How to remove minimize button from QMessageBox

[Kucchan]

Hi,

I am using Qt Creator in RaspberryPi3(Linux) , When I create a message box Minimize Button is displayed .

How to remove Minimize button ?
As another method,
Is there a way to ignore it even if I press the minimize button?

The development environment is as follows.

RaspberryPi3 , Raspbian GNU/Linux 9.1 (stretch)
Qt Creator 4.2.0、Qt 5.7.1 (GCC 6.2.1 20161124, 32 bit)

[jsulm]

@Kucchan See http://doc.qt.io/qt-5/qwidget.html#windowFlags-prop and Qt::WindowMinimizeButtonHint

[Kucchan]

Dear jsulm
Thank you for your comment.
But I can not solve the problem.

I tried the following contents, but I could hide the minimize button in Windows OS, but in RaspberryPi 3 (Linux) I could not hide the minimize button.
http://doc.qt.io/qt-5/qtwidgets-widgets-windowflags-example.html

How can I hide the minimize button on RaspberryPi 3?

[JonB]

@Kucchan
You may not be able to. It depends on whether your OS/desktop allows this, Qt is using platform's native windows, Windows does, there is no guarantee that Pi/Ubuntu/GNOME or whatever you are using supports removing just the minimize button.

For example, from the Qt docs:

In Linux with KDE this code make a window without an close and minimize and maximize buttons in title bar.

setWindowFlags( Qt::Dialog | Qt::WindowTitleHint );

[dream_captain]

QMessageBox box.
box.setText("randomText");
box.setWindowFlags(box.windowFlags() & (~Qt::WindowMinimizeButtonHint));

Should do the trick, but as @JNBarchan mentioned earlier it's platform dependent.

[JonB]

@dream_captain
Since he says:

I tried the following contents, but I could hide the minimize button in Windows OS, but in RaspberryPi 3 (Linux) I could not hide the minimize button.

I presume that indicates he has the right code, it works under Windows but not under Linux....

[Kucchan]

Thank you everyone.

I tried '~ Qt :: WindowMinimizeButtonHint' but it was useless.
It seems impossible to remove Minimize button.
So,Please tell me how to not minimize the window by clicking the minimize button.

[SGaist]

Hi,

Can you show the code you are currently using for your message box ?

[Kucchan]

Dear SGaist

It is the code that challenged to remove minimize button of MainWindow and QMessageBox.

MsgBox.pro

QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = MsgBox
TEMPLATE = app
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += main.cpp
mainwindow.cpp
HEADERS += mainwindow.h
FORMS += mainwindow.ui

main.cpp

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
Qt::WindowFlags flags;

QApplication a(argc, argv);
MainWindow w;
flags = w.windowFlags();
flags = flags & ~Qt::WindowMinimizeButtonHint;
w.setWindowFlags(flags);
w.show();
return a.exec();

}

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMessageBox>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
}

MainWindow::~MainWindow()
{
delete ui;
}

void MainWindow::on_pushButton_clicked()
{
QMessageBox msgBox(this);
msgBox.setText(tr("MessageText"));
msgBox.setWindowTitle(tr("Title"));
msgBox.setIcon(QMessageBox::Critical);
msgBox.setWindowFlags(Qt::Window | Qt::Dialog | Qt::MSWindowsFixedSizeDialogHint | Qt::WindowTitleHint | Qt::WindowSystemMenuHint | Qt::WindowCloseButtonHint);
msgBox.exec();
}

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private slots:
void on_pushButton_clicked();

private:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

mainwindow.ui

Only QpushButton is placed in MainWindow.

[dream_captain]

@Kucchan
I was able to add and then remove minimize button from QMessageBox on my Linux Mint by setting Qt::Window flag first and then removing Qt::WindowMinimizeButtonHint

QMessageBox msgBox;
msgBox.setText("MessageText");
msgBox.setWindowTitle("Title");
msgBox.setWindowFlags(Qt::Window );     // add minimize button
msgBox.setWindowFlags(msgBox.windowFlags()&(~Qt::WindowMinimizeButtonHint)); // remove minimize button
msgBox.setIcon(QMessageBox::Critical);
msgBox.exec();

Give it a try. Set Qt::Window and then remove Qt::WindowMinimizeButtonHint

[Kucchan]

Dear dream_captain

Thank you for your comment.
But It was useless in the RaspberryPi3.

If the minimize button can be remove, without
' ~Qt::WindowMinimizeButtonHint:WindowMinimizeButtonHint '.
(WindowsOS and Ubuntu)

RaspberryPi3 seems to be unique.

[dream_captain]

@Kucchan
I don't think that you can inherit from QMessageBox and just ignore minimize event, since it's controlled by window manager.

Does QDialog come with minimize button by default on your rasp?

[Kucchan]

@dream_captain

Does QDialog come with minimize button by default on your rasp?

I tried QDialog on RaspberryPi3 and the minimize button was displayed.
(Not change WindowFlags.WindowFlags is default value)

QDialog can’t remove minimize button by changing WindowFlags.

[jsulm]

@Kucchan I think this is not a problem with Qt but with window manager used. As far as I know Raspbian uses its own (Pixel?).

[Kucchan]

Is there no way?
Do I need to give up?

[dream_captain]

@Kucchan
You can try an ugly workaround: derive from QDialog and play around Qt::FramelessWindowHint to hide top buttons completely. Then add QPushButton on form and create a connection connect(ui->closeButton, &QPushButton::clicked, this, &QDialog::accept);' to imitate QMessageBox behavior.

[Kucchan]

@dream_captain

Thank you for your comment.
I will make a message box by QDialog.