Forward Declaration error

[pragati]

I did changed to Namespace DMM...but prob is I have to create an instance of this DMM in other directory class like this:
Start.h
@
#ifndef START_H
#define START_H

#include "../../DMM/Include/DMM.h"

/****************************************************************************/
/**

• \brief This class handles the initialization of the user interface.
  /
  /***************************************************************************/
  namespace Start {

class Startup : public QObject
{
Q_OBJECT

public:
Startup();
virtual ~Startup();
void GuiInit();

private:

Ui::DMMMenu *MainWindow;

};

}

#endif // START_H
@

Start.cpp:

@

#include "../../Start/Include/Start.h"

namespace Start {

Startup::Startup() : QObject()
{

// GUI components

MainWindow = new DMM::DMMMenu();

}

Startup::~Startup()
{
try {
// GUI Components

    delete MainWindow;
}
catch (...) {}

}

/***************************************************************************/
/!

• \brief Initializes the user interface
  /
  /***************************************************************************/
  void Startup::GuiInit()
  {
  MainWindow->show();

}

}

@

So now I am getting errors like these upon changing namespace to DMM:

1. /home/pragati/MultiFuncTester/Components/Start/Build/../Source/Start.cpp:-1: In constructor 'Start::Startup::Startup()':

/home/pragati/MultiFuncTester/Components/Start/Build/../Source/Start.cpp:12: error: cannot convert 'DMM::DMMMenu' to 'Ui::DMMMenu*' in assignment*

2./home/pragati/MultiFuncTester/Components/Start/Build/../Source/Start.cpp:35: error: invalid use of incomplete type 'struct Ui::DMMMenu'

3./home/pragati/MultiFuncTester/Components/Start/Build/../../DMM/Include/DMM.h:9: error: forward declaration of 'struct Ui::DMMMenu'

[r3willia]

That's good - it means the compiler's got past the problem you were having before - now you've got the problem that you're using the wrong type for your member of Start::Startup.

I expect you want Start::Startup's declaration to read:

@class Startup : public QObject
{
Q_OBJECT

public:
Startup();
virtual ~Startup();
void GuiInit();

private:

DMM::DMMMenu *MainWindow;

};@

DMM::DMMMenu has a Ui::DMMMenu, but DMM::DMMMenu is not a Ui::DMMMenu (to use Object-orientated is-a / has-a terminology).

[pragati]

:(

I used it already before but as soon as I do this:
@DMM::DMMMenu *MainWindow;
@
I get error that
1./home/pragati/MultiFuncTester/Components/Start/Build/../../Start/Include/Start.h:27: error: 'DMM' does not name a type

and

2./home/pragati/MultiFuncTester/Components/Start/Build/../Source/Start.cpp:35: error: 'MainWindow' was not declared in this scope

[r3willia]

You're referencing DMM from within the namespace Start; it's possible you may have to be specific i.e. declare the parameter:
@::DMM::DMMMenu *MainWindow;@

Also make certain that "../../DMM/Include/DMM.h" does indeed define DMM::DMMMenu.

[pragati]

r3Willia,

I am still getting errors but not regarding this....anyways thank you so much...you came when I was not getting help from anyone....Thank you so much....wish I cud have personally thanked you...bt anyways....all the best and again ty....

[pragati]

hi...

Everything is working fine until when I write in main. In main I included one of the subdirectory's .h file and wrote some function like this I am posting here both the codes of main and that directory....

Error I am getting is :

/home/pragati/MultiFuncTester/Components/Main/Source/Main.cpp:-1: error: undefined reference to `Start::Startup::Startup()'

/home/pragati/MultiFuncTester/Components/Main/Source/Main.cpp:-1: error: undefined reference to `Start::Startup::GuiInit()'
/home/pragati/MultiFuncTester/Components/Main/Source

/Main.cpp:-1: error: undefined reference to `Start::Startup::~Startup()'

Similiar error for GuiInit....

Start.h

@
#ifndef START_H
#define START_H

#include "../../DMM/Include/DMM.h"

/****************************************************************************/
/**

• \brief This class handles the initialization of the user interface.
  /
  /***************************************************************************/
  namespace Start {

class Startup : public QObject
{
Q_OBJECT

public:

Startup();
virtual ~Startup();
void GuiInit();

private:

DMM::DMMMenu *MainWindow;

};

}

#endif // START_H

@

Start.cpp

@

#include "../../Start/Include/Start.h"
namespace Start {

Startup::Startup() : QObject()
{

// // GUI components

MainWindow = new DMM::DMMMenu();

}

/***************************************************************************/
/!

• \brief Initializes the user interface
  /
  /***************************************************************************/
  void Startup::GuiInit()
  {
  MainWindow->show();

}

}
@

Main.cpp

@
#include "../../Start/Include/Start.h"
#include <QApplication>
#include <QtGui>

int main(int argc, char *argv[])

{
QApplication app(argc, argv);
Start::Startup start;
start.GuiInit();
return app.exec();
}

@