sdrangel/sdrgui/gui/checklist.h

#ifndef CHECKLIST
#define CHECKLIST

#include <QWidget>
#include <QComboBox>
#include <QStandardItemModel>
#include <QLineEdit>
#include <QEvent>
#include <QStyledItemDelegate>
#include <QListView>

#include "export.h"

/**
* @brief QComboBox with support of checkboxes
* http://stackoverflow.com/questions/8422760/combobox-of-checkboxes
*/
class SDRGUI_API CheckList : public QComboBox
{
    Q_OBJECT

public:
    /**
    * @brief Additional value to Qt::CheckState when some checkboxes are Qt::PartiallyChecked
    */
    static const int StateUnknown = 3;

private:
    QStandardItemModel* m_model;
    /**
      * @brief Text to display regardless of what is checked
      */
    QString m_text;
    /**
    * @brief Text displayed when no item is checked
    */
    QString m_noneCheckedText;
    /**
    * @brief Text displayed when all items are checked
    */
    QString m_allCheckedText;
    /**
    * @brief Text displayed when some items are partially checked
    */
    QString m_unknownlyCheckedText;

signals:
    void globalCheckStateChanged(int);

public:
    CheckList(QWidget* parent = nullptr);
    ~CheckList();

    void setText(const QString &text);
    void setAllCheckedText(const QString &text);
    void setNoneCheckedText(const QString &text);
    void setUnknownlyCheckedText(const QString &text);

    bool isChecked(int index) const;

    void setSortRole(int role);

    /**
    * @brief Adds a item to the checklist
    * @return the new QStandardItem
    */
    QStandardItem* addCheckItem(const QString &label, const QVariant &data, const Qt::CheckState checkState);

    /**
    * @brief Computes the global state of the checklist :
    *      - if there is no item: StateUnknown
    *      - if there is at least one item partially checked: StateUnknown
    *      - if all items are checked: Qt::Checked
    *      - if no item is checked: Qt::Unchecked
    *      - else: Qt::PartiallyChecked
    */
    int globalCheckState();

protected:
    bool eventFilter(QObject* _object, QEvent* _event);

private:
    void updateText();

private slots:
    void on_modelDataChanged();

    void on_itemPressed(const QModelIndex &index);

public:
    class QCheckListStyledItemDelegate : public QStyledItemDelegate
    {
    public:
        QCheckListStyledItemDelegate(QObject* parent = 0) : QStyledItemDelegate(parent) {}

        void paint(QPainter * painter_, const QStyleOptionViewItem & option_, const QModelIndex & index_) const
        {
            QStyleOptionViewItem & refToNonConstOption = const_cast<QStyleOptionViewItem &>(option_);
            refToNonConstOption.showDecorationSelected = false;
            QStyledItemDelegate::paint(painter_, refToNonConstOption, index_);
        }
    };
};

#endif