как я могу получить делегат для QTableWidget?

Проблема в получении делегатов в QTableWidget, я пытаюсь использовать два делегата (comboboxdelegate, spinbox делегат) для управления пользовательским вводом в QTableWidget с 2 столбцами и одной строкой, но после чтения страницы классов делегатов и просмотра SpinBox & Пример использования comboox: я подумал, что разобрался, как все работает, но явно нет.

(извините за мой английский), любая помощь приветствуется.

Код выглядит следующим образом.

файл notepad.h

#ifndef NOTEPAD_H
#define NOTEPAD_H
#include <QtGui>

class Notepad : public QMainWindow
{
Q_OBJECT

public:
//Notepad(QWidget *parent = 0, Qt::WFlags flags = 0);
Notepad();
void test();
QTableWidget* table ;
public slots:
void add();
void Delete();
void mouseReleaseEvent ( QMouseEvent * event );

private:
QAction *add_action;
QAction *Delete_action;

};

class SpinBoxDelegate : public QStyledItemDelegate,public Notepad
{
Q_OBJECT
public:
SpinBoxDelegate(QObject *parent = 0);
QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
const QModelIndex &index) /*const Q_DECL_OVERRIDE*/;

void setEditorData(QWidget *editor, const QModelIndex &index) /*const Q_DECL_OVERRIDE*/;
void setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) /*const Q_DECL_OVERRIDE*/;

void updateEditorGeometry(QWidget *editor,
const QStyleOptionViewItem &option, const QModelIndex &index) /*const Q_DECL_OVERRIDE*/;
};

class ComboBoxDelegate : public QStyledItemDelegate,public Notepad
{
Q_OBJECT

public:
ComboBoxDelegate(QObject *parent = 0);

QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
const QModelIndex &index) const;

void setEditorData(QWidget *editor, const QModelIndex &index) const;
void setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) const;

void updateEditorGeometry(QWidget *editor,
const QStyleOptionViewItem &option, const QModelIndex &index) const;
};

#endif // NOTEPAD_H

файл notepad.cpp

#include "notepad.h"#include <QMessageBox>
#include <QTableView>
#include <QMouseEvent>
#include <QSpinBox>
#include <QComboBox>
#include <QStandardItemModel>
Notepad::Notepad()
{
table = new QTableWidget();
test() ;
SpinBoxDelegate();
ComboBoxDelegate();
add_action = new QAction(tr("Add cell"), this);
add_action->setIcon(QIcon("add.jpg"));
Delete_action = new QAction(tr("Delete cell"), this);
Delete_action->setIcon(QIcon("delete.jpg"));

connect(Delete_action, SIGNAL(triggered()), this, SLOT(Delete()));
connect(add_action, SIGNAL(triggered()), this, SLOT(add()));

//tableItem->setFlags(tableItem->flags() ^ Qt::ItemIsEditable);

centralWidget()->setAttribute(Qt::WA_TransparentForMouseEvents);
centralWidget()->setAttribute(Qt::WA_MouseTracking,true);

setMouseTracking(true);

}
void Notepad::test()
{

QTableWidgetItem* tableItem = new QTableWidgetItem();

table->setRowCount(1);
table->setColumnCount(3);
table->setItem(0,0,new QTableWidgetItem());
table->setItem(0,1,new QTableWidgetItem());
table->setItem(0,2,new QTableWidgetItem());

table->setMouseTracking(true);
table->viewport()->setMouseTracking(true);
table->installEventFilter(this);
table->viewport()->installEventFilter(this);

table->setSelectionBehavior(QAbstractItemView::SelectRows);
table->setSelectionMode(QAbstractItemView::SingleSelection);

QStandardItemModel model((table->rowCount()),(table->columnCount()));
SpinBoxDelegate sdelegate;

ComboBoxDelegate comDel;
for (int row = 0; row < 4; ++row)
{
QWidget *parent;
QStyleOptionViewItem option;
for (int column = 0; column < 1; ++column)
{

table->setItemDelegateForColumn( column, &comDel);
QModelIndex index = model.index(row, column, QModelIndex());
model.setData(index, QVariant((row + 1) * (column + 1)));
}
for (int column = 1; column < 2; ++column)
{

table->setItemDelegateForColumn( column, &sdelegate  );
QModelIndex index = model.index(row, column, QModelIndex());
model.setData(index, QVariant((row + 1) * (column + 1)));
}
}table->setHorizontalHeaderItem(0, new QTableWidgetItem("combobox"));
table->setHorizontalHeaderItem(1, new QTableWidgetItem("spinbox"));
table->setHorizontalHeaderItem(2, new QTableWidgetItem("lineEdit"));
tableItem->setFlags(tableItem->flags() ^ Qt::ItemIsEditable);
table->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);
setCentralWidget(table);

}

void Notepad::mouseReleaseEvent (QMouseEvent * event )
{
QMessageBox* msgBox;
if(event->button() == Qt::RightButton)
{
QMouseEvent *mouseEvent = static_cast<QMouseEvent*> (event);
QMenu *menu = new QMenu(this);
menu->addAction(add_action);
menu->addAction(Delete_action);
menu->exec(mouseEvent->globalPos());
//msgBox->setInformativeText("u pressed right button");
}
}
void Notepad::add()
{

table->insertRow( 1);

setCentralWidget(table);
centralWidget()->setAttribute(Qt::WA_TransparentForMouseEvents);
setMouseTracking(true);
}
void Notepad::Delete()
{

table->removeRow(1);

setCentralWidget(table);
centralWidget()->setAttribute(Qt::WA_TransparentForMouseEvents);
setMouseTracking(true);
}SpinBoxDelegate::SpinBoxDelegate(QObject *parent)
: QStyledItemDelegate(parent)
{
}
QWidget *SpinBoxDelegate::createEditor(QWidget *parent,
const QStyleOptionViewItem &/* option */,
const QModelIndex &/* index */)/* const*/
{

QSpinBox *editor = new QSpinBox(parent);
editor->setFrame(false);
editor->setMinimum(0);
editor->setMaximum(100);
return editor;
}

void SpinBoxDelegate::setEditorData(QWidget *editor,
const QModelIndex &index) /*const*/
{
int value = index.model()->data(index, Qt::EditRole).toInt();
QSpinBox *spinBox = static_cast<QSpinBox*>(editor);
spinBox->setValue(value);
}

void SpinBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) /*const*/
{
QSpinBox *spinBox = static_cast<QSpinBox*>(editor);
spinBox->interpretText();
int value = spinBox->value();
model->setData(index, value, Qt::EditRole);
}

void SpinBoxDelegate::updateEditorGeometry(QWidget *editor,
const QStyleOptionViewItem &option, const QModelIndex &/* index */) /*const*/
{
editor->setGeometry(option.rect);
}

ComboBoxDelegate::ComboBoxDelegate(QObject *parent)
: QStyledItemDelegate(parent)
{
}

QWidget *ComboBoxDelegate::createEditor(QWidget *parent,
const QStyleOptionViewItem &/* option */,
const QModelIndex &/* index */) const
{
QComboBox *editor = new QComboBox(parent);
QStringList list ;
list << "srikanth" << "dilip";
editor->addItems(list);
//editor->installEventFilter(const_cast<ComboBoxDelegate*>(this));

return editor;
}

void ComboBoxDelegate::setEditorData(QWidget *editor,
const QModelIndex &index) const
{
QString value = index.model()->data(index, Qt::DisplayRole).toString();

QComboBox *comboBox = static_cast<QComboBox*>(editor);
comboBox->addItem(value);
}

void ComboBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) const
{
QComboBox *comboBox = static_cast<QComboBox*>(editor);
QString value = comboBox->currentText();

model->setData(index, value);
}

void ComboBoxDelegate::updateEditorGeometry(QWidget *editor,
const QStyleOptionViewItem &option, const QModelIndex &/* index */) const
{
editor->setGeometry(option.rect);
}

файл main.cpp

#include <QtGui>
#include <notepad.h>
int main(int argv, char **args)  {
QApplication app(argv, args);

Notepad notepad;

notepad.show();

return app.exec();
}