Send Variable values from QDialog to QMainwindow function - c++

Question

My UI MainWindow has a QListWidget and , upon clicking of its items ,a corresponding QDialog box must pop up , which prompts the user to enter some values in QDialog box, The values entered into line_edits of QDialog box must stored into a QString variable and this variable should be accessed/used in a function of MainWindow,
for Example: I have a QListWidget, with 3 items "New York","Glasgow","Mumbai", and when i double click item named "New York", a pop-up shows up asking me this
and after i enter 3 and Hilton , the item in QListWidget which was initially "New York" must be changed to
"New York -3 , The safehouse is in Hilton"
my code for MainWindow.cpp is
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtCore>
#include <QtGui>
#include <sstream>
#include <QtWidgets/qmessagebox.h>
#include <QtWidgets/qlistwidget.h>
using namespace std;
MainWindow::MainWindow(QWidget* parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->My_listwidget->addItem("New York");
ui->My_listwidget->addItem("Glasgow");
ui->My_listwidget->addItem("Mumbai");
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_My_listwidget_itemDoubleClicked(QListWidgetItem* item)
{
QString test = item->text();
std::string test_s = test.toStdString();
if (test_s.find("New York") != std::string::npos) // check if item contains text "New York"
{
WinApp winApp;
winApp.setModal(true); //Displaying the window here
winApp.exec();
}
if (test_s.find("Glasgow") != std::string::npos)
{
// show another dialog box asking some questions
}
if (test_s.find("Mumbai") != std::string::npos)
{
// show another dialog box asking some questions
}
}
My code for mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QtWidgets/QMainWindow>
#include "ExecutionContext.h"
#include <QtWidgets/qlistwidget.h>
//#include "secdialog.h"
#include <qregexp.h>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT //Used to handle events
public:
MainWindow(QWidget* parent = 0);
~MainWindow(); //Destructor used to free resources
private slots:
void on_xml_scripts_textbox_itemDoubleClicked(QListWidgetItem* item);
Ui::MainWindow* ui; // pointing to UI class
private:
};
#endif // MAINWINDOW_H
my code for WinApp.h , winapp is the name of my dialog
#include <QtWidgets/qdialog.h>
#include "ui_WinApp.h"
class WinApp : public QDialog, public Ui::WinApp
{
Q_OBJECT
public:
WinApp(QWidget *parent = Q_NULLPTR);
~WinApp();
private slots:
private:
Ui::WinApp ui;
};
WinApp.cpp
#include "WinApp.h"
WinApp::WinApp(QWidget *parent)
: QDialog(parent)
{
ui.setupUi(this);
}
WinApp::~WinApp()
{
}

Answer 1

you need to add in the WinApp dialog class the test getter, it should be something like:
QString getFavouriteHotel() const {
return ui.<favourite-hotel-label>.text()
}
In the MainWindow after the line winApp.exec(); I suggest adding an if to check if the user accepted or declined the dialog (docs). If the user accepted the dialog then you can retrieve the text with the getters you just added.
Tips: avoid using exec, as said in the docs use the open
-- UPDATE -- QDialog accept --
Always check the docs
connect(&WinApp, &QDialog::finished, this, [this](int result) {
if(result == QDialog::Accepted){
// do aswomness
return
}
});

Answer 2

Have the function initiating the QDialog object pass the QString argument in the constructor and override accept().
#include <QtWidgets/qdialog.h>
#include "ui_WinApp.h"
class WinApp : public QDialog, public Ui::WinApp
{
Q_OBJECT
public:
WinApp(QString& stringToModify, QWidget *parent = Q_NULLPTR);
~WinApp();
private slots:
void accept() override;
private:
Ui::WinApp ui;
};
and define the acccept() slot which will get the QString from lineEdit and update the stringToModify with it.
void WinApp::accept(){
//do stuff with QString
this->close();
}