How to show images from database as icons in QListView

[LeshaS]

Hi guys,

I have a database which stores images as BLOB field.
What I'm trying to achieve is to show those images (thumbnails of them) as icons in QListView. I use QSqlQueryModel as a model to access the database.

Can anyone give me any idea how to implement that? If I chose wrong classes, can you suggest better ones for that purpose?

Thanks,
Alex

[wysota]

Is there anything in particular you are having problems with?

[LeshaS]

Hi wysota, thanks for reply.
I just had no idea how to implement it.
Now I have done it the following way:

I've created a new model class based on QSqlQueryModel and implemented data() method:

QVariant SqlQueryModel::data ( const QModelIndex & item, int role) const
{
  if (role == Qt::DecorationRole)
  {
    switch(item.column())
    {
    case 0: // column 0 contains text data
      QPixmap image;
      image.loadFromData(record(item.row()).value(1).toByteArray()); // column 1 contains BLOB data
      return image.scaled(160, 160, Qt::KeepAspectRatio, Qt::SmoothTransformation);
    }
  }
  return QSqlQueryModel::data(item, role);
}

QVariant SqlQueryModel::data ( const QModelIndex & item, int role) const
{
  if (role == Qt::DecorationRole)
  {
    switch(item.column())
    {
    case 0: // column 0 contains text data
      QPixmap image;
      image.loadFromData(record(item.row()).value(1).toByteArray()); // column 1 contains BLOB data
      return image.scaled(160, 160, Qt::KeepAspectRatio, Qt::SmoothTransformation);
    }
  }
  return QSqlQueryModel::data(item, role);
}

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Then I connected it to QListView like this:

m_pQueryModel = new SqlQueryModel(this);
  m_pQueryModel->setQuery(m_sQuery, m_sqlDatabase);
  QListView *pView = new QListView(ui.tab_2);
  pView->setViewMode(QListView::IconMode);
  pView->setModelColumn(0);
  pView->setModel(m_pQueryModel);

m_pQueryModel = new SqlQueryModel(this);
  m_pQueryModel->setQuery(m_sQuery, m_sqlDatabase);
  QListView *pView = new QListView(ui.tab_2);
  pView->setViewMode(QListView::IconMode);
  pView->setModelColumn(0);
  pView->setModel(m_pQueryModel);

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I'm curious whether it's correct solution or it can be improved somehow.
Thanks,
Alex