Linking problems boundary="==_Exmh_13452812500" boundary="==_Exmh_13601327980"

[Oliver Elphick]

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I have the following errors when trying to compile and link a class that
derives from QListBox:

 g++ -g -o  try try.cc try1.cc -I/usr/include/X11/qt -L/usr/X11R6/lib -lqt 
-lg++
 /tmp/cca197912.o: In function `ListBox::ListBox(QWidget *, char const *, 
unsigned int)':
 /usr/home/olly/cprogs/priory_db/try1.cc:44: undefined reference to 
`ListBox::QPaintDevice virtual table'
 /usr/home/olly/cprogs/priory_db/try1.cc:44: undefined reference to `ListBox 
virtual table'

I attach a minimal set of files which demonstrate the bug.

I don't know if this is in fact a bug in the GNU compiler or in QT.

Version levels:
Debian Linux 1.2
GCC     2.7.2.1
libg++  2.7.2
QT      1.0

Oliver Elphick                                          olly@lfix.co.uk
Isle of Wight                      http://homepages.enterprise.net/olly


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Content-Description: try.cc
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/* Test program */

 #include <qapp.h>              // Every program needs one!
 #include <qwidget.h>

 #include "listitem.h"          // Main window's header file



int main (int argc, char **argv)
{
    QApplication a(argc, argv);
  =

    QWidget mw;
    a.setMainWidget(&mw);
    ListItem *li =3D new ListItem;
    mw.show();
  =

    return a.exec();
}


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Content-Description: try1.h
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/************************************************************************=
*****

        Priory database

        listitem.h  Header file for listitem, one of the four data windows

*************************************************************************=
****/

 #ifndef LISTITEM_H
 #define LISTITEM_H

 #include <qgrpbox.h>
 #include <qlistbox.h>
 #include <qlabel.h>
 #include <String.h>
 #include <qlist.h>

class QLabel;

class ListItem : public QListBoxText
{
  Q_OBJECT
public:
  ListItem(const char *k=3D0, const char *t=3D0);
  void setKey(const char *);
  void setValues(const char *, const char *);
  const char *key() const;
protected:
  void resizeEvent(QResizeEvent *);
private:
  String *ky;
};

//////////

class ListBox : public QListBox
{
  Q_OBJECT
public:
  ListBox(QWidget *parent=3D0, const char *name=3D0, WFlags f=3D0);
  const char * key(int);
  const char * currentKey();
  void removeItem(int);
  void insertItem(const ListItem * li, int i=3D-1);
  void clear();
private:
  QList<const char *> *kix;
};

 #endif LISTITEM_H

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Content-Description: try1.cc
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/************************************************************************=
*****

        Priory database

        listitem.cc  Class file for listitem, which groups two labels
        together for use in a list box; one label is for use as a hidden
        key to some other table

*************************************************************************=
****/


 #include <qapp.h>
 #include <qlabel.h>
 #include "try1.h"

ListItem::ListItem(const char *k=3D0, const char *t=3D0)
        : QListBoxText(t)
{
  cerr << "ListItem::ListItem\n";
  ky =3D new String(k);
}


void ListItem::setKey(const char *k)
{
  delete ky;
  ky =3D new String(k);    =

}

const char * ListItem::key() const
{
  return (const char *) ky;
}

void ListItem::setValues(const char *k, const char *t)
{
  setText(t);
  setKey(k);
}

////////////

ListBox::ListBox(QWidget *parent, const char *name, WFlags f)
  : QListBox(parent, name, f)
{
  kix =3D new QList<const char *>();
}

const char * ListBox::key(int i)
{
  return *(kix->at(i));
}

const char * ListBox::currentKey()
{
  return key(currentItem());
}

void ListBox::insertItem(const ListItem *it, int ix)
{
  QListBox::insertItem(
                       it->text(),
                       ix);
  if (ix >=3D 0)
    {
      kix->insert((unsigned int) ix, (const char * const *)it->key());
    }
  else
    {
      kix->append((const char * const *)it->key());
    }
}

void ListBox::clear()
{
  QListBox::clear();
  kix->clear();
}

void ListBox::removeItem(int ix)
{
  QListBox::removeItem(ix);
  (void) kix->remove(ix);
}

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