QTableView connected with QSqlTableModel flickers (scrolls to the bottom and returns)

Question

ironexmaidenAug. 25, 2017, 3:05 a.m.

QTableView connected with QSqlTableModel flickers (scrolls to the bottom and returns)

qt, qsql, QSqlDataBase, QSqlTableModel, QTableView

Hello guys I have a problem using table view. I have a tableview connected with a QSqlTableModel. On its 2nd column I want to have check state to control the row's Status (active/inactive) but when I try to push the check box QTableView scrolls to the bottom and returns to it's previous position. Is there any solution?

    bool ProjectsModel::setData(const QModelIndex &index, const QVariant &value, int role)
    {
        if(index.column() == STATUS_INDEX) {
            QSqlRecord rec = this->record(index.row());
            QString qrstr;
     
            qrstr = (rec.field(index.column()).value().toInt() == 1) ? "update " + tableName() + " set Status=0 where BRACE_ID=" : "update " + tableName() + " set Status=1 where BRACE_ID=";
            qrstr += QString().setNum(index.row()+1);
     
            braceDatabase->exec(qrstr.toUtf8().constData());
            return true;
        }
     
        return false;
    }
     
    void DataBase::updateTablesSlot()
    {
        if(projectsModel)
            projectsModel->select();
        if(attributesModel)
            attributesModel->select();
        if(targetsModel)
            targetsModel->select();
    }
     
    void DataBase::exec(const std::string &querystr)
    {
    		QSqlQuery qr(db);
            qr.exec(querystr.c_str());
            //qDebug() <<"Command :" << querystr.c_str() << "-> "<< query->lastError().text();
            updateTables(); 
    }

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Aug. 25, 2017, 12:49 p.m.

Hello!
I think you need to use QItemDelegate for this (or same claas which was inherited from this class). Or You can use QTableWidget.
You can research article with checkboxes in QTableWidget .
May be it will be usefull for You.

Aug. 25, 2017, 1:41 p.m.

And may be you need use for scroll method scrollTo()

For this You should to save QModelIndex with which you work now, and after getting information from SQL DataBase, You should invoke method scrollTo(storedIndex) for scroll to needed position.

i

Aug. 25, 2017, 1:45 p.m.
(edited)

Hello my friend and thank you for the help unfortunately I can't use QTableWidget for performance reasons, I must load big databases from csv files. If I try the second solution with the scroll It will have a disturbing effect the table will hop up and down every time the user presses the check state.

Christos,
Greeting from Thessaloniki, Greece

Evgenii Legotckoi → ironexmaiden
#

Aug. 25, 2017, 2:14 p.m.

Ok. May be You need to use custom ItemDelegate for this.

class CheckBoxDelegate: public QItemDelegate
{
    Q_OBJECT
public:
    CheckBoxDelegate(QObject *parent = 0);

    void paint( QPainter *painter,
                        const QStyleOptionViewItem &option,
                        const QModelIndex &index ) const;


    QWidget *createEditor( QWidget *parent,
                        const QStyleOptionViewItem &option,
                        const QModelIndex &index ) const;

    void setEditorData( QWidget *editor,
                        const QModelIndex &index ) const;

    void setModelData( QWidget *editor,
                        QAbstractItemModel *model,
                        const QModelIndex &index ) const;

    void updateEditorGeometry( QWidget *editor,
                        const QStyleOptionViewItem &option,
                        const QModelIndex &index ) const;

    mutable QCheckBox * theCheckBox;

private slots:

    void setData(bool val);


};

And set delegate

ui->myTable->setItemDelegateForColumn(5,new CheckBoxDelegate(ui->myTable));

Best Regards from Prague.

i

Aug. 25, 2017, 2:20 p.m.

 QString qrstr;
     
            qrstr = (rec.field(index.column()).value().toInt() == 1) ? "update " + tableName() + " set Status=0 where BRACE_ID=" : "update " + tableName() + " set Status=1 where BRACE_ID=";
            qrstr += QString().setNum(index.row()+1);
     
            braceDatabase->exec(qrstr.toUtf8().constData());

Thank you my friend I will check this solution and I will report keep on mind that another guy informed me that the query exec clears the model and reset the data, and this reset is the reason of the flickering he proposed me the solution of QSqlTableModel::setData
I changed my code to this one but the check state on click didn't change :(

    bool AttributesModel::setData(const QModelIndex &index, const QVariant &value, int role)
    {
        if(index.column() == STATUS_INDEX) {
            bool ret = QSqlTableModel::setData(index, value == Qt::Checked ? Qt::Unchecked : Qt::Checked, role);
            database().commit();
            this->submitAll();
            return ret;
        }
        return QSqlTableModel::setData(index, value, role);
    }

Evgenii Legotckoi → ironexmaiden
#

Aug. 25, 2017, 2:25 p.m.
(edited)

I am not sure, but problem of this solution may be in Qt::Checked and Qt::Unchecked.

Because this enum has 3 states

enum CheckState {
        Unchecked,
        PartiallyChecked,
        Checked
    };

Unchecked = 0
PartiallyChecked = 1
Checked = 2

But You use two states 0 and 1 in your csv files, if I see correctly.

i

Aug. 25, 2017, 2:30 p.m.

That's the point I want the status of the row to be Active/Inactive PartiallyChecked option is useless for me. Do you refer that I had an error on this line ?

bool ret = QSqlTableModel::setData(index, value == Qt::Checked ? Qt::Unchecked : Qt::Checked, role);

Evgenii Legotckoi → ironexmaiden
#

Aug. 25, 2017, 2:32 p.m.

I am not sure, but may be you can try to check the following code in this row:

bool ret = QSqlTableModel::setData(index, value == Qt::Checked ? 0 : 1, role);

QTableView connected with QSqlTableModel flickers (scrolls to the bottom and returns)

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