spreadsheet.cpp Example File

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 #include <QtWidgets>
 #include <QPrinter>
 #include <QPrintDialog>
 #include <QPrintPreviewDialog>

 #include "spreadsheet.h"
 #include "spreadsheetdelegate.h"
 #include "spreadsheetitem.h"
 #include "printview.h"

 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());

     createActions();
     updateColor(0);
     setupMenuBar();
     setupContents();
     setupContextMenu();
     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()));

     printAction = new QAction(tr("&Print"), this);
     connect(printAction, SIGNAL(triggered()), this, SLOT(print()));

     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(printAction);
     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(tr("Cell: (%1)").arg(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(tr("sum %1 %2").arg(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(tr("%1 %2 %3").arg(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);
 }

 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;
     }
 }

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

 void SpreadSheet::print()
 {
 #ifndef QT_NO_PRINTER
     QPrinter printer(QPrinter::ScreenResolution);
     QPrintPreviewDialog dlg(&printer);
     PrintView view;
     view.setModel(table->model());
     connect(&dlg, SIGNAL(paintRequested(QPrinter*)),
             &view, SLOT(print(QPrinter*)));
     dlg.exec();
 #endif
 }