Best way QDialog should communicate with MainWindow?

[WhatIf]

Hello,

I have a QDialog with 2 buttons. One button performs an operation and the other is a cancel button. The button the performs an operation, emits a signal then closes the dialog.

I want to know which of the two buttons was clicked when the QDialog closes and control returns to MainWindow. I read in other posts that the QDialog should not be messing with variable created in its parent, MainWindow.

Thank you

[Chrisw01]

Hi, I believe the Cancel button returns QDialog::Rejected; I recommend that you have your other button do its stuff then call accept(); Thus returning either QDialog::Accepted or QDialog::Rejected.

So in your code you could do as

result = dialog.exec();

Then result will either be Accepted or Rejected depending on the button pressed.

[Chris Kawa]

QDialog::Accept and QDialog::Reject are the built-in result types, as @Chrisw01 mentioned.
If you want more customized options you can use any integer value with done(). Create a public enum in your dialog class with the options and then connect your buttons to slots that call done() with that enum values.
A user of your dialog can then call exec() and inspect the return value by comparing it to the enum values.