QTextEdit drag and drop problem

[konradm]

I have one more question concerning this topic..I changed approach a little bit and i tried subclassing QTextEdit this way(The body of this functions is taken directly from drag-and-drop documentation of QTextEdit):

#ifndef TEXTEDITOR_H
#define TEXTEDITOR_H
#include <QtGui>
class TextEditor: public QTextEdit
{
Q_OBJECT
 
protected:
    bool canInsertFromMimeData( const QMimeData *source ) const;
    void insertFromMimeData( const QMimeData *source );
};
 
#endif // TEXTEDITOR_H

#ifndef TEXTEDITOR_H
#define TEXTEDITOR_H
#include <QtGui>
class TextEditor: public QTextEdit
{
Q_OBJECT

protected:
    bool canInsertFromMimeData( const QMimeData *source ) const;
    void insertFromMimeData( const QMimeData *source );
};

#endif // TEXTEDITOR_H

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Then I put my new widget- TextEditor, using QT Creator, to my project but unfotunatelly there's error when compiling it:

debug/mainwindow.o:mainwindow.cpp.text$_ZN13Ui_MainWindow7setupUiEP11QMainWindow[Ui_MainWindow::setupUi(QMainWindow*)]+0xcc0): undefined reference to `TextEditor::TextEditor(QWidget*)'

collect2: ld returned 1 exit status

Does anybody know why such error occurs and how to fix it?
Regards!