src/decorations/LegendModel.h

0001 /*
0002  * This file is part of KQuickCharts
0003  * SPDX-FileCopyrightText: 2019 Arjen Hiemstra <ahiemstra@heimr.nl>
0004  *
0005  * SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
0006  */
0007
0008 #ifndef LEGENDMODEL_H
0009 #define LEGENDMODEL_H
0010
0011 #include <vector>
0012
0013 #include <QAbstractListModel>
0014 #include <QColor>
0015
0016 class Chart;
0017 class ChartDataSource;
0018
0019 struct LegendItem {
0020     QString name;
0021     QString shortName;
0022     QColor color;
0023     QVariant value;
0024 };
0025
0026 /**
0027  * A model that extracts information from a chart that can be displayed as a legend.
0028  */
0029 class LegendModel : public QAbstractListModel
0030 {
0031     Q_OBJECT
0032     Q_PROPERTY(Chart *chart READ chart WRITE setChart NOTIFY chartChanged)
0033     Q_PROPERTY(int sourceIndex READ sourceIndex WRITE setSourceIndex NOTIFY sourceIndexChanged)
0034
0035 public:
0036     enum Roles { NameRole = Qt::UserRole, ShortNameRole, ColorRole, ValueRole };
0037
0038     enum SourceIndex { UseSourceCount = -2 };
0039     Q_ENUM(SourceIndex)
0040
0041     explicit LegendModel(QObject *parent = nullptr);
0042
0043     QHash<int, QByteArray> roleNames() const override;
0044     int rowCount(const QModelIndex &parent) const override;
0045     QVariant data(const QModelIndex &index, int role) const override;
0046
0047     Chart *chart() const;
0048     void setChart(Chart *newChart);
0049     Q_SIGNAL void chartChanged();
0050
0051     int sourceIndex() const;
0052     void setSourceIndex(int index);
0053     Q_SIGNAL void sourceIndexChanged();
0054
0055 private:
0056     void queueUpdate();
0057     void queueDataChange();
0058     void update();
0059     void updateData();
0060     int countItems();
0061     QVariant getValueForItem(int item);
0062
0063     Chart *m_chart = nullptr;
0064     int m_sourceIndex = UseSourceCount;
0065     bool m_updateQueued = false;
0066     bool m_dataChangeQueued = false;
0067     std::vector<QMetaObject::Connection> m_connections;
0068     std::vector<LegendItem> m_items;
0069 };
0070
0071 #endif // LEGENDMODEL_H