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  1. 13th May 2013, 16:45 #4
    Santosh Reddy's Avatar
    Santosh Reddy
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    Default Re: QsqlQueryModel Subclass

    Here is an example
    ProxyModel.jpg
    Qt Code: 
    1. #include <QtGui>
    2. #include <QtSql>
    3. #include <QApplication>
    4.  
    5. // Add one extra column at the beginning
    6. class ProxyModel : public QAbstractProxyModel
    7. {
    8.     Q_OBJECT
    9. public:
    10.     explicit ProxyModel(QObject * parent = 0)
    12.     {
    13.         ;
    14.     }
    15.  
    16.     void setSourceModel(QAbstractItemModel *sourceModel)
    17.     {
    18.         if(this->sourceModel() != sourceModel)
    19.         {
    20.             if(this->sourceModel() != 0)
    21.             {
    22.                 disconnect(this->sourceModel(), SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
    23.                            this, SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)));
    24.                 disconnect(this->sourceModel(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
    25.                            this, SIGNAL(rowsInserted(const QModelIndex &, int, int)));
    26.                 disconnect(this->sourceModel(), SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)),
    27.                            this, SIGNAL(columnsAboutToBeInserted (const QModelIndex &, int, int)));
    28.                 disconnect(this->sourceModel(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
    29.                            this, SIGNAL(columnsInserted(const QModelIndex &, int, int)));
    30.                 disconnect(this->sourceModel(), SIGNAL(modelAboutToBeReset()),
    31.                            this, SIGNAL(modelAboutToBeReset()));
    32.                 disconnect(this->sourceModel(), SIGNAL(modelReset()),
    33.                            this, SIGNAL(modelReset()));
    34.                 disconnect(this->sourceModel(), SIGNAL(layoutAboutToBeChanged()),
    35.                            this, SIGNAL(layoutAboutToBeChanged()));
    36.                 disconnect(this->sourceModel(), SIGNAL(layoutChanged()),
    37.                            this, SIGNAL(layoutChanged()));
    38.                 disconnect(this->sourceModel(), SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
    39.                            this, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)));
    40.             }
    41.  
    42.             QAbstractProxyModel::setSourceModel(sourceModel);
    43.  
    44.             connect(this->sourceModel(), SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)),
    45.                     this, SIGNAL(rowsAboutToBeInserted(const QModelIndex &, int, int)));
    46.             connect(this->sourceModel(), SIGNAL(rowsInserted(const QModelIndex &, int, int)),
    47.                     this, SIGNAL(rowsInserted(const QModelIndex &, int, int)));
    48.             connect(this->sourceModel(), SIGNAL(columnsAboutToBeInserted (const QModelIndex &, int, int)),
    49.                     this, SIGNAL(columnsAboutToBeInserted(const QModelIndex &, int, int)));
    50.             connect(this->sourceModel(), SIGNAL(columnsInserted(const QModelIndex &, int, int)),
    51.                     this, SIGNAL(columnsInserted(const QModelIndex &, int, int)));
    52.             connect(this->sourceModel(), SIGNAL(modelAboutToBeReset()),
    53.                     this, SIGNAL(modelAboutToBeReset()));
    54.             connect(this->sourceModel(), SIGNAL(modelReset()),
    55.                     this, SIGNAL(modelReset()));
    56.             connect(this->sourceModel(), SIGNAL(modelReset()),
    57.                     this, SIGNAL(modelReset()));
    58.             connect(this->sourceModel(), SIGNAL(layoutAboutToBeChanged()),
    59.                     this, SIGNAL(layoutAboutToBeChanged()));
    60.             connect(this->sourceModel(), SIGNAL(layoutChanged()),
    61.                     this, SIGNAL(layoutChanged()));
    62.             connect(this->sourceModel(), SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)),
    63.                     this, SIGNAL(dataChanged(const QModelIndex &, const QModelIndex &)));
    64.         }
    65.     }
    66.  
    67.     QModelIndex index(int row, int column, const QModelIndex & parent = QModelIndex()) const
    68.     {
    69.         if(!parent.isValid())
    70.         {
    71.             if(column == 0)
    72.                 return createIndex(row, column, -1);
    73.             else
    74.                 return createIndex(row, column, 0);
    75.         }
    76.         return QModelIndex();
    77.     }
    78.  
    79.     QModelIndex parent(const QModelIndex & /*child*/) const
    80.     {
    81.         return QModelIndex();
    82.     }
    83.  
    84.     int rowCount(const QModelIndex & parent = QModelIndex()) const
    85.     {
    86.         if(!parent.isValid())
    87.             return sourceModel()->rowCount(parent);
    88.         return 0;
    89.     }
    90.  
    91.     int columnCount(const QModelIndex & parent = QModelIndex()) const
    92.     {
    93.         if(!parent.isValid())
    94.             return sourceModel()->columnCount(parent) + 1;
    95.         return 0;
    96.     }
    97.  
    98.     QModelIndex mapToSource(const QModelIndex & proxyIndex) const
    99.     {
    100.         if(proxyIndex.column() <= 0)
    101.             return QModelIndex();
    102.  
    103.         return sourceModel()->index(proxyIndex.row(), proxyIndex.column() - 1);
    104.     }
    105.  
    106.     QModelIndex mapFromSource(const QModelIndex & sourceIndex) const
    107.     {
    108.         return index(sourceIndex.row(), sourceIndex.column() + 1);
    109.     }
    110.  
    111.     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const
    112.     {
    113.         if(orientation == Qt::Horizontal)
    114.         {
    115.             if(section <= 0)
    116.                 return QString("Proxy Column");
    117.             return sourceModel()->headerData(section - 1, orientation, role);
    118.         }
    119.         return sourceModel()->headerData(section, orientation, role);
    120.     }
    121.  
    122.     QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const
    123.     {
    124.         if((index.column() <= 0) and (role == Qt::DisplayRole))
    125.             return QString("Proxy Data - Row:%1").arg(index.row());
    126.  
    127.         return sourceModel()->data(mapToSource(index), role);
    128.     }
    129.  
    130.     bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole)
    131.     {
    132.         if((index.column() <= 0) and (role == Qt::EditRole))
    133.         {
    134.             // TODO: store data into ProxyModel
    135.             return true;
    136.         }
    137.         return sourceModel()->setData(mapToSource(index), role);
    138.     }
    139. };
    140.  
    141. int main(int argc, char *argv[])
    142. {
    143.     QApplication app(argc, argv);
    144.  
    145.     QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    146.     db.setDatabaseName("Qt.sqlite");
    147.  
    149.  
    150.     ProxyModel proxy;
    151.     proxy.setSourceModel(&model);
    152.  
    153.     QTableView view;
    154.     view.setWindowTitle("QSqlQueryModel View");
    155.     view.setModel(&model);
    156.     view.show();
    157.  
    158.     QTableView proxyView;
    159.     proxyView.setWindowTitle("ProxyModel View");
    160.     proxyView.setModel(&proxy);
    161.     proxyView.show();
    162.  
    163.     if(db.open())
    164.         model.setQuery("SELECT Country, Location FROM Locations");
    165.  
    166.     view.resizeColumnsToContents();
    167.     proxyView.resizeColumnsToContents();
    168.  
    169.     return app.exec();
    170. }
    171.  
    172. #include "main.moc"
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  2. The following user says thank you to Santosh Reddy for this useful post:

    Delphi (15th May 2013)
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