QSortFilterProxyModel: inconsistent changes reported by source model

kunashir

In source model:
@
bool CatalogTableModel::removeRows (int row, int count, const QModelIndex &parent)
{
//TODO:
Q_UNUSED (parent);
beginRemoveRows(QModelIndex(), row, row + count - 1);
//int column = row + count;
for (int i = 0; i < count; ++i)
{
delete listItem->at(row);
listItem->removeAt(row);
}
emit layoutChanged();
endRemoveRows();
return true;
}
@
I don't sure correctly it is or not..

ZapB

I don't think that you need to emit the layoutChanged() signal. The {begin|end}RemoveRows() functions do everything that is needed for you. Try removing that emit end see if it works then.

I suspect what is happening is that the proxy and views are receiving signals from you and from {begin|end}RemoveRows() in an unexpected order which causes them to misbehave.

kunashir

With out emit the layoutChanged() programm to crash!
Maybe link between source model and proxy is not correct?

ZapB

Setting a proxy is a one-liner so I doubt it is that. I suspect you have a problem in your model. I suggest that you run your model with the qmodeltest helper which diagnoses common model implementation problems. This "wiki article":http://developer.qt.nokia.com/wiki/Model_Test describes how to use qmodeltest and the source can be downloaded from "gitorious":https://qt.gitorious.org/qt/qt/trees/4.7/tests/auto/modeltest.

kunashir

Let's me stupid question - gitotious of model test have pro-file, but wiki article say about pri-file. How I can get pri file?

ZapB

Ah the instructions must be slightly out of date wrt the code. It used to be in it's own repository on Qt-labs. I think you can just copy the modeltest.{h,cpp} files to a little test project and instatiate them as shown in the above wiki article.

kunashir

I use modeltest and have next message:

ratbr QModelIndex(-1,-1,0x0,QObject(0x0) ) 73 73
rr QModelIndex(-1,-1,0x0,QObject(0x0) ) 73 73

and other simular.
Is it Ok? I check mapping index from proxy to source - it ok.
What else I may do?

ZapB

Debug your removeRows() function to make sure it is working properly. Step through it in a debugger to see where it crashes and why.

kunashir

I get error:
@
void QSortFilterProxyModelPrivate::source_items_removed(
const QModelIndex &source_parent, int start, int end, Qt::Orientation orient)
{
if ((start < 0) || (end < 0))
return;
IndexMap::const_iterator it = source_index_mapping.constFind(source_parent);
if (it == source_index_mapping.constEnd()) {
// Don't care, since we don't have mapping for this index
return;
}

Mapping *m = it.value();
QVector<int> &source_to_proxy = (orient == Qt::Vertical) ? m->proxy_rows : m->proxy_columns;
QVector<int> &proxy_to_source = (orient == Qt::Vertical) ? m->source_rows : m->source_columns;

if (end >= source_to_proxy.size())
    end = source_to_proxy.size() - 1;

// Shrink the source-to-proxy mapping to reflect the new item count
int delta_item_count = end - start + 1;
source_to_proxy.remove(start, delta_item_count); //This crash

@

gonzomcgraw

As ZapB said
[quote author="ZapB" date="1310123242"]Setting a proxy is a one-liner[/quote]unless you must overwrite a standard function of QSortFilterProxyModel.

Normally removing rows will be done in the sourcemodel. As you do a selection in the view you have to map the indexes getting from the view to the source with
@// single selection
QModelIndex SourceIndex = tableProxyModel->mapToSource(viewIndex);

// multiple selection
QModelIndexList SourceIndexList;
for (int i=0; i<viewIndexList.length(); i++)
{
SourceIndexList.append(tableProxyModel->mapToSource(viewIndexList[i]));
}
@

Also, if you have multiple selection you must sort the indexlist before removing like this:
@void CatalogTableModel::removeSelectedRows(const QModelIndexList &indexlist)
{
QList<int> rows;
foreach(const QModelIndex & index, indexlist)
{
rows.append(index.row());
}

qSort(rows);

int prev = -1;
for(int i=rows.count()-1; i>=0; i-=1 )
{
    int current = rows[i];
    if(current != prev)
    {
        QModelIndex _index = createIndex(current, 0);
        removeLabel(_index);
        prev = current;
    }
}

}
@

Cheers,
Thomas

Edit: Uuups, little bit late ...