[SOLVED] How to see if file is selected in list view with QFileSystemModel

[mar0029]

Hello!

I have created a simple file viewer. It consists of a QTreeView as the directory viewer and a QListView as the file viewer. Both views use the QFileSystemModel as their model. I want to be able to check if a folder has been selected or not in the QListView.

I've tried things like

• if(ui->listView->currentIndex()) == (-1)), which gives a 'no match for operator ==' error

• different connect statements that check for file types of the QFileSystemModel

I really want to be able to write an if... else... statement. The psuedocode being :
if(noFileSelected)
modalDialog for error
else
doThisOtherThing

Any tips in the right direction? I've scoured the documentation and have come up empty.

[SGaist]

Hi and welcome to devnet,

You can use isValid from QModelIndex

[mar0029]

@SGaist
Thank you for your reply!! A quick question:
How would I go about implementing QModelIndex::isValid() ? I can't call isValid without a QModelIndex object and I can't redefine my QFileSystemModel object as a QModelIndex.

Any tips would be greatly appreciated.

[raf924]

@mar0029 Get the index with the index()method : http://doc.qt.io/qt-5/qfilesystemmodel.html#index-1 I think

[mar0029]

@raf924

Thank you for your reply!

I am able to use "myModelIndex.isValid()" as a boolean value now but only if I set

myModelIndex = myModel->index(myFilePath,0)

where in index(), QString myFilePath = "C:/" and the integer is an arbitrary column value.
I know I need myFilePath to be that of the index value in my signal function void QAbstractItemView::clicked(const QModelIndex & index). Question is, how do I go about doing that?

[raf924]

@mar0029 I'm not sure what you mean. This ?

QString QFileSystemModel::filePath(const QModelIndex & index) const
Returns the path of the item stored in the model under the index given.

[SGaist]

Before going further, can you post the code you are currently using ? That way we are all on the same page about what you are trying to achieve and how.

[mar0029]

@raf924
@SGaist
Here are the two functions of concern.

void MainWindow::on_dirView_clicked(const QModelIndex &index)
{
     QString sPath = dirModel->fileInfo(index).absoluteFilePath();
     ui->listView->setRootIndex(listModel->setRootPath(sPath));
}

void MainWindow::loadButton()
{
	//index = new QModelIndex(this);

	//qDebug() << "Load Button Test" << endl; //testing purposes.

   // index = new QModelIndex(this);

 	//QString sPath = listModel->filePath(index);

	QString sPath = "C:/";

	QModelIndex test = listModel->index(sPath,0);

      if (test.isValid() == false)
    {
        QDialog* loadMessage = new QDialog;
        loadMessage->setFixedSize(250,150);

        QVBoxLayout *vertLayout = new QVBoxLayout;

        QLabel *messageLabel = new QLabel("No File was selected. Please select a .dat file.");
        
        QPushButton *messageOKButton = new QPushButton("OK");

        vertLayout->addWidget(messageLabel);
        vertLayout->addWidget(messageOKButton);

        loadMessage->setLayout(vertLayout);
        connect(messageOKButton, SIGNAL(clicked(bool)), loadMessage, SLOT(accept()));
        loadMessage->exec();
    }
      else
      {
          ui->mpfTAB->setCurrentIndex(1);
      }
}

aside: Thank you for your help!!
edit(s): figured out formatting

[SGaist]

You have a memory leak, you're not deleting loadMessage.

So if I understand you correctly, when you call loadButton, you would like to act on the currently selected item from listModel, right ?

[mar0029]

@SGaist

Whoops. I'll do a

connect(loadMessage, SIGNAL(finished(int)), loadMessage, SLOT(deleteLater)));

to clean up my leak.

That is correct. Really, there should never be an invalid file type because I specified the file type in MainWindow with listModel->setNameFilters(matFilters); where matFilters is specified as .dat. So all I really need to see is if any selection has been made in listView.

[SGaist]

Then you use QListView::selectedIndexes to retrieve the current selection and work with that directly

[SGaist]

By the way setting the Qt::WA_DeleteOnClose attribute on the widget will be cleaner

[mar0029]

@SGaist
Thank you so much for your replies.
After much ado, we've solved the problem!

I had to do

QModelIndexList test = ui->listView->selectionModel()->selectedIndexes();
if(test.empty() == true)
{
...
}

Thank you again everyone!

[SGaist]

You're welcome !

By the way, now you can use the "Topic Tool" button to mark the thread as solved, it keeps the things cleaner :)