Filter Columns in a QFileSystemModel

From Qt Wiki
Revision as of 09:54, 24 February 2015 by Maintenance script (talk | contribs)
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.


How to Filter Columns in a QFileSystemModel

Sometimes one does not want to display all the columns of a "QFileSystemModel":http://doc.qt.nokia.com/stable/qfilesystemmodel.html, like discussed in "this forum thread":http://developer.qt.nokia.com/forums/viewthread/3114/.

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 <code&gt;QHeaderView&lt;/code&gt;, but the alternative to subclass "QSortFilterProxyModel&quot;:http://doc.qt.nokia.com/stable/qsortfilterproxymodel.html and reimplement the <code&gt;filterAcceptsColumn()</code&gt; method also works well.

Column hiding using QHeaderView

All multi-column views provide access to a "QHeaderView&quot;:http://doc.qt.nokia.com/stable/qheaderview.html . 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.

<br />//hide the third and fourth column, note that the column numbers are 0-based<br />QHeaderView* hHeader = m_theTableview-&gt;horizontalHeader();<br />hHeader-&gt;hideSection(2);<br />hHeader-&gt;hideSection(3);<br />

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

<br />#include &lt;QSortFilterProxyModel&amp;gt; ====

class FSMProxy : public QSortFilterProxyModel<br />{<br /> Q_OBJECT

public:<br /> FSMProxy(QObject *parent);

protected:<br /> bool filterAcceptsColumn(int source_column, const QModelIndex &amp;source_parent) const;<br />};<br />

==== fsmproxy.cpp

<br />FSMProxy::FSMProxy(QObject *parent)<br /> : QSortFilterProxyModel(parent)<br />{<br />} ====

bool FSMProxy::filterAcceptsColumn(int source_column, const QModelIndex &amp;source_parent) const<br />{<br /> Q_UNUSED(source_parent)

    // adjust the columns you want to filter out here<br />    // return false for those that will be hidden<br /> if(source_column  2 || source_column  3)<br /> return false;<br /> return true;<br />}<br />

Usage
<br />    QFileSystemModel *fsm = new QFileSystemModel(this);<br />    FSMProxy *proxy = new FSMProxy(this);<br />    proxy-&gt;setSourceModel(fsm);<br />    treeView-&gt;setModel(proxy);<br />