Clarified box-and-whiskers chart documentation

The documentation now explains that the label is the category of
QBarCategoryAxis that is used for slots in box-and-whiskers chart.

Change-Id: I6a16a0f02f49790ab923c1a4432dc308d8246fc2
Task-number: QTRD-3697
Reviewed-by: Mika Salmela <mika.salmela@theqtcompany.com>

3 files changed, 20 insertions, 8 deletions

diff --git a/src/charts/boxplotchart/qboxplotseries.cpp b/src/charts/boxplotchart/qboxplotseries.cpp
index 5e67130a..e8a3fa7e 100644
--- a/src/charts/boxplotchart/qboxplotseries.cpp
+++ b/src/charts/boxplotchart/qboxplotseries.cpp
@@ -37,14 +37,20 @@ QT_CHARTS_BEGIN_NAMESPACE
     \inmodule Qt Charts
     \brief Series for creating box-and-whiskers chart.
 
-    QBoxPlotSeries represents a series of data shown as box-and-whisker bars. The purpose of this class is to act as
-    a container for single box-and-whisker items. Each item is drawn to own slot. If chart includes multiple instances of
-    QBoxPlotSeries then box-and-whiskers items with the same index are drawn to same slot.
+    QBoxPlotSeries represents a series of data shown as box-and-whisker bars. The purpose of this
+    class is to act as a container for single box-and-whisker items. Each item is drawn to own slot.
+    If chart includes multiple instances of QBoxPlotSeries then box-and-whiskers items with the same
+    index are drawn to same slot.
 
-    See the \l {Box and Whiskers Example} {box-and-whiskers chart example} to learn how to create a box-and-whiskers chart.
+    \note The slot, each item in QBoxPlotSeries is drawn, represents a category in QBarCategoryAxis.
+    The category labels have to be unique. If same category label is defined for several
+    box-and-whisker items only the first one is drawn.
+
+    See the \l {Box and Whiskers Example} {box-and-whiskers chart example} to learn how to create a
+    box-and-whiskers chart.
     \image examples_boxplotchart.png
 
-    \sa QBoxSet
+    \sa QBoxSet, QBarCategoryAxis
 */
 /*!
     \fn QBoxPlotSeries::boxsetsAdded(QList<QBoxSet *> sets)
diff --git a/src/charts/boxplotchart/qboxset.cpp b/src/charts/boxplotchart/qboxset.cpp
index 9b1ad08f..a9e79887 100644
--- a/src/charts/boxplotchart/qboxset.cpp
+++ b/src/charts/boxplotchart/qboxset.cpp
@@ -162,7 +162,7 @@ void QBoxSet::append(const QList<qreal> &values)
 }
 
 /*!
-    Sets new \a label for set.
+    Sets new \a label for the category of the set.
 */
 void QBoxSet::setLabel(const QString label)
 {
@@ -170,7 +170,7 @@ void QBoxSet::setLabel(const QString label)
 }
 
 /*!
-    Returns label of the set.
+    Returns the label of the the category of the set.
 */
 QString QBoxSet::label() const
 {
diff --git a/src/chartsqml2/declarativeboxplotseries.cpp b/src/chartsqml2/declarativeboxplotseries.cpp
index 63f5384a..c5835a3b 100644
--- a/src/chartsqml2/declarativeboxplotseries.cpp
+++ b/src/chartsqml2/declarativeboxplotseries.cpp
@@ -43,7 +43,7 @@ QT_CHARTS_BEGIN_NAMESPACE
 */
 /*!
     \qmlproperty string BoxSet::label
-    Defines the label of the box-and-whiskers set.
+    Defines the label of the category of the box-and-whiskers set.
 */
 /*!
     \qmlproperty int BoxSet::count
@@ -122,6 +122,10 @@ QT_CHARTS_BEGIN_NAMESPACE
     slot. If chart includes multiple instances of BoxPlotSeries then box-and-whiskers items with the
     same index are drawn to same slot.
 
+    \note The slot, each item in BoxPlotSeries is drawn, represents a category in BarCategoryAxis.
+    The category labels have to be unique. If same category label is defined for several
+    box-and-whisker items only the first one is drawn.
+
     The following QML shows how to create a simple box-and-whiskers chart:
     \code
     import QtQuick 2.0
@@ -150,6 +154,8 @@ QT_CHARTS_BEGIN_NAMESPACE
     \image examples_qmlboxplot.png
     \endfloat
     \clearfloat
+
+    \sa BoxSet, BarCategoryAxis
 */
 
 /*!