Populate QTreeWidget with hierarchic structure from absolute filepaths

Question

I have a file which has absolute filepaths listed, 1 per line. The listed files are in order, so all files in e.g. the /Documents/ dir will be listed after eachother in the file.

What I want to do is to place all these files in a QTreeWidget in a nice hierarchic structure, just like a normal filesystem. How would I do that from my file of absolute paths I have?

This is how far I've gotten with my coding on this:

QFile file(FILENAME_ENCRYPTED);
QString line;
QDir dir;

QTreeWidgetItem *item;
if (file.open(QIODevice::ReadOnly)) {
    QTextStream stream( &file );
    do {
        line = stream.readLine();
        if (!line.isNull()) {
            dir = QDir(line);
            item = new QTreeWidgetItem();
            item->setText(0, dir.dirName());
            this->ui->treeWidget->addTopLevelItem(item);
        }
    } while (!line.isNull());
}
file.close();

This works fine, but it only lists all the filenames after eachother. I guess I have to do some recursive function but recursion is not my best friend, I prefer iteration! Could someone give me a push in the right direction? :)

Anthony · Accepted Answer · 2012-04-27T17:06:18.810

No recursion should be necessary. You can use QString::split() to split the file path into separate QStrings in a QStringList based on a separator (i.e., "/"), then iterate through each QString to determine the file structure.

EDIT: Here is an example:

#include <QtGui>

const QString s1 = "Docs/Testing/textFile1.txt";
const QString s2 = "Docs/Testing/textFile2.txt";
const QString s3 = "Docs/Testing/textFile3.txt";
const QString s4 = "Docs/Testing/AnotherFolder/textFile4.txt";
const QString s5 = "ThisIsGonnaBeCrazy/WholeNewFolder/AndAnother/file.pdf";
const QString s6 = "ThisIsGonnaBeCrazy/file.doc";

class MainWindow : public QMainWindow
{
public:
    MainWindow()
    {
        QTreeWidget *treeWidget = new QTreeWidget;

        QStringList fileNames;
        fileNames << s1 << s2 << s3 << s4 << s5 << s6;

        QTreeWidgetItem *topLevelItem = NULL;
        foreach (const QString &fileName, fileNames)
        {
            QStringList splitFileName = fileName.split("/");

            // add root folder as top level item if treeWidget doesn't already have it
            if (treeWidget->findItems(splitFileName[0], Qt::MatchFixedString).isEmpty())
            {
                topLevelItem = new QTreeWidgetItem;
                topLevelItem->setText(0, splitFileName[0]);
                treeWidget->addTopLevelItem(topLevelItem);
            }

            QTreeWidgetItem *parentItem = topLevelItem;

            // iterate through non-root directories (file name comes after)
            for (int i = 1; i < splitFileName.size() - 1; ++i)
            {
                // iterate through children of parentItem to see if this directory exists
                bool thisDirectoryExists = false;
                for (int j = 0; j < parentItem->childCount(); ++j)
                {
                    if (splitFileName[i] == parentItem->child(j)->text(0))
                    {
                        thisDirectoryExists = true;
                        parentItem = parentItem->child(j);
                        break;
                    }
                }

                if (!thisDirectoryExists)
                {
                    parentItem = new QTreeWidgetItem(parentItem);
                    parentItem->setText(0, splitFileName[i]);
                }
            }

            QTreeWidgetItem *childItem = new QTreeWidgetItem(parentItem);
            childItem->setText(0, splitFileName.last());
        }

        setCentralWidget(treeWidget);
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

Note that you can use QTreeWidgetItem::setData() to set the file name for each file if you like. My example does not do that, though.

Is the split operation not slow? – user1767754 Oct 13 '15 at 03:22 — user1767754, Oct 13 '15 at 03:22

score 1 · Answer 2 · answered Jun 06 '14 at 04:40

This works for me:

QStringList tokens = path.split ( '/' );

QTreeWidgetItem* treeWidgetItem = NULL;

for ( int32_t j = 0 ; j < packageTreeWidget->topLevelItemCount(); ++j )
{
    if ( packageTreeWidget->topLevelItem ( j )->text ( 0 ) == tokens.at ( 0 ) )
    {
        treeWidgetItem = packageTreeWidget->topLevelItem ( j );
        break;
    }
}

if ( treeWidgetItem == NULL )
{
    treeWidgetItem = new QTreeWidgetItem;
    treeWidgetItem->setText ( 0, tokens.at ( 0 ) );
    packageTreeWidget->addTopLevelItem ( treeWidgetItem );
}

for ( int32_t j = 1; j < tokens.size(); ++j )
{
    int32_t k;
    for ( k = 0 ; k < treeWidgetItem->childCount(); ++k )
    {
        if ( treeWidgetItem->child ( k )->text ( 0 ) == tokens.at ( j ) )
        {
            treeWidgetItem = treeWidgetItem->child ( k );
            break;
        }
    }
    if ( k == treeWidgetItem->childCount() )
    {
        QTreeWidgetItem* newTreeWidgetItem = new QTreeWidgetItem;
        newTreeWidgetItem->setText ( 0, tokens.at ( j ) );
        treeWidgetItem->addChild ( newTreeWidgetItem );
        treeWidgetItem = newTreeWidgetItem;
    }
}

The index 'i' is missing from the loops because is the one I used to iterate the file paths, replace 'packageTreeWidget' with the name of your Tree Widget, I am using this to display the contents of a zip-like package file.

Populate QTreeWidget with hierarchic structure from absolute filepaths

2 Answers2