[Solved] qml: problem with TableView refresh on model update

[_rth_]

Hello everyone!

I have simple QML app with TableView on screen. This view displays data from my custom model - derived from QAbstractTableModel:

@#include "pswlistmodel.h"
#include <QDebug>

PswListModel::PswListModel(QObject parent)
: QAbstractTableModel(parent)
, hidePsws(true)
{
//test
for (int i=0; i<10; ++i)
{
PswElement e = new PswElement();
e->login = "login " + QString::number(i);
e->name = "name " + QString::number(i);
e->password = "password " + QString::number(i);
this->elements.append(e);
}
}

PswListModel::~PswListModel()
{
qDeleteAll(this->elements);
this->elements.clear();
}

int PswListModel::rowCount(const QModelIndex& /parent/) const
{
return this->elements.size();
}

int PswListModel::columnCount(const QModelIndex& /parent/) const
{
return 3;
}

QVariant PswListModel::data(const QModelIndex& index, int role) const
{
if (this->elements.isEmpty())
return QVariant();

if (index.row() >= this->elements.size())
    return QVariant();


PswElement *e = this->elements[index.row()];

if (role == Qt::DisplayRole)
{
    //name
    if (index.column() == 0)
        return e->name;

    //login
    if (index.column() == 1)
        return e->login;

    //password
    if (index.column() == 2)
    {
        if (!this->hidePsws)
            return e->password;
        else
            return "***";
    }
}
else if (role == PswNameRole)
    return e->name;
else if (role == PswLoginRole)
    return e->login;
else if (role == PswPswRole)
{
    qDebug() << "get psw (" << index.row() << "), hide: " << this->hidePsws;
    if (!this->hidePsws)
        return e->password;
    else
        return "***";
}

return QVariant();

}

QVariant PswListModel::headerData(int section, Qt::Orientation orientation, int role) const
{
if (orientation == Qt::Horizontal)
{
if (role == Qt::DisplayRole)
{
if (section == 0)
return QString("Name");
else if (section == 1)
return QString("Login");
else if (section == 2)
return QString("Password");
}
else if (role == PswNameRole)
return "Name";
else if (role == PswLoginRole)
return "Login";
else if (role == PswPswRole)
return "Password";
}
else
if (orientation == Qt::Vertical)
return QString();

return QVariant::Invalid;

}

QHash<int, QByteArray> PswListModel::roleNames() const
{
QHash<int, QByteArray> roles;
roles[PswNameRole] = "name";
roles[PswLoginRole] = "login";
roles[PswPswRole] = "password";
return roles;
}

void PswListModel::showPasswords(bool value)
{
qDebug() << "showPasswords: " << value;
this->hidePsws = value;

QModelIndex idTop = QAbstractTableModel::index(0, 0);
QModelIndex idBottom = QAbstractTableModel::index(this->elements.size(), 4);

emit dataChanged(idTop, idBottom);

}@

TableView in qml works fine, it displays all data from model.

Now there is CheckBox in qml screen for toggling passwords. When state changes I am calling PswListModel::showPasswords from my custom model (from qDebug, I can see that value is changing). This should toggle the passwords visibility from "***" to real passwords. However, even if emitting dataChanged signal, TableView view in qlm is not refreshed.

I am using Qt is 5.4.0, QtQuick 2.4 and QtQuick.Controls 1.3. Platform: Windows 7.

Thanks in advance.

[p3c0]

Hi,
@
QModelIndex idTop = QAbstractTableModel::index(0, 0);
QModelIndex idBottom = QAbstractTableModel::index(this->elements.size(), 4);
@

I think since idTop starts from 0, idBottom should be 1 less.

[_rth_]

Good point. Unfortunately that didn't help. Even if the range is correct (from elements.size()-1 to 3), table view in qml is not updated. This approach seems to be wrong.

I finally figured it out:

@void PswListModel::showPasswords(bool value)
{
qDebug() << "showPasswords: " << value;
this->showPsws = value;

this->beginResetModel();
this->endResetModel();

} @

Reseting model invokes update of table in qml.

[andreaplanet]

you may could tell the view that your data changed instead of resetting the whole model. You can specify which data. Here for the whole table:

@emit dataChanged(index(0,0), index(rowCount()-1,columnCount()-1));@

[_rth_]

That was my original problem: emitting dataChanged signal didn't refreshed the TableView.

[andreaplanet]

uhm. dataChanged works. There is something wrong elsewhere.
index in dataChanged is wrong, not only elementsSize()-1 but also for the columns you are using 4 instead of 2. That could be a reason.

Did you tried to see if data is invoked after the call to showPasswords.

Also in showPassword you are updating this->showPsws while in data you are using this->hidePsws. Could be that data is called but you are returing always the same value.