Add spline-series example

Example shows using of points selection and adding light markers to plot.
User can select shapes for markers and light markers and set images for them.

[QtCharts][Example] Added Example

Task-number: QTBUG-89445
Task-number: QTBUG-92884
Change-Id: Id0c9a5a7b696b7a51804575f645578d06c717d4e
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
(cherry picked from commit 5070d1fc3ee4b63c8a04f1fdf9226b779a6cb167)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

8 files changed, 439 insertions, 0 deletions

diff --git a/examples/charts/pointsselectionandmarkers/CMakeLists.txt b/examples/charts/pointsselectionandmarkers/CMakeLists.txt
new file mode 100644
index 00000000..c2e68bd3
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/CMakeLists.txt
@@ -0,0 +1,54 @@
+# Generated from pointsselectionandmarkers.pro.
+
+cmake_minimum_required(VERSION 3.14)
+project(pointsselectionandmarkers LANGUAGES CXX)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+  set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/charts/pointsselectionandmarkers")
+
+find_package(Qt6 COMPONENTS Core)
+find_package(Qt6 COMPONENTS Gui)
+find_package(Qt6 COMPONENTS Charts)
+
+qt_add_executable(pointsselectionandmarkers
+    utilities.h utilities.cpp
+    main.cpp
+)
+
+set_target_properties(pointsselectionandmarkers PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(pointsselectionandmarkers PUBLIC
+    Qt::Charts
+    Qt::Core
+    Qt::Gui
+)
+
+set(pointsselectionandmarkers_resource_files
+    "blue_triangle.png"
+    "green_triangle.png"
+)
+
+qt6_add_resources(pointsselectionandmarkers "images"
+    PREFIX
+        "/"
+    FILES
+        ${pointsselectionandmarkers_resource_files}
+)
+
+install(TARGETS pointsselectionandmarkers
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)
diff --git a/examples/charts/pointsselectionandmarkers/blue_triangle.png b/examples/charts/pointsselectionandmarkers/blue_triangle.png
new file mode 100644
index 00000000..7790453c
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/blue_triangle.png
diff --git a/examples/charts/pointsselectionandmarkers/green_triangle.png b/examples/charts/pointsselectionandmarkers/green_triangle.png
new file mode 100644
index 00000000..29ae043f
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/green_triangle.png
diff --git a/examples/charts/pointsselectionandmarkers/main.cpp b/examples/charts/pointsselectionandmarkers/main.cpp
new file mode 100644
index 00000000..376d49f9
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/main.cpp
@@ -0,0 +1,158 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Charts module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "utilities.h"
+
+#include <QApplication>
+#include <QChart>
+#include <QChartView>
+#include <QCheckBox>
+#include <QComboBox>
+#include <QGridLayout>
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QMainWindow>
+#include <QSplineSeries>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    QMainWindow mainWindow;
+    mainWindow.setWindowTitle("Chart");
+
+    //![1]
+    constexpr qreal marker_size = 20.;
+
+    QSplineSeries *series = new QSplineSeries();
+    series->append({QPointF(0., 0.),
+                    QPointF(0.5, 2.27),
+                    QPointF(1.5, 2.2),
+                    QPointF(3.3, 1.7),
+                    QPointF(4.23, 3.1),
+                    QPointF(5.3, 2.3),
+                    QPointF(6.47, 4.1)
+                   });
+    series->setMarkerSize(marker_size);
+    series->setLightMarker(Utilities::redRectangle(marker_size));
+    series->setSelectedLightMarker(Utilities::blueTriangle(marker_size));
+    QObject::connect(series, &QXYSeries::clicked, series, [&](const QPointF &point) {
+       int index = series->points().indexOf(point);
+       if (index != -1)
+           series->toggleSelection({index});
+    });
+    //![1]
+
+    //![2]
+    QChart *chart = new QChart();
+    chart->addSeries(series);
+    chart->createDefaultAxes();
+    chart->legend()->setVisible(false);
+
+    QChartView *chartView = new QChartView(chart);
+    chartView->setRenderHint(QPainter::Antialiasing);
+
+    QWidget *controlWidget = new QWidget(&mainWindow);
+    QGridLayout *controlLayout = new QGridLayout(controlWidget);
+    //![2]
+
+    //![3]
+    QComboBox *charPointCombobox = new QComboBox();
+    QComboBox *charPointSelectedCombobox = new QComboBox();
+    QComboBox *lineColorCombobox = new QComboBox();
+    QCheckBox *showUnselectedPointsCheckbox = new QCheckBox();
+    //![3]
+
+    //![4]
+    QLabel *charPoint = new QLabel(QCoreApplication::tr("Char point: "));
+    charPointCombobox->addItems({QCoreApplication::tr("Red rectangle"),
+                                 QCoreApplication::tr("Green triangle"),
+                                 QCoreApplication::tr("Orange circle")
+                                });
+    QObject::connect(charPointCombobox, &QComboBox::currentIndexChanged, series, [&](const int index) {
+        if (showUnselectedPointsCheckbox->isChecked())
+            series->setLightMarker(Utilities::getPointRepresentation(Utilities::PointType(index), marker_size));
+    });
+    //![4]
+
+    //![5]
+    QLabel *charPointSelected = new QLabel(QCoreApplication::tr("Char point selected: "));
+    charPointSelectedCombobox->addItems({QCoreApplication::tr("Blue triangle"),
+                                         QCoreApplication::tr("Yellow rectangle"),
+                                         QCoreApplication::tr("Lavender circle")
+                                        });
+    QObject::connect(charPointSelectedCombobox, &QComboBox::currentIndexChanged, series, [&](const int index) {
+        series->setSelectedLightMarker(Utilities::getSelectedPointRepresentation(Utilities::SelectedPointType(index), marker_size));
+    });
+
+    QLabel *lineColorLabel = new QLabel(QCoreApplication::tr("Line color: "));
+    lineColorCombobox->addItems({QCoreApplication::tr("Blue"),
+                                 QCoreApplication::tr("Black"),
+                                 QCoreApplication::tr("Mint")
+                                });
+    QObject::connect(lineColorCombobox, &QComboBox::currentIndexChanged, series, [&](const int index) {
+        series->setColor(Utilities::makeLineColor(Utilities::LineColor(index)));
+    });
+    //![5]
+
+    //![6]
+    QLabel *showUnselectedPointsLabel = new QLabel(QCoreApplication::tr("Display unselected points: "));
+    showUnselectedPointsCheckbox->setChecked(true);
+    QObject::connect(showUnselectedPointsCheckbox, &QCheckBox::stateChanged, series, [&](const int state) {
+        if (state) {
+            series->setLightMarker(Utilities::getPointRepresentation(Utilities::PointType(charPointCombobox->currentIndex()), marker_size));
+        } else {
+            series->setLightMarker(QImage());
+        }
+    });
+    //![6]
+
+    //![7]
+    controlLayout->addWidget(charPoint, 0, 0);
+    controlLayout->addWidget(charPointCombobox, 0, 1);
+
+    controlLayout->addWidget(charPointSelected, 1, 0);
+    controlLayout->addWidget(charPointSelectedCombobox, 1, 1);
+
+    controlLayout->addWidget(lineColorLabel, 2, 0);
+    controlLayout->addWidget(lineColorCombobox, 2, 1);
+
+    controlLayout->addWidget(showUnselectedPointsLabel, 3, 0);
+    controlLayout->addWidget(showUnselectedPointsCheckbox, 3, 1, 1, 2);
+
+    QWidget *mainWidget = new QWidget(&mainWindow);
+    QHBoxLayout *mainLayout = new QHBoxLayout(mainWidget);
+    mainLayout->addWidget(chartView);
+    mainLayout->addWidget(controlWidget);
+
+    mainWindow.setCentralWidget(mainWidget);
+    mainWindow.resize(1080, 720);
+    mainWindow.show();
+    return a.exec();
+    //![7]
+}
diff --git a/examples/charts/pointsselectionandmarkers/pointsselectionandmarkers.pro b/examples/charts/pointsselectionandmarkers/pointsselectionandmarkers.pro
new file mode 100644
index 00000000..ac8adffb
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/pointsselectionandmarkers.pro
@@ -0,0 +1,15 @@
+QT += charts \
+      widgets
+
+SOURCES += \
+    main.cpp \
+    utilities.cpp
+
+HEADERS += \
+    utilities.h
+
+RESOURCES += \
+    pointsselectionandmarkers.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/charts/pointsselectionandmarkers
+INSTALLS += target
diff --git a/examples/charts/pointsselectionandmarkers/pointsselectionandmarkers.qrc b/examples/charts/pointsselectionandmarkers/pointsselectionandmarkers.qrc
new file mode 100644
index 00000000..920bf0cc
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/pointsselectionandmarkers.qrc
@@ -0,0 +1,6 @@
+<RCC>
+    <qresource prefix="/">
+        <file>blue_triangle.png</file>
+        <file>green_triangle.png</file>
+    </qresource>
+</RCC>
diff --git a/examples/charts/pointsselectionandmarkers/utilities.cpp b/examples/charts/pointsselectionandmarkers/utilities.cpp
new file mode 100644
index 00000000..7b3ef7f4
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/utilities.cpp
@@ -0,0 +1,140 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Charts module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "utilities.h"
+
+#include <QBrush>
+#include <QList>
+#include <QPainter>
+#include <QPainterPath>
+
+namespace Utilities
+{
+    QImage redRectangle(qreal imageSize)
+    {
+        QImage image(imageSize, imageSize, QImage::Format_RGB32);
+        QPainter painter;
+        painter.begin(&image);
+        painter.fillRect(0, 0, imageSize, imageSize, Qt::red);
+        painter.end();
+        return image;
+    }
+
+    QImage yellowRectangle(qreal imageSize)
+    {
+        QImage image(imageSize, imageSize, QImage::Format_RGB32);
+        QPainter painter;
+        painter.begin(&image);
+        painter.fillRect(0, 0, imageSize, imageSize, Qt::yellow);
+        painter.end();
+        return image;
+    }
+
+    QImage blueTriangle(qreal imageSize)
+    {
+        return QImage(":/blue_triangle.png").scaled(imageSize, imageSize);
+    }
+
+    QImage greenTriangle(qreal imageSize)
+    {
+        return QImage(":/green_triangle.png").scaled(imageSize, imageSize);
+    }
+
+    QImage orangeCircle(qreal imageSize)
+    {
+        QImage image(imageSize, imageSize, QImage::Format_ARGB32);
+        image.fill(QColor(0, 0, 0, 0));
+        QPainter paint;
+        paint.begin(&image);
+        paint.setBrush(QColor(255,127,80));
+        QPen pen = paint.pen();
+        pen.setWidth(0);
+        paint.setPen(pen);
+        paint.drawEllipse(0, 0, imageSize * 0.9, imageSize * 0.9);
+        paint.end();
+        return image;
+    }
+
+    QImage lavenderCircle(qreal imageSize)
+    {
+        QImage image(imageSize, imageSize, QImage::Format_ARGB32);
+        image.fill(QColor(0, 0, 0, 0));
+        QPainter paint;
+        paint.begin(&image);
+        paint.setBrush(QColor(147,112,219));
+        QPen pen = paint.pen();
+        pen.setWidth(0);
+        paint.setPen(pen);
+        paint.drawEllipse(0, 0, imageSize * 0.9, imageSize * 0.9);
+        paint.end();
+        return image;
+    }
+
+    QImage getPointRepresentation(PointType pointType, int imageSize)
+    {
+        switch (pointType) {
+        case Utilities::PointType::RedRectangle:
+            return redRectangle(imageSize);
+        case Utilities::PointType::GreenTriangle:
+            return greenTriangle(imageSize);
+        case Utilities::PointType::OrangeCircle:
+            return orangeCircle(imageSize);
+        default:
+            return redRectangle(imageSize);
+        }
+    }
+
+    QImage getSelectedPointRepresentation(SelectedPointType pointType, int imageSize)
+    {
+        switch (pointType) {
+        case Utilities::SelectedPointType::BlueTriangle:
+            return blueTriangle(imageSize);
+        case Utilities::SelectedPointType::YellowRectangle:
+            return yellowRectangle(imageSize);
+        case Utilities::SelectedPointType::LavenderCircle:
+            return lavenderCircle(imageSize);
+        default:
+            return blueTriangle(imageSize);
+        }
+    }
+
+    QColor makeLineColor(LineColor lineColor)
+    {
+        switch (lineColor) {
+        case Utilities::LineColor::Blue:
+            return QColor(65, 105, 225);
+        case Utilities::LineColor::Black:
+            return QColor(0,0,0);
+        case Utilities::LineColor::Mint:
+            return QColor(70, 203, 155);
+        default:
+            return QColor(0, 0, 0);
+        }
+    }
+}
diff --git a/examples/charts/pointsselectionandmarkers/utilities.h b/examples/charts/pointsselectionandmarkers/utilities.h
new file mode 100644
index 00000000..79a6a0c6
--- /dev/null
+++ b/examples/charts/pointsselectionandmarkers/utilities.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Charts module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef UTILITIES_H
+#define UTILITIES_H
+
+#include <QImage>
+
+namespace Utilities
+{
+    enum class PointType {
+        RedRectangle,
+        GreenTriangle,
+        OrangeCircle
+    };
+
+    enum class SelectedPointType {
+        BlueTriangle,
+        YellowRectangle,
+        LavenderCircle
+    };
+
+    enum class LineColor {
+        Blue,
+        Black,
+        Mint
+    };
+
+    QImage redRectangle(qreal imageSize);
+    QImage yellowRectangle(qreal imageSize);
+    QImage blueTriangle(qreal imageSize);
+    QImage greenTriangle(qreal imageSize);
+    QImage orangeCircle(qreal imageSize);
+    QImage lavenderCircle(qreal imageSize);
+    QImage getPointRepresentation(PointType pointType, int imageSize);
+    QImage getSelectedPointRepresentation(SelectedPointType pointType, int imageSize);
+    QColor makeLineColor(LineColor lineColor);
+}
+
+#endif // UTILITIES_H