount + 1);
 
         // Calculate segment positions
         int index = 0;
         if (!m_evenMinSegment) {
             m_gridPositions[0] = 0.0f;
             m_labelPositions[0] = 0.0f;
-            m_labelValues[0] = qreal(m_min);
+            if (m_showEdgeLabels)
+                m_labelStrings << qptr()->stringForValue(qreal(m_min), labelFormat);
+            else
+                m_labelStrings << QString();
             index++;
         }
         for (int i = 0; i < segmentCount; i++) {
             float gridValue = float((minDiff + qreal(i)) / qreal(logRangeNormalizer));
             m_gridPositions[index] = gridValue;
             m_labelPositions[index] = gridValue;
-            m_labelValues[index] = qPow(m_base, minDiff + qreal(i) + logMin);
+            m_labelStrings << qptr()->stringForValue(qPow(m_base, minDiff + qreal(i) + logMin),
+                                                    labelFormat);
             index++;
         }
         // Ensure max value doesn't suffer from any rounding errors
         m_gridPositions[segmentCount] = 1.0f;
         m_labelPositions[segmentCount] = 1.0f;
-        m_labelValues[segmentCount] = qreal(m_max);
+        QString finalLabel;
+        if (m_showEdgeLabels || m_evenMaxSegment)
+            finalLabel = qptr()->stringForValue(qreal(m_max), labelFormat);
+
+        if (m_labelStrings.size() > segmentCount)
+            m_labelStrings.replace(segmentCount, finalLabel);
+        else
+            m_labelStrings << finalLabel;
     } else {
         // Grid lines and label positions are the same as the parent class, so call parent impl
         // first to populate those
         QValue3DAxisFormatterPrivate::doRecalculate();
 
-        // Label value array needs to be repopulated
+        // Label string list needs to be repopulated
         segmentStep = 1.0 / qreal(segmentCount);
-        for (int i = 0; i < m_labelPositions.size(); i++)
-            m_labelValues[i] = qExp(segmentStep * qreal(i) * m_logRangeNormalizer + m_logMin);
+
+        m_labelStrings << qptr()->stringForValue(qreal(m_min), labelFormat);
+        for (int i = 1; i < m_labelPositions.size() - 1; i++)
+            m_labelStrings[i] = qptr()->stringForValue(qExp(segmentStep * qreal(i)
+                                                           * m_logRangeNormalizer + m_logMin),
+                                                      labelFormat);
+        m_labelStrings << qptr()->stringForValue(qreal(m_max), labelFormat);
 
         m_evenMaxSegment = true;
         m_evenMinSegment = true;
@@ -426,15 +424,9 @@ float QLogValue3DAxisFormatterPrivate::valueAt(float position) const
     return float(qExp(logValue));
 }
 
-QString QLogValue3DAxisFormatterPrivate::labelForIndex(int index) const
+QLogValue3DAxisFormatter *QLogValue3DAxisFormatterPrivate::qptr()
 {
-    if (((index == m_gridPositions.size() - 1 && !m_evenMaxSegment)
-            || (index == 0 && !m_evenMinSegment))
-            && !m_showEdgeLabels) {
-        return QString();
-    } else {
-        return QValue3DAxisFormatterPrivate::labelForIndex(index);
-    }
+    return static_cast<QLogValue3DAxisFormatter *>(q_ptr);
 }
 
 QT_END_NAMESPACE_DATAVISUALIZATION
diff --git a/src/datavisualization/axis/qlogvalue3daxisformatter.h b/src/datavisualization/axis/qlogvalue3daxisformatter.h
index e9683821..62714a7d 100644
--- a/src/datavisualization/axis/qlogvalue3daxisformatter.h
+++ b/src/datavisualization/axis/qlogvalue3daxisformatter.h
@@ -52,14 +52,11 @@ signals:
     void showEdgeLabelsChanged(bool enabled);
 
 protected:
-    virtual bool allowNegatives() const;
-    virtual bool allowZero() const;
     virtual QValue3DAxisFormatter *createNewInstance() const;
     virtual void recalculate();
     virtual float positionAt(float value) const;
     virtual float valueAt(float position) const;
     virtual void populateCopy(QValue3DAxisFormatter &copy) const;
-    virtual QString labelForIndex(int index) const;
 
     QLogValue3DAxisFormatterPrivate *dptr();
     const QLogValue3DAxisFormatterPrivate *dptrc() const;
diff --git a/src/datavisualization/axis/qlogvalue3daxisformatter_p.h b/src/datavisualization/axis/qlogvalue3daxisformatter_p.h
index 6638e2c7..af056a06 100644
--- a/src/datavisualization/axis/qlogvalue3daxisformatter_p.h
+++ b/src/datavisualization/axis/qlogvalue3daxisformatter_p.h
@@ -50,7 +50,6 @@ public:
 
     float positionAt(float value) const;
     float valueAt(float position) const;
-    QString labelForIndex(int index) const;
 
 protected:
     QLogValue3DAxisFormatter *qptr();
diff --git a/src/datavisualization/axis/qvalue3daxis.cpp b/src/datavisualization/axis/qvalue3daxis.cpp
index b957de4d..3a8b902f 100644
--- a/src/datavisualization/axis/qvalue3daxis.cpp
+++ b/src/datavisualization/axis/qvalue3daxis.cpp
@@ -223,11 +223,11 @@ QValue3DAxisPrivate::~QValue3DAxisPrivate()
 {
 }
 
-void QValue3DAxisPrivate::setRange(float min, float max)
+void QValue3DAxisPrivate::setRange(float min, float max, bool suppressWarnings)
 {
     bool dirty = (min != m_min || max != m_max);
 
-    QAbstract3DAxisPrivate::setRange(min, max);
+    QAbstract3DAxisPrivate::setRange(min, max, suppressWarnings);
 
     if (dirty)
         emitLabelsChanged();
@@ -266,17 +266,9 @@ void QValue3DAxisPrivate::updateLabels()
 
     m_labelsDirty = false;
 
-    int labelCount = m_formatter->labelPositions().size();
-
-    QStringList newLabels;
-    newLabels.reserve(labelCount);
-
     m_formatter->d_ptr->recalculate();
-    for (int i = 0; i < labelCount; i++)
-        newLabels.append(m_formatter->labelForIndex(i));
 
-    if (m_labels != newLabels)
-        m_labels = newLabels;
+    m_labels = m_formatter->labelStrings();
 }
 
 bool QValue3DAxisPrivate::allowZero()
diff --git a/src/datavisualization/axis/qvalue3daxis_p.h b/src/datavisualization/axis/qvalue3daxis_p.h
index b49447af..eeccf527 100644
--- a/src/datavisualization/axis/qvalue3daxis_p.h
+++ b/src/datavisualization/axis/qvalue3daxis_p.h
@@ -42,7 +42,7 @@ public:
     QValue3DAxisPrivate(QValue3DAxis *q);
     virtual ~QValue3DAxisPrivate();
 
-    virtual void setRange(float min, float max);
+    virtual void setRange(float min, float max, bool suppressWarnings = false);
     virtual void setMin(float min);
     virtual void setMax (float max);
 
diff --git a/src/datavisualization/axis/qvalue3daxisformatter.cpp b/src/datavisualization/axis/qvalue3daxisformatter.cpp
index 92940a1b..4cd84d88 100644
--- a/src/datavisualization/axis/qvalue3daxisformatter.cpp
+++ b/src/datavisualization/axis/qvalue3daxisformatter.cpp
@@ -75,12 +75,28 @@ QValue3DAxisFormatter::~QValue3DAxisFormatter()
 }
 
 /*!
+ * Allow the parent axis to have negative values if \a allow is true.
+ */
+void QValue3DAxisFormatter::setAllowNegatives(bool allow)
+{
+    d_ptr->m_allowNegatives = allow;
+}
+
+/*!
  * \return \c true if negative values are valid values for parent axis.
  * The default implementation always returns true.
  */
 bool QValue3DAxisFormatter::allowNegatives() const
 {
-    return true;
+    return d_ptr->m_allowNegatives;
+}
+
+/*!
+ * Allow the parent axis to have zero value if \a allow is true.
+ */
+void QValue3DAxisFormatter::setAllowZero(bool allow)
+{
+    d_ptr->m_allowZero = allow;
 }
 
 /*!
@@ -89,7 +105,7 @@ bool QValue3DAxisFormatter::allowNegatives() const
  */
 bool QValue3DAxisFormatter::allowZero() const
 {
-    return true;
+    return d_ptr->m_allowZero;
 }
 
 /*!
@@ -104,16 +120,16 @@ QValue3DAxisFormatter *QValue3DAxisFormatter::createNewInstance() const
 }
 
 /*!
- * This method resizes and populates the label and grid line position arrays and the label value
+ * This method resizes and populates the label and grid line position arrays and the label strings
  * array, as well as calculates any values needed for mapping between value and position.
  * It is allowed to access the parent axis from inside this function.
  *
- * This method must be reimplemented in a subclass.
+ * This method must be reimplemented in a subclass if the default array contents are not suitable.
  *
- * See gridPositions(), subGridPositions(), labelPositions(), and labelValues() methods for
+ * See gridPositions(), subGridPositions(), labelPositions(), and labelStrings() methods for
  * documentation about the arrays that need to be resized and populated.
  *
- * \sa gridPositions(), subGridPositions(), labelPositions(), labelValues(), axis()
+ * \sa gridPositions(), subGridPositions(), labelPositions(), labelStrings(), axis()
  */
 void QValue3DAxisFormatter::recalculate()
 {
@@ -121,28 +137,14 @@ void QValue3DAxisFormatter::recalculate()
 }
 
 /*!
- * The parent axis uses this method to request axis label strings for label \a index,
- * using the value stored in label values array and QValue3DAxis::labelFormat property.
- * Reimplement this method in a subclass if the default labeling is not sufficient.
- * If an empty string is returned, the label is not shown.
- *
- * \return A string formatted using axis label formatter.
- *
- * \sa stringForValue(), labelValues(), QValue3DAxis::labelFormat
- */
-QString QValue3DAxisFormatter::labelForIndex(int index) const
-{
-    return d_ptr->labelForIndex(index);
-}
-
-/*!
+ * This method is used to format a string using the specified value and the specified format.
  * Reimplement this method in a subclass to resolve the formatted string for a given \a value
  * if the default formatting rules specified for QValue3DAxis::labelFormat property are not
  * sufficient.
  *
- * \return the formatted label string using \a value and \a format.
+ * \return the formatted label string using a \a value and a \a format.
  *
- * \sa recalculate(), labelForIndex(), QValue3DAxis::labelFormat
+ * \sa recalculate(), labelStrings(), QValue3DAxis::labelFormat
  */
 QString QValue3DAxisFormatter::stringForValue(qreal value, const QString &format) const
 {
@@ -257,15 +259,15 @@ QVector<float> &QValue3DAxisFormatter::labelPositions() const
 }
 
 /*!
- * \return a reference to the array of values used to generate label strings.
+ * \return a reference to the string list containing formatter label strings.
  * The array size must be equal to the size of the label positions array and
  * the indexes correspond to that array as well.
  *
  * \sa labelPositions()
  */
-QVector<qreal> &QValue3DAxisFormatter::labelValues() const
+QStringList &QValue3DAxisFormatter::labelStrings() const
 {
-    return d_ptr->m_labelValues;
+    return d_ptr->m_labelStrings;
 }
 
 // QValue3DAxisFormatterPrivate
@@ -277,7 +279,9 @@ QValue3DAxisFormatterPrivate::QValue3DAxisFormatterPrivate(QValue3DAxisFormatter
       m_max(0.0f),
       m_rangeNormalizer(0.0f),
       m_axis(0),
-      m_preparsedParamType(Utils::ParamTypeUnknown)
+      m_preparsedParamType(Utils::ParamTypeUnknown),
+      m_allowNegatives(true),
+      m_allowZero(true)
 {
 }
 
@@ -303,12 +307,14 @@ void QValue3DAxisFormatterPrivate::doRecalculate()
 {
     int segmentCount = m_axis->segmentCount();
     int subGridCount = m_axis->subSegmentCount() - 1;
+    QString labelFormat =  m_axis->labelFormat();
 
     m_gridPositions.resize(segmentCount + 1);
     m_subGridPositions.resize(segmentCount * subGridCount);
 
     m_labelPositions.resize(segmentCount + 1);
-    m_labelValues.resize(segmentCount + 1);
+    m_labelStrings.clear();
+    m_labelStrings.reserve(segmentCount + 1);
 
     // Use qreals for intermediate calculations for better accuracy on label values
     qreal segmentStep = 1.0 / qreal(segmentCount);
@@ -322,7 +328,8 @@ void QValue3DAxisFormatterPrivate::doRecalculate()
         qreal gridValue = segmentStep * qreal(i);
         m_gridPositions[i] = float(gridValue);
         m_labelPositions[i] = float(gridValue);
-        m_labelValues[i] = gridValue * rangeNormalizer + qreal(m_min);
+        m_labelStrings << q_ptr->stringForValue(gridValue * rangeNormalizer + qreal(m_min),
+                                                labelFormat);
         if (m_subGridPositions.size()) {
             for (int j = 0; j < subGridCount; j++)
                 m_subGridPositions[i * subGridCount + j] = gridValue + subSegmentStep * (j + 1);
@@ -332,6 +339,7 @@ void QValue3DAxisFormatterPrivate::doRecalculate()
     // Ensure max value doesn't suffer from any rounding errors
     m_gridPositions[segmentCount] = 1.0f;
     m_labelPositions[segmentCount] = 1.0f;
+    m_labelStrings << q_ptr->stringForValue(qreal(m_max), labelFormat);
 }
 
 void QValue3DAxisFormatterPrivate::populateCopy(QValue3DAxisFormatter &copy)
@@ -351,12 +359,6 @@ void QValue3DAxisFormatterPrivate::doPopulateCopy(QValue3DAxisFormatterPrivate &
     copy.m_subGridPositions = m_subGridPositions;
 }
 
-QString QValue3DAxisFormatterPrivate::labelForIndex(int index) const
-{
-    Q_ASSERT(index < m_labelValues.size());
-    return q_ptr->stringForValue(m_labelValues.at(index), m_axis->labelFormat());
-}
-
 QString QValue3DAxisFormatterPrivate::stringForValue(qreal value, const QString &format)
 {
     if (m_previousLabelFormat.compare(format)) {
@@ -383,10 +385,15 @@ void QValue3DAxisFormatterPrivate::setAxis(QValue3DAxis *axis)
 {
     Q_ASSERT(axis);
 
+    // These signals are all connected to markDirtyNoLabelChange slot, even though most of them
+    // do require labels to be regenerated. This is because the label regeneration is triggered
+    // elsewhere in these cases.
     connect(axis, &QValue3DAxis::segmentCountChanged,
             this, &QValue3DAxisFormatterPrivate::markDirtyNoLabelChange);
     connect(axis, &QValue3DAxis::subSegmentCountChanged,
             this, &QValue3DAxisFormatterPrivate::markDirtyNoLabelChange);
+    connect(axis, &QValue3DAxis::labelFormatChanged,
+            this, &QValue3DAxisFormatterPrivate::markDirtyNoLabelChange);
     connect(axis, &QAbstract3DAxis::rangeChanged,
             this, &QValue3DAxisFormatterPrivate::markDirtyNoLabelChange);
 
@@ -396,10 +403,12 @@ void QValue3DAxisFormatterPrivate::setAxis(QValue3DAxis *axis)
 void QValue3DAxisFormatterPrivate::markDirty(bool labelsChange)
 {
     m_needsRecalculate = true;
-    if (labelsChange)
-        m_axis->dptr()->emitLabelsChanged();
-    if (m_axis && m_axis->orientation() != QAbstract3DAxis::AxisOrientationNone)
-        emit m_axis->dptr()->formatterDirty();
+    if (m_axis) {
+        if (labelsChange)
+            m_axis->dptr()->emitLabelsChanged();
+        if (m_axis && m_axis->orientation() != QAbstract3DAxis::AxisOrientationNone)
+            emit m_axis->dptr()->formatterDirty();
+    }
 }
 
 void QValue3DAxisFormatterPrivate::markDirtyNoLabelChange()
diff --git a/src/datavisualization/axis/qvalue3daxisformatter.h b/src/datavisualization/axis/qvalue3daxisformatter.h
index 970087d3..5ecc798d 100644
--- a/src/datavisualization/axis/qvalue3daxisformatter.h
+++ b/src/datavisualization/axis/qvalue3daxisformatter.h
@@ -22,6 +22,8 @@
 #include <QtDataVisualization/qdatavisualizationglobal.h>
 #include <QtCore/QObject>
 #include <QtCore/QScopedPointer>
+#include <QtCore/QVector>
+#include <QtCore/QStringList>
 
 QT_BEGIN_NAMESPACE_DATAVISUALIZATION
 
@@ -31,7 +33,6 @@ class QValue3DAxis;
 class QT_DATAVISUALIZATION_EXPORT QValue3DAxisFormatter : public QObject
 {
     Q_OBJECT
-
 protected:
     explicit QValue3DAxisFormatter(QValue3DAxisFormatterPrivate *d, QObject *parent = 0);
 public:
@@ -39,11 +40,13 @@ public:
     virtual ~QValue3DAxisFormatter();
 
 protected:
-    virtual bool allowNegatives() const;
-    virtual bool allowZero() const;
+    void setAllowNegatives(bool allow);
+    bool allowNegatives() const;
+    void setAllowZero(bool allow);
+    bool allowZero() const;
+
     virtual QValue3DAxisFormatter *createNewInstance() const;
     virtual void recalculate();
-    virtual QString labelForIndex(int index) const;
     virtual QString stringForValue(qreal value, const QString &format) const;
     virtual float positionAt(float value) const;
     virtual float valueAt(float position) const;
@@ -55,7 +58,7 @@ protected:
     QVector<float> &gridPositions() const;
     QVector<float> &subGridPositions() const;
     QVector<float> &labelPositions() const;
-    QVector<qreal> &labelValues() const;
+    QStringList &labelStrings() const;
 
     QScopedPointer<QValue3DAxisFormatterPrivate> d_ptr;
 
diff --git a/src/datavisualization/axis/qvalue3daxisformatter_p.h b/src/datavisualization/axis/qvalue3daxisformatter_p.h
index 7e661b62..f7fd001e 100644
--- a/src/datavisualization/axis/qvalue3daxisformatter_p.h
+++ b/src/datavisualization/axis/qvalue3daxisformatter_p.h
@@ -29,7 +29,6 @@
 #include "datavisualizationglobal_p.h"
 #include "qvalue3daxisformatter.h"
 #include "utils_p.h"
-#include <QtCore/QVector>
 
 #ifndef QVALUE3DAXISFORMATTER_P_H
 #define QVALUE3DAXISFORMATTER_P_H
@@ -51,7 +50,6 @@ public:
     void populateCopy(QValue3DAxisFormatter &copy);
     void doPopulateCopy(QValue3DAxisFormatterPrivate &copy);
 
-    QString labelForIndex(int index) const;
     QString stringForValue(qreal value, const QString &format);
     float positionAt(float value) const;
     float valueAt(float position) const;
@@ -74,7 +72,7 @@ protected:
     QVector<float> m_gridPositions;
     QVector<float> m_subGridPositions;
     QVector<float> m_labelPositions;
-    QVector<qreal> m_labelValues;
+    QStringList m_labelStrings;
 
     QValue3DAxis *m_axis;
 
@@ -82,6 +80,9 @@ protected:
     QByteArray m_labelFormatArray;
     Utils::ParamType m_preparsedParamType;
 
+    bool m_allowNegatives;
+    bool m_allowZero;
+
     friend class QValue3DAxisFormatter;
 };