how to disable ESC key "close" the QProgressDialog ?

[joeQ]

I use the QProgressDialog in my project, but i find, when i pressed the esc key, the QProgressDialog close. i just want to click the cancelButton and then the dialog close.

so, i subclass QProgressDialog, and reimplement the closeEvent, and keyPressEvent. i can ignore the closeEvent. But, the esc key also can close the dialog.

i read some reference. they said use the eventFilter in mainwindow, but i try it. not work.

help me. thank u very much.

in the eventFilter, i find, when i press the esc key, the event type is "hide -> hideToParent". not the close.

[J.Hilk]

@joeQ
do you call event->accept() and event->ignore() in your keyPress event?

void keyPressEvent(QKeyEvent *event){
    if(event->key() == Qt::Key_Escape){
        event->accept();
    }else 
       event->ignore();
}

iirc, this should not pass the EsC-Key event to the QProgressDialog.

[joeQ]

@J.Hilk i try it, but not work.

bool Dialog::eventFilter(QObject *obj, QEvent *event)
{
    if(event->type() == QEvent::Hide || event->type() == QEvent::HideToParent){
        qDebug() << obj << "--" << event->type();
        event->accept();
        return true;
    }else if(event->type() == QEvent::KeyPress) {
        QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
        qDebug() << "Ate key press" << keyEvent->key();
        event->accept();
        return true;
    } else {
        // pass the event on to the parent class
        return QDialog::eventFilter(obj, event);
    }
}

void Dialog::on_btn_clicked()
{
    int numFiles = 100;
    ProgressDialog progress("Copying files...", "Abort Copy", 0, numFiles, this);
    progress.installEventFilter(this);
    progress.setWindowModality(Qt::WindowModal);

    for (int i = 0; i < numFiles; i++) {
        progress.setValue(i);
        QThread::msleep(100);
        if (progress.wasCanceled())
            break;
        //... copy one file
    }
    progress.setValue(numFiles);
}

[joeQ]

@J.Hilk i also tried it, also not work. ProgressDialog is subclass of QProgressDialog

void ProgressDialog::closeEvent(QCloseEvent *event)
{
    event->ignore(); // work
}

void ProgressDialog::keyPressEvent(QKeyEvent *event)
{
    if(event->key() == Qt::Key_Escape){
        event->ignore(); // not work
    }else{
        QProgressDialog::keyPressEvent(event);
    }
}

void ProgressDialog::hideEvent(QHideEvent *event)
{
    event->ignore(); // not work
}

[J.Hilk]

@joeQ said in how to disable ESC key "close" the QProgressDialog ?:

void ProgressDialog::keyPressEvent(QKeyEvent *event)
{
if(event->key() == Qt::Key_Escape){
event->ignore(); // not work
}else{
QProgressDialog::keyPressEvent(event);
}
}

That want work, event->ignore() means, that the event is passed on same as QProgressDialog::keyPressEvent(event); You'll have to accept the event and do nothing with it.
eg:

 void ProgressDialog::keyPressEvent(QKeyEvent *event)
 {
     if(event->key() == Qt::Key_Escape){
         event->accept(); 
         return;
     }else{
         QProgressDialog::keyPressEvent(event);
     }
 }

[joeQ]

@J.Hilk The key is I cann't capture the ESC press event in keyPressEvent function, ProgressDialog is subclass of QProgressDialog. like it;

void ProgressDialog::keyPressEvent(QKeyEvent *event)
{
    if(event->key() == Qt::Key_Escape){
        qDebug("Esc press!"); // when i pressed the esc key , there was nothing print...
    }else{
        QProgressDialog::keyPressEvent(event);
    }

    return;
}

When i pressed the esc key, what event happend?

[joeQ]

@J.Hilk I tried others key. I can capture all the key press event , except the esc press event;

[joeQ]

@J.Hilk I also tried the event fliter.

bool Dialog::eventFilter(QObject *obj, QEvent *event)
{
    qDebug() << obj << "====" << event->type(); // I want to know, what event passed when i pressed the esc key.
    if(event->type() == QEvent::KeyPress){
        qDebug("Key press");
        return true;
    }else{
        // pass the event on to the parent class
        return QDialog::eventFilter(obj, event);
    }
}

void Dialog::on_btn_clicked()
{
    int numFiles = 100;
    ProgressDialog progress("Copying files...", "Abort Copy", 0, numFiles, this);
    progress.installEventFilter(this);
    progress.setWindowModality(Qt::WindowModal);

    for (int i = 0; i < numFiles; i++) {
        progress.setValue(i);
        QThread::msleep(100);
        if (progress.wasCanceled())
            break;
        //... copy one file
    }
    progress.setValue(numFiles);
}

QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
...
...
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(UpdateRequest)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Paint)
QProgressDialog(0x28c5d4) ==== QEvent::Type(ShortcutOverride) // at here, i pressed the esc key.
QProgressDialog(0x28c5d4) ==== QEvent::Type(WindowDeactivate)
QProgressDialog(0x28c5d4) ==== QEvent::Type(ActivationChange)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Hide)
QProgressDialog(0x28c5d4) ==== QEvent::Type(HideToParent)
QProgressDialog(0x28c5d4) ==== QEvent::Type(Leave)
QWidget(0x28c5d4) ==== QEvent::Type(PlatformSurface)
QWidget(0x28c5d4) ==== QEvent::Type(WinIdChange)
QWidget(0x28c5d4) ==== QEvent::Type(Destroy)

I don't want let the esc key to close the QProgressdialog, How to do ?

[J.Hilk]

@joeQ OK, I looked into it a bit more.

And from my understanding there is most likly a bug here.
That pressing ESC canceles the Dialog is a Shortcut defined in the constructor of the Dialog, -> not easy if at all to prevent /disable.

Therefor you would have to override the slot its connected to which is, void QProgressDialog::cancel(), which in my Test-program I was not able to override, at all....

So here's a work around from, me.

Disable the SIGNAL/SLOT connection of the cancel Signal in your constructor:

disconnect(this, SIGNAL(canceled()), this, SLOT(cancel()));

and connect it to your custom myCancelSlot

connect(this, SIGNAL(canceled()), this, SLOT(myCancel)));

void myCancel{
  if(condition){
     cancel();
  }
}

If you dont handle the canceled Signal yourself, than the only way to forcefully close the dialog would be by pressing the X-Button in the upper corner.

you should be able to work with that?

[joeQ]

@J.Hilk (^o^)/~,Thank u. Good idea. That is what i want. Thank u very much.

[the_gollum]

for me only overriding event(QEvent*) worked good:

protected:
  bool event(QEvent* event)
  {
    QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
    if(keyEvent && keyEvent->key() == Qt::Key_Escape)
    {
      keyEvent->accept();
      return true;
    }
    return QProgressDialog::event(event);
  }