Qt4.1.1: Sorting QCombobox entries

[Byngl]

With Qt3, you could use combo->listbox()->sort()

Is there a simple way to do this using Qt4 now that the standard listbox is provided by a QListView instead of a QListBox?

[jpn]

Mmmh.. interesting!

It seems that a combo with a "model" sorts itself fine, but a combo with "items" does not.

#include <QtGui>
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
 
	QStringList items;
	for (int i = 9; i >= 0; --i)
		items << QString::number(i);
 
	QComboBox modelCombo;
	modelCombo.setWindowTitle("Model");
	modelCombo.setModel(new QStringListModel(items));
	modelCombo.model()->sort(0);
	modelCombo.show();
 
    QComboBox itemCombo;
	itemCombo.setWindowTitle("Item");
	itemCombo.addItems(items);
	itemCombo.model()->sort(0);
	itemCombo.show();
 
    a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
    return a.exec();
}

#include <QtGui>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

	QStringList items;
	for (int i = 9; i >= 0; --i)
		items << QString::number(i);
	
	QComboBox modelCombo;
	modelCombo.setWindowTitle("Model");
	modelCombo.setModel(new QStringListModel(items));
	modelCombo.model()->sort(0);
	modelCombo.show();

    QComboBox itemCombo;
	itemCombo.setWindowTitle("Item");
	itemCombo.addItems(items);
	itemCombo.model()->sort(0);
	itemCombo.show();

    a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
    return a.exec();
}

To copy to clipboard, switch view to plain text mode 

[jpn]

Btw, the only entry (related even a bit to this) I found in the task tracker.

[Byngl]

OK, I can force the model to be a QStringListModel so I can sort it, but if I do, I seem to be losing the ability to assign data to the entries.

//
	QComboBox itemCombo;
	itemCombo.setWindowTitle("Item");
	for (int i = 9; i >= 0; --i)
	{
		itemCombo.addItem(QString::number(i), 100 + i);
	}
	for (int i = 0; i < itemCombo.count(); ++i)
	{
		cout << i << ' ' << itemCombo.itemText(i).toLatin1().data() << ' ';
		cout << itemCombo.itemData(i).toInt();
		cout << " [" << itemCombo.itemData(i).toString().toLatin1().data() << ']';
		cout << endl;
	}
 
	//
	// Clear the contents and try again, this time with
	// a non-default model
	//
	itemCombo.clear();
	itemCombo.setModel(new QStringListModel());
	for (int i = 9; i >= 0; --i)
	{
		itemCombo.addItem(QString::number(i), 100 + i);
	}
	cout << "==============" << endl;
	for (int i = 0; i < itemCombo.count(); ++i)
	{
		cout << i << ' ' << itemCombo.itemText(i).toLatin1().data() << ' ';
		cout << itemCombo.itemData(i).toInt();
		cout << " [" << itemCombo.itemData(i).toString().toLatin1().data() << ']';
		cout << endl;
	}
 
	itemCombo.model()->sort(0);
	itemCombo.show();

//
	QComboBox itemCombo;
	itemCombo.setWindowTitle("Item");
	for (int i = 9; i >= 0; --i)
	{
		itemCombo.addItem(QString::number(i), 100 + i);
	}
	for (int i = 0; i < itemCombo.count(); ++i)
	{
		cout << i << ' ' << itemCombo.itemText(i).toLatin1().data() << ' ';
		cout << itemCombo.itemData(i).toInt();
		cout << " [" << itemCombo.itemData(i).toString().toLatin1().data() << ']';
		cout << endl;
	}

	//
	// Clear the contents and try again, this time with
	// a non-default model
	//
	itemCombo.clear();
	itemCombo.setModel(new QStringListModel());
	for (int i = 9; i >= 0; --i)
	{
		itemCombo.addItem(QString::number(i), 100 + i);
	}
	cout << "==============" << endl;
	for (int i = 0; i < itemCombo.count(); ++i)
	{
		cout << i << ' ' << itemCombo.itemText(i).toLatin1().data() << ' ';
		cout << itemCombo.itemData(i).toInt();
		cout << " [" << itemCombo.itemData(i).toString().toLatin1().data() << ']';
		cout << endl;
	}

	itemCombo.model()->sort(0);
	itemCombo.show();

To copy to clipboard, switch view to plain text mode 

This produces the following output:

0 9 109 [109]
1 8 108 [108]
2 7 107 [107]
3 6 106 [106]
4 5 105 [105]
5 4 104 [104]
6 3 103 [103]
7 2 102 [102]
8 1 101 [101]
9 0 100 [100]
==============
0 9 0 []
1 8 0 []
2 7 0 []
3 6 0 []
4 5 0 []
5 4 0 []
6 3 0 []
7 2 0 []
8 1 0 []
9 0 0 []

0 9 109 [109]
1 8 108 [108]
2 7 107 [107]
3 6 106 [106]
4 5 105 [105]
5 4 104 [104]
6 3 103 [103]
7 2 102 [102]
8 1 101 [101]
9 0 100 [100]
==============
0 9 0 []
1 8 0 []
2 7 0 []
3 6 0 []
4 5 0 []
5 4 0 []
6 3 0 []
7 2 0 []
8 1 0 []
9 0 0 []

To copy to clipboard, switch view to plain text mode 

I just checked in qstringlistmodel.cpp and it only returns data for Qt::DisplayRole and Qt::EditRole, not Qt::UserRole. Guess I get to write my own extension...

[jpn]

I guess an easy solution could be to inherit QStandardItemModel (which QComboBox internally uses) and implement the sorting functionality..