ForeignKeyDelegate.h

#ifndef FOREIGN_KEY_DELEGATE_HPP_
#define FOREIGN_KEY_DELEGATE_HPP_
 
#include <QScopedPointer>
#include <QStyledItemDelegate>
 
class CandidateKeyFilter;
 
//
// Class ForeignKeyDelegate
//
//  Item delegate for editing a foreign key item in a one or many
//  to one relationship. A QComboBox is used as an item delegate
//  for the edit role.
//
class ForeignKeyDelegate final : public QStyledItemDelegate {
  public:
    // many to many relationship
    explicit ForeignKeyDelegate(QAbstractItemModel *referenced_model,
                                int referenced_key_column,
                                QObject *parent = nullptr,
                                int referenced_key_role = Qt::EditRole);
 
    // one to many (referenced to referencing) relationship
    explicit ForeignKeyDelegate(QAbstractItemModel *referenced_model,
                                QAbstractItemModel const *referencing_model,
                                int referenced_key_column,
                                int referencing_key_column,
                                QObject *parent = nullptr,
                                int referenced_key_role = Qt::EditRole,
                                int referencing_key_role = Qt::EditRole);
    ~ForeignKeyDelegate();
 
    QWidget *createEditor(QWidget *parent, QStyleOptionViewItem const &,
                          QModelIndex const &) const override;
 
  private:
    QScopedPointer<CandidateKeyFilter> candidate_key_filter_;
};
 
#endif