keyPressEvent subclass works only in debug

Mark81

I'm not sure what I'm doing wrong here.
In my QDialog form I want to customize the pressing of some keys, like esc.
So I wrote:

DialogComponents.h

protected:
    void keyPressEvent(QKeyEvent *e);

DialogComponents.cpp

void DialogComponents::keyPressEvent(QKeyEvent *e)
{
    qDebug() << e->key();
    if (e->key() == Qt::Key_Escape) emit swapCurrentStack();
    else QDialog::keyPressEvent(e);
}

if I run the debugger (run a debug build is not enough) it works like expected:

it prints the key() value
if I press key is esc it emits the signal and executes the connected slot
if I press another key, i.e. enter the default behavior is unchanged

but if I run the application (even built as debug) without attach the debugger, it just does nothing: no qDebug() and no effect at all. Of course all other qDebug() I have work fine.

The mistake is in the code above?

aha_1980

@Mark81 said in keyPressEvent subclass works only in debug:

protected:
void keyPressEvent(QKeyEvent *e);

You can add override to make sure you really re-implement the base implementation:

void keyPressEvent(QKeyEvent *e) override;

Otherwise I don't see what could be wrong with your code.

Regards

Mark81

@aha_1980 well, the override keyword does nothing, apparently.
But I found a more specific criteria for the weird behavior.

Now I can say the wrong behavior is not due to the debugger.
Sorry for the misleading title.

When I run the application the keyPressEvent is not fired until I minimize and restore the window.
I don't know why.

Some other stuff that might be related.
I also implemented the showEvent function to update the QTableView model when the dialog is shown:

void DialogComponents::showEvent(QShowEvent *event)
{
    Q_UNUSED(event)
    qDebug() << "show event fired";
    ui->table->clearSelection();
    _model->select();
}

but this fires anyway, even when I open it the first time, of course.

SGaist

Hi,

Are you sure your dialog has the keyboard focus and not one of the widget inside of it ?

Mark81

@SGaist said in keyPressEvent subclass works only in debug:

Are you sure your dialog has the keyboard focus and not one of the widget inside of it ?

It should - at least I assume that - because if I remove the override function, when I press esc the QDialog closes (actually, rejects) under the same conditions.

J.Hilk

What version of Qt are we talking about, and what OS?

Mark81

Qt 5.12.2, Windows 7

J.Hilk

@Mark81 I would suggest to update to at least the latest version of 5.12, as it is a LTS version.

Also you know, that support for win 7 will be close to non existent come January ?

qwasder85

My guess is the keyboard focus. Try setFocus() on your dialog when it opens.

Mark81

@qwasder85 said in keyPressEvent subclass works only in debug:

My guess is the keyboard focus. Try setFocus() on your dialog when it opens.

Yes, it's definitely related to the focus. It's strange that the default event works in any case.