Using QFileSystemModel, QTreeView, and QSortFilterProxyModel

jeremy_k

It would help to have a minimal working example program to look at. This functions for me as I expect with Qt 6.9 on macOS:

#include <QApplication>
#include <QFileSystemModel>
#include <QSortFilterProxyModel>
#include <QTreeView>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QFileSystemModel model;
    model.setRootPath("/tmp");

    QSortFilterProxyModel proxyModel;
    proxyModel.setSourceModel(&model);

    QTreeView view;
    view.setModel(&proxyModel);
    view.show();

    return a.exec();
}

Zbigniew-Sch

Sorry, but you didn't read the question. It's about the following: renaming a directory and
deleting a file from that directory, but the file item isn't being deleted from QTreeView.

JonB

@Zbigniew-Sch
You still need to provide a minimal example of code you use which shows this behaviour:

We need to see exactly what your code is.
If someone wants to test behaviour why should they have to write code from scratch? (I did read your question yesterday, but no code => I'm not going to try anything.)

So... can you confirm that if you try precisely the code in @jeremy_k's code the problem arises for you? Assuming so, then: as I understand it, you are performing a directory rename and then a delete file within the renamed directory, both of these actions from the QTreeView? (You are not doing these file operations externally to your program on the file system, are you?) So someone else needs to do that while running the same code as you. I don't know whether the QTreeView bound to a file system offers you "rename" and "delete" automatically, but if not then we need you add whatever minimal for that to the code for people to try.

jeremy_k

@Zbigniew-Sch said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

Sorry, but you didn't read the question. It's about the following: renaming a directory and
deleting a file from that directory, but the file item isn't being deleted from QTreeView.

Yes, I did read the question. The MWE I posted behaves as I expect, given an out-of-process directory renaming and file deletion.

There may be a bug. Without a program to examine, it's unclear whether it is likely to lie in the OS, library, application code, or understanding of how each behaves.

JonB

@jeremy_k said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

given an out-of-process directory renaming and file deletion

Oh, I had thought it more likely OP was doing in-process operations via code on the QTreeView! Shows how simple details matter :)

jeremy_k

@JonB said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

@jeremy_k said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

given an out-of-process directory renaming and file deletion

Oh, I had thought it more likely OP was doing in-process operations via code on the QTreeView! Shows how simple details matter :)

+1 on details mattering. I didn't see a point in guessing and complicating the code for an example of a MWE.

JonB

@jeremy_k
OP is Windows, you are MacOS. I am Linux but not tested. May have to await a Windows user. If it's out-of-process it relies on the QFileSystemWatcher and the OS behaviour for notifications, that might or might not be relevant. If it's that area OP could debug-out to confirm the QFSW signals being emitted.

If it's a fault in higher-level Qt logic instead we should be able to reproduce, but OP may have to confirm exactly what he does in outside world.

And if it is an issue only when there is a QSortFilterProxyModel we need to know whether OP has set any sorting or filtering on it.

jeremy_k

@JonB said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

If it's out-of-process it relies on the QFileSystemWatcher and the OS behaviour for notifications, that might or might not be relevant.

This seems unlikely to be relevant. The original post says that connecting the file system model directly to the view does what is expected. I don't expect to find any file or operating system specific code in the proxy model.

Zbigniew-Sch

I wrote a small program and I'm having the same problem.
This is definitely a bug in Qt, without QSortFilterProxyModel, everything works correctly.
I renamed the directory in my program and deleted a file from that directory
using Windows Explorer – it works correctly now. I'm out of ideas.

jeremy_k

The general advice from this thread remains valid:

The existence of a test program doesn't help confirm or deny if nobody else can see the program.
Bug reports can be filed at https://bugreports.qt.io/. Chances are high that whoever responds will also ask for a demonstrator.

Christian Ehrlicher

@jeremy_k said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

Chances are high that whoever responds will also ask for a demonstrator.

Higher than high - otherwise it will be closed sooner or later with 'Needs more information'

Zbigniew-Sch

How can I upload an entire example project as a ZIP file?

JonB

@Zbigniew-Sch
People don't like looking at external and zip files. The forum does not offer this. We don't need a project for this issue.

People are expecting a minimal reproducible example. Like a hundred lines. Stripped of anything and everything not required to show the behaviour, which you spend time doing. You have @jeremy_k's starting point code earlier in 20-odd lines. How much do you need to add to that to show it goes wrong for you?

Zbigniew-Sch

Here is my example program to reproduce the problem:

Header of QMainWindow:

class LZImageViewerTest : public QMainWindow
{
    Q_OBJECT

public:
    LZImageViewerTest(QWidget *parent = nullptr);
    ~LZImageViewerTest();

    QLZFileSystemModel *pcoGetFileSystemModel() { return m_pcoFileSystemModel; };
    QSortFilterProxyModel *pcoSortFilterProxyModel() { return m_pcoSortFilterProxyModel;}

    static LZImageViewerTest* pcoGetMainWindow() { return m_stMainWindow; }

    static LZImageViewerTest* m_stMainWindow;

private:
    Ui::LZImageViewerTestClass ui;

    QModelIndex m_coRootModelIndex;
    QLZTreeView *m_pcoTreeView;
    QHBoxLayout *m_pcoMainLayout;
    QLZMainWidget *m_pcoMainWidget;
    QLZFileSystemModel *m_pcoFileSystemModel;
    QSortFilterProxyModel *m_pcoSortFilterProxyModel;
};

QMainWindow cpp file:

LZImageViewerTest *LZImageViewerTest::m_stMainWindow = nullptr;

LZImageViewerTest::LZImageViewerTest(QWidget *parent)
    : QMainWindow(parent)
{
    ui.setupUi(this);

    m_stMainWindow = this;
    QScreen* pcoScreen = QGuiApplication::primaryScreen();
    QRect coScreenGeometry = pcoScreen->geometry();
    resize(QSize(coScreenGeometry.width() - 1400, coScreenGeometry.height() - 600));

    // Center main window 
    QRect mainFrameViewRect = frameGeometry();
    QPoint centerPoint = screen()->availableGeometry().center();

    mainFrameViewRect.moveCenter(centerPoint);
    move(mainFrameViewRect.topLeft());

    m_pcoTreeView = new QLZTreeView();
    m_pcoFileSystemModel = new QLZFileSystemModel();
    m_coRootModelIndex= m_pcoFileSystemModel->setRootPath("D:\\Test");

    m_pcoSortFilterProxyModel = new QSortFilterProxyModel();
    m_pcoSortFilterProxyModel->setSourceModel(m_pcoFileSystemModel);
    m_pcoSortFilterProxyModel->setFilterCaseSensitivity(Qt::CaseInsensitive);
    m_pcoSortFilterProxyModel->setSortCaseSensitivity(Qt::CaseInsensitive);

    m_pcoTreeView->setModel(m_pcoSortFilterProxyModel);
    m_pcoTreeView->setRootIndex(m_pcoSortFilterProxyModel->mapFromSource(m_coRootModelIndex));

    m_pcoMainWidget = new QLZMainWidget(this);
    m_pcoMainWidget->setContentsMargins(3, 4, 4, 4);
    m_pcoMainLayout = new QHBoxLayout(this);

    m_pcoMainLayout->addWidget(m_pcoTreeView);
    m_pcoMainWidget->setLayout(m_pcoMainLayout);
    setCentralWidget(m_pcoMainWidget);
}

LZImageViewerTest::~LZImageViewer
{}

QLZFileSystemModel cpp file:


QLZFileSystemModel::QLZFileSystemModel(QObject* parent)
    : QFileSystemModel(parent)
{

}

Qt::ItemFlags QLZFileSystemModel::flags(const QModelIndex& index) const
{
    Qt::ItemFlags flags = QFileSystemModel::flags(index);
    flags |= Qt::ItemIsEditable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
    return flags;
}

QLZFileSystemModel::~QLZFileSystemModel()
{
}

QLZTreeView cpp file:

QLZTreeView::QLZTreeView(QWidget* parent): QTreeView(parent)
{
	setContextMenuPolicy(Qt::CustomContextMenu);
	connect(this, &QWidget::customContextMenuRequested, this, &QLZTreeView::customContextMenu);
}

QLZTreeView::~QLZTreeView()
{
}

void QLZTreeView::customContextMenu(const QPoint& point)
{
	QMenu coContextMenu;
	QModelIndex coCurrentIndex = currentIndex();

	if (!coCurrentIndex.isValid())
		return;

	QAction* pcoRenameObjectsAction = coContextMenu.addAction(tr("Rename"));
	connect(pcoRenameObjectsAction, &QAction::triggered, this, [this, coCurrentIndex] { renameCurrentObject(coCurrentIndex); });

	QAction* pcoDeleteObjectsAction = coContextMenu.addAction(tr("Delete"));
	connect(pcoDeleteObjectsAction, &QAction::triggered, this, [this, coCurrentIndex] { deleteCurrentObject(coCurrentIndex); });

	coContextMenu.exec(viewport()->mapToGlobal(point));

	QList<QAction*> coActionsList = coContextMenu.actions();
	foreach(QAction * pcoAction, coActionsList)
		delete pcoAction;
}

void QLZTreeView::renameCurrentObject(QModelIndex coCurrentIndex)
{
	if (!coCurrentIndex.isValid())
		return;

	int iCurrentRow = coCurrentIndex.column();
	if (iCurrentRow != 0)
		return;

	edit(currentIndex());

	QList<QLineEdit*> coEditorList = findChildren<QLineEdit*>();
	if (coEditorList.size() == 0)
		return;

	coEditorList[0]->installEventFilter(this);
	coEditorList[0]->setAlignment(Qt::AlignCenter);
}

void QLZTreeView::closeEditor(QWidget* coEditor, QAbstractItemDelegate::EndEditHint hint)
{
	QSortFilterProxyModel* pcoSortFilterProxyModel = LZImageViewerTest::pcoGetMainWindow()->pcoSortFilterProxyModel();
	pcoSortFilterProxyModel->invalidate();
	QTreeView::closeEditor(coEditor, hint);
}

void QLZTreeView::deleteCurrentObject(QModelIndex coCurrentIndex)
{
	if (!coCurrentIndex.isValid())
		return;

	int iCurrentRow = coCurrentIndex.column();
	if (iCurrentRow != 0)
		return;

	QList<QString> coSelectedIndexesPathList;
	QModelIndexList coIndexesList = selectedIndexes();
	QFileSystemModel *pcoFileSystemModel = LZImageViewerTest::pcoGetMainWindow()->pcoGetFileSystemModel();
	QSortFilterProxyModel *pcoSortFilterProxyModel = LZImageViewerTest::pcoGetMainWindow()->pcoSortFilterProxyModel();

	for (int i = 0; i < coIndexesList.size(); i++)
	{
		if (coIndexesList[i].column() == 0)
		{
                        // Delete file using "QFile::moveToTrash()"
			//QString coSelectedObjectPath = pcoFileSystemModel->filePath(pcoSortFilterProxyModel->mapToSource(coIndexesList[i]));
			//bool bRes = QFile::moveToTrash(coSelectedObjectPath);
                       
                        // Delete file using "pcoFileSystemModel->remove()"
			bool bRes = pcoFileSystemModel->remove(pcoSortFilterProxyModel->mapToSource(coIndexesList[i]));
			pcoSortFilterProxyModel->invalidate();
		}
	}
}

Christian Ehrlicher

This is to much. No need for an ui file , no context menu stuff and other stuff.

Zbigniew-Sch

Sorry, I don't understand you. This is a minimal example to reproduce the problem.
If I completely reduce the source code, you won't see the dependencies and you won't be able to reproduce the problem.

Christian Ehrlicher

If you can't provide a real mre then I am out, sorry.

Zbigniew-Sch

Does nobody have any suggestions as to what the error could be, or is this actually a Qt bug?

JonB

@Zbigniew-Sch said in Using QFileSystemModel, QTreeView, and QSortFilterProxyModel:

I'm using Windows 11 and Qt 6.10. I think this is a bug, or does anyone have a solution?

Is there any chance what you are seeing using 6.10 turns out to be caused by https://forum.qt.io/topic/164009/qsortfilterproxy-sorting-works-on-linux-but-fails-on-windows/6 and https://qt-project.atlassian.net/browse/QTBUG-141830 ? But I think that only occurs when using a static build? Yours isn't a static build is it?

Zbigniew-Sch

I am using Qt 6.10.1 under Windows 11
Static build - NO