signals and slots, newbie problem

[testQtowiec]

Hello

I got a job to do and I came across the problem of a beginner, I do not know yet how to find the signals and slots.

OK, my problem is that I have declared the two methods in a class and I must conncet with the class Controller using signals and slots. So when you squeeze the button that has to execute method of the class.

Please help and some examples of solutions.

[anda_skoa]

http://qt-project.org/doc/qt-4.8/signalsandslots.html

Cheers,
_

[testQtowiec]

Thanks but ...
I have class controller.
I have class Search, where I have slot on_pushButton_clicked()
and i have c++ class Find, where I have method.
Program works that, the main windows start, next I click Search Window and on the Search Window i press pushButton and i would like to start method from class Find.
How connect this 3 things in controller.

[anda_skoa]

The linked documentation covers:
- declaration of a signal
- declaration of a slot
- connecting a signal to a slot

So what kind of additional information are you looking for?

Cheers,
_

[testQtowiec]

I get lost in files.

SearchWindow.h

signals:
    void searchButtonSelected();
 
public slots:
    void on_pushButton_clicked();

signals:
    void searchButtonSelected();

public slots:
    void on_pushButton_clicked();

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SearchWindow.cpp

void SearchListWindow::on_pushButton_clicked()
{
    qDebug()  << "Search push button clicked";
    emit searchButtonSelected();
}

void SearchListWindow::on_pushButton_clicked()
{
    qDebug()  << "Search push button clicked";
    emit searchButtonSelected();
}

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Controller.h

signals:
    void startMethodProcess();
 
private slots:
    void searchButtonSelected();

signals:
    void startMethodProcess();

private slots:
    void searchButtonSelected();

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Controller.cpp

void Controller::setupsearchlistwindow(SearchListWindow* searchWindow)
{
   connect( ? );  
}

void Controller::setupsearchlistwindow(SearchListWindow* searchWindow)
{
   connect( ? );  
}

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Method.cpp

void Method::process();

void Method::process();

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How to call method process in connect.

[anda_skoa]

Does Controller have a pointer to an instance of Method?
Do you want Controller::searchButtonSelected() to call Method:rocess() or is Method:rocess() a slot itself?

Cheers,
_

[testQtowiec]

I want to call Method process when button is press

Controller haven't a pointer to an instance of Method, how make it?

[anda_skoa]

I want to call Method process when button is press

Yes, but that is not what I was asking.
Is Method:rocess() a slot, i.e. do you want to connect the signal to it, or is it just a normal method, i.e. do you want to call it inside the slot of Controller?

Controller haven't a pointer to an instance of Method, how make it?

Basic C++: create an instance of Method in Controller or pass a Method object to the Controller object.

Cheers,
_

[testQtowiec]

It's normal method

[anda_skoa]

Well then

void Controller::setupsearchlistwindow(SearchListWindow* searchWindow)
{
   connect( searchWindow, SIGNAL(searchButtonSelected()), this, SLOT(searchButtonSelected()));  
}

void Controller::setupsearchlistwindow(SearchListWindow* searchWindow)
{
   connect( searchWindow, SIGNAL(searchButtonSelected()), this, SLOT(searchButtonSelected()));  
}

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void Controller::searchButtonSelected()
{
  objectOfMethod->process();
}

void Controller::searchButtonSelected()
{
  objectOfMethod->process();
}

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Cheers,
_

[testQtowiec]

Thanks for patience

I write this code but doesn' work. I try with qDebug message.

Main.cpp

#include "mainwindow.h"
#include "searchlistwindow.h"
#include <QApplication>
#include "controller.hpp"
 
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    SearchListWindow x;
    Controller controller;
    controller.setupmainwindows(&w);
    controller.setupsearchlistwindow(&x);
    w.show();
 
    return a.exec();
}

#include "mainwindow.h"
#include "searchlistwindow.h"
#include <QApplication>
#include "controller.hpp"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    SearchListWindow x;
    Controller controller;
    controller.setupmainwindows(&w);
    controller.setupsearchlistwindow(&x);
    w.show();

    return a.exec();
}

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Controller.cpp

void Controller::setupmainwindows(MainWindow *mainWindow)
{
 
}
void Controller::setupsearchlistwindow(SearchListWindow* searchWindow)
{
   connect(searchWindow, SIGNAL(searchButtonSelected()), this, SLOT(searchButtonSelected()));
 
}
 
void Controller::searchButtonSelected()
{
    qDebug()<<"Test";
}

void Controller::setupmainwindows(MainWindow *mainWindow)
{

}
void Controller::setupsearchlistwindow(SearchListWindow* searchWindow)
{
   connect(searchWindow, SIGNAL(searchButtonSelected()), this, SLOT(searchButtonSelected()));

}

void Controller::searchButtonSelected()
{
    qDebug()<<"Test";
}

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and show only text from on_pushButton_clicked

void SearchListWindow::on_pushButton_clicked()
{
    emit searchButtonSelected();
    qDebug()  << "Search push button clicked";
}

void SearchListWindow::on_pushButton_clicked()
{
    emit searchButtonSelected();
    qDebug()  << "Search push button clicked";
}

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[anda_skoa]

What is the return value of the connect call?

Do you get any runtime warning?

Cheers,
_

[testQtowiec]

I delete connect in setupmainwindows.

0 warnings

in mainWindow.cpp I create searchWindows

void MainWindow::on_Button()
{
    SearchListWindow* searchWindow = new SearchListWindow(this);
    searchWindow->show();
}

void MainWindow::on_Button()
{
    SearchListWindow* searchWindow = new SearchListWindow(this);
    searchWindow->show();
}

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[anda_skoa]

Well, that instance of SearchListWindow is not connected, is it?
How do you expect the signal to reach the slot without it being connected?

Cheers,
_

[testQtowiec]

ok, but I don't know how connect this istance.

[anda_skoa]

Well, since you have a method for doing that connect, one way to connect this instance of the dialog would be to pass it to that method.

But since you create an instance of the SearchListWindow in main(), maybe you want to use that in Mainwindow instead of creating another one?

Cheers,
_

[testQtowiec]

Yes I want to use instance of SearchListWindows from MainWindow

[anda_skoa]

You want to use the ifirst nstance you created in main() inside Mainwindow, or use the second instance you created in Mainwindow:n_button?

Cheers,
_