Qt: subclassing QStyledDelegate problems

[marinamarina]

I'm subclassing QStyledItemDelegate to give my table a custom editor widget. Triplet is the class whose instances I'm keeping in the table. There are several problems.

1. By far the most interesting one is in table_editor.cpp where I'm connecting signals. The second signal I'm connecting comes from a Cancel button and it connects with QDialogButtonBox's reject slot, which does exist, according to the docs, but not according to my compiler! I'm using Qt Creator 3.2.0.

2. When I click on a table cell, the editor appears as a separate dialog (what I want), but outside the main window, in the top left corner. Its position seems to mimic the QModelIndex: if I click a cell in the third column, the editor appears more to the right.

Should I just drop the delegate and and go for setting up my table model so that its signal triggers the editor into being as a normal popup dialog when the cell is clicked?

3. My editor doesn't seem to be changing the data in the actual table. I choose the values, click Ok and the editor closes, but the data in the cell is still the same.

Here it all is:

the delegate:

table_delegate.h:
@

#include <QStyledItemDelegate>

class table_delegate : public QStyledItemDelegate
{
Q_OBJECT

public:
table_delegate(QWidget *parent);

void paint(QPainter *painter, const QStyleOptionViewItem &option,
           const QModelIndex &index) const;
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;

private slots:
void commitAndCloseEditor();
};

@

table_delegate.cpp:
@#include "table_delegate.h"
#include "table_editor.h"
#include "triplet.h"
#include "table_model.h"
#include <QPainter>

table_delegate::table_delegate(QWidget *parent):QStyledItemDelegate(parent)
{

}

void table_delegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
const QModelIndex &index) const
{
if (index.data().canConvert<triplet>()) {
triplet t = qvariant_cast<triplet>(index.data());

    painter->drawText(option.rect, t.showTriplet());
}

}

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

{
if (index.data().canConvert<triplet>()) {
table_editor *editor = new table_editor(parent);
editor->setGeometry(200, 200, 200, 200);
editor->n_state->addItems(table_model::get_state());
editor->n_symbol->addItems(table_model::get_symbols());
editor->move->addItems(table_model::get_move_options());

    connect(editor, SIGNAL(editingFinished()),
            this, SLOT(commitAndCloseEditor()));
    return editor;
} else {
    return QStyledItemDelegate::createEditor(parent, option, index);
}

}

void table_delegate::setEditorData(QWidget *editor,
const QModelIndex &index) const
{
if (index.data().canConvert<triplet>()) {
triplet t = qvariant_cast<triplet>(index.data());
table_editor *edit = qobject_cast<table_editor *>(editor);
edit->setTriplet(t);
} else {
QStyledItemDelegate::setEditorData(editor, index);
}
}

void table_delegate::setModelData(QWidget *editor, QAbstractItemModel *model,
const QModelIndex &index) const
{
if (index.data().canConvert<triplet>()) {
table_editor *edit = qobject_cast<table_editor *>(editor);
model->setData(index, QVariant::fromValue(edit->getTriplet()));
} else {
QStyledItemDelegate::setModelData(editor, model, index);
}
}

void table_delegate::commitAndCloseEditor()
{
table_editor *editor = qobject_cast<table_editor *>(sender());
emit commitData(editor);
emit closeEditor(editor);
}
@
the editor

table_editor.h:
@
#include <QPushButton>
#include <QGroupBox>
#include "triplet.h"

class table_editor: public QWidget
{
Q_OBJECT

    public:
        table_editor(QWidget *parent);
        QMap<QString, signed int> shifts;
        QComboBox* n_state;
        QComboBox* n_symbol;
        QComboBox* move;
        void setTriplet(triplet a);
        triplet getTriplet();

    signals:
        void editingFinished();

    protected:
        void paintEvent(QPaintEvent* e) {
            QWidget::paintEvent(e);
        }

    private:
        triplet t;
    };

@
table_editor.cpp:
@
#include "table_editor.h"
#include "table_model.h"
#include "fshema_widget.h"
#include <QFormLayout>
#include <QGroupBox>
#include <QDialogButtonBox>
#include <QLineEdit>
#include <QLabel>

table_editor::table_editor(QWidget *parent)
{

QFormLayout *layout = new QFormLayout();
n_state=new QComboBox();
n_symbol=new QComboBox();
move = new QComboBox();
layout->addRow(new QLabel("Iduće stanje: "), n_state);
layout->addRow(new QLabel("Izlazni simbol: "), n_symbol);
layout->addRow(new QLabel("Pomak: "), move);

QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok
                                 | QDialogButtonBox::Cancel);



layout->addRow(buttonBox);
this->setLayout(layout);

t.nextState=n_state->currentText().toInt();
t.nextSymbol=n_symbol->currentText();
t.shift=shifts.value(move->currentText());

connect(buttonBox, SIGNAL(accepted()), this, SIGNAL(editingFinished()));
connect(buttonBox, SIGNAL(rejected()), buttonBox, SLOT(reject()));

}

void table_editor::setTriplet(triplet a)
{
t.nextState=a.nextState;
t.nextSymbol=a.nextSymbol;
t.shift=a.shift;
}

triplet table_editor::getTriplet()
{
return t;
}
@