1 files changed, 114 insertions, 0 deletions
diff --git a/examples/datavisualization/graphgallery/variantbardataproxy.cpp b/examples/datavisualization/graphgallery/variantbardataproxy.cpp
new file mode 100644
index 00000000..8fe73abc
--- /dev/null
+++ b/examples/datavisualization/graphgallery/variantbardataproxy.cpp
@@ -0,0 +1,114 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "variantbardataproxy.h"
+
+VariantBarDataProxy::VariantBarDataProxy() = default;
+
+VariantBarDataProxy::~VariantBarDataProxy()
+{
+    delete m_dataSet;
+}
+
+void VariantBarDataProxy::setDataSet(VariantDataSet *newSet)
+{
+    if (!m_dataSet.isNull())
+        QObject::disconnect(m_dataSet.data(), nullptr, this, nullptr);
+
+    m_dataSet = newSet;
+
+    if (!m_dataSet.isNull()) {
+        QObject::connect(m_dataSet.data(), &VariantDataSet::itemsAdded, this,
+                         &VariantBarDataProxy::handleItemsAdded);
+        QObject::connect(m_dataSet.data(), &VariantDataSet::dataCleared, this,
+                         &VariantBarDataProxy::handleDataCleared);
+    }
+    resolveDataSet();
+}
+
+VariantDataSet *VariantBarDataProxy::dataSet()
+{
+    return m_dataSet.data();
+}
+
+void VariantBarDataProxy::setMapping(VariantBarDataMapping *mapping)
+{
+    if (!m_mapping.isNull()) {
+        QObject::disconnect(m_mapping.data(), &VariantBarDataMapping::mappingChanged, this,
+                            &VariantBarDataProxy::handleMappingChanged);
+    }
+
+    m_mapping = mapping;
+
+    if (!m_mapping.isNull()) {
+        QObject::connect(m_mapping.data(), &VariantBarDataMapping::mappingChanged, this,
+                         &VariantBarDataProxy::handleMappingChanged);
+    }
+
+    resolveDataSet();
+}
+
+VariantBarDataMapping *VariantBarDataProxy::mapping()
+{
+    return m_mapping.data();
+}
+
+void VariantBarDataProxy::handleItemsAdded(int index, int count)
+{
+    Q_UNUSED(index);
+    Q_UNUSED(count);
+
+    // Resolve new items
+    resolveDataSet();
+}
+
+void VariantBarDataProxy::handleDataCleared()
+{
+    // Data cleared, reset array
+    resetArray(nullptr);
+}
+
+void VariantBarDataProxy::handleMappingChanged()
+{
+    resolveDataSet();
+}
+
+// Resolve entire dataset into QBarDataArray.
+//! [0]
+void VariantBarDataProxy::resolveDataSet()
+{
+    // If we have no data or mapping, or the categories are not defined, simply clear the array
+    if (m_dataSet.isNull() || m_mapping.isNull() || !m_mapping->rowCategories().size()
+            || !m_mapping->columnCategories().size()) {
+        resetArray(nullptr);
+        return;
+    }
+    const VariantDataItemList &itemList = m_dataSet->itemList();
+
+    int rowIndex = m_mapping->rowIndex();
+    int columnIndex = m_mapping->columnIndex();
+    int valueIndex = m_mapping->valueIndex();
+    const QStringList &rowList = m_mapping->rowCategories();
+    const QStringList &columnList = m_mapping->columnCategories();
+
+    // Sort values into rows and columns
+    using ColumnValueMap = QHash<QString, float>;
+    QHash <QString, ColumnValueMap> itemValueMap;
+    for (const VariantDataItem *item : itemList) {
+        itemValueMap[item->at(rowIndex).toString()][item->at(columnIndex).toString()]
+                = item->at(valueIndex).toReal();
+    }
+
+    // Create a new data array in format the parent class understands
+    auto *newProxyArray = new QBarDataArray;
+    for (const QString &rowKey : rowList) {
+        auto *newProxyRow = new QBarDataRow(columnList.size());
+        for (qsizetype i = 0; i < columnList.size(); ++i)
+            (*newProxyRow)[i].setValue(itemValueMap[rowKey][columnList.at(i)]);
+        newProxyArray->append(newProxyRow);
+    }
+
+    // Finally, reset the data array in the parent class
+    resetArray(newProxyArray);
+}
+//! [0]