1 files changed, 138 insertions, 0 deletions
diff --git a/examples/datavisualization/qmlaxishandling/customformatter.cpp b/examples/datavisualization/qmlaxishandling/customformatter.cpp
new file mode 100644
index 00000000..b0473159
--- /dev/null
+++ b/examples/datavisualization/qmlaxishandling/customformatter.cpp
@@ -0,0 +1,138 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include "customformatter.h"
+#include <QtDataVisualization/qvalue3daxis.h>
+#include <QtQml/qqmlextensionplugin.h>
+
+static const qreal oneDayMs = 60.0 * 60.0 * 24.0 * 1000.0;
+
+CustomFormatter::CustomFormatter(QObject *parent) :
+    QValue3DAxisFormatter(parent)
+{
+    qRegisterMetaType<QValue3DAxisFormatter *>();
+}
+
+CustomFormatter::~CustomFormatter()
+{
+}
+
+//! [1]
+QValue3DAxisFormatter *CustomFormatter::createNewInstance() const
+{
+    return new CustomFormatter();
+}
+
+void CustomFormatter::populateCopy(QValue3DAxisFormatter &copy) const
+{
+    QValue3DAxisFormatter::populateCopy(copy);
+
+    CustomFormatter *customFormatter = static_cast<CustomFormatter *>(&copy);
+    customFormatter->m_originDate = m_originDate;
+    customFormatter->m_selectionFormat = m_selectionFormat;
+}
+//! [1]
+
+//! [2]
+void CustomFormatter::recalculate()
+{
+    // We want our axis to always have gridlines at date breaks
+
+    // Convert range into QDateTimes
+    QDateTime minTime = valueToDateTime(qreal(axis()->min()));
+    QDateTime maxTime = valueToDateTime(qreal(axis()->max()));
+
+    // Find out the grid counts
+    QTime midnight(0, 0);
+    QDateTime minFullDate(minTime.date(), midnight);
+    int gridCount = 0;
+    if (minFullDate != minTime)
+        minFullDate = minFullDate.addDays(1);
+    QDateTime maxFullDate(maxTime.date(), midnight);
+
+    gridCount += minFullDate.daysTo(maxFullDate) + 1;
+    int subGridCount = axis()->subSegmentCount() - 1;
+
+    // Reserve space for position arrays and label strings
+    gridPositions().resize(gridCount);
+    subGridPositions().resize((gridCount + 1) * subGridCount);
+    labelPositions().resize(gridCount);
+    labelStrings().reserve(gridCount);
+
+    // Calculate positions and format labels
+    qint64 startMs = minTime.toMSecsSinceEpoch();
+    qint64 endMs = maxTime.toMSecsSinceEpoch();
+    qreal dateNormalizer = endMs - startMs;
+    qreal firstLineOffset = (minFullDate.toMSecsSinceEpoch() - startMs) / dateNormalizer;
+    qreal segmentStep = oneDayMs / dateNormalizer;
+    qreal subSegmentStep = 0;
+    if (subGridCount > 0)
+        subSegmentStep = segmentStep / qreal(subGridCount + 1);
+
+    for (int i = 0; i < gridCount; i++) {
+        qreal gridValue = firstLineOffset + (segmentStep * qreal(i));
+        gridPositions()[i] = float(gridValue);
+        labelPositions()[i] = float(gridValue);
+        labelStrings() << minFullDate.addDays(i).toString(axis()->labelFormat());
+    }
+
+    for (int i = 0; i <= gridCount; i++) {
+        if (subGridPositions().size()) {
+            for (int j = 0; j < subGridCount; j++) {
+                float position;
+                if (i)
+                    position =  gridPositions().at(i - 1) + subSegmentStep * (j + 1);
+                else
+                    position =  gridPositions().at(0) - segmentStep + subSegmentStep * (j + 1);
+                if (position > 1.0f || position < 0.0f)
+                    position = gridPositions().at(0);
+                subGridPositions()[i * subGridCount + j] = position;
+            }
+        }
+    }
+}
+//! [2]
+
+//! [3]
+QString CustomFormatter::stringForValue(qreal value, const QString &format) const
+{
+    Q_UNUSED(format);
+
+    return valueToDateTime(value).toString(m_selectionFormat);
+}
+//! [3]
+
+QDate CustomFormatter::originDate() const
+{
+    return m_originDate;
+}
+
+QString CustomFormatter::selectionFormat() const
+{
+    return m_selectionFormat;
+}
+
+void CustomFormatter::setOriginDate(QDate date)
+{
+    if (m_originDate != date) {
+        m_originDate = date;
+        markDirty(true);
+        emit originDateChanged(date);
+    }
+}
+
+void CustomFormatter::setSelectionFormat(const QString &format)
+{
+    if (m_selectionFormat != format) {
+        m_selectionFormat = format;
+        markDirty(true); // Necessary to regenerate already visible selection label
+        emit selectionFormatChanged(format);
+    }
+}
+
+//! [0]
+QDateTime CustomFormatter::valueToDateTime(qreal value) const
+{
+    return m_originDate.startOfDay().addMSecs(qint64(oneDayMs * value));
+}
+//! [0]