QTableView populating question

[onefootswill]

I am populating a QTableView using the following code:

int row = ui.booksTable->rowCount();
ui.booksTable->insertRow(row);
QTableWidgetItem *item0 = new QTableWidgetItem;
item0->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
ui.booksTable->setItem(row, 0, item0);
 
QTableWidgetItem *item1 = new QTableWidgetItem;
item1->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
ui.booksTable->setItem(row, 1, item1);
 
QTableWidgetItem *item2 = new QTableWidgetItem;
item2->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
ui.booksTable->setItem(row, 2, item2);

int row = ui.booksTable->rowCount();
ui.booksTable->insertRow(row);
QTableWidgetItem *item0 = new QTableWidgetItem;
item0->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
ui.booksTable->setItem(row, 0, item0);

QTableWidgetItem *item1 = new QTableWidgetItem;
item1->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
ui.booksTable->setItem(row, 1, item1);

QTableWidgetItem *item2 = new QTableWidgetItem;
item2->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
ui.booksTable->setItem(row, 2, item2);

To copy to clipboard, switch view to plain text mode 

For some reason, it is adding a spare blank row at the end. This gets messy as each time the button is pressed, the number of blank rows at the end of the table increases. How do I prevent this behaviour?

Also, I note that after you call clear() or clearContents() on a QTableView, the rowCount() does not reduce back to 0. That seems weird. I mean, shouldn't clear mean clear the table of all the rows and reduce the number of rows to zero?

[spirit]

this code works perfectly

QTableWidget *tw = new QTableWidget(this);
tw->setColumnCount(3);
int row = tw->rowCount();
tw->insertRow(row);
QTableWidgetItem *item0 = new QTableWidgetItem;
item0->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
tw->setItem(row, 0, item0);
 
QTableWidgetItem *item1 = new QTableWidgetItem;
item1->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
tw->setItem(row, 1, item1);
 
QTableWidgetItem *item2 = new QTableWidgetItem;
item2->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
tw->setItem(row, 2, item2);

QTableWidget *tw = new QTableWidget(this);
tw->setColumnCount(3);
int row = tw->rowCount();
tw->insertRow(row);
QTableWidgetItem *item0 = new QTableWidgetItem;
item0->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
tw->setItem(row, 0, item0);

QTableWidgetItem *item1 = new QTableWidgetItem;
item1->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
tw->setItem(row, 1, item1);

QTableWidgetItem *item2 = new QTableWidgetItem;
item2->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
tw->setItem(row, 2, item2);

To copy to clipboard, switch view to plain text mode 

[onefootswill]

There's something not right somewhere. I'm hitting the function that contains that code twice, and it is adding a 3rd row (an empty row). I cannot explain it.

[aamer4yu]

ui.booksTable->insertRow(row);

What if you dont call this ? Is it necessary before setItem() ??

[spirit]

if you remove

insertRow(row)

insertRow(row)

To copy to clipboard, switch view to plain text mode 

then a row isn't created.
number of rows and columns should be specified before inserting items.

[spirit]

There's something not right somewhere. I'm hitting the function that contains that code twice, and it is adding a 3rd row (an empty row). I cannot explain it.

can you post code where you create a widget, table and inserting of items in the table?

[onefootswill]

Sure,

Here's the code:

void stuffLender::viewBkButtonSlot()
{
	tag = BooksView;
	setBooksEnv(tag);
 
	switch(booksTableHit)
	{
		case false: populateBooks(); break;
		default: break;
	}
 
	populateBooksTable();
	addRowToBooks();
}
 
void stuffLender::populateBooks()
{
	QSqlQuery queryBooks;
	QSqlQuery queryBookAuthors;
	bookList = new QList<book>;
	int bkNr = 0;
 
	queryBooks.exec("SELECT nr, title, edition FROM books;");
	while(queryBooks.next())
	{
		bkNr = queryBooks.value(0).toInt();
		QVector<author> authors;
		QString selStmt = "SELECT nr, fname, lname, minitial FROM  authors WHERE nr IN (SELECT authorNr FROM bookAuthors WHERE bookNr = ";
		selStmt += QString::number(bkNr);
		selStmt += ");";
 
		queryBookAuthors.exec(selStmt);
		while(queryBookAuthors.next())
		{
			author newAuthor(queryBookAuthors.value(0).toInt(), queryBookAuthors.value(1).toString(), queryBookAuthors.value(2).toString(), queryBookAuthors.value(3).toString());
			authors.append(newAuthor);
		}
 
		book newBk(bkNr, queryBooks.value(1).toString(), queryBooks.value(2).toInt(), authors);
		bookList->append(newBk);
	}
 
	booksTableHit = true;
}
 
void stuffLender::populateBooksTable()
{
	ui.booksOnLoan->hide();
	ui.booksTable->setRowCount(0);
 
	ui.booksTable->show();
	ui.booksTable->setHorizontalHeaderLabels(QStringList() << "Title" << "Author/s" << "Ed.");
	int nrOfAuthors = 0;
 
	for(int row = 0; row < bookList->count(); row++)
	{
		addRowToBooks();
		QString authors;
		const QVector<author> *theAuthors = bookList->at(row).getAuthors();
		nrOfAuthors = theAuthors->count();
		for(int idx = 0; idx < nrOfAuthors; idx++)
		{
			if(idx == nrOfAuthors - 1)
				authors += theAuthors->at(idx).getFname() + " " + theAuthors->at(idx).getLname() + " " + theAuthors->at(idx).getMinitial();
			else
				authors += theAuthors->at(idx).getFname() + " " + theAuthors->at(idx).getLname() + " " + theAuthors->at(idx).getMinitial() + ", ";
		}
		ui.booksTable->item(row, 0)->setText(bookList->at(row).getTitle());
		ui.booksTable->item(row, 1)->setText(authors);
		ui.booksTable->item(row, 2)->setText(QString::number(bookList->at(row).getEdition()));
	}
	//ui.booksTable->removeRow(ui.booksTable->rowCount());
}
 
void stuffLender::addRowToBooks()
{
	int row = ui.booksTable->rowCount();
	ui.booksTable->insertRow(row);
	QTableWidgetItem *item0 = new QTableWidgetItem;
	item0->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
	ui.booksTable->setItem(row, 0, item0);
 
	QTableWidgetItem *item1 = new QTableWidgetItem;
	item1->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
	ui.booksTable->setItem(row, 1, item1);
 
	QTableWidgetItem *item2 = new QTableWidgetItem;
	item2->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
	ui.booksTable->setItem(row, 2, item2);
}

void stuffLender::viewBkButtonSlot()
{
	tag = BooksView;
	setBooksEnv(tag);

	switch(booksTableHit)
	{
		case false: populateBooks(); break;
		default: break;
	}

	populateBooksTable();
	addRowToBooks();
}

void stuffLender::populateBooks()
{
	QSqlQuery queryBooks;
	QSqlQuery queryBookAuthors;
	bookList = new QList<book>;
	int bkNr = 0;

	queryBooks.exec("SELECT nr, title, edition FROM books;");
	while(queryBooks.next())
	{
		bkNr = queryBooks.value(0).toInt();
		QVector<author> authors;
		QString selStmt = "SELECT nr, fname, lname, minitial FROM  authors WHERE nr IN (SELECT authorNr FROM bookAuthors WHERE bookNr = ";
		selStmt += QString::number(bkNr);
		selStmt += ");";

		queryBookAuthors.exec(selStmt);
		while(queryBookAuthors.next())
		{
			author newAuthor(queryBookAuthors.value(0).toInt(), queryBookAuthors.value(1).toString(), queryBookAuthors.value(2).toString(), queryBookAuthors.value(3).toString());
			authors.append(newAuthor);
		}

		book newBk(bkNr, queryBooks.value(1).toString(), queryBooks.value(2).toInt(), authors);
		bookList->append(newBk);
	}

	booksTableHit = true;
}

void stuffLender::populateBooksTable()
{
	ui.booksOnLoan->hide();
	ui.booksTable->setRowCount(0);

	ui.booksTable->show();
	ui.booksTable->setHorizontalHeaderLabels(QStringList() << "Title" << "Author/s" << "Ed.");
	int nrOfAuthors = 0;

	for(int row = 0; row < bookList->count(); row++)
	{
		addRowToBooks();
		QString authors;
		const QVector<author> *theAuthors = bookList->at(row).getAuthors();
		nrOfAuthors = theAuthors->count();
		for(int idx = 0; idx < nrOfAuthors; idx++)
		{
			if(idx == nrOfAuthors - 1)
				authors += theAuthors->at(idx).getFname() + " " + theAuthors->at(idx).getLname() + " " + theAuthors->at(idx).getMinitial();
			else
				authors += theAuthors->at(idx).getFname() + " " + theAuthors->at(idx).getLname() + " " + theAuthors->at(idx).getMinitial() + ", ";
		}
		ui.booksTable->item(row, 0)->setText(bookList->at(row).getTitle());
		ui.booksTable->item(row, 1)->setText(authors);
		ui.booksTable->item(row, 2)->setText(QString::number(bookList->at(row).getEdition()));
	}
	//ui.booksTable->removeRow(ui.booksTable->rowCount());
}

void stuffLender::addRowToBooks()
{
	int row = ui.booksTable->rowCount();
	ui.booksTable->insertRow(row);
	QTableWidgetItem *item0 = new QTableWidgetItem;
	item0->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
	ui.booksTable->setItem(row, 0, item0);

	QTableWidgetItem *item1 = new QTableWidgetItem;
	item1->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
	ui.booksTable->setItem(row, 1, item1);

	QTableWidgetItem *item2 = new QTableWidgetItem;
	item2->setTextAlignment(Qt::AlignLeft | Qt::AlignVCenter);
	ui.booksTable->setItem(row, 2, item2);
}

To copy to clipboard, switch view to plain text mode 

The addRowToBooks() function is being hit twice (confirmed in debugging). So, I don't know why the 3rd empty row. It makes no sense.

[spirit]

I think trouble is here:

populateBooksTable();
    addRowToBooks();

populateBooksTable();
    addRowToBooks();

To copy to clipboard, switch view to plain text mode 

you insert rows several times in

populateBooksTable();

populateBooksTable();

To copy to clipboard, switch view to plain text mode 

and then add extra row by calling

addRowToBooks();

addRowToBooks();

To copy to clipboard, switch view to plain text mode 

[onefootswill]

Oh my gosh, that was such a dumb mistake. addRowToBooks should never have been called in viewBkButtonSlot at all. It must have been one of those things where I was looking at it so hard that I just could not see what was right there in front of me.

Thank you very much for your help.