Qt method call from another class? - c++

Question

I got two windows(two classes), one window that opens another when i click a button.
then the user inputs something into the newly opened window and then transfer that information to the first window when a button is clicked
The problem is I can't seem to send something to the second window so i can send the user input back to the main window. I read a few places that I should use Q_object but not really sure how that works
I should mention that I am new to Qt and didn't know about the designer there is in qt creator before i was way to ahead with the program.
Hope you have some ideas to how I can do this
edit1:
I should show the relevant code i have
Mainwindow.cpp
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent)
{
//alot of stuff not relevant right now creating different stuff
changeProfile= new QPushButton("ændre valgte profil",this);
profileList = new QComboBox(this);
cProfile = new CreateProfile;
connect(changeProfile,SIGNAL(clicked()),this,SLOT(ProfileChange()));
}
void MainWindow::ProfileChange()
{
file pfile(profileList->currentText().toStdString());
string tempName = pfile.read(light);
cProfile->setValue(light,tempName);
cPr
ofile->show();
}
void MainWindow::setProfileList(QString Pname_)
{
bool found = 0;
for (int i = 0;i<5;i++)
{
if (Pname_ ==profileList->itemText(i))
found = 1;
}
if (found !=1)
profileList->addItem(Pname_);
}
createProfile.cpp
CreateProfile::CreateProfile(QWidget *parent)
:QMainWindow(parent)
{
//alot of other irrelevant stuff here
saveP = new QPushButton("Save",this);
connect(saveP,SIGNAL(clicked()),this,SLOT(saveProfile()));
}
void CreateProfile::saveProfile()
{
temp = pName->text();
file pFile(temp.toStdString());
bool lights[2] = {light1->checkState(),light2->checkState()};
if (temp.length() == 0)
{
MessageBox(NULL,"Du har ikke skrevet noget navn ind\n Prov igen","Error",MB_ICONWARNING+MB_SETFOREGROUND);
}
else
{
pFile.save(lights);
//call function setProfileList
this->hide();
}
}
If that makes sence, If you need the .h file too i can show them also
I need to call setProfileList from the mainwindow in the function saveprofile(there is in createprofile window) or if there is a way i can change the combobox in the wainwindow from the createprofile window?
edit 2:
mainwindow.h
#include "createprofile.h"
class MainWindow : public QMainWindow
{
Q_OBJECT
public slots:
void ProfileChange();
//some other button clicks
public:
CreateProfile *cProfile;
void setProfileList(QString Pname_);
//other irelevant stuff
private:
// and some private members
};
createProfile.h
class CreateProfile : public QMainWindow
{
Q_OBJECT
public slots:
void saveProfile();
public:
explicit CreateProfile(QWidget *parent = 0);
~CreateProfile();
//and other stuff there isnt relevant
};

Answer 1

You are looking for the Qt signal-slot mechanism, namely:
class SecondWindow : public QMainWindow
{
Q_OBJECT
public:
SecondWindow(QWidget *parent = Q_NULLPTR) : QObject(Q_NULLPTR)
{
// ...
connect(secondWindowButton, SIGNAL(clicked(bool)), SLOT(handleClicked()));
// ...
}
public slots:
void SecondWindow::handleClicked()
{
// Gather information from the UI as you wish
firstWindow->foo();
}
// ...
}
or, if you have a container class for the windows, you could handle it in there, too, as follows:
connect(secondWindow->myButton, SIGNAL(clicked(bool)), SLOT(handleClicked()));

Answer 2

I found a very different way to do this, so I have made a QComboBox in the constructor of createProfile.cpp and then I have access to the profileList this way.