Qt 4.3: main.cpp Example File (demos/spreadsheet/main.cpp)

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# main.cpp Example File
demos/spreadsheet/main.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2004-2007 Trolltech ASA. All rights reserved.
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** This file may be used under the terms of the GNU General Public
     ** License version 2.0 as published by the Free Software Foundation
     ** and appearing in the file LICENSE.GPL included in the packaging of
     ** this file.  Please review the following information to ensure GNU
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     **
     ** If you are unsure which license is appropriate for your use, please
     ** review the following information:
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     ** or contact the sales department at sales@trolltech.com.
     **
     ** In addition, as a special exception, Trolltech gives you certain
     ** additional rights. These rights are described in the Trolltech GPL
     ** Exception version 1.0, which can be found at
     ** http://www.trolltech.com/products/qt/gplexception/ and in the file
     ** GPL_EXCEPTION.txt in this package.
     **
     ** In addition, as a special exception, Trolltech, as the sole copyright
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     ** Trolltech reserves all rights not expressly granted herein.
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     ****************************************************************************/

     #include <QtGui>

     static QString encode_pos(int row, int col) {
         return QString(col + 'A') + QString::number(row + 1);
     }

     static void decode_pos(const QString &pos, int *row, int *col)
     {
         if (pos.isEmpty()) {
             *col = -1;
             *row = -1;
         } else {
             *col = pos.at(0).toLatin1() - 'A';
             *row = pos.right(pos.size() - 1).toInt() - 1;
         }
     }

     class SpreadSheetDelegate : public QItemDelegate
     {
         Q_OBJECT
     public:
         SpreadSheetDelegate(QObject *parent = 0);
         QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &,
             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();
     };

     SpreadSheetDelegate::SpreadSheetDelegate(QObject *parent)
         : QItemDelegate(parent) {}

     QWidget *SpreadSheetDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem&,
         const QModelIndex &index) const
     {
         if(index.column() == 1){
             QDateTimeEdit *editor = new QDateTimeEdit(parent);
             editor->setDisplayFormat("dd/M/yyyy");
             editor->setCalendarPopup(true);
             return editor;
         }
         QLineEdit *editor = new QLineEdit(parent);
         //create a completer with the strings in the column as model.
         QStringList allStrings;
         for(int i = 1; i<index.model()->rowCount(); i++){
             QString strItem(index.model()->data(index.sibling(i, index.column()), Qt::EditRole).toString());
             if(!allStrings.contains(strItem))
                 allStrings.append(strItem);
         }
         QCompleter *autoComplete = new QCompleter(allStrings);
         editor->setCompleter(autoComplete);
         connect(editor, SIGNAL(editingFinished()), this, SLOT(commitAndCloseEditor()));
         return editor;
     }

     void SpreadSheetDelegate::commitAndCloseEditor()
     {
         QLineEdit *editor = qobject_cast<QLineEdit *>(sender());
         emit commitData(editor);
         emit closeEditor(editor);
     }

     void SpreadSheetDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
     {
         QLineEdit *edit = qobject_cast<QLineEdit *>(editor);
         if (edit) {
             edit->setText(index.model()->data(index, Qt::EditRole).toString());
         }
         else {
             QDateTimeEdit *dateEditor = qobject_cast<QDateTimeEdit *>(editor);
             if (dateEditor) {
                 dateEditor->setDate(QDate::fromString(index.model()->data(index, Qt::EditRole).toString(), "d/M/yyyy"));
             }
         }
     }

     void SpreadSheetDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
         const QModelIndex &index) const
     {
         QLineEdit *edit = qobject_cast<QLineEdit *>(editor);
         if (edit) {
             model->setData(index, edit->text());
         }
         else {
             QDateTimeEdit *dateEditor = qobject_cast<QDateTimeEdit *>(editor);
             if (dateEditor) {
                 model->setData(index, dateEditor->date().toString("dd/M/yyyy"));
             }
         }
     }

     class SpreadSheetItem : public QTableWidgetItem
     {
     public:
         SpreadSheetItem();
         SpreadSheetItem(const QString &text);

         QTableWidgetItem *clone() const;

         QVariant data(int role) const;
         void setData(int role, const QVariant &value);
         QVariant display() const;

         inline QString formula() const
             { return QTableWidgetItem::data(Qt::DisplayRole).toString(); }

         static QVariant computeFormula(const QString &formula,
                                        const QTableWidget *widget,
                                        const QTableWidgetItem *self = 0);

     private:
         mutable bool isResolving;
     };

     SpreadSheetItem::SpreadSheetItem()
         : QTableWidgetItem(), isResolving(false) {}

     SpreadSheetItem::SpreadSheetItem(const QString &text)
         : QTableWidgetItem(text), isResolving(false) {}

     QTableWidgetItem *SpreadSheetItem::clone() const
     {
         SpreadSheetItem *item = new SpreadSheetItem();
         *item = *this;
         return item;
     }

     QVariant SpreadSheetItem::data(int role) const
     {
         if (role == Qt::EditRole || role == Qt::StatusTipRole)
             return formula();

         if (role == Qt::DisplayRole)
             return display();

         QString t = display().toString();
         bool isNumber = false;
         int number = t.toInt(&isNumber);

         if (role == Qt::TextColorRole) {
             if (!isNumber)
                 return qVariantFromValue(QColor(Qt::black));
             else if (number < 0)
                 return qVariantFromValue(QColor(Qt::red));
             return qVariantFromValue(QColor(Qt::blue));
         }

         if (role == Qt::TextAlignmentRole)
             if (!t.isEmpty() && (t.at(0).isNumber() || t.at(0) == '-'))
                 return (int)(Qt::AlignRight | Qt::AlignVCenter);

         return QTableWidgetItem::data(role);
     }

     void SpreadSheetItem::setData(int role, const QVariant &value)
     {
         QTableWidgetItem::setData(role, value);
         if (tableWidget())
             tableWidget()->viewport()->update();
     }

     QVariant SpreadSheetItem::display() const
     {
         // avoid circular dependencies
         if (isResolving)
             return QVariant();
         isResolving = true;
         QVariant result = computeFormula(formula(), tableWidget(), this);
         isResolving = false;
         return result;
     }

     QVariant SpreadSheetItem::computeFormula(const QString &formula,
                                              const QTableWidget *widget,
                                              const QTableWidgetItem *self)
     {
         // check if the string is actually a formula or not
         QStringList list = formula.split(' ');
         if (list.isEmpty() || !widget)
             return formula; // its a normal string

         QString op = list.value(0).toLower();

         int firstRow = -1;
         int firstCol = -1;
         int secondRow = -1;
         int secondCol = -1;

         if (list.count() > 1)
             decode_pos(list.value(1), &firstRow, &firstCol);
         if (list.count() > 2)
             decode_pos(list.value(2), &secondRow, &secondCol);

         const QTableWidgetItem *start = widget->item(firstRow, firstCol);
         const QTableWidgetItem *end = widget->item(secondRow, secondCol);

         int firstVal = start ? start->text().toInt() : 0;
         int secondVal = end ? end->text().toInt() : 0;

         QVariant result;
         if (op == "sum") {
             int sum = 0;
             for (int r = firstRow; r <= secondRow; ++r) {
                 for (int c = firstCol; c <= secondCol; ++c) {
                     const QTableWidgetItem *tableItem = widget->item(r, c);
                     if (tableItem && tableItem != self)
                         sum += tableItem->text().toInt();
                 }
             }
             result = sum;
         } else if (op == "+") {
             result = (firstVal + secondVal);
         } else if (op == "-") {
             result = (firstVal - secondVal);
         } else if (op == "*") {
             result = (firstVal * secondVal);
         } else if (op == "/") {
             if (secondVal == 0)
                 result = QString("nan");
             else
                 result = (firstVal / secondVal);
         } else if (op == "=") {
             if (start)
             result = start->text();
         } else {
             result = formula;
         }

         return result;
     }

     #if !defined(QT_NO_DBUS) && defined(Q_OS_UNIX)
     #include <QtDBus/QtDBus>

     class SpreadSheetAdaptor : public QDBusAbstractAdaptor
     {
         Q_OBJECT
         Q_CLASSINFO("D-Bus Interface", "com.trolltech.DBus.SpreadSheetDemo")

     public:
         SpreadSheetAdaptor(QTableWidget *table) : QDBusAbstractAdaptor(table), table(table)
         { QDBusConnection::sessionBus().registerObject("/SpreadSheetDemo", table); }

     public slots:
         QString computeFormula(const QString &formula)
         { return SpreadSheetItem::computeFormula(formula, table).toString(); }
     private:
         QTableWidget *table;
     };
     #endif // QT_NO_DBUS

     class SpreadSheet : public QMainWindow
     {
         Q_OBJECT
     public:
         SpreadSheet(int rows, int cols, QWidget *parent = 0);

     public slots:
         void updateStatus(QTableWidgetItem *item);
         void updateColor(QTableWidgetItem *item);
         void updateLineEdit(QTableWidgetItem *item);
         void returnPressed();
         void selectColor();
         void selectFont();
         void clear();
         void showAbout();

         void actionSum();
         void actionSubtract();
         void actionAdd();
         void actionMultiply();
         void actionDivide();

     protected:
         void setupContextMenu();
         void setupContents();

         void setupMenuBar();
         void createActions();

         void actionMath_helper(const QString &title, const QString &op);
         bool runInputDialog(const QString &title,
                             const QString &c1Text,
                             const QString &c2Text,
                             const QString &opText,
                             const QString &outText,
                             QString *cell1, QString *cell2, QString *outCell);

     private:
         QToolBar *toolBar;
         QAction *colorAction;
         QAction *fontAction;
         QAction *firstSeparator;
         QAction *cell_sumAction;
         QAction *cell_addAction;
         QAction *cell_subAction;
         QAction *cell_mulAction;
         QAction *cell_divAction;
         QAction *secondSeparator;
         QAction *clearAction;
         QAction *aboutSpreadSheet;
         QAction *exitAction;

         QLabel *cellLabel;
         QTableWidget *table;
         QLineEdit *formulaInput;
     };

     SpreadSheet::SpreadSheet(int rows, int cols, QWidget *parent)
         : QMainWindow(parent)
     {
         addToolBar(toolBar = new QToolBar());
         formulaInput = new QLineEdit();

         cellLabel = new QLabel(toolBar);
         cellLabel->setMinimumSize(80, 0);

         toolBar->addWidget(cellLabel);
         toolBar->addWidget(formulaInput);

         table = new QTableWidget(rows, cols, this);
         for (int c = 0; c < cols; ++c) {
             QString character(QChar('A' + c));
             table->setHorizontalHeaderItem(c, new QTableWidgetItem(character));
         }
         table->setItemPrototype(table->item(rows - 1, cols - 1));
         table->setItemDelegate(new SpreadSheetDelegate());
     #if !defined(QT_NO_DBUS) && defined(Q_OS_UNIX)
         new SpreadSheetAdaptor(table);
     #endif
         createActions();

         updateColor(0);
         setupMenuBar();
         setupContextMenu();
         setupContents();
         setCentralWidget(table);

         statusBar();
         connect(table, SIGNAL(currentItemChanged(QTableWidgetItem*, QTableWidgetItem*)),
                 this, SLOT(updateStatus(QTableWidgetItem*)));
         connect(table, SIGNAL(currentItemChanged(QTableWidgetItem*, QTableWidgetItem*)),
                 this, SLOT(updateColor(QTableWidgetItem*)));
         connect(table, SIGNAL(currentItemChanged(QTableWidgetItem*, QTableWidgetItem*)),
                 this, SLOT(updateLineEdit(QTableWidgetItem*)));
         connect(table, SIGNAL(itemChanged(QTableWidgetItem*)),
                 this, SLOT(updateStatus(QTableWidgetItem*)));
         connect(formulaInput, SIGNAL(returnPressed()), this, SLOT(returnPressed()));
         connect(table, SIGNAL(itemChanged(QTableWidgetItem*)),
                 this, SLOT(updateLineEdit(QTableWidgetItem*)));
         setWindowTitle(tr("Spreadsheet"));
     }

     void SpreadSheet::createActions()
     {
         cell_sumAction = new QAction(tr("Sum"), this);
         connect(cell_sumAction, SIGNAL(triggered()), this, SLOT(actionSum()));

         cell_addAction = new QAction(tr("&Add"), this);
         cell_addAction->setShortcut(Qt::CTRL | Qt::Key_Plus);
         connect(cell_addAction, SIGNAL(triggered()), this, SLOT(actionAdd()));

         cell_subAction = new QAction(tr("&Subtract"), this);
         cell_subAction->setShortcut(Qt::CTRL | Qt::Key_Minus);
         connect(cell_subAction, SIGNAL(triggered()), this, SLOT(actionSubtract()));

         cell_mulAction = new QAction(tr("&Multiply"), this);
         cell_mulAction->setShortcut(Qt::CTRL | Qt::Key_multiply);
         connect(cell_mulAction, SIGNAL(triggered()), this, SLOT(actionMultiply()));

         cell_divAction = new QAction(tr("&Divide"), this);
         cell_divAction->setShortcut(Qt::CTRL | Qt::Key_division);
         connect(cell_divAction, SIGNAL(triggered()), this, SLOT(actionDivide()));

         fontAction = new QAction(tr("Font..."), this);
         fontAction->setShortcut(Qt::CTRL|Qt::Key_F);
         connect(fontAction, SIGNAL(triggered()), this, SLOT(selectFont()));

         colorAction = new QAction(QPixmap(16, 16), tr("Background &Color..."), this);
         connect(colorAction, SIGNAL(triggered()), this, SLOT(selectColor()));

         clearAction = new QAction(tr("Clear"), this);
         clearAction->setShortcut(Qt::Key_Delete);
         connect(clearAction, SIGNAL(triggered()), this, SLOT(clear()));

         aboutSpreadSheet = new QAction(tr("About Spreadsheet"), this);
         connect(aboutSpreadSheet, SIGNAL(triggered()), this, SLOT(showAbout()));

         exitAction = new QAction(tr("E&xit"), this);
         connect(exitAction, SIGNAL(triggered()), qApp, SLOT(quit()));

         firstSeparator = new QAction(this);
         firstSeparator->setSeparator(true);

         secondSeparator = new QAction(this);
         secondSeparator->setSeparator(true);

     }

     void SpreadSheet::setupMenuBar()
     {
         QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
         fileMenu->addAction(exitAction);

         QMenu *cellMenu = menuBar()->addMenu(tr("&Cell"));
         cellMenu->addAction(cell_addAction);
         cellMenu->addAction(cell_subAction);
         cellMenu->addAction(cell_mulAction);
         cellMenu->addAction(cell_divAction);
         cellMenu->addAction(cell_sumAction);
         cellMenu->addSeparator();
         cellMenu->addAction(colorAction);
         cellMenu->addAction(fontAction);

         menuBar()->addSeparator();

         QMenu *aboutMenu = menuBar()->addMenu(tr("&Help"));
         aboutMenu->addAction(aboutSpreadSheet);
     }

     void SpreadSheet::updateStatus(QTableWidgetItem *item)
     {
         if (item && item == table->currentItem()) {
             statusBar()->showMessage(item->data(Qt::StatusTipRole).toString(), 1000);
             cellLabel->setText("Cell: (" + encode_pos(table->row(item), table->column(item)) + ")");
         }
     }

     void SpreadSheet::updateColor(QTableWidgetItem *item)
     {
         QPixmap pix(16, 16);
         QColor col;
         if (item)
             col = item->backgroundColor();
         if (!col.isValid())
             col = palette().base().color();

         QPainter pt(&pix);
         pt.fillRect(0, 0, 16, 16, col);

         QColor lighter = col.light();
         pt.setPen(lighter);
         QPoint lightFrame[] = { QPoint(0, 15), QPoint(0, 0), QPoint(15, 0) };
         pt.drawPolyline(lightFrame, 3);

         pt.setPen(col.dark());
         QPoint darkFrame[] = { QPoint(1, 15), QPoint(15, 15), QPoint(15, 1) };
         pt.drawPolyline(darkFrame, 3);

         pt.end();

         colorAction->setIcon(pix);
     }

     void SpreadSheet::updateLineEdit(QTableWidgetItem *item)
     {
         if (item != table->currentItem())
             return;
         if (item)
             formulaInput->setText(item->data(Qt::EditRole).toString());
         else
             formulaInput->clear();
     }

     void SpreadSheet::returnPressed()
     {
         QString text = formulaInput->text();
         int row = table->currentRow();
         int col = table->currentColumn();
         QTableWidgetItem *item = table->item(row, col);
         if (!item)
             table->setItem(row, col, new SpreadSheetItem(text));
         else
             item->setData(Qt::EditRole, text);
         table->viewport()->update();
     }

     void SpreadSheet::selectColor()
     {
         QTableWidgetItem *item = table->currentItem();
         QColor col = item ? item->backgroundColor() : table->palette().base().color();
         col = QColorDialog::getColor(col, this);
         if (!col.isValid())
             return;

         QList<QTableWidgetItem*> selected = table->selectedItems();
         if (selected.count() == 0)
             return;

         foreach(QTableWidgetItem *i, selected)
             if (i) i->setBackgroundColor(col);

         updateColor(table->currentItem());
     }

     void SpreadSheet::selectFont()
     {
         QList<QTableWidgetItem*> selected = table->selectedItems();
         if (selected.count() == 0)
             return;
         bool ok = false;
         QFont fnt = QFontDialog::getFont(&ok, font(), this);
         if (!ok)
             return;
         foreach(QTableWidgetItem *i, selected)
             if (i) i->setFont(fnt);
     }

     bool SpreadSheet::runInputDialog(const QString &title,
                                      const QString &c1Text,
                                      const QString &c2Text,
                                      const QString &opText,
                                      const QString &outText,
                                      QString *cell1, QString *cell2, QString *outCell)
     {

         QStringList rows, cols;
         for (int c = 0; c < table->columnCount(); ++c)
             cols << QChar('A' + c);
         for (int r = 0; r < table->rowCount(); ++r)
             rows << QString::number(1 + r);

         QDialog addDialog(this);
         addDialog.setWindowTitle(title);

         QGroupBox group(title, &addDialog);
         group.setMinimumSize(250, 100);

         QLabel cell1Label(c1Text, &group);
         QComboBox cell1RowInput(&group);
         int c1Row, c1Col;
         decode_pos(*cell1, &c1Row, &c1Col);
         cell1RowInput.addItems(rows);
         cell1RowInput.setCurrentIndex(c1Row);
         QComboBox cell1ColInput(&group);
         cell1ColInput.addItems(cols);
         cell1ColInput.setCurrentIndex(c1Col);

         QLabel operatorLabel(opText, &group);
         operatorLabel.setAlignment(Qt::AlignHCenter);

         QLabel cell2Label(c2Text, &group);
         QComboBox cell2RowInput(&group);
         int c2Row, c2Col;
         decode_pos(*cell2, &c2Row, &c2Col);
         cell2RowInput.addItems(rows);
         cell2RowInput.setCurrentIndex(c2Row);
         QComboBox cell2ColInput(&group);
         cell2ColInput.addItems(cols);
         cell2ColInput.setCurrentIndex(c2Col);

         QLabel equalsLabel("=", &group);
         equalsLabel.setAlignment(Qt::AlignHCenter);

         QLabel outLabel(outText, &group);
         QComboBox outRowInput(&group);
         int outRow, outCol;
         decode_pos(*outCell, &outRow, &outCol);
         outRowInput.addItems(rows);
         outRowInput.setCurrentIndex(outRow);
         QComboBox outColInput(&group);
         outColInput.addItems(cols);
         outColInput.setCurrentIndex(outCol);

         QPushButton cancelButton(tr("Cancel"), &addDialog);
         connect(&cancelButton, SIGNAL(clicked()), &addDialog, SLOT(reject()));

         QPushButton okButton(tr("OK"), &addDialog);
         okButton.setDefault(true);
         connect(&okButton, SIGNAL(clicked()), &addDialog, SLOT(accept()));

         QHBoxLayout *buttonsLayout = new QHBoxLayout;
         buttonsLayout->addStretch(1);
         buttonsLayout->addWidget(&okButton);
         buttonsLayout->addSpacing(10);
         buttonsLayout->addWidget(&cancelButton);

         QVBoxLayout *dialogLayout = new QVBoxLayout(&addDialog);
         dialogLayout->addWidget(&group);
         dialogLayout->addStretch(1);
         dialogLayout->addItem(buttonsLayout);

         QHBoxLayout *cell1Layout = new QHBoxLayout;
         cell1Layout->addWidget(&cell1Label);
         cell1Layout->addSpacing(10);
         cell1Layout->addWidget(&cell1ColInput);
         cell1Layout->addSpacing(10);
         cell1Layout->addWidget(&cell1RowInput);

         QHBoxLayout *cell2Layout = new QHBoxLayout;
         cell2Layout->addWidget(&cell2Label);
         cell2Layout->addSpacing(10);
         cell2Layout->addWidget(&cell2ColInput);
         cell2Layout->addSpacing(10);
         cell2Layout->addWidget(&cell2RowInput);

         QHBoxLayout *outLayout = new QHBoxLayout;
         outLayout->addWidget(&outLabel);
         outLayout->addSpacing(10);
         outLayout->addWidget(&outColInput);
         outLayout->addSpacing(10);
         outLayout->addWidget(&outRowInput);

         QVBoxLayout *vLayout = new QVBoxLayout(&group);
         vLayout->addItem(cell1Layout);
         vLayout->addWidget(&operatorLabel);
         vLayout->addItem(cell2Layout);
         vLayout->addWidget(&equalsLabel);
         vLayout->addStretch(1);
         vLayout->addItem(outLayout);

         if (addDialog.exec()) {
             *cell1 = cell1ColInput.currentText() + cell1RowInput.currentText();
             *cell2 = cell2ColInput.currentText() + cell2RowInput.currentText();
             *outCell = outColInput.currentText() + outRowInput.currentText();
             return true;
         }

         return false;
     }

     void SpreadSheet::actionSum()
     {

         int row_first = 0;
         int row_last = 0;
         int row_cur = 0;

         int col_first = 0;
         int col_last = 0;
         int col_cur = 0;

         QList<QTableWidgetItem*> selected = table->selectedItems();
         if (!selected.isEmpty()) {
             QTableWidgetItem *first = selected.first();
             QTableWidgetItem *last = selected.last();
             row_first = table->row(first);
             row_last = table->row(last);
             col_first = table->column(first);
             col_last = table->column(last);
         }

         QTableWidgetItem *current = table->currentItem();
         if (current) {
             row_cur = table->row(current);
             col_cur = table->column(current);
         }

         QString cell1 = encode_pos(row_first, col_first);
         QString cell2 = encode_pos(row_last, col_last);
         QString out = encode_pos(row_cur, col_cur);

         if (runInputDialog(tr("Sum cells"), tr("First cell:"), tr("Last cell:"),
                            QString("%1").arg(QChar(0x03a3)), tr("Output to:"),
                            &cell1, &cell2, &out)) {
             int row, col;
             decode_pos(out, &row, &col);
             table->item(row, col)->setText("sum " + cell1 + " " + cell2);
         }
     }

     void SpreadSheet::actionMath_helper(const QString &title, const QString &op)
     {
         QString cell1 = "C1";
         QString cell2 = "C2";
         QString out = "C3";

         QTableWidgetItem *current = table->currentItem();
         if (current)
             out = encode_pos(table->currentRow(), table->currentColumn());

         if (runInputDialog(title, tr("Cell 1"), tr("Cell 2"), op, tr("Output to:"),
                            &cell1, &cell2, &out)) {
             int row, col;
             decode_pos(out, &row, &col);
             table->item(row, col)->setText(op + " " + cell1 + " " + cell2);
         }
     }

     void SpreadSheet::actionAdd()
     {
         actionMath_helper(tr("Addition"), "+");
     }

     void SpreadSheet::actionSubtract()
     {
         actionMath_helper(tr("Subtraction"), "-");
     }

     void SpreadSheet::actionMultiply()
     {
         actionMath_helper(tr("Multiplication"), "*");
     }

     void SpreadSheet::actionDivide()
     {
         actionMath_helper(tr("Division"), "/");
     }

     void SpreadSheet::clear()
     {
         foreach (QTableWidgetItem *i, table->selectedItems())
             i->setText("");
     }

     void SpreadSheet::setupContextMenu()
     {
         addAction(cell_addAction);
         addAction(cell_subAction);
         addAction(cell_mulAction);
         addAction(cell_divAction);
         addAction(cell_sumAction);
         addAction(firstSeparator);
         addAction(colorAction);
         addAction(fontAction);
         addAction(secondSeparator);
         addAction(clearAction);
         setContextMenuPolicy(Qt::ActionsContextMenu);
     }

     void SpreadSheet::setupContents()
     {
         QColor titleBackground(Qt::lightGray);
         QFont titleFont = table->font();
         titleFont.setBold(true);

         // column 0
         table->setItem(0, 0, new SpreadSheetItem("Item"));
         table->item(0, 0)->setBackgroundColor(titleBackground);
         table->item(0, 0)->setToolTip("This column shows the purchased item/service");
         table->item(0, 0)->setFont(titleFont);
         table->setItem(1, 0, new SpreadSheetItem("AirportBus"));
         table->setItem(2, 0, new SpreadSheetItem("Flight (Munich)"));
         table->setItem(3, 0, new SpreadSheetItem("Lunch"));
         table->setItem(4, 0, new SpreadSheetItem("Flight (LA)"));
         table->setItem(5, 0, new SpreadSheetItem("Taxi"));
         table->setItem(6, 0, new SpreadSheetItem("Dinner"));
         table->setItem(7, 0, new SpreadSheetItem("Hotel"));
         table->setItem(8, 0, new SpreadSheetItem("Flight (Oslo)"));
         table->setItem(9, 0, new SpreadSheetItem("Total:"));
         table->item(9, 0)->setFont(titleFont);
         table->item(9,0)->setBackgroundColor(Qt::lightGray);
         // column 1
         table->setItem(0, 1, new SpreadSheetItem("Date"));
         table->item(0, 1)->setBackgroundColor(titleBackground);
         table->item(0, 1)->setToolTip("This column shows the purchase date, double click to change");
         table->item(0, 1)->setFont(titleFont);
         table->setItem(1, 1, new SpreadSheetItem("15/6/2006"));
         table->setItem(2, 1, new SpreadSheetItem("15/6/2006"));
         table->setItem(3, 1, new SpreadSheetItem("15/6/2006"));
         table->setItem(4, 1, new SpreadSheetItem("21/5/2006"));
         table->setItem(5, 1, new SpreadSheetItem("16/6/2006"));
         table->setItem(6, 1, new SpreadSheetItem("16/6/2006"));
         table->setItem(7, 1, new SpreadSheetItem("16/6/2006"));
         table->setItem(8, 1, new SpreadSheetItem("18/6/2006"));
         table->setItem(9, 1, new SpreadSheetItem());
         table->item(9,1)->setBackgroundColor(Qt::lightGray);
         // column 2
         table->setItem(0, 2, new SpreadSheetItem("Price"));
         table->item(0, 2)->setBackgroundColor(titleBackground);
         table->item(0, 2)->setToolTip("This column shows the price of the purchase");
         table->item(0, 2)->setFont(titleFont);
         table->setItem(1, 2, new SpreadSheetItem("150"));
         table->setItem(2, 2, new SpreadSheetItem("2350"));
         table->setItem(3, 2, new SpreadSheetItem("-14"));
         table->setItem(4, 2, new SpreadSheetItem("980"));
         table->setItem(5, 2, new SpreadSheetItem("5"));
         table->setItem(6, 2, new SpreadSheetItem("120"));
         table->setItem(7, 2, new SpreadSheetItem("300"));
         table->setItem(8, 2, new SpreadSheetItem("1240"));
         table->setItem(9, 2, new SpreadSheetItem());
         table->item(9,2)->setBackgroundColor(Qt::lightGray);
         // column 3
         table->setItem(0, 3, new SpreadSheetItem("Currency"));
         table->item(0, 3)->setBackgroundColor(titleBackground);
         table->item(0, 3)->setToolTip("This column shows the currency");
         table->item(0, 3)->setFont(titleFont);
         table->setItem(1, 3, new SpreadSheetItem("NOK"));
         table->setItem(2, 3, new SpreadSheetItem("NOK"));
         table->setItem(3, 3, new SpreadSheetItem("EUR"));
         table->setItem(4, 3, new SpreadSheetItem("EUR"));
         table->setItem(5, 3, new SpreadSheetItem("USD"));
         table->setItem(6, 3, new SpreadSheetItem("USD"));
         table->setItem(7, 3, new SpreadSheetItem("USD"));
         table->setItem(8, 3, new SpreadSheetItem("USD"));
         table->setItem(9, 3, new SpreadSheetItem());
         table->item(9,3)->setBackgroundColor(Qt::lightGray);
         // column 4
         table->setItem(0, 4, new SpreadSheetItem("Ex.Rate"));
         table->item(0, 4)->setBackgroundColor(titleBackground);
         table->item(0, 4)->setToolTip("This column shows the exchange rate to NOK");
         table->item(0, 4)->setFont(titleFont);
         table->setItem(1, 4, new SpreadSheetItem("1"));
         table->setItem(2, 4, new SpreadSheetItem("1"));
         table->setItem(3, 4, new SpreadSheetItem("8"));
         table->setItem(4, 4, new SpreadSheetItem("8"));
         table->setItem(5, 4, new SpreadSheetItem("7"));
         table->setItem(6, 4, new SpreadSheetItem("7"));
         table->setItem(7, 4, new SpreadSheetItem("7"));
         table->setItem(8, 4, new SpreadSheetItem("7"));
         table->setItem(9, 4, new SpreadSheetItem());
         table->item(9,4)->setBackgroundColor(Qt::lightGray);
         // column 5
         table->setItem(0, 5, new SpreadSheetItem("NOK"));
         table->item(0, 5)->setBackgroundColor(titleBackground);
         table->item(0, 5)->setToolTip("This column shows the expenses in NOK");
         table->item(0, 5)->setFont(titleFont);
         table->setItem(1, 5, new SpreadSheetItem("* C2 E2"));
         table->setItem(2, 5, new SpreadSheetItem("* C3 E3"));
         table->setItem(3, 5, new SpreadSheetItem("* C4 E4"));
         table->setItem(4, 5, new SpreadSheetItem("* C5 E5"));
         table->setItem(5, 5, new SpreadSheetItem("* C6 E6"));
         table->setItem(6, 5, new SpreadSheetItem("* C7 E7"));
         table->setItem(7, 5, new SpreadSheetItem("* C8 E8"));
         table->setItem(8, 5, new SpreadSheetItem("* C9 E9"));
         table->setItem(9, 5, new SpreadSheetItem("sum F2 F9"));
         table->item(9,5)->setBackgroundColor(Qt::lightGray);

     }

     const char *htmlText =
     "<HTML>"
     "<p><b>This demo shows use of <c>QTableWidget</c> with custom handling for"
     " individual cells.</b></p>"
     "<p>Using a customized table item we make it possible to have dynamic"
     " output in different cells. The content that is implemented for this"
     " particular demo is:"
     "<ul>"
     "<li>Adding two cells.</li>"
     "<li>Subtracting one cell from another.</li>"
     "<li>Multiplying two cells.</li>"
     "<li>Dividing one cell with another.</li>"
     "<li>Summing the contents of an arbitrary number of cells.</li>"
     "</HTML>";

     void SpreadSheet::showAbout()
     {
         QMessageBox::about(this, "About Spreadsheet", htmlText);
     }

     int main(int argc, char** argv) {
         Q_INIT_RESOURCE(spreadsheet);
         QApplication app(argc, argv);
         SpreadSheet sheet(10, 6);
         sheet.setWindowIcon(QPixmap(":/images/interview.png"));
         sheet.resize(640, 420);
         sheet.show();
         return app.exec();
     }

     #include "main.moc"