Storing variables from dialog and using it in a qvtkwidget - qt

Question

I've created a dialog where I ask for some lengths of a number of slices, as xmax, ymax, and zmax as the number of slices. I intend to use those numbers in the mainwindow in the qvtkwidget. I'll simplify and make the example to only one variable so you can understand and help me.
Here's my dialog.cpp
#include <QtGui/QApplication>
#include <QDir>
#include <iostream>
using namespace std;
#include "dialog.h"
#include "ui_dialog.h"
// Create getters to transfer variables to main.cpp
double Dialog::getxpax()
{
return xpax;
}
// Start the mainwindow
void Dialog::startplanevolume()
{
// Getting some proprieties for the lenght of the volume
QString XMAX=ui->lineEdit->text();
xpax=XMAX.toDouble();
if (xpax==0)
{
ui->label_17->setText("Error: Can't start, invalid \nmeasures");
ui->label_17->setStyleSheet("QLabel { color : red; }");
}
else
{
this->accept();
}
}
Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
// Control volume measures
// Making the lineedit objects only accept numbers
ui->lineEdit->setValidator(new QDoubleValidator(this));
// Start planevolume
connect(ui->pushButton, SIGNAL(clicked()), this, SLOT(startplanevolume()));
connect(ui->pushButton_2, SIGNAL(clicked()), this, SLOT(hide()));
}
The pushbutton is the ok button and the pushbutton_2 is the cancel button.
In my mainwindow I created a setter function to set the value of the xmax.
here's some code.
// Get stored data from dialog
void planevolume::setxpax(double xpax)
{
xp=xpax;
}
and when I use qDebug() the xp inside the settter shows me that the xp actually gets the xpax value.
here's my main.cpp
#include <QtGui/QApplication>
#include <iostream>
using namespace std;
#include "planevolume.h"
#include "dialog.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Dialog *dialog= new Dialog;
if (dialog->exec())
{
planevolume mainwindow;
mainwindow.setxpax(dialog->getxpax());
mainwindow.show();
return app.exec();
}
return 0;
}
So the only problem is that is here, at mainwindow as planevolume.cpp when I need it, the value has not been set,
planevolume::planevolume(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::planevolume)
{
ui->setupUi(this);
// My vtk statements are here in the code, but they are
// executed before the setter gives the value to my new
// variable xp, so when I need the value it has not been set yet.
Any ideas guys?

Answer 1

If the planevolume constructor needs these data, they could be passed as parameter to the constructor itself (you can also make the dialog return all the variables inside a struct to have a single parameter to pass, instead of having an accessor for each one).
Another solution would be to call the vtk part after the event loop has started by putting it in a slot and schedule its execution with a QTimer::singleShot.
In that last case, your code should like this:
planevolume::planevolume(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::planevolume)
{
ui->setupUi(this);
QTimer::singleShot(0, this, SLOT(setupVtk()));
}
// declared as a slot in the class
void planevolume::setupVtk()
{
// Your VTK statements would be here
}