Qcombobox remove and add item in C++ Qt - c++

Question

Creating a combobox in Qtableview2 column 1 and passing values from Qtableview1 column1
so i am storing column1 table1 values in Qstringlist and passing to combobox
void cymodel::rowvalues() {
QAbstractItemModel* table1 = ui.tableView->model();
QAbstractItemModel* table2 = ui.tableView_2->model();
QStringList colvallist1;
for (int r = 0, maxI = table1->rowCount(); r < maxI; ++r)
colvallist1.append(table1->data(table1->index(r, 0)).toString());//store value in stringlist
for (int i = 0, maxI = table2->rowCount(); i < maxI; ++i)//for all rows
{
const QModelIndex idx = table2->index(i, 1);
QComboBox* combo = qobject_cast<QComboBox*>(ui.tableView_2->indexWidget(idx));
if (!combo)
{
combo = new QComboBox(); // make combo
ui.tableView_2->setIndexWidget(idx, combo);// add combo
}
// combo->model()->removeRows(0, combo->count(), combo->rootModelIndex());
colvallist1.removeDuplicates(); // clear duplicates in colvallist1
colvallist1.removeAll(QString("")); //remove empty row data
combo->setPlaceholderText(QString(" "));
combo->addItems(colvallist1);
}
}
connect(ui.tableView->model(), &QAbstractItemModel::dataChanged, this,
&cymodel::rowvalues);
Using removerows() all items are removed everytime,,if I added some values in column0 table1 then select in combobox and again adding values in table1 Column0 that time combobox selection go away
but if i don't use removerows() then when I'm adding new item to combobox then its adding multiple time like 2 values added then i add 2 more in table1 col then in combobox it become 4
So, how to add those that appear in colvallist1 but are not already in the combo & remove those that don't appear in colvallist1 ??
Thanks Plz help!!

Answer 1

thnks,,,i solved this..
to remove the items in combobox which are not in colvallist1..without change in selection
here is the code--
void cymodel::rowvalues() {
QAbstractItemModel* table1 = ui.tableView->model();
QAbstractItemModel* table2 = ui.tableView_2->model();
QStringList colvallist1;
for (int r = 0, maxI = table1->rowCount(); r < maxI; ++r)
colvallist1.append(table1->data(table1->index(r, 0)).toString());//store value in stringlist
for (int i = 0, maxI = table2->rowCount(); i < maxI; ++i)//for all rows
{
const QModelIndex idx = table2->index(i, 1);
QComboBox* combo1 = qobject_cast<QComboBox*>(ui.tableView_2-
>indexWidget(idx));
if (!combo1)
{
combo1 = new QComboBox(); // make combo
ui.tableView_2->setIndexWidget(idx, combo);// add combo
}
colvallist1.removeDuplicates(); // clear duplicates in colvallist1
colvallist1.removeAll(QString("")); //remove empty row data
combo1->setPlaceholderText(QString(" "))
QString selected = combo1->currentText();
int indx = combo1->currentIndex();
combo1->clear();
combo1->addItems(colvallist1);
combo1->findData(selected);
combo1->setCurrentIndex(indx);
combo1->setCurrentText(selected);
}