Displaying image in QSqlTableModel

[gabor53]

Hi,
I have a QSqlTableModel and I want to use it to display an image from a databasecin a TableView. I have the following code so far:

#include "fixdb.h"
#include "ui_fixdb.h"
#include <QDebug>

FixDb::FixDb(QWidget* parent) :
  QDialog(parent),
  ui(new Ui::FixDb) {
  ui->setupUi(this);

  correctFriend ();
}

FixDb::~FixDb() {
  delete ui;
}

void FixDb::correctFriend() {
  QSqlQuery query_fix;



  int recNum = 0;
  query_fix.prepare ("SELECT COUNT(*) FROM Items");
  query_fix.exec ();

  if(query_fix.next ()) {
    recNum = query_fix.value (0).toInt ();
  };

  qDebug() << "Record count in fixdb: " << recNum;



  QSqlDatabase db = QSqlDatabase::addDatabase ("QSQLITE");
  db.setDatabaseName ("C:/Programming/Projects/Folkfriends_bzr/trunk/db.db");
  if(!db.open ())
    QMessageBox::information (this, "Error", "Couldn't open database.");


  QSqlTableModel* fixModel = new QSqlTableModel(this);
  fixModel->setTable ("Items");
  fixModel->setEditStrategy (QSqlTableModel::OnFieldChange);
  fixModel->setSort (1, Qt::DescendingOrder);

  fixModel->select ();

  ui->tableView_Fix->setModel (fixModel);

  QSqlQuery fixQueryDisp;
  fixQueryDisp.prepare("SELECT * FROM Items");
  fixQueryDisp.exec ();

  for(int row1 = 0; row1 < recNum; row1++) {
    ui->tableView_Fix->setRowHeight (row1, 100);

    while (fixQueryDisp.next ()) {
      fixPixmap.loadFromData (fixQueryDisp.value (2).toByteArray ());
      fixPixmap = fixPixmap.scaled (100, 100, Qt::KeepAspectRatio);
      fixModel->setData (fixModel->index (row1, 3), fixPixmap, Qt::DecorationRole);
    }
  };

  ui->tableView_Fix->horizontalHeader ()->setStyleSheet ("QHeaderView{font: 14pt Arial; color: blue; font-weight: bold; text-decoration: underline;}");
  ui->tableView_Fix->verticalHeader ()->setVisible (false);
  ui->tableView_Fix->setAlternatingRowColors (true);
  ui->tableView_Fix->setStyleSheet ("alternate-background-color: rgb(224,255,248); background-color: white; font: 14pt Arial; ");

  fixModel->setHeaderData (0, Qt::Horizontal, QObject::tr ("ID"));
  fixModel->setHeaderData (1, Qt::Horizontal, QObject::tr ("Name"));
  fixModel->setHeaderData (3, Qt::Horizontal, QObject::tr ("What"));
  fixModel->setHeaderData (2, Qt::Horizontal, QObject::tr ("Image"));
  fixModel->setHeaderData (4, Qt::Horizontal, QObject::tr ("Material"));
  fixModel->setHeaderData (5, Qt::Horizontal, QObject::tr ("Color"));
  fixModel->setHeaderData (6, Qt::Horizontal, QObject::tr ("Description"));
  fixModel->setHeaderData (7, Qt::Horizontal, QObject::tr ("Adoption Date"));
  fixModel->setHeaderData (8, Qt::Horizontal, QObject::tr ("Signed by"));
  fixModel->setHeaderData (9, Qt::Horizontal, QObject::tr ("History"));
  fixModel->setHeaderData (10, Qt::Horizontal, QObject::tr ("Age"));
  fixModel->setHeaderData (11, Qt::Horizontal, QObject::tr ("Notes"));


  ui->tableView_Fix->setColumnWidth (0, 60);
  ui->tableView_Fix->setColumnWidth (1, 120);
  ui->tableView_Fix->setColumnWidth (2, 150);
  ui->tableView_Fix->setColumnWidth (3, 100);
  ui->tableView_Fix->setColumnWidth (4, 130);
  ui->tableView_Fix->setColumnWidth (5, 120);
  ui->tableView_Fix->setColumnWidth (6, 400);
  ui->tableView_Fix->setColumnWidth (7, 150);
  ui->tableView_Fix->setColumnWidth (8, 200);
  ui->tableView_Fix->setColumnWidth (9, 400);
  ui->tableView_Fix->setColumnWidth (10, 130);
  ui->tableView_Fix->setColumnWidth (11, 300);

  ui->tableView_Fix->setWordWrap (true);

}//end of correctFriend

There is no error message, but the images are not displayed. The image column is #3. Please help me find what I missed.

[VRonin]

Don't set the data, QSqlTableModel is read only for any role other than Qt::EditRole, subclass QStyledItemDelegate, reimplement paint() to take the QByteArray and paint the QPixmap, then just set the delegate to the last column

[gabor53]

@VRonin
Would you please show an example? Thank you.

[gabor53]

@VRonin
I tried to implement the code at the link, so I created

 bool QSqlTableModel::setData(const QModelIndex& index, const QVariant& value, int role);

in fixdb.h and

bool FixDb::QSqlTableModel::setData(const QModelIndex& index, const QVariant& value, int role) {

}

in fixdb.cpp. I got he following error message:
C:\Programming\Projects\Folkfriends_bzr\checkout\fixdb.h:39: error: cannot declare member function 'QSqlTableModel::setData' within 'FixDb'
bool QSqlTableModel::setData(const QModelIndex& index, const QVariant& value, int role);
^
How can I avoid this error?

[mrjj]

@gabor53
Hi
As it says. You cannot create a member function for one class in another class
FixDb::QSqlTableModel::setData

To override setData the class must be a child of QSqlTableModel. so not sure what you try to to do.

As @VRonin says, you need to use a QStyledItemDelegate to draw the image
this one is good example
http://doc.qt.io/qt-5/qtwidgets-itemviews-stardelegate-example.html