How to Filter Columns in a QFileSystemModel

Sometimes one does not want to display all the columns of a QFileSystemModel [doc.qt.nokia.com], like discussed in this forum thread [developer.qt.nokia.com].

This can be achieved in two ways, either by hiding the columns in the view, by using a specialized proxy model. The easiest way is to hide the columns using the QHeaderView, but the alternative to subclass QSortFilterProxyModel [doc.qt.nokia.com] and reimplement the filterAcceptsColumn() method also works well.

Column hiding using QHeaderView

All multi-column views provide access to a QHeaderView [doc.qt.nokia.com] . This is the widget that provides the headers above the columns of data, and allows the user to resize those columns, or click the headers to trigger a sorting order. You can also use this widget to hide columns in your view.

The alternative method of using a custom proxy model is outlined below.

Column hiding using QSortFilterProxyModel

Be aware that the column count is 0-based and that it is hard coded.

fsmproxy.h

1. #include <QSortFilterProxyModel>
2.  
3. class FSMProxy : public QSortFilterProxyModel
4. {
5.     Q_OBJECT
6.  
7. public:
8.     FSMProxy(QObject *parent);
9.  
10. protected:
11.     bool filterAcceptsColumn(int source_column, const QModelIndex &source_parent) const;
12. };

fsmproxy.cpp

1. FSMProxy::FSMProxy(QObject *parent)
2.     : QSortFilterProxyModel(parent)
3. {
4. }
5.  
6.  
7. bool FSMProxy::filterAcceptsColumn(int source_column, const QModelIndex &source_parent) const
8. {
9.     Q_UNUSED(source_parent)
10.  
11.     // adjust the columns you want to filter out here
12.     // return false for those that will be hidden
13.     if(source_column == 2 || source_column == 3)
14.         return false;
15.     return true;
16. }

Usage

1.     QFileSystemModel *fsm = new QFileSystemModel(this);
2.     FSMProxy *proxy = new FSMProxy(this);
3.     proxy->setSourceModel(fsm);
4.     treeView->setModel(proxy);

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