QTreeView/QDirModel persisting current directory selection

[bigduv]

Hi, I am trying to work out how to persist the current selection in a QDirModel/QTreeView using QSettings so that I can expand the tree to that directory when the app restarts.

I am using Qt 4.3.4.

QTreeView does not appear to support saveState()/restoreState() so I guess I have to write a string URL for the currentItem() in the tree to QSettings and retrieve it later. In this case how do I convert from a string URL into a QModelItem in the View/Model?

Is there a better way to use the built in mechanisms than the one I've outlined above? I already use QSettings to persist QApplication state and table header state but I can't see any built in mechanism for doing this on a tree.

Thanks
Dave

[wysota]

With QDirModel it is quite simple. Store the path in the settings and then upon initializing the application simply read it and expand its parents.

[bigduv]

Just to close this off I found a reasonable solution.
Calling setCurrentIndex() expands to the selected node.
Calling setExpanded() expands the selected node too.

class DirectoryTree : public QTreeView
{
public:
    void readSettings(QSettings& oSettings)
    {
        QString sLastSelection = oSettings.value("LastSelection").toString();
        if (!sLastSelection.isEmpty()) {
            QModelIndex index = m_oModel.index(sLastSelection);
            setCurrentIndex(index);
            setExpanded(index, true);
        }
    }
 
    void writeSettings(QSettings& oSettings) {
        oSettings.setValue("LastSelection", m_oModel.filePath(currentIndex()));
    }
 
protected:
    QDirModel& m_oModel;
};

class DirectoryTree : public QTreeView
{
public:
    void readSettings(QSettings& oSettings)
    {
        QString sLastSelection = oSettings.value("LastSelection").toString();
        if (!sLastSelection.isEmpty()) {
            QModelIndex index = m_oModel.index(sLastSelection);
            setCurrentIndex(index);
            setExpanded(index, true);
        }
    }

    void writeSettings(QSettings& oSettings) {
        oSettings.setValue("LastSelection", m_oModel.filePath(currentIndex()));
    }

protected:
    QDirModel& m_oModel;
};

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cheers
Dave