QListView with QStandardItemModel does not show selection highlight through code - qt

Question

I have a QListView that is populated with either a QStandardItemModel or a QStringListModel (based on simplicity of contents... number of columns).
On load, or switching between widgets, I search for the item that should be selected, and try to highlight it.
if (first)
{
m_myListView.setModel(m_standardItemModel);
QList<QStandardItem*> lst = m_standardItemModel->findItems(m_value1, Qt::MatchExactly, 1);
if(!lst.isEmpty())
{
QModelIndex index = lst.at(0)->index();
qDebug() << index.row(); // tells me correct row
//m_myListView.setCurrentIndex(index); // no change if I use
m_myListView.selectionModel()->select(index, QItemSelectionModel::ClearAndSelect);
m_myListView.scrollTo(index);
}
}
else
{
m_myListView.setModel(m_stringListModel);
int i = m_stringListModel->stringList().indexOf(m_value2);
if (i >= 0)
{
QModelIndex index = m_stringListModel->index(i);
m_myListView.selectionModel()->select(index, QItemSelectionModel::ClearAndSelect);
m_myListView.scrollTo(index);
}
}
The m_stringListModel version correctly highlights (and scrolls to item).
The m_standardItemModel version does not highlight row, and does not scroll to item. But in the uses afterwards, it correctly provides the data for selected index:
QModelIndexList indexList = m_myListView.selectionModel()->selectedIndexes();
if (!indexList.isEmpty())
{
QModelIndex index = indexList.first();
if (index.isValid())
{
row = index.row();
data1 = m_standardItemModel->index(row, 1).data().toString();
...
So... it seems that the selection works, but if it does, why do I not see a highlight ? (and the scrollTo() )
Note - the code is pretty giant but I verified for the possibility of reloading the model and possibly losing the selection - and besides, the QStringListModel version works correctly.
Is that a typical behavior of QStandardItemModel, or is there something I must do, like setting a BackgroundRole type data ?
How can I highlight the selection of the list view with the QStandardItemModel applied ?

Answer 1

I see your code, probably you want to select the first element of your model? Let's try:
void MyClass::selectFirstElement() {
const QModelIndex firsIndex = _myModel->index(0,0);
if (index.isValid())
ui->listView->setCurrentIndex(firstIndex);
ui->listView->scrollTo(firstIndex);
}
}
Could you share the m_standardItemModel implementation? Also configure your list correctly:
ui->listView->setSelectionMode(QAbstractItemView::SingleSelection);
ui->listView->setSelectionBehavior(QAbstractItemView::SelectRows); // Or Columns
Check if your QStandarItem has the selection flag enable. See http://doc.qt.io/qt-4.8/qt.html#ItemFlag-enum for more info.
Finally, you could ensure that the index is stored in the correct model by getting the index in the same row & column directly from the model, something like this:
QModelIndex index = lst.at(0)->index();
index = _model->index(index.row(), index.column());
Sorry, for my poor english :S

Answer 2

Because the item found is different than the display item, the list view is unable to select it...
2 solutions: either create a different QModelIndex from the one found, pointing to the display column, or select an entire row containing the desired index:
m_myListView.selectionModel()->select(index, QItemSelectionModel::ClearAndSelect | QItemSelectionModel::Rows);