Send signals to MainWindow from another window

Peter_Dev

Hi, everyone!
I created second dialogue window from my MainWindow by

SecondWindow *SW = new SecondWindow();
SW->show();

SecondWindow contains 6 QPushButtons inside. I'd like to be able to send 6 different clicked()signals from SecondWindow to MainWindow, so that each button has it's own signal. I guess, the best to do this is by connect(), but i still can't figure out how to implement it in code.

Lemat

on the secondWindow, create signal in header for each button. then when you will clicked on a button, the on_clicked slot you implemented from ui for each button would emits the specific signal.
Like this:

SecondWindow.h :

signals:
 Void button0 ();
 Void button1 ();
 //same for 4 remaining buttons

SecondWindow.cpp : (after create slots from ui)

Void on_button0_clicked ()
{
emit button0();
}
//repeat for 5 others buttons

MainWindow cpp:

SecondWindow *SW = new SecondWindow();
connect (SW, SIGNAL (button0()), this, SLOT(desired_slot ()));
//repeat for 5 others signals
SW->show();

Test it!!!!

qt.1234

do the connection in your MainWindow.
declare signal clicked() in your SecondWindow.h
and declare slot buttonClickSlot() in your MainWindow.cpp and MainWindow.h
QObject::connect(SW, SIGNAL(clicked()), this, SLOT(buttonClickSlot()), Qt::AutoConnection);

Peter_Dev

Should i somehow connect to buttons? I followed your instructions but, unfortunately, when i press any of buttons, i get no response.

Lemat

You have theses buttons on ui or declared in QMainWindow cpp?

Peter_Dev

@Lemat , I created these buttons on ui of SecondWindow and i want to connect their signals (if they were clicked) to slots in MainWindow

Lemat

From my knowledge, declare the specifics slots in MainWindow as public, and instantiate MainWindow in SecondWindow. After try this:

connect (this->qpushbutton, SIGNAL(clicked  (bool)), MainWindow, SLOT(specific_slot (bool)), Qt::DirectConnection);

this refer to SecondWindow

Hope it will work for you, test it!!!!

Peter_Dev

@Lemat , how can i get MainWindow in connect (this->qpushbutton, SIGNAL(clicked (bool)), MainWindow, SLOT(specific_slot (bool)), Qt::DirectConnection);?
if i use

MainWindow *win = new MainWindoow();

i guess there's a endless cycle creates because i open a SecondWindow from MainWindow and i don't see any window. Program just uses my processor.

Lemat

Wow, my apologies!!!, i have not pay attention...

Lemat

on the secondWindow, create signal in header for each button. then when you will clicked on a button, the on_clicked slot you implemented from ui for each button would emits the specific signal.
Like this:

SecondWindow.h :

signals:
 Void button0 ();
 Void button1 ();
 //same for 4 remaining buttons

SecondWindow.cpp : (after create slots from ui)

Void on_button0_clicked ()
{
emit button0();
}
//repeat for 5 others buttons

MainWindow cpp:

SecondWindow *SW = new SecondWindow();
connect (SW, SIGNAL (button0()), this, SLOT(desired_slot ()));
//repeat for 5 others signals
SW->show();

Test it!!!!

Peter_Dev

@Lemat , thanks a lot for your time. I followed your instructions, but still i don't receive a signal from SecondWindow, though i get no error message. Does your code work for you?

jsulm

@Peter_Dev Please post your code.
Did you make sure connect() succeeded (it returns a bool)?

Lemat

@Peter_Dev , hello please post your code...

Peter_Dev

@Lemat, my code is very mess. I'm trying to clean it now. I think i know where i made mistake..
Thanks a lot for your time. I tried your solution on another project and it works perfect!

Lemat

@Peter_Dev
Glad it worked for you. it's a solution I use very often. if everything is ok, pass this subject to resolved.