QTreeview Custom model and QSortFilterProxyModel

prady_80

I have a custom Hierarchical model Implemented which is basically displayed in a QtreeView. My requirement is to filter data on multiple columns. The code of the model is as follows:
model:

@namespace {
const int ColumnCount = 7;
enum Column {Application=0, StartTime, AccountedTime,Activity,Purpose,OffLine,MachineName};
}

QVariant CSapActvtyTreeModel::data(const QModelIndex &index, int role) const
{
qDebug()<<"CSapActvtyTreeModel::data ... start"<<endl;
if (!m_pObjRootItem || !index.isValid() || index.column() < 0 ||
index.column() >= ColumnCount) {
return QVariant();
}

//This is the data display role
if (COnlineSapActvtyItem *item = itemForIndex(index)) {
    if (role == Qt::DisplayRole) {
        switch (index.column()) {
        //Application, StartTime, AccountedTime,Activity,Purpose
        case Application: return item->GetTaskName();
        case StartTime: return item->GetStartTimeStr();
        case AccountedTime: return item->GetAccountedTimeStr();
        case Activity: return item->GetActivityType();
        case Purpose: return item->GetActivityPurpose();
        case OffLine: return (item->IsOnline() ? "1" : "0");
        case MachineName: return item->GetMachineName();
        default: return QVariant();
        }
    }
}
return QVariant();

}

int CSapActvtyTreeModel::rowCount(const QModelIndex &parent) const
{
qDebug() << "CSapActvtyTreeModel::rowCount" << endl;
if (parent.isValid() && parent.column() != 0)
return 0;
COnlineSapActvtyItem *parentItem = itemForIndex(parent);
int irowCount = (parentItem ? parentItem->childCount() : 0);
qDebug()<<"Returning row count: "<<irowCount <<endl;
return irowCount;
}

int CSapActvtyTreeModel::columnCount(const QModelIndex &parent) const
{
qDebug() << "CSapActvtyTreeModel::columnCount" << endl;
int iColCount = (parent.isValid() && parent.column() != 0 ? 0 : ColumnCount);
qDebug()<<"Returning Col count: "<<iColCount <<endl;
return iColCount;
}

QModelIndex CSapActvtyTreeModel::index(int row, int column,
const QModelIndex &parent) const
{
qDebug() << "CSapActvtyTreeModel::index" << endl;
if (!m_pObjRootItem || row < 0 || column < 0 || column >= ColumnCount
|| (parent.isValid() && parent.column() != 0))
return QModelIndex();
COnlineSapActvtyItem *parentItem = itemForIndex(parent);
if(parentItem) {
if (COnlineSapActvtyItem *item = parentItem->childAt(row))
return createIndex(row, column, item);
}
return QModelIndex();
}

COnlineSapActvtyItem* CSapActvtyTreeModel::itemForIndex(const QModelIndex &index) const
{
qDebug() << "CSapActvtyTreeModel::itemForIndex" << endl;
if (index.isValid()) {
if (COnlineSapActvtyItem item = static_cast<COnlineSapActvtyItem>(
index.internalPointer())) {
return item;
}
}
return m_pObjRootItem;
}

QStringList CSapActvtyTreeModel::pathForIndex(const QModelIndex &index) const
{
qDebug() << "CSapActvtyTreeModel::pathForIndex" << endl;
QStringList path;
QModelIndex thisIndex = index;
while (thisIndex.isValid()) {
path.prepend(data(thisIndex).toString());
thisIndex = thisIndex.parent();
}
return path;
}

QModelIndex CSapActvtyTreeModel::indexForPath(const QStringList &path) const
{
qDebug() << "CSapActvtyTreeModel::indexForPath" << endl;
return indexForPath(QModelIndex(), path);
}

QModelIndex CSapActvtyTreeModel::indexForPath(const QModelIndex &parent,
const QStringList &path) const
{
qDebug() << "CSapActvtyTreeModel::indexForPath2" << endl;
if (path.isEmpty())
return QModelIndex();
for (int row = 0; row < rowCount(parent); ++row) {
QModelIndex thisIndex = index(row, 0, parent);
if (data(thisIndex).toString() == path.at(0)) {
if (path.count() == 1)
return thisIndex;
thisIndex = indexForPath(thisIndex, path.mid(1));
if (thisIndex.isValid())
return thisIndex;
}
}
return QModelIndex();
}@

These are the major overloaded functions implemented for my model. When I use this model, the treeView displays data correct. But When I changed the treeview to use a custom proxy model which just overrides filterAcceptRows the tree view does not display anything. Also, I added a debug trace in the filterAcceptRows. The filterAcceptRows is not getting called.

The way I set up the treeView and models is:

@m_pFilterProxyModel = new CSapFilterProxyModel(); //Derived from QSortFilterProxyModel
treeView->setModel(m_pFilterProxyModel);

m_pMainTreeModel = new CSapActvtyTreeModel(); //My Main model

PopulateMainModel();
m_pFilterProxyModel->setSourceModel(m_pMainTreeModel);
@

Sample Xml using which I build the tree
@
<TA NM="Qt Creator" OL="1" MN="PRADY-LP">

        <TA NM="SapienceTray" OL="1" MN="PRADY-LP">

            <TM ST="2013-03-29T04:47:02" TT="2100"/>

            <AC AT="Development" AP="Sapience Multi Client"/>

        </TA>

</TA>
<TA NM="Ms Visual Studio" OL="1" MN="PRADY-LP">

    <TA NM="Test" OL="1" MN="PRADY-LP">

        <TM ST="2013-03-29T02:47:02" TT="3000"/>

        <AC AT="Development" AP="Sapience Multi Client"/>

    </TA>

    <TA NM="Number Crunching" OL="1" MN="PRADY-LP">

        <TM ST="2013-03-29T01:47:02" TT="2000"/>

        <AC AT="Development" AP="Sapience Multi Client"/>

    </TA>

</TA>
@

This is how the proxymodel is implemented.

FilterAcceptsRow is not getting called. What could be the problem???

andre

Are you positive that your overloaded filterAcceptsRow is really an overload? I mean: does the signature match the one from the base class exactly? Look for a missing const, for instance...

prady_80

Andre, yes my function overload is correct.
My trimmed down derivation of QSortFilterProxyModel is as follows:
////.h
@
#include <QDate>
#include <QSortFilterProxyModel>

class CSapFilterProxyModel : public QSortFilterProxyModel {
Q_OBJECT

public:
CSapFilterProxyModel(QObject* parent = 0);
virtual ~CSapFilterProxyModel();

//All the filtering criteria go in here...

protected:
bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const;

private:
//Data members and helper functions here
};
@

and the .cpp file is :
@
bool CSapFilterProxyModel::filterAcceptsRow(int sourceRow,
const QModelIndex &sourceParent) const {
qDebug() << "filterAcceptsRow called" << endl;
bool bIsAccepted = true;
bIsAccepted = bIsAccepted && MatchMe(1,sourceRow,sourceParent);
return bIsAccepted;

}

bool CSapFilterProxyModel::MatchMe(int iCol,int sourceRow,
const QModelIndex &sourceParent) const {
//return true or false based on matching criteria
}
@

Also the way I load the XML into my data structure (for reference just in case),
where pObjTask contains the root item pointer.
@
void CSapActvtyTreeModel::readTasks(QXmlStreamReader *reader, COnlineSapActvtyItem *pObjTask)
{
qDebug() << "CSapActvtyTreeModel::readTasks" << endl;
while ((reader && !reader->atEnd())) {
reader->readNext();
if (reader->isStartElement()) {
if (reader->name() == TaskTag) { //TA
QString strName = reader->attributes()
.value(NameAttribute).toString();

            bool bIsOnLine = reader->attributes()
                    .value(OnLineAttribute)
                    == "1";

            QString strMachineName = reader->attributes()
                    .value(MachinNameAttribute).toString();
            pObjTask = new COnlineSapActvtyItem(NULL,pObjTask);
            pObjTask->SetTaskName(strName);
            pObjTask->SetOnlineFlag(bIsOnLine);
            pObjTask->SetMachineName(strMachineName);

        } else if(reader->name() == TimeTag) { //TM
            Q_ASSERT(pObjTask);

            QDateTime objStartTime = QDateTime::fromString(
                        reader->attributes().value(StartTimeAttribute)
                        .toString(), Qt::ISODate);
            int iTotalTime =
                    reader->attributes().value(TotalTimeAttribute)
                    .toString().toInt();
            pObjTask->SetStartTime(objStartTime);
            pObjTask->SetAccountedTime(iTotalTime);
        }
        else if (reader->name() == ActvtyTag) { //AC
            Q_ASSERT(pObjTask);
            QString strActvtyType =
                    reader->attributes().value(ActvtyTypeAttribute)
                    .toString();
            QString strActvtyPurpose =
                    reader->attributes().value(ActvtyPurposeAttribute)
                    .toString();
            pObjTask->SetActvtyType(strActvtyType);
            pObjTask->SetActvtyPurpose(strActvtyPurpose);
        }
    }
    else if (reader->isEndElement()) {
        if (reader->name() == TaskTag) { //TA end
            Q_ASSERT(pObjTask);
            pObjTask = pObjTask->parent();
            Q_ASSERT(pObjTask);
        }
    }
}

}
@

Please let me know. Thanks

prady_80

Any one has any ideas on the above?

prady_80

I have been able to solve this using the QDomModel example from Qt examples which works very well with QSortFilterProxyModel.