1 files changed, 71 insertions, 0 deletions
diff --git a/examples/charts/chartsgallery/boxplotdatareader.cpp b/examples/charts/chartsgallery/boxplotdatareader.cpp
new file mode 100644
index 00000000..47172704
--- /dev/null
+++ b/examples/charts/chartsgallery/boxplotdatareader.cpp
@@ -0,0 +1,71 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include "boxplotdatareader.h"
+
+#include <QBoxSet>
+
+#include <algorithm>
+
+BoxPlotDataReader::BoxPlotDataReader(QIODevice *device)
+    : m_textStream(device)
+{
+}
+
+void BoxPlotDataReader::readFile(QIODevice *device)
+{
+    m_textStream.setDevice(device);
+}
+
+bool BoxPlotDataReader::atEnd() const
+{
+    return m_textStream.atEnd();
+}
+
+QBoxSet *BoxPlotDataReader::readBox()
+{
+    //! [1]
+    QString line = m_textStream.readLine();
+    if (line.startsWith("#"))
+        return nullptr;
+    //! [1]
+
+    //! [2]
+    QStringList strList = line.split(QLatin1Char(' '), Qt::SkipEmptyParts);
+    //! [2]
+
+    //! [3]
+    m_sortedList.clear();
+    for (int i = 1; i < strList.count(); i++)
+        m_sortedList.append(strList.at(i).toDouble());
+
+    std::sort(m_sortedList.begin(), m_sortedList.end());
+    //! [3]
+
+    int count = m_sortedList.count();
+
+    //! [4]
+    auto box = new QBoxSet(strList.first());
+    box->setValue(QBoxSet::LowerExtreme, m_sortedList.first());
+    box->setValue(QBoxSet::UpperExtreme, m_sortedList.last());
+    box->setValue(QBoxSet::Median, findMedian(0, count));
+    box->setValue(QBoxSet::LowerQuartile, findMedian(0, count / 2));
+    box->setValue(QBoxSet::UpperQuartile, findMedian(count / 2 + (count % 2), count));
+    //! [4]
+
+    return box;
+}
+
+qreal BoxPlotDataReader::findMedian(int begin, int end)
+{
+    //! [5]
+    int count = end - begin;
+    if (count % 2) {
+        return m_sortedList.at(count / 2 + begin);
+    } else {
+        qreal right = m_sortedList.at(count / 2 + begin);
+        qreal left = m_sortedList.at(count / 2 - 1 + begin);
+        return (right + left) / 2.0;
+    }
+    //! [5]
+}