Problem with dialog child

[Pantof]

Hi all,
i've done this little project to explain my problem.

when i exec a QDialog i connect a LineEdit returnPressed to a PushButton (click) but the slot clicked() run twice when the return in the line edit is pressed.

i did the same in the main window that work correctly but not in the executed dialog
[0_1515019274947_PROVA.zip](Uploading 100%)

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <dialog.h>
#include <QDebug>


MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_pushButton_clicked()
{
    qDebug()<< "test ";
    qDebug()<< "dsdas";
    Dialog dia(this);
    dia.exec();
}

#include "dialog.h"
#include "ui_dialog.h"
#include <QDebug>

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
}

Dialog::~Dialog()
{
    delete ui;
}

void Dialog::on_pushButton_clicked()
{
    qDebug()<< "test dialog ";
    qDebug()<< "dsdas";
}


[Charlie_Hdz]

Do you mean that "test dialog" output was prompted twice?

[Pantof]

Yes, the on_pushbutton_clicked is called twice

[Charlie_Hdz]

@Pantof

Can you share the output, please?

[Pantof]

this happens when only one return in line edit is pressed:

[Pantof]

I try another way with the same result:

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    QObject::connect(ui->lineEdit,&QLineEdit::returnPressed,this,&Dialog::onReturnPressed);
    QObject::connect(ui->pushButton, &QPushButton::clicked, this, &Dialog::onReturnPressed);
}

Dialog::~Dialog()
{
    delete ui;
}

void Dialog::onReturnPressed()
{
    qDebug()<< "test dialog ";
    qDebug()<< "dsdas";
}

it seems there is a problem between signal click() and clicked()

[mpergand]

It's normal, a dialog has a defaut button, when pressing enter, the defaut button emits the clicked signal.

see: default button

[Charlie_Hdz]

@Pantof

Can you share the declarations (.h) of your classes?

In the while, can you try to develop this project without using the Design to see what happens?

[mrjj]

Hi
I agree with @mpergand and also thinks its the dialog helping.

Pressing enter in line edits triggers this

QObject::connect(ui->lineEdit,&QLineEdit::returnPressed,this,&Dialog::onReturnPressed);
However, the lineedit do not eat the enter. its send to button.
the button is "default" (when created with Designer at least) meaning pressing enter
trigger it and it emits
QObject::connect(ui->pushButton, &QPushButton::clicked, this, &Dialog::onReturnPressed);

[JonB]

I don't understand what the problem here is.

There are two separate signals going on here.

• You have clicked RETURN in a QLineEdit, and you have chosen to catch that signal.

• Since QLineEdit, unlike QTextEdit, is single-line, it does not accept RETURN. So it passes it on to the QDialog to handle. Which (as @mpergand said) has a default button, which is invoked when RETURN is pressed. That only happens in a dialog, not a window.

What is the issue? The obvious question is why you are interested in handling QLineEdit::returnPressed() signal at all?

[Pantof]

you're all right sorry for ignorance,
i'm intrested in QLineEdit::returnPressed because with this dialog a user could insert more than 1 record in database and he could do it with returnPressed from QLineEdit.
i think i should do it in another way :D

[JonB]

@Pantof
Nothing to be sorry for!

i'm intrested in QLineEdit::returnPressed because with this dialog a user could insert more than 1 record in database and he could do it with returnPressed from QLineEdit.

What do you mean by this?

It sounds a little odd, but if you have a legitimate reason it may be that the better solution is to prevent that RETURN from causing the default dialog action. The principle QDialog is working on is that a RETURN --- unless it is intended for the current widget --- is aimed at the dialog. That sounds like it may not correspond to what you are intending.

[Pantof]

@JonB
normally the application show show a table from database when you click a pushbutton you open a Form (done with qDialog) that give you the possibility to insert new records. to speed up this job i use the return pressed from qLineEdit so you shouldn't move out to grab the mouse.
actually i switch to qWidget.

[JonB]

@Pantof

i use the return pressed from qLineEdit

If you choose to do that, I would think you need to not let that key/return press to do it's normal action of activating the dialog's default button action. Such as, you could use event filter on the dialog perhaps. Or, I imagine a QDialog can be told not to have a default button/return press.