QStackedLayout dialog flicker

[ArkKup]

Hi,

I was trying out example about Stacked Layouts from the book "C++ GUI Programming with Qt 4, Second Edition" its Chapter 6.

PreferenceDialog::PreferenceDialog(QWidget *parent)
    : QDialog(parent)
{
    ...
    listWidget = new QListWidget;
    listWidget->addItem(tr("Appearance"));
    listWidget->addItem(tr("Web Browser"));
    listWidget->addItem(tr("Mail & News"));
    listWidget->addItem(tr("Advanced"));
 
    stackedLayout = new QStackedLayout;
    stackedLayout->addWidget(appearancePage);
    stackedLayout->addWidget(webBrowserPage);
    stackedLayout->addWidget(mailAndNewsPage);
    stackedLayout->addWidget(advancedPage);
    connect(listWidget, SIGNAL(currentRowChanged(int)),
            stackedLayout, SLOT(setCurrentIndex(int)));
    ...
    listWidget->setCurrentRow(0);
}

PreferenceDialog::PreferenceDialog(QWidget *parent)
    : QDialog(parent)
{
    ...
    listWidget = new QListWidget;
    listWidget->addItem(tr("Appearance"));
    listWidget->addItem(tr("Web Browser"));
    listWidget->addItem(tr("Mail & News"));
    listWidget->addItem(tr("Advanced"));

    stackedLayout = new QStackedLayout;
    stackedLayout->addWidget(appearancePage);
    stackedLayout->addWidget(webBrowserPage);
    stackedLayout->addWidget(mailAndNewsPage);
    stackedLayout->addWidget(advancedPage);
    connect(listWidget, SIGNAL(currentRowChanged(int)),
            stackedLayout, SLOT(setCurrentIndex(int)));
    ...
    listWidget->setCurrentRow(0);
}

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void MainWindow::configurationOptions()
{
    PreferenceDialog *optionsDlg = new PreferenceDialog();
    optionsDlg->exec();
    delete optionsDlg;
}

void MainWindow::configurationOptions()
{
    PreferenceDialog *optionsDlg = new PreferenceDialog();
    optionsDlg->exec();
    delete optionsDlg;
}

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The problem is that when I start the example I see ugly flicker on a dialog, hence my question how can this be eliminated ? I have try to use resize to make the dialog bigger by default but that didn't help.

[ChrisW67]

You'll have to define "ugly flicker" and when exactly you see it. Reizing the dialog, switching pages, as you type, one one particular page etc. Does the Config Dialog Example display similar flickering?

[ArkKup]

sorry for not being too specific by "ugly flicker" I meant that the dialog windows shows and I can see that its being resize quickly.
Config Dialog Example works just fine.

[amleto]

as an aside, please don't write code like this

void MainWindow::configurationOptions()
{
    PreferenceDialog *optionsDlg = new PreferenceDialog();
    optionsDlg->exec();
    delete optionsDlg;
}

void MainWindow::configurationOptions()
{
    PreferenceDialog *optionsDlg = new PreferenceDialog();
    optionsDlg->exec();
    delete optionsDlg;
}

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We are not java programmers... Instead write

void MainWindow::configurationOptions()
{
    PreferenceDialog optionsDlg
    optionsDlg.exec();
}

void MainWindow::configurationOptions()
{
    PreferenceDialog optionsDlg
    optionsDlg.exec();
}

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Shorter, quicker, easier to read, less prone to errors.