Change color of a row of a QSqlQueryModel (QTableView)?

[c64zottel]

@Panoss I don't have a setData function. The code I use for reset is:

void BattlefieldModel::refresh( const QSet< LinearCoordinate > & indices ) {
    for( int lc : indices ) {
        QModelIndex a = index( lc );
        emit dataChanged( a, a );
    }
}

But this is only ok because, ... well lets not get into it.

The arguments of index ( row, column) is just the position you want to update. Since I have just rows, I update just rows.

[VRonin]

First of all, let me start by saying that using a QStandardItemModel filled manually from a QSqlQuery is probably the fastest way to go.

having said that you can use this proxy model to make it work:

Sorry for C++

#include <QIdentityProxyModel>
class  ExtraRolesProxyModel : public QIdentityProxyModel
{
    Q_OBJECT
    Q_DISABLE_COPY(ExtraRolesProxyModel)
public:
    explicit ExtraRolesProxyModel(QObject* parent=Q_NULLPTR)
        :QIdentityProxyModel(parent)
    {}
    virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const Q_DECL_OVERRIDE{
        const qint64 hashKey = (static_cast<qint64>(index.row()) << 32) | static_cast<qint64>(index.column());
        auto tableIter = m_extraRoles.constFind(hashKey);
        if(tableIter==m_extraRoles.constEnd())
            return QIdentityProxyModel::data(index,role);
        auto roleIter = tableIter.value().constFind(role);
        if(roleIter==tableIter.value().constEnd())
            return QIdentityProxyModel::data(index,role);
        return roleIter.value();
    }
    virtual bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) Q_DECL_OVERRIDE {
        if(!index.isValid())
            return false;
        Q_ASSERT(index.model()==this);
        const qint64 hashKey = (static_cast<qint64>(index.row()) << 32) | static_cast<qint64>(index.column());
        if(value.isValid()){
            m_extraRoles[hashKey][role] = value;
            emit dataChanged(index,index,QVector<int>(1,role));
            return true;
        }
        auto tableIter = m_extraRoles.find(hashKey);
        if(tableIter==m_extraRoles.end())
            return false;
        auto roleIter = tableIter.value().find(role);
        if(roleIter==tableIter.value().end())
            return false;
        tableIter.value().erase(roleIter);
        if(tableIter.value().isEmpty())
            m_extraRoles.erase(tableIter);
        emit dataChanged(index,index,QVector<int>(1,role));
        return true;
    }

private:
    QHash<qint64,QHash<qint32,QVariant> > m_extraRoles;
};

[Panoss]

How can this line be explained in plain english?

const qint64 hashKey = (static_cast<qint64>(index.row()) << 32) | static_cast<qint64>(index.column());

If index.row() is smaller than 32 thne hashkey = index.row().
Else hashkey = index.column()?

[VRonin]

@Panoss That row means: prepare an integer with 64 bits, the 32 leftmost bits will contain the row, the 32 rightmost the column. The bitshift operator is the same even in python https://wiki.python.org/moin/BitwiseOperators

[Panoss]

I translated it likes this: (I get no error on this line, seems ok)

hashKey = index.row() << 32 | index.column()

But this one;

 auto tableIter = m_extraRoles.constFind(hashKey);

Converted to python:

tableIter = m_extraRoles.constFind(hashKey)

Says variable m_extraRoles 'Unresolved reference'. It has not been declared anywhere.

[VRonin]

shouldn't it be this.m_extraRoles.constFind(hashKey) ?

[Panoss]

Yes, you 're right VRonin:

tableIter = self.m_extraRoles.constFind(hashKey)

This shows no underlined code in Pychrm (if there were any errors, it would be underlined. With red color.)

But this look very hard to convert to python:

Q_ASSERT(index.model()==this)

Q_ASSERT?? omg

[VRonin]

You can actually remove that line altogether, it's just a check that is done only in debug mode

[Panoss]

Only one (!!) line is left:

emit dataChanged(index,index,QVector<int>(1,role));

Translated to:

self.dataChanged.emit(index,index,QVector(int((1,role)))

But there is no QVector in Python.
(I mean it doesn't exist in any library like PyQt4.QtCore)

[VRonin]

Leave it with just self.dataChanged.emit(index,index) then. the last one is an optional parameter and even Qt's native models don't use it

[Panoss]

I set for source of the proxy model (ExtraRolesProxyModel) a QSqlQueryModel.
But I get an error:
'tableIter = self.m_extraRoles.constFind(hashKey)
AttributeError: 'ExtraRolesProxyModel' object has no attribute 'm_extraRoles'

[Panoss]

And this is the whole code (of the class):

class ExtraRolesProxyModel(QIdentityProxyModel ):
    def __init__(self, dbcursor=None):
        super(ExtraRolesProxyModel, self).__init__()        
    def data(self, index, role):
        hashKey = index.row() << 32 | index.column()
        tableIter = self.m_extraRoles.constFind(hashKey)
        if tableIter==self.m_extraRoles.constEnd:
            return QtSql.QSqlQueryModel.data(index,role);
        roleIter = tableIter.value().constFind(role)
        if roleIter==tableIter.value().constEnd():
            return QtSql.QSqlQueryModel.data(index,role);
        return roleIter.value()

    def setData(self, index, value, role=None):
        if not index.isValid():
            return False
        hashKey = index.row() << 32 | index.column()
        if value:
            self.m_extraRoles[hashKey][role] = value
            self.dataChanged.emit(index,index)
            return True;
        tableIter = self.m_extraRoles.find(hashKey)
        if tableIter== self.m_extraRoles.end():
            return False
        roleIter = tableIter.value().find(role)
        if roleIter==tableIter.value().end():
            return False
        tableIter.value().erase(roleIter)
        if tableIter.value().isEmpty():
            self.m_extraRoles.erase(tableIter)
        self.dataChanged.emit(index, index)
        return True

[VRonin]

@Panoss said in Change color of a row of a QSqlQueryModel (QTableView)?:

AttributeError: 'ExtraRolesProxyModel' object has no attribute 'm_extraRoles'

You have to declare it in the __init__ method (not sure how you deal with templates in python though)

---

@Panoss said in Change color of a row of a QSqlQueryModel (QTableView)?:

if tableIter==self.m_extraRoles.constEnd:

Missing ()

---

if value:

Does it work?

[Panoss]

I made the suggested corrections:

if tableIter==self.m_extraRoles.constEnd():

And:

if value.isValid():

But I don't knw how to declare the m_extraRoles, so I declared it as list, which obviously, is incorrect.

class ExtraRolesProxyModel(QIdentityProxyModel ):
    def __init__(self, dbcursor=None):
        super(ExtraRolesProxyModel, self).__init__()
        self.m_extraRoles = []

(the '= []' means 'define it as list' )

[VRonin]

you probably have to use a dict. Let's try this:

I do not know python so consider this just a guideline

class ExtraRolesProxyModel(QIdentityProxyModel ):
    def __init__(self, dbcursor=None):
        super(ExtraRolesProxyModel, self).__init__()
        self.m_extraRoles=dict()
    def data(self, index, role):
        hashKey = QByteArray()
        keyStream = QDataStream(hashKey,QIODevice::WriteOnly)
        keyStream.writeInt32(index.row())
        keyStream.writeInt32(index.column())
        keyStream.writeInt32(role)
        if self.m_extraRoles.has_key(hashKey):
            return self.m_extraRoles[hashKey]
        return QtSql.QSqlQueryModel.data(index,role)            

    def setData(self, index, value, role=None):
        if not index.isValid():
            return False
        hashKey = QByteArray()
        keyStream = QDataStream(hashKey,QIODevice::WriteOnly)
        keyStream.writeInt32(index.row())
        keyStream.writeInt32(index.column())
        keyStream.writeInt32(role)
        if value.isValid():
            self.m_extraRoles[hashKey]=value
            self.dataChanged.emit(index,index)
            return True
        if self.m_extraRoles.has_key(hashKey):
            del self.m_extraRoles[hashKey]
            self.dataChanged.emit(index,index)
            return True
        return False
        

[Panoss]

if self.m_extraRoles.has_key(hashKey):

AttributeError: 'dict' object has no attribute 'has_key'

But I see that dict does have an attributte named 'has_key'.

EDIT: in fact, it's been removed since python 3.
So I replaced:

if self.m_extraRoles.has_key(hashKey):

with:

if hashKey not in self.m_extraRoles:

But now I get another error:
return self.m_extraRoles[hashKey]
KeyError: PyQt4.QtCore.QByteArray(b'\x00\x00\x00\x04\x00\x00\x00\x02\x00\x00\x00\x08')

KeyError? What is this now?

EDIT:
I think hashKey has to be converted from QString to string.
I tried this:

hashKey = unicode([PyQt4.QtCore.QString(u'hashKey')])

But this line returns me an error:
AttributeError: 'module' object has no attribute 'QString'