Qt – QDialog – How to remove the minimize button

kdeqdialogqt

Qt 4.8 based, application – Issue with QDialog, minimize button

Windows and Gnome (linux)
- The modal dialog appears with the close button on the right top, and the minimize button is nonexistent.
- The minimize option are grayed out in every dialog.
- This makes sense, since the QDialog is modal – if you minimize it, the whole application will be blocked.

But here comes the issue:

in KDE (linux) the minimize-maximize button appears.

It seems that this is a platform dependent feature –

I am not quite sure on what do do.

Any ideas…? (I tried already with a few windowsFlags but could not find the one set that works.

Tried:

setWindowFlags( Qt::CustomizeWindowHint | Qt::WindowCloseButtonHint );
Qt::WindowFlags flags = getWindowFlags( ); flags |= Qt::WindowMinimizeButtonHint; setWindowFlags(flags)

— But the basic question is why the behavior on Windows/GNOME is different from KDE

Best Answer

if you want the MainWindow don't have any buttons on top use this in constructor of MainWindow:

this->setWindowFlags(Qt::SubWindow);

and if you want to remove just the minimize button use this:

this->setWindowFlags(Qt::Dialog);

Related Solutions

C++ – How to change the modality of QDialog at runtime

You can use eitherQDialog::setModal(bool) or setWindowModality(Qt::ApplicationModal). But the documentation of setWindowModality() says something extra which is..

Changing this property while the window is visible has no effect;
you must hide() the widget first, then show() it again.

So your code should look like following..

void ToggleModalDialog::changeModality(bool checkState)
{
    if(checkState)
    {
        this->setWindowModality(Qt::NonModal);
        ui->changeModalityButton->setChecked(true);
    }
    else
    {
        this->setWindowModality(Qt::ApplicationModal);
        ui->changeModalityButton->setChecked(true);
    }

    this->hide();
    this->show();
}

C++ – QDialog remove title bar

I needed to do the same thing as this question for dialogs but I wanted a border on the dialog without the window bar. The solution was actually quite simple. Just set the dialog's flags to Qt::CustomizeWindowHint:

dialog.setWindowFlags(Qt::CustomizeWindowHint);

You can also OR this with specific flags to further customize the windows appearance as noted in the documentation.

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