Qt-interest Archive, January 2008
Assert in QSortFilterProxyModel
Message 1 in thread
Hi Everyone,
I use QT 4.2.3 as my GUI application toolkit on Linux platform.
I have a QTabWidget with 3 tabs inside. Each tab is a QTreeView.
I also have a QStandardItemModel as 1st QTreeView model. Then
the 2nd and 3rd QTreeView is using QSortFilterProxyModel from
1st QStandardItemModel.
But I found I got assertion in QT when I try to removeRow from 1st
QStandardItemModel.
The removed items will only appear in 2nd QSortFilterProxyModel.
They will be filtered by 3rd QSortFilterProxyModel.
Also, I have change selection before the remove action.
It asserts inside :
/*!
\internal
updates the mapping of the children when inserting or removing items
*/
void QSortFilterProxyModelPrivate::updateChildrenMapping(const QModelIndex
&source_parent, Mapping *parent_mapping,
Qt::Orientation
orient, int start, int end, int delta_item_count, bool remove)
{
// see if any mapped children should be (re)moved
QVector<QModelIndex>::iterator it2 =
parent_mapping->mapped_children.begin();
for ( ; it2 != parent_mapping->mapped_children.end();) {
const QModelIndex source_child_index = *it2;
const int pos = (orient == Qt::Vertical)
? source_child_index.row()
: source_child_index.column();
if (pos < start) {
// not affected
++it2;
} else if (remove && pos <= end) {
// in the removed interval
it2 = parent_mapping->mapped_children.erase(it2);
remove_from_mapping(source_child_index);
} else {
// below the removed items -- recompute the index
QModelIndex new_index;
const int newpos = remove ? pos - delta_item_count : pos +
delta_item_count;
if (orient == Qt::Vertical) {
new_index = model->index(newpos,
source_child_index.column(),
source_parent);
} else {
new_index = model->index(source_child_index.row(),
newpos,
source_parent);
}
*it2 = new_index;
++it2;
// update mapping
Mapping *cm = source_index_mapping.take(source_child_index);
Q_ASSERT(cm);
<=========================== it asserts here !!
cm->map_iter = source_index_mapping.insert(new_index, cm);
}
}
}
Could anybody help me out ?
Regards,
Pagan
--
[ signature omitted ]
Message 2 in thread
Hi Everyone,
I found more detailed information after I step inside QT source code
to debug.
void QSortFilterProxyModelPrivate::updateChildrenMapping(const QModelIndex &source_parent, Mapping *parent_mapping,
Qt::Orientation orient, int start, int end, int delta_item_count, bool remove)
Inside this API, it will traverse
QVector<QModelIndex>::iterator it2 = parent_mapping->mapped_children.begin();
for ( ; it2 != parent_mapping->mapped_children.end();) {
const QModelIndex source_child_index = *it2;
If I turn off the sorting of this model corresponding view, I found the source_child_index
start from 0 to the end when I removeRow from source model.
If I turn on the sorting, I found the source_child_index start from an arbitrary row.
But in this API more further below :
// update mapping
Mapping *cm = source_index_mapping.take(source_child_index);
Q_ASSERT(cm);
cm->map_iter = source_index_mapping.insert(new_index, cm);
It needs assumption for the traverse start from 0. Otherwise, it will erase all index.
Is it a QT internal bug ?
I've checked all related tasks in QT Task Tracker but found none matches.
Regards,
Pagan
"Pagan Chou" <pagan_chou@xxxxxxxxxxxxxx> 在郵件 news:fncgi8$pf3$1@xxxxxxxxxxxxxxxxxx 中撰寫...
> Hi Everyone,
> I use QT 4.2.3 as my GUI application toolkit on Linux platform.
>
> I have a QTabWidget with 3 tabs inside. Each tab is a QTreeView.
> I also have a QStandardItemModel as 1st QTreeView model. Then
> the 2nd and 3rd QTreeView is using QSortFilterProxyModel from
> 1st QStandardItemModel.
>
> But I found I got assertion in QT when I try to removeRow from 1st
> QStandardItemModel.
> The removed items will only appear in 2nd QSortFilterProxyModel.
> They will be filtered by 3rd QSortFilterProxyModel.
>
> Also, I have change selection before the remove action.
>
