Dialog displayed late

[Stefanoxjx]

Hi, I've a problemi with a Dialog.
I've this code:

QString ImportExportMap::ImportMap(QStringList *InfoData)
{
    QString FileName;

    FileName = QFileDialog::getOpenFileName(this, "MAP File", cMapArchive, "File map (*.map)");

    if(FileName.isEmpty()) return NULL;

    QFileInfo f(FileName);
    FileName = f.fileName();

    QDialog *Dlg = new QDialog;
    Dlg->setWindowFlags(Qt::FramelessWindowHint | Qt::Dialog);
    QHBoxLayout *h = new QHBoxLayout;
    Dlg->setLayout(h);
    QLabel *l = new QLabel("Loading file, please wait...");
    h->addWidget(l);
    Dlg->show();

    QFile InputFile(cMapArchive+"/"+FileName);
    if (InputFile.open(QIODevice::ReadOnly))
    {
        QTextStream in(&InputFile);
        while (!in.atEnd())
        {
             ...
        }
    }

    InputFile.close();
    Dlg->close();
    delete Dlg;

    return FileName;
}

The problem is that Dlg is shown late, when the file has already been loaded.
How I can starts with loading file only if Dlg is completely shown?
Thanks.

[JonB]

@Stefanoxjx said in Dialog displayed late:

How I can starts with loading file only if Dlg is completely shown?

Split your function into two separate ones. The first one ends at Dlg->show();. The remainder of your code should be in a function called from the QDialog::showEvent() method, which is called when a widget is actually shown. You will need to subclass QDialog for your dialog to achieve that, so that you can override that method. You might have your overridden method emit a signal, so that your ImportExportMap class can put a slot on that and you can keep the code in the ImportExportMap class rather than having to put it in the sub-classed dialog code, as you please.

Given your usage, a rather dirty/naughty way may be to put QCoreApplication::processEvents() after your current Dlg->show();. That might be enough to just show the dialog initially, I'm not sure.

Note that Qt has a QProgressDialog, or even a QProgressBar class, which you might prefer to use, since all you seem to want the dialog for is to inform the user while loading/parsing the file, and you may find simpler/preferable to the above.

[Stefanoxjx]

Hi JonB, thanks for your help.
I used QDialog::showEvent :)