Qt+VTK: build successful but run failed...

[adam-tum]

Hello,
am trying to implement a main window that shows a vtk widget.
Build is successful but run fails with no errors...Please, could you help me.
Am using Ubuntu 11.10, Netbeans 7.0.1. & my files are look like:

TestSoftWare.cxx:

@#include "SoftWare.h"
#include <QApplication>
#include <QVTKWidget.h>
#include <QtGui/QWidget>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkImageViewer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkJPEGReader.h>

int main(int argc, char** argv)
{
QApplication app(argc, argv);
MainWindow* mainWin;
QVTKWidget* widget;
mainWin->resize(256,256);

//---vtk stuff here---//

widget->SetRenderWindow(renderWindow);
mainWin->show();
app.exec();
return EXIT_SUCCESS;
}
@

SoftWare.h:

@#ifndef SOFTWARE_H
#define SOFTWARE_H

#include <QMainWindow>
class QAction;
class QMenu;

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
MainWindow();

protected:
void closeEvent(QCloseEvent *event);

private slots:
void open();

private:
void createActions();
void createMenus();
void createToolBars();
void createStatusBar();

QString curPath;
QMenu *fileMenu;
QToolBar *fileToolBar;
QAction *openAct;

};
#endif@

SoftWare.cpp:

@#include "SoftWare.h"
#include <QtGui>

MainWindow::MainWindow()
{
QVTKWidget widget;
setCentralWidget(widget);
createActions();
createMenus();
createToolBars();
createStatusBar();
}

void MainWindow::open()
{
QString fileName = QFileDialog::getOpenFileName(this, tr("Select Directory"), "/home");
}

void MainWindow::createActions()
{
openAct = new QAction(QIcon(":/images/open.png"), tr("&Open..."), this);
connect(openAct, SIGNAL(triggered()), this, SLOT(open()));
}

void MainWindow::createMenus()
{
fileMenu = menuBar()->addMenu(tr("&File"));
fileMenu->addAction(openAct);
}

void MainWindow::createToolBars()
{
fileToolBar = addToolBar(tr("File"));
fileToolBar->addAction(openAct);
}

void MainWindow::createStatusBar()
{
statusBar()->showMessage(tr("Ready"));
}@

[Hostel]

Did you try debug?

[adam-tum]

Hi Hostel,

thanks for the idea.
I tried debug but I always get :
Signal received: SIGSEGV (?) with sigcode ? (?)
From process: ?
For program TestSoftWare, pid 7,247

even when I skipped it, still get it & can't continue.

Thanks for help.

[Hostel]

Run in debug mode a program step by step - maybe you will find a line which makes problem. Maybe you are using a null pointer? You have a pointer type MainWindow and QVTKWidget - did you properly create objects by new?

[adam-tum]

Hi Hostel,

First of all, Happy New Year for you.

-About creating the pointer type, I tried to write
MainWindow* mainWin= new MainWindow();

but I got a build error:
undefined reference to MainWindow:MainWindow()

-About the debug, I built with vtkdebug & then did debug with netbeans, I got the same signal error BUT with debug error:
no registers

this happens only in the lines:
mainWin->resize(256,256);
mainWin->show();

so, when I commented these lines, it runs but of course I can't see anything (no application window).

[Hostel]

Thanx, and Happy New Year for you too :)

If you have in code a pointer to MainWindow without constructiong by new a object, then when you call
@
mainWin->resize();
@
then you have a SIGSEGV.

You have to make a object.

You should resolve a build error with 'undefined reference(...)'.

Try solve it by:
@
MainWindow::MainWindow() :
QMainWindow() // you forget about constructor of base class
{
-QVTKWidget widget;- // this not looks good - this should be a member in private section of class
widget = new QVTKWidget(); // change to this
// your code
}
@

then run qmake and try build again.

[adam-tum]

Hello Hostel,

Thanks alot.
You seem an expert with coding.

Let me tell you what I did changed, to see if I got you correctly:

in .cpp
@MainWindow::MainWindow() : QMainWindow()
{
widget = new QVTKWidget();
}@

in main
@ MainWindow* mainWin = new MainWindow();@

I did this, but still get undefined reference error.

[Chris H]

Can we see the header file for your MainWindow class? In particular, how have you defined the constructor? Your error is still "Undefined reference to MainWindow::MainWindow()"?

[adam-tum]

here is the header file.
exactly, this is the error.

@#ifndef SOFTWARE_H
#define SOFTWARE_H

#include <QMainWindow>
#include <QVTKWidget.h>

QT_BEGIN_NAMESPACE
class QAction;
class QMenu;
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
MainWindow();

protected:
void closeEvent(QCloseEvent *event);

private slots:
void open();
bool exportAs();
void about();

private:
QVTKWidget widget;

void createActions();
void createMenus();
void createToolBars();
void createStatusBar();

void setCurrentPath(const QString &fileName);
QString curPath;

QMenu *fileMenu;
QToolBar *fileToolBar;

QAction *openAct;
QAction *exportAsAct;
QAction *exitAct;
QAction *aboutAct;

};

#endif
@

[Hostel]

Can we see your .pro file?

[adam-tum]

here it is:

@HEADERS = SoftWare.h
SOURCES = TestSoftWare.cpp
SoftWare.cpp

RESOURCES = application.qrc

install

target.path = $$/home/adam-linux/Documents/TestSoftWare-Debug
sources.files = $$SOURCES $$HEADERS $$RESOURCES $$FORMS application.pro images
sources.path = $$/home/adam-linux/Documents/TestSoftWare-Debug
INSTALLS += target sources@

[Hostel]

I don't know why this is not working. Try re-run qmake and re-build all. If not help then try remove this lines from .pro file:
@
install
target.path = $$/home/adam-linux/Documents/TestSoftWare-Debug
sources.files = $$SOURCES $$HEADERS $$RESOURCES $$FORMS application.pro images
sources.path = $$/home/adam-linux/Documents/TestSoftWare-Debug
INSTALLS += target sources
@
and re-run qmake and re-build all.

I don't have any new ideas.