What can I do for my QtWidget-Program's Window correctly positioned on the screen？

foghere2023

First , My Program is made by QtWidget for Linux Desktop, with the X11 , it work perfectly. but if I turn My Ubuntu to Wayland, From a functional point of view, although it can also work normally, the positioning of its message popup window is messed up.

From the source code, what should I do so that when this program runs in the wayland environment, its sub-windows and key-triggered messages can be correctly positioned on the upper layer of the main program window?

alt text

jsulm

@foghere2023 How do you show those messages?
See https://doc.qt.io/qt-6/qdialog.html#QDialog : if you provide parent to dialog constructor the dialog should be automatically centered on the parent.

foghere2023

@jsulm yes , I have done , just like this, Each message window has a clear parent window defined:

it work well in x11，but wayland

void MainWindow::on_btnOpenSchema_clicked()
{
    QString curPath=QDir::currentPath();
    QString dlgTitle="打一个Schema文件";
    QString filter = "schema文件(*.schema.yaml)";
    QString aFileName=QFileDialog::getOpenFileName(this,dlgTitle,curPath,filter);
    if(aFileName.isEmpty())
        return;


    if(!aFileName.contains(".schema.yaml")){

        QMessageBox::information(this, "请选择 schema 文件", "请先择 schema 文件，带 schema 标识的文件！",
                                 QMessageBox::Ok,QMessageBox::NoButton);

        return;}

    disclick(true);
    dischange(true);
    bool ok = readSchema.openYamlByStream(aFileName);
    if(ok)
        QMessageBox::information(this,"提示消息","已成功读档！");
    if(readSchema.getRamState()){
        ui->labelCurrentData->setText("配置文件已装载！");
        ui->labelCurrentData->setAlignment(Qt::AlignHCenter);
        ui->btnListenSchema->setEnabled(false);
        ui->btnListenDict->setEnabled(false);
        ui->labelCurrState->setText("已触发监听禁用");
    }
    swapNum = readSchema.getLogicBits();
    initSwitches();
    iniCheckBox();
    ui->btnSaveSchema->setEnabled(readSchema.getRamState());
    readSchema.inihotKeys();
    iniModelFromStringList();
}

foghere2023

This is the simplest Demo:

void MainWindow::on_pushButton_clicked()
{
    QMessageBox::information(this,"提示消息","已成功读档！");
}

the key word【this】can't find his farther!

alt text

foghere2023

@jsulm

QMessageBox can't find his parent window position by the key word 'this' in wayland ，but it work well in X11，could you help me , I have gave a simple Demo here

JonB

@foghere2023
I believe it has already been reported that you cannot move/position windows under Wayland, and I believe the only workaround is to use Xorg. Search this forum for similar posts.

foghere2023

@JonB Sorry, I cann't find the similar posts by keyword 'wayland'，I think QtWidget APP's QMessageBox cann't locate his parent window position should be a serious mistake，could you give me some similar posts links?

JonB

@foghere2023
Google qt wayland move window

foghere2023

@jsulm Hi guys ，I find someone had the same problem as me：

The QDialog default position should locate at centered on top of the parent's top-level widget.
But QDialog in Wayland shows on a random position. Even I try to use "move" to assign a specific position, it doesn't work.

qdialog-in-wayland-works-incomplete

foghere2023

@jsulm

According to the normal logic, the pop-up message prompt should be suspended on the upper layer of the parent window.

QMessageBox and some child Dialog cannot on top of its parent window in Wayland，this looks like Qwidget's bug.

What should i do ?

JonB

@foghere2023
See if it works under Xorg?
If so wait for it to work under Wayland at a future date, assuming it can?

foghere2023

@JonB thank you guys, it works very well under Xorg，and I have test a simple Demo like is :

void MainWindow::on_pushButton_clicked()
{
    QMessageBox::information(this,"提示消息","已成功读档！");
}

This Demo only have one line of command here for QMessageBox , I have spent all day for the workaround，I don't know this is my false or Qt-team‘s. :(

alt text

as your piont ,this is not my false ?

SGaist

@foghere2023 hi,

It's neither. See the Wayland doc.

JoeCFD

@SGaist https://community.nxp.com/t5/i-MX-Processors/QDialog-in-Wayland-works-incomplete/m-p/1544891#M196925

foghere2023

@SGaist So guys，Reading the docs is just too difficult for me, someone tell me to wait, because there is a day that Qwidget App's Popups and parent windows can locate correctly .

Is there any way we can get the program to work now?

foghere2023

@JoeCFD

I had find this post，And I don't know what is weston.

foghere2023

Can someone help me?

foghere2023

Looking forward to friends repeating this bug

SGaist

@foghere2023 please show some patience and allow at least 24 hours to pass before bumping your own thread. This is a voluntary driven forum and people may not live in the same timezone as you.

Weston is the reference implementation of a Wayland compositor.

As for your issue, the Wayland specification is explicit, windows cannot move themselves around the desktop.

JonB

@SGaist said in What can I do for my QtWidget-Program's Window correctly positioned on the screen？:

As for your issue, the Wayland specification is explicit, windows cannot move themselves around the desktop.

Thank you for this :)