[Qt-interest] QTreeView, proxy model and expandable state

[Scott Aron Bloom]

> -----Original Message-----
> From: qt-interest-bounces at trolltech.com [mailto:qt-interest-
> bounces at trolltech.com] On Behalf Of Dmitry Baryshev
> Sent: Monday, April 13, 2009 10:13 AM
> To: qtInterest
> Subject: Re: [Qt-interest] QTreeView, proxy model and expandable state
> 
> 2009/4/13 Dmitry Baryshev <ksquirrel.iv at gmail.com>:
> > 2009/4/13 Scott Aron Bloom <Scott.Bloom at sabgroup.com>:
> >> It will really depend on what you implemented in your filterAcceptsRows
> >> method.
> >>
> >> Without seeing the guts of it, I have no idea how to help you.
> >>
> >> Scott
> >>
> >> -----Original Message-----
> >> From: qt-interest-bounces at trolltech.com
> >> [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Dmitry Baryshev
> >> Sent: Monday, April 13, 2009 8:26 AM
> >> To: qt-interest at trolltech.com
> >> Subject: [Qt-interest] QTreeView, proxy model and expandable state
> >>
> >> Hi.
> >>
> >> I use QTreeView+QFileSystemModel. It seems to work fine, all directory
> >> items have expanable flag ("+" on the left side). Now I've added
> >> QSortFilterProxyModel with only one reimplemented method - "bool
> >> SortFilterProxyModel::filterAcceptsRow(int row, const QModelIndex
> >> &parent) const". Now all directory items in QTreeView lost its
> >> expandable state - no '+' elements.
> >> QTreeView::setItemsExpandable(true) doesn't help. I don't understand
> >> the logic why filtering affects expandable states? Could you please
> >> help me with this strange problem? Thanks!
> >>
> >> --
> >> _______________________________________________
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> >> Qt-interest at trolltech.com
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> >>
> >> _______________________________________________
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> >>
> >
> > In any case it doesn't work. For example:
> >
> > bool MySortFilterProxyModel::filterAcceptsRow(int row, const
> > QModelIndex &parent) const
> > {
> >    return true;
> > }
> >
> > --
> >
> 
> Full source code to reproduce:
> 
> .h
> --
> 
> #ifndef FLL_H
> #define FLL_H
> 
> #include <QTreeView>
> 
> class fl : public QTreeView
> {
>     Q_OBJECT
> 
>     public:
>         fl(QWidget *parent = 0);
> };
> 
> #endif
> 
> .cpp
> ----
> 
> #include <QFileSystemModel>
> #include <QSortFilterProxyModel>
> 
> #include "fl.h"
> 
> class SortFilterProxyModel : public QSortFilterProxyModel
> {
>     public:
>         SortFilterProxyModel(QObject *parent) : QSortFilterProxyModel(parent)
>         {
>             setFilterRegExp(".*");
>         }
> 
>     protected:
>         bool filterAcceptsRow(int /* row */, const QModelIndex &/*
> parent */) const
>         {
>             return true;
>         }
> };
> 
> #define USE_PROXY_MODEL
> 
> fl::fl(QWidget *parent) : QTreeView(parent)
> {
>     QFileSystemModel *model;
> 
>     model = new QFileSystemModel;
>     model->setResolveSymlinks(true);
>     model->setNameFilterDisables(false);
>     model->setReadOnly(true);
> 
>     SortFilterProxyModel *proxyModel;
> 
>     proxyModel = new SortFilterProxyModel(this);
>     proxyModel->setSourceModel(model);
>     proxyModel->setDynamicSortFilter(true);
> 
> #ifdef USE_PROXY_MODEL
>     QModelIndex root =
> proxyModel->mapFromSource(model->setRootPath(QDir::rootPath()));
>     setModel(proxyModel);
> #else
>     QModelIndex root = model->setRootPath(QDir::rootPath());
>     setModel(model);
> #endif
> 
>     setRootIndex(root);
> }
> 
> /*********************************/
> 
> define or undef USE_PROXY_MODEL to test two cases with and without proxy
> model.
> 
> Result:
> 
> 1) without proxy model: http://img258.imageshack.us/img258/7271/fl1.png
> 2) with proxy model: http://img258.imageshack.us/img258/1606/fl2.png
> 
> The system is Debian Lenny with Qt 4.4.3.
> 
> Maybe it is a bug?
> 
> --
> 
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at trolltech.com
> http://lists.trolltech.com/mailman/listinfo/qt-interest

Its probably your setFilterRegExp call...  Try turning that off, and leaving the filterAcceptsRow... See what happens

Scott