Something fishy about Model, data doesn't show up!

[zlosynus]

Hi, I am using Qt Jambi. I was trying to subclass QAbstractListModel and use it with QListView. But no data appears at all. Here is code of my subclassed model:

class SmenaDispeceriModel extends QAbstractListModel
{
    private List dispeceri = new ArrayList(); // data
 
    public int rowCount(QModelIndex parent)
    {   
        return dispeceri.size();
    }
 
    public Object data(QModelIndex index, int role)
    {   
        if (index.row() < 0 || index.row() >= dispeceri.size())
            return new Object();
 
        if (role == Qt.ItemDataRole.DisplayRole)
            return ((SmenaDispecer) dispeceri.get(index.row())).getDlouheJmeno();
        else
            return new Object();
    }
 
    public void addDispecera(Long id, String jmeno, String prijmeni)
    {
        dispeceri.add(new SmenaDispecer(id, jmeno, prijmeni));
    }
}

class SmenaDispeceriModel extends QAbstractListModel
{
    private List dispeceri = new ArrayList(); // data

    public int rowCount(QModelIndex parent)
    {   
        return dispeceri.size();
    }

    public Object data(QModelIndex index, int role)
    {   
        if (index.row() < 0 || index.row() >= dispeceri.size())
            return new Object();

        if (role == Qt.ItemDataRole.DisplayRole)
            return ((SmenaDispecer) dispeceri.get(index.row())).getDlouheJmeno();
        else
            return new Object();
    }

    public void addDispecera(Long id, String jmeno, String prijmeni)
    {
        dispeceri.add(new SmenaDispecer(id, jmeno, prijmeni));
    }
}

To copy to clipboard, switch view to plain text mode 

Now in dialog I have following sample code:

dispeceriModel = new SmenaDispeceriModel();
 
        dispeceriModel.addDispecera(new Long(1), "Karel", "Novak");
        dispeceriModel.addDispecera(new Long(2), "Tomas", "Marny");
        ui.listDispeceri.setModel(dispeceriModel);

dispeceriModel = new SmenaDispeceriModel();
            
        dispeceriModel.addDispecera(new Long(1), "Karel", "Novak");
        dispeceriModel.addDispecera(new Long(2), "Tomas", "Marny");
        ui.listDispeceri.setModel(dispeceriModel);

To copy to clipboard, switch view to plain text mode 

But the view is empty! When I tried following code, it works fine:

model = new QStandardItemModel();
        model.setRowCount(2);
        model.setColumnCount(1);
        model.setData(model.index(0, 0), "Some text");
        model.setData(model.index(1, 0), "Other text");
        ui.listDispeceri.setModel(model);

model = new QStandardItemModel();
        model.setRowCount(2);
        model.setColumnCount(1);
        model.setData(model.index(0, 0), "Some text");
        model.setData(model.index(1, 0), "Other text");
        ui.listDispeceri.setModel(model);

To copy to clipboard, switch view to plain text mode 

So there have to be some problem with my model, but i dont know where. Please help.

Thanks.

[caduel]

Try implementing columnCount() as well.
If that does not help: add debug-statements in data() to check if/for what indexes/roles it gets called.

HTH

[zlosynus]

Hi,

I cant implement columnCount, because I use QAbstractListModel, which has it already implemented.

I addded debuging statement and I got following:

public Object data(QModelIndex index, int role)
{   
System.out.println(index);
System.out.println(role);
if (index.row() < 0 || index.row() >= dispeceri.size())
return new Object();
 
if (role == Qt.ItemDataRole.DisplayRole)
return ((SmenaDispecer) dispeceri.get(index.row())).getDlouheJmeno();
else
return new Object();
}

public Object data(QModelIndex index, int role)
{   
System.out.println(index);
System.out.println(role);
if (index.row() < 0 || index.row() >= dispeceri.size())
return new Object();
    
if (role == Qt.ItemDataRole.DisplayRole)
return ((SmenaDispecer) dispeceri.get(index.row())).getDlouheJmeno();
else
return new Object();
}

To copy to clipboard, switch view to plain text mode 

[zlosynus]

Hi,

I cant implement columnCount, because I use QAbstractListModel, which has it already implemented.

I addded debuging statement:

public Object data(QModelIndex index, int role)
{   
     System.out.println(index);
     System.out.println(role);
     if (index.row() < 0 || index.row() >= dispeceri.size())
          return new Object();
 
     if (role == Qt.ItemDataRole.DisplayRole)
          return ((SmenaDispecer) dispeceri.get(index.row())).getDlouheJmeno();
     else
          return new Object();
}

public Object data(QModelIndex index, int role)
{   
     System.out.println(index);
     System.out.println(role);
     if (index.row() < 0 || index.row() >= dispeceri.size())
          return new Object();
    
     if (role == Qt.ItemDataRole.DisplayRole)
          return ((SmenaDispecer) dispeceri.get(index.row())).getDlouheJmeno();
     else
          return new Object();
}

To copy to clipboard, switch view to plain text mode 

and got following (running in ant):

[java] QModelIndex(row=0,col=0,internal=0)
[java] 13
[java] QModelIndex(row=1,col=0,internal=0)
[java] 13
[java] QModelIndex(row=2,col=0,internal=0)
[java] 13
[java] QModelIndex(row=3,col=0,internal=0)
[java] 13
[java] QModelIndex(row=4,col=0,internal=0)
[java] 13

[java] QModelIndex(row=0,col=0,internal=0)
[java] 13
[java] QModelIndex(row=1,col=0,internal=0)
[java] 13
[java] QModelIndex(row=2,col=0,internal=0)
[java] 13
[java] QModelIndex(row=3,col=0,internal=0)
[java] 13
[java] QModelIndex(row=4,col=0,internal=0)
[java] 13

To copy to clipboard, switch view to plain text mode 

Pretty weard is, that when I use QTableView instead of QListView, everything works fine!

[caduel]

I am not experienced with Jambi.
And the code does look ok to me.

Try calling the base class instead of 'only' returning "new Object()".