Beginner question: How to tell when Dialog is exposed?

mstoth

A beginner question:

I need to be aware when a dialog is exposed. showEvent() only is called when the panel is shown. If a panel then covers the first dialog, when that second panel goes away, my first dialog needs to check a parameter but it currently has no idea the covering panel has been closed.

Is there a callback or delegate routine that gets called when a dialog is exposed after a covering window goes away?

jsulm

@mstoth By "exposed" you mean "has focus"?

mstoth

Yes, the dialog invokes another dialog both of which are full screen (on a beaglebone). Once the covering dialog goes away the focus is returned to the covered dialog which is now exposed. If I try to use focusInEvent however, this routine does not get called when the first dialog is exposed.

Pablo J. Rogina

@mstoth how are you displaying the dialogs, in particular the second one?
From documentation:

The most common way to display a modal dialog is to call its exec() function. When the user closes the dialog, exec() will provide a useful return value.

mstoth

These are not modal.
In the first dialog, the onRelease handler for one of the buttons is

void MainMenu::on_configureConsoleButton_released()
{
    dc=new DialogConsoleConfigA(this);
    dc->show();
}

DialogConsoleConfigA covers the main menu dialog.
Then when DialogConsoleConfigA is removed,

void DialogConsoleConfigA::on_pushButton_released()
{
    this->hide();
}

Now the first dialog is exposed again. I need to find a way for the MainMenu dialog to be aware that the DialogConsoleConfigA dialog has been hidden.

Taz742

@mstoth
use signal slot mechanism.

Dialog *dialog = new Dialog;
connect(dialog, &Dialog::rejected, this, [=](){
    //something
});
dialog->show();

or in your Dialog class listen a closeEvent:

void Dialog::closeEvent (QCloseEvent *event) {
     emit closed();
event->accept();
}

.h file:

signals:
void closed();

protected:
void closeEvent(QCloseEvent *event);

Dialog *dialog = new Dialog;
connect(dialog, &Dialog::closed, this, [=](){
    //something
});
dialog->show();

Diracsbracket

This post is deleted!

Diracsbracket

@Taz742 said in Beginner question: How to tell when Dialog is exposed?:

connect(dialog, &Dialog::rejected, this, =

Hi, why rejected?

Taz742

@Diracsbracket
When form 'X' button click, when a dialog is closed QDialog does not call a rejected signal ?

Diracsbracket

@Taz742 said in Beginner question: How to tell when Dialog is exposed?:

When form 'X' button click, when a dialog is closed QDialog does not call a rejected signal

Yes, but when you reject a config dialog, then that usually means nothing needs to be done...? I would have used the accepted() signal. But hey, let's wait and see what exactly @mstoth has in mind.

Taz742

@Diracsbracket
I think no one is right, he only wants to hide the dialog? Waiitt ))

Diracsbracket

@Taz742 said in Beginner question: How to tell when Dialog is exposed?:

he only wants to hide the dialog

@mstoth said in Beginner question: How to tell when Dialog is exposed?:

when that second panel goes away, my first dialog needs to check a parameter

I think he wants to check if any of the settings were changed when the dialog was closed^^. In any case, thanks for posting the solution!

mstoth

Indeed, all I need to do is see if something has happened when the first dialog is visible again. I thought about signals/slots but there is more than one case where this first dialog becomes visible again. For instance, the first dialog has 6 buttons, each presents a different new dialog. When any of those appear, they hide the first one. To use signals, i'd have to connect to each of those 6 dialogs.

I was hoping for something more elegant like a event handler I could override in the first dialog that gets called when the first dialog becomes visible again. (something like onExposed()) . I have not seen anything like that.

Thanks by the way for all the help! I appreciate your thoughts.

Taz742

@mstoth
Good! I think you have an idea of what to do. Then mark this topic to be solved.

mstoth

ok, so my solution is to use signals to indicate the condition i'm interested in. It's a bit messy since there are so many places I need to connect to but from what I'm hearing, that is the only way.

I'll mark it as solved but unfortunately it is not the kind of solution I was hoping for. If anyone else has a more elegant way of handling this feel free to let me know.

I do appreciate everyone's time and effort on this problem! Thank you very much.