How to remove minimize button from QMessageBox

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.

Ulises Galgo

@Kucchan Too late with the answer, but this works for me on a RPi3 with Raspbian:

msgBox.setWindowFlags( ( Qt::Window | Qt::CustomizeWindowHint ) &~
   ( Qt::WindowTitleHint | Qt::WindowSystemMenuHint | 
     Qt::WindowMinimizeButtonHint | Qt::WindowCloseButtonHint ) );

someone else could be looking for the same answer as I did.