- Qt 5.5
- Qt Widgets
- Spreadsheet
- spreadsheetitem.cpp Example File
- Qt 5.5.1 Reference Documentation

# spreadsheetitem.cpp Example File

itemviews/spreadsheet/spreadsheetitem.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL21$
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    ** GNU Lesser General Public License Usage
    ** Alternatively, this file may be used under the terms of the GNU Lesser
    ** General Public License version 2.1 or version 3 as published by the Free
    ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
    ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
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    #include "spreadsheetitem.h"

    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 QVariant::fromValue(QColor(Qt::black));
            else if (number < 0)
                return QVariant::fromValue(QColor(Qt::red));
            return QVariant::fromValue(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 s tring is actually a formula or not
        QStringList list = formula.split(' ');
        if (list.isEmpty() || !widget)
            return formula; // it is 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;
    }