Coin3d + Qt: SIGLNALs and SLOTs

[vonCZ]

In my attempts last week to render a Coin3d scene in a Qt application, I used Qt's hellogl demo program as a template and modified it. The Coin scene renders nicely now, but I cannot get it to recognize Qt's signals & slots. My window.cpp file still contains this:

connect(xSlider, SIGNAL(valueChanged(int)), coinWidget, SLOT(setXRotation(int)));
connect(coinWidget, SIGNAL(xRotationChanged(int)), xSlider, SLOT(setValue(int)));

connect(xSlider, SIGNAL(valueChanged(int)), coinWidget, SLOT(setXRotation(int)));
connect(coinWidget, SIGNAL(xRotationChanged(int)), xSlider, SLOT(setValue(int)));

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My CoinWidget constructor looks like this:

CoinWidget::CoinWidget(QWidget *parent) : QMainWindow(parent)
{
  SoQt::init(this);  
 
  SoSeparator *root = new SoSeparator;
  SoRotationXYZ *rootRot = new SoRotationXYZ;
  root->ref();
 
  root->addChild(rootRot);
  root->addChild(new SoCone);
 
  rootRot->angle=xRot;
 
  SoQtExaminerViewer *eviewer = new SoQtExaminerViewer(this);
  eviewer->setDecoration(false);
  eviewer->setSceneGraph(root);
  eviewer->show();
 
}

CoinWidget::CoinWidget(QWidget *parent) : QMainWindow(parent)
{
  SoQt::init(this);  

  SoSeparator *root = new SoSeparator;
  SoRotationXYZ *rootRot = new SoRotationXYZ;
  root->ref();

  root->addChild(rootRot);
  root->addChild(new SoCone);

  rootRot->angle=xRot;

  SoQtExaminerViewer *eviewer = new SoQtExaminerViewer(this);
  eviewer->setDecoration(false);
  eviewer->setSceneGraph(root);
  eviewer->show();

}

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...such that the xRot variable *should* be modified by moving the slider (and thus cause my model to rotate), but it's not happening. I'm thinking that when using SoQt, there may be an additional step involved. Any suggestions?

[marcel]

Does connect outputs any warnings/errors?

[wysota]

Did you remember about adding Q_OBJECT macro to your class header?

[vonCZ]

yes, I've included the Q_OBJECT macro. Marcel, no errors that I know of, but I wouldn't expect any: the signal/slot code and functions are lifted straight from the HelloGL demo, so I think everything is working fine there. I'll add a QLCDNumber widget now, just to make sure the xRot value is changing when I move the slider. (although I put a temporary exit() statement in the setXRotation() function just to make sure it was being called, and it was.)

[marcel]

Trey using qDebug in the suspect slots to see if they are called. You should open your app from the console in this case.

[pdolbey]

What are setRotationX/Y/Z actually doing?

Pete

[vonCZ]

Thanks for the tip, Marcel: i hadn't used qDebug before; very useful. As it turns out, the function was being called but the values weren't updating properly. That's fixed now, but it's still not working, but at least now I know the problem is on the Coin3d side, which I think I've almost got worked out.

Pete- the model in my Coin3d scene should rotate around the X, Y, or Z axis when setRotationX/Y/Z are called.

[pdolbey]

As a techie I was sort of expecting a code listing - but from your answer, I could see you having a great future in "requirements"

Have you sorted it yet?

Pete

[vonCZ]

No, I've not sorted it yet.

I've learned that I need to add a Coin3d field, SoSFFloat, to my program, and use this (rather than a standard float) to update the rotation value. Here's the code-

coinwidget.h

#ifndef COINWIDGET_H
#define COINWIDGET_H
 
#include <QMainWindow>
 
#include <Inventor/Qt/SoQt.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
#include <Inventor/fields/SoSFFloat.h>
 
class CoinWidget : public QMainWindow
{
  Q_OBJECT
 
public:
  CoinWidget(QWidget *parent = 0);
  ~CoinWidget();
 
  QSize minimumSizeHint() const;
  QSize sizeHint() const;
 
  float deg2rad(int angle) { return (angle * 3.1416/180.00); }
 
//  SoSFFloat xRot;
 
public slots:
  void setXRotation(int angle);
  void setYRotation(int angle);
  void setZRotation(int angle);
 
signals:
  void xRotationChanged(int angle);
  void yRotationChanged(int angle);
  void zRotationChanged(int angle);
 
protected:
 
private:
  void normalizeAngle(int *angle);
 
};
 
#endif

#ifndef COINWIDGET_H
#define COINWIDGET_H

#include <QMainWindow>

#include <Inventor/Qt/SoQt.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
#include <Inventor/fields/SoSFFloat.h>

class CoinWidget : public QMainWindow
{
  Q_OBJECT

public:
  CoinWidget(QWidget *parent = 0);
  ~CoinWidget();

  QSize minimumSizeHint() const;
  QSize sizeHint() const;

  float deg2rad(int angle) { return (angle * 3.1416/180.00); }

//  SoSFFloat xRot;

public slots:
  void setXRotation(int angle);
  void setYRotation(int angle);
  void setZRotation(int angle);

signals:
  void xRotationChanged(int angle);
  void yRotationChanged(int angle);
  void zRotationChanged(int angle);

protected:

private:
  void normalizeAngle(int *angle);

};

#endif

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coinwidget.cpp

#include <QtGui>
#include <Inventor/Qt/SoQt.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
#include <Inventor/fields/SoSFFloat.h>
 
#include <math.h>
 
#include "coinwidget.h"
 
CoinWidget::CoinWidget(QWidget *parent) : QMainWindow(parent)
{
 
  SoQt::init(this);
 
  SoSeparator *root = new SoSeparator;
  SoRotationXYZ *rootRot = new SoRotationXYZ;
 
//  rootRot->angle=xRot.getValue();
  root->ref();
 
  root->addChild(rootRot);
  root->addChild(new SoCone);
 
  SoQtExaminerViewer *eviewer = new SoQtExaminerViewer(this);
  eviewer->setDecoration(false);
  eviewer->setSceneGraph(root);
  eviewer->show();
 
}
 
CoinWidget::~CoinWidget()
{
}
 
QSize CoinWidget::minimumSizeHint() const {
  return QSize(200, 200);
}
 
QSize CoinWidget::sizeHint() const {
  return QSize(400, 400);
}
 
void CoinWidget::setXRotation(int angle)
{
  float a = deg2rad(angle);
  qDebug("angle = %.4f\n", a);
 
/*
  if(a != rootRot->angle.getValue())  {
    rootRot->angle=a;
  }
*/
}
 
void CoinWidget::setYRotation(int angle) {
}
 
void CoinWidget::setZRotation(int angle) {
}

#include <QtGui>
#include <Inventor/Qt/SoQt.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
#include <Inventor/fields/SoSFFloat.h>

#include <math.h>

#include "coinwidget.h"

CoinWidget::CoinWidget(QWidget *parent) : QMainWindow(parent)
{

  SoQt::init(this);

  SoSeparator *root = new SoSeparator;
  SoRotationXYZ *rootRot = new SoRotationXYZ;

//  rootRot->angle=xRot.getValue();
  root->ref();

  root->addChild(rootRot);
  root->addChild(new SoCone);

  SoQtExaminerViewer *eviewer = new SoQtExaminerViewer(this);
  eviewer->setDecoration(false);
  eviewer->setSceneGraph(root);
  eviewer->show();

}

CoinWidget::~CoinWidget()
{
}

QSize CoinWidget::minimumSizeHint() const {
  return QSize(200, 200);
}

QSize CoinWidget::sizeHint() const {
  return QSize(400, 400);
}

void CoinWidget::setXRotation(int angle)
{
  float a = deg2rad(angle);
  qDebug("angle = %.4f\n", a);

/*
  if(a != rootRot->angle.getValue())  {
    rootRot->angle=a;
  }
*/
}

void CoinWidget::setYRotation(int angle) {
}

void CoinWidget::setZRotation(int angle) {
}

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you can ignore the setXRotation() function for now. My problem is: if I simply uncomment the "SoSFFloat xRot;" statement in the class declaration, my program will compile/link but I get a "Microsoft Visual C++ Runtime Library" dialog-box error message:

Assertion failed!

Program c:\qt_tutorial\testprog.exe
File: c:\orig_coindir\source\Coin-2.4.6\src\fields\sosffloat.cpp
Line: 49
Expression: SoSFFloat::classTypeId != SoType::badType()

If I declare the same variable within the CoinWidget constructor, however, it runs fine... the problem here, though, is that I cannot then access the variable from other member functions, notably setXRotation().

I should mention/say: the file

File: c:\orig_coindir\source\Coin-2.4.6\src\fields\sosffloat.cpp

doesn't actually exist. This was the location of my initial Coin3d installation, which has since been deleted. In my Visual Studio project, in the "vsvar32.txt" file, and in my system Environment Variables: this directory doesn't exist! ...so I don't know why it's referring to it here. Anyway, I don't think this is related to my problem, since I only seem to have a problem with the SoSFFloat variable when I declare it in the Class Declaration and not in the constructor.

Any ideas? Anyone? Buehler?

[marcel]

Leave xRot a member but try to initialize it somehow( I don't know what ways of initialization are there - but I am sure there is at least one ) in the constructor.

It seems this is the problem, you use xRot uninitialized.

Regards

[pdolbey]

You've got one or 2 gotchas in that code. I'm still trying to understand Coin3d myself but there's a few fundamental problems with your code.

The first problem is that the root of your scenegraph and the rotation node is orphaned once you've left the scope of the CoinWidget constructor. That should be an easy fix - move their pointers into the header file i.e. define (I now tend to use my.. as a member prefix)

protected:
    SoSeparator *myRoot;  
    SoRotationXYZ *myRootRot;

protected:
    SoSeparator *myRoot;  
    SoRotationXYZ *myRootRot;

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and change the constructor to

.
myRoot = new SoSeparator;  
myRootRot = new SoRotationXYZ;
.

.
myRoot = new SoSeparator;  
myRootRot = new SoRotationXYZ;
.

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Now you've got initialised objects available throughout your class. You should add a

delete myRoot;  
delete myRootRot;

delete myRoot;  
delete myRootRot;

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in the destructor. The next problem seems to be that you have never initialised the xRot variable. I think you can change the definition of xRot in the header to

float xRot;

float xRot;

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Now in the constructor change the code to

.
myRootRot = new SoRotationXYZ; 
xRot = 0.0f
myRootRot->angle.setValue(xRot);
myRoot->ref();   
myRoot->addChild(rootRot);  
myRoot->addChild(new SoCone);
.

.
myRootRot = new SoRotationXYZ; 
xRot = 0.0f
myRootRot->angle.setValue(xRot);
myRoot->ref();   
myRoot->addChild(rootRot);  
myRoot->addChild(new SoCone);
.

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Thex setXRotation has something like

if(a != xRot)  
{
    xRot = a;
    myRootRot->angle.setValue(xRot);
}

if(a != xRot)  
{
    xRot = a;
    myRootRot->angle.setValue(xRot);
}

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The assert is likely to have been displayed because the SosFFloat was never initialised with a setValue - and I guess your still linking to a debug libary that has an internal reference to the original source code that you've now deleted. You might want to consider using an "SoRotation" instead later when you try to combine the other axes.

Hope this helps

Pete

[vonCZ]

Thanks Pete/Marcel for the suggestions. Pete: you mentioned "move their pointers into the header file." Good idea, except I couldn't do this before because I needed to state

SoQt::init(this);

SoQt::init(this);

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before I could refer to any of the Coin classes (SoRotationXYZ, SoSFFloat, etc). But the SoQt::init() is in the CoinWidget constructor, so I couldn't refer to SoSFFloat in the coinwidget.h file. I've gotten around this now by creating a separate class, "Model," to hold all of my Coin geometry. These are my files:

main.cpp
window.h/.cpp (the Qt interface)
coinwidget.h/.cpp (the Coin3d initialization)
model.h/.cpp (the Coin3d geometry)

My problem now, however: I declare a "coinWidget" object in my Window class, and then a "model" object in my "CoinWidget" class... but now I don't know how I can send signals from my Qt objects (i.e. "xSlider") to my "model" signals. (I haven't defined the signal/slot functions in my Model class yet; they're still in the CoinWidget class. I wanted to see if it's possible, first.)

Should I, for example, go ahead and pass the signals from Window to CoinWidget as I'm doing now, then emit the signal again from CoinWidget to the Model class (after I set up the slots in the Model class, of course)?

I apologize in advance: i'm going to post the program files, below. If it's innappropriate for me to do so, let me know Wysota.

++++++   main.cpp   ++++++
#include <QApplication>
 
#include "window.h"
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}
 
++++++   window.h   ++++++
#ifndef WINDOW_H
#define WINDOW_H
 
#include <QWidget>
 
class CoinWidget;
class QSlider;
 
class Window : public QWidget
{
    Q_OBJECT
 
public:
    Window();
 
private:
 
    QSlider        *createSlider();
 
    CoinWidget     *coinWidget;
    QSlider        *xSlider;
 
};
 
#endif
 
++++++   window.cpp   ++++++
#include <QtGui>
 
#include "coinwidget.h"
#include "window.h"
 
Window::Window()
{
    coinWidget = new CoinWidget;
 
    xSlider = createSlider();
 
    connect(xSlider, SIGNAL(valueChanged(int)), coinWidget, SLOT(setXRotation(int)));
    connect(coinWidget, SIGNAL(xRotationChanged(int)), xSlider, SLOT(setValue(int)));
 
// NOTE:  above is how I did it when I thought I could place the model in
//        the CoinWidget class.  Now that I've a separate class, Model,
//        which contains the model, I don't know how I can pass SIGNALs to
//        a Model object without declaring the object here first...  but which
//        doesn't make sense to do.  I declare the "model" object in the
//        Coinwidget::Coinwidget()  constructor.   ...although, as I asked above:
//        perhaps I should leave this as it is, then forward the signal on to the
//        model class?
 
    QHBoxLayout *mainLayout = new QHBoxLayout;
    mainLayout->addWidget(coinWidget);
    mainLayout->addWidget(xSlider);
    setLayout(mainLayout);
 
    xSlider->setValue(12);
    setWindowTitle(tr("Hello COIN"));
}
 
QSlider *Window::createSlider()
{
    QSlider *slider = new QSlider(Qt::Vertical);
    slider->setRange(0, 360);
    slider->setSingleStep(36);
    slider->setPageStep(12);
    slider->setTickInterval(12);
    slider->setTickPosition(QSlider::TicksRight);
    return slider;
}
 
++++++   coinwidget.h   ++++++
#ifndef COINWIDGET_H
#define COINWIDGET_H
 
#include <QMainWindow>
#include <Inventor/Qt/SoQt.h>
 
class CoinWidget : public QMainWindow
{
  Q_OBJECT
 
public:
  CoinWidget(QWidget *parent = 0);
  ~CoinWidget();
 
  QSize minimumSizeHint() const;
  QSize sizeHint() const;
 
  float deg2rad(int angle) { return (angle * 3.1416/180.00); }
 
public slots:
 
  //  refer to other comments
  void setXRotation(int angle);
 
signals:
 
  // refer to other comments
  void xRotationChanged(int angle);
 
protected:
 
 
private:
  void normalizeAngle(int *angle);
 
};
 
#endif
 
++++++   coinwidget.cpp   ++++++
#include <QtGui>
#include <QtCore>
 
#include <Inventor/Qt/SoQt.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
 
#include "coinwidget.h"
#include "model.h"
 
 
CoinWidget::CoinWidget(QWidget *parent) : QMainWindow(parent)
{
 
  SoQt::init(this);
 
  Model *model = new Model(this);
 
  setCentralWidget(model->getWidget());
  model->setDefaultScene();
 
}
 
CoinWidget::~CoinWidget() {
 
//  delete model;     // :  error C2065: 'model' : undeclared identifier
                      // So I added  "delete this;" in  Model::~Model();
                      // Is this the proper way to delete pointer/allocated memory
                      // to the "model" object?
 
}
 
QSize CoinWidget::minimumSizeHint() const {
 
  return QSize(200, 200);
 
}
 
QSize CoinWidget::sizeHint() const {
 
  return QSize(400, 400);
 
}
 
void CoinWidget::setXRotation(int angle)
{
 
  // I was thinking that I should delete this member function, since this Class is set up
  //   only to initialize the Coin3d window...  but--again, as I asked above--maybe I should
  //   keep it, and pass the signal again to the Model class.   I realize, btw, that the 
  //   function doesn't do anything currently.  I'll sort that out after I figure out how to
  //   route the signals/slots.
 
  float a = deg2rad(angle);
  qDebug("angle = %.4f", a);
}
 
++++++   model.h   ++++++
#ifndef MODEL_H
#define MODEL_H
 
#include <Inventor/Qt/SoQt.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/fields/SoSFFloat.h>
 
class Model : public SoQtExaminerViewer
{
 
  public:
 
    Model( QWidget *parent = NULL, const char *name=NULL, const SbBool embed=TRUE);
    ~Model(void);
 
    void setDefaultScene();
 
  protected:
 
  private:
 
    SoSeparator      *root;
    SoRotationXYZ   *myRot;
    SoSFFloat         xRot;
 
};
 
#endif
 
++++++   model.cpp   ++++++
#include <Inventor/Qt/SoQt.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
//#include <Inventor/fields/SoSFFloat.h>
 
 
#include <model.h>
 
 
Model::Model( QWidget *parent, const char * name, const SbBool embed)
  : SoQtExaminerViewer( parent, name, embed, SoQtFullViewer::BUILD_ALL, SoQtViewer::BROWSER, TRUE) {
 
  QWidget *widget = this->buildWidget(this->getParentWidget());
  this->setBaseWidget(widget);
  this->setDecoration(false);
}
 
 
Model::~Model() {
 
  delete this;
 
 /* FYI  Pete:
"You can not call delete on nodes [including SoSeparators, SoRotationXYZ, etc.]
because the destructor is protected.  Nodes are deleted when you call unref() on
them and the reference count goes to zero.  You must of course first ref() a node
before you can unref() it."   from a Coin3d developer
*/
  root->unref();
  myRot->unref();   //actually, I guess I shouldn't do this since I didn't "ref()" it.
 
}
 
void Model::setDefaultScene(void) {
 
    root = new SoSeparator;
    root->ref();
    root->addChild(new SoCone);
 
    this->setSceneGraph(root);
    this->show();
 
}

++++++   main.cpp   ++++++
#include <QApplication>

#include "window.h"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    Window window;
    window.show();
    return app.exec();
}

++++++   window.h   ++++++
#ifndef WINDOW_H
#define WINDOW_H

#include <QWidget>

class CoinWidget;
class QSlider;

class Window : public QWidget
{
    Q_OBJECT

public:
    Window();

private:

    QSlider        *createSlider();

    CoinWidget     *coinWidget;
    QSlider        *xSlider;

};

#endif

++++++   window.cpp   ++++++
#include <QtGui>

#include "coinwidget.h"
#include "window.h"

Window::Window()
{
    coinWidget = new CoinWidget;

    xSlider = createSlider();

    connect(xSlider, SIGNAL(valueChanged(int)), coinWidget, SLOT(setXRotation(int)));
    connect(coinWidget, SIGNAL(xRotationChanged(int)), xSlider, SLOT(setValue(int)));

// NOTE:  above is how I did it when I thought I could place the model in
//        the CoinWidget class.  Now that I've a separate class, Model,
//        which contains the model, I don't know how I can pass SIGNALs to
//        a Model object without declaring the object here first...  but which
//        doesn't make sense to do.  I declare the "model" object in the
//        Coinwidget::Coinwidget()  constructor.   ...although, as I asked above:
//        perhaps I should leave this as it is, then forward the signal on to the
//        model class?

    QHBoxLayout *mainLayout = new QHBoxLayout;
    mainLayout->addWidget(coinWidget);
    mainLayout->addWidget(xSlider);
    setLayout(mainLayout);

    xSlider->setValue(12);
    setWindowTitle(tr("Hello COIN"));
}

QSlider *Window::createSlider()
{
    QSlider *slider = new QSlider(Qt::Vertical);
    slider->setRange(0, 360);
    slider->setSingleStep(36);
    slider->setPageStep(12);
    slider->setTickInterval(12);
    slider->setTickPosition(QSlider::TicksRight);
    return slider;
}

++++++   coinwidget.h   ++++++
#ifndef COINWIDGET_H
#define COINWIDGET_H

#include <QMainWindow>
#include <Inventor/Qt/SoQt.h>

class CoinWidget : public QMainWindow
{
  Q_OBJECT

public:
  CoinWidget(QWidget *parent = 0);
  ~CoinWidget();

  QSize minimumSizeHint() const;
  QSize sizeHint() const;

  float deg2rad(int angle) { return (angle * 3.1416/180.00); }

public slots:

  //  refer to other comments
  void setXRotation(int angle);

signals:

  // refer to other comments
  void xRotationChanged(int angle);

protected:


private:
  void normalizeAngle(int *angle);

};

#endif

++++++   coinwidget.cpp   ++++++
#include <QtGui>
#include <QtCore>

#include <Inventor/Qt/SoQt.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>

#include "coinwidget.h"
#include "model.h"


CoinWidget::CoinWidget(QWidget *parent) : QMainWindow(parent)
{

  SoQt::init(this);

  Model *model = new Model(this);

  setCentralWidget(model->getWidget());
  model->setDefaultScene();

}

CoinWidget::~CoinWidget() {

//  delete model;     // :  error C2065: 'model' : undeclared identifier
                      // So I added  "delete this;" in  Model::~Model();
                      // Is this the proper way to delete pointer/allocated memory
                      // to the "model" object?

}

QSize CoinWidget::minimumSizeHint() const {

  return QSize(200, 200);

}

QSize CoinWidget::sizeHint() const {

  return QSize(400, 400);

}

void CoinWidget::setXRotation(int angle)
{

  // I was thinking that I should delete this member function, since this Class is set up
  //   only to initialize the Coin3d window...  but--again, as I asked above--maybe I should
  //   keep it, and pass the signal again to the Model class.   I realize, btw, that the 
  //   function doesn't do anything currently.  I'll sort that out after I figure out how to
  //   route the signals/slots.

  float a = deg2rad(angle);
  qDebug("angle = %.4f", a);
}

++++++   model.h   ++++++
#ifndef MODEL_H
#define MODEL_H

#include <Inventor/Qt/SoQt.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/fields/SoSFFloat.h>

class Model : public SoQtExaminerViewer
{

  public:

    Model( QWidget *parent = NULL, const char *name=NULL, const SbBool embed=TRUE);
    ~Model(void);

    void setDefaultScene();

  protected:

  private:

    SoSeparator      *root;
    SoRotationXYZ   *myRot;
    SoSFFloat         xRot;

};

#endif

++++++   model.cpp   ++++++
#include <Inventor/Qt/SoQt.h>
#include <Inventor/nodes/SoSeparator.h>
#include <Inventor/nodes/SoRotationXYZ.h>
#include <Inventor/nodes/SoCone.h>
#include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
//#include <Inventor/fields/SoSFFloat.h>


#include <model.h>


Model::Model( QWidget *parent, const char * name, const SbBool embed)
  : SoQtExaminerViewer( parent, name, embed, SoQtFullViewer::BUILD_ALL, SoQtViewer::BROWSER, TRUE) {

  QWidget *widget = this->buildWidget(this->getParentWidget());
  this->setBaseWidget(widget);
  this->setDecoration(false);
}


Model::~Model() {

  delete this;

 /* FYI  Pete:
"You can not call delete on nodes [including SoSeparators, SoRotationXYZ, etc.]
because the destructor is protected.  Nodes are deleted when you call unref() on
them and the reference count goes to zero.  You must of course first ref() a node
before you can unref() it."   from a Coin3d developer
*/
  root->unref();
  myRot->unref();   //actually, I guess I shouldn't do this since I didn't "ref()" it.

}

void Model::setDefaultScene(void) {

    root = new SoSeparator;
    root->ref();
    root->addChild(new SoCone);

    this->setSceneGraph(root);
    this->show();

}

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[vonCZ]

In case a simple visual will help, here it is. Again, the problem is I don't know how to connect the SIGNAL from the slider, to the cone rotation.

[marcel]

I didn't look at the code yet, but the normal approach is to create wrappers in the classes that are liked to the signal and slot you want to connect.

For example if class A contains object obj1 and class B contains object obj2, then to connect a signal from obj1 to a slot in obj2:
obj1 signal -> class A slot -> class A signal -> class B slot -> obj2 slot.

Of course, this has to be done from a class that hass access to both A and B.
This you can do if you don't want to redesign too much.

Regards

[vonCZ]

First I should say: it is no problem at all to do a complete redesign. I think there is a simple solution, on how to connect a Qt widget to Coin geometry/fields/etc, I just don't know how to do it yet. (I think I said this before: Qt is awesome, with all the sample code to figure out how to do things. Coin on the other hand: almost nothing, not even a simple demo to integrate Coin & Qt.)

Do I understand you correctly: by "wrapper", do you mean create a new class that derives from both the Window and Model classes (the Qt widget and Coin geometry classes), and use functions from this class to access the Model fields? For example:

given:
qt _obj
model_obj

qt_obj signal -> WrapperClass slot -> function in WrapperClass updates field_value in model_obj (i.e. SoSFFloat xRot)

[marcel]

No, I said "wrapper functions" - signals and slots.

[vonCZ]

OK, Marcel, from what I gather you're talking standard SIGNALs and SLOTs stuff, right? So I need to be able to add SLOTs in my Model class.

but: my Model class (in "model.cpp") doesn't (and cannot?) have any SLOTs, because it derives only from a Coin3d class, "SoQtExaminerViewer". I want to put fields/variables in my Model class that are updated by input from Window-class SIGNALs. What is the best way to add them?? I must include the Q_OBJECT macro and, presumably, derive my Model class not only from the SoQtExaminerViewer class, but also from a Qt class. Which class should I choose? ...or is this even the right path?

[jacek]

I've posted this in the Newbie section without much luck yet; figured I'd try here.

Please, don't post multiple threads on the same topic.

but: my Model class (in "model.cpp") doesn't (and cannot?) have any SLOTs, because it derives only from a Coin3d class, "SoQtExaminerViewer".

Then use multiple inheritance. Just note that, due moc limitations, QObject must be listed as the first super class.

[vonCZ]

Please, don't post multiple threads on the same topic.

plz delete #18 above; it's confusing here twice.

[pdolbey]

Here's a bit of a hackaround with your code.

I've used the old setXRotation in the coinwidget as a wrapper for the model (now promoted to be a class member). Model now its own setXRotation(float angle), but this is just a standard method available to the proxy. The order of adding children to the root is important - think left to right - so

root->addChild(myRot);
root->addChild(new SoCone);

root->addChild(myRot);
root->addChild(new SoCone);

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works but

root->addChild(new SoCone);
root->addChild(myRot);

root->addChild(new SoCone);
root->addChild(myRot);

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appears not to as the cone is now left of the rotation. Anyway the attached zip file was working for me. But remember that this technique is rotating the objects in "world space" - not just rotating the camera postion around the scene.

Pete