Qt C++ use method of creating class in created objects - c++

Question

I`m still stuck.
I have a GUI-class that creates an Object. From a method of this new Object I want to use methods of the creating class
I have a Gui(PBV) with line_Edits and a Combobox. In this Combobox I can choose between different Geometries. Geo_1, Geo_2,… that inherit from Geometry. According to the entries in the combobox I want to create different Objects (Geo_1,Geo_2,…) that then set the lineEdits of the creating class according to the needs of the Geo_n-Object.
I don`want to do that with signal-slot
I asked different questions on that but I can`t get further.
I somehow feel this is kind of recursive... Is there a solution fort hat?
Here is my code:
PBV.h:
#include "../Geometry/Geo_1.h"
class PBV : public Tab
{
Q_OBJECT
public:
explicit PBV (QWidget *parent = 0);
~ PBV ();
virtual void printContent( QStringList *const qsl);
private:
Geo_1 *GEO_1;
Geometry *GEO;
}
PBV.cpp:
…
Geo_1 *GEO_1;
GEO_1 = new Geo_1(this);
GEO_1->set_LNE_default();
…
.
Geo_1.h:
#ifndef GEO_1_H
#define GEO_1_H
#include "Geometry.h"
#include "../Tabs/PBV.h"
class Geo_1: public Geometry
{
Q_OBJECT
public:
Geo_1 (QObject *_parent = 0);
virtual void set_LNE_default();
};
#endif // GEO_1_H
.
Geo_1.cpp:
#include "Geometry.h"
#include <QDebug>
#include "Geo_1.h"
#include "../Tabs/PBV.h"
Geo_1::Geo_1(QObject*_parent)
: Geometry(_parent) {}
void Geo_1::set_LNE_default()
{
// here I want to use printContent
}
.
Geometry.h:
#ifndef GEOMETRY_H
#define GEOMETRY_H
#include <QObject>
class Geometry : public QObject
{
Q_OBJECT
public:
Geometry(QObject *_parent=0);
~Geometry();
virtual void set_LNE_default();
};
#endif // GEOMETRY_H
.
Geometry.cpp:
#include "Geometry.h"
#include <QDebug>
Geometry::Geometry(QObject *_parent)
: QObject(_parent) {}
Geometry::~Geometry(){}
void Geometry::set_LNE_default() { }

Answer 1

When PBV allocates a Geo_1 instance, it is already passing a pointer to itself in the constructor:
GEO_1 = new Geo_1(this); // "this" is your PBV instance
Why not save the pointer to use later?
Geo_1::Geo_1(PBV*_parent) : Geometry((QObject*)_parent)
{
this->pbv = _parent; // Save reference to parent
}
Then you can do:
void Geo_1::set_LNE_default()
{
// here I want to use printContent
this->pbv->printContent(...); // this->pbv is your saved ptr to the PBV that created this instance
}
EDIT
Additonally, you might run into the problem that you will have to cross-include the two headers (PBV and Geo_1), to fix this, remove the include for Geo_1 from PBV.h and forward-declare Geo_1. Just like this:
class Geo_1;
Before declaring your PBV class.