Improve the QDateTime support

src/xlsx/xlsxcell.h

@@ -44,9 +44,8 @@ public:
         String,
         Number,
         Formula,
-        ArrayFormula,
         Boolean,
-        DateTime
+        Error
     };
 
     DataType dataType() const;

src/xlsx/xlsxutility.cpp

@@ -30,6 +30,8 @@
 #include <QMap>
 #include <QStringList>
 #include <QColor>
+#include <QDateTime>
+#include <QDebug>
 
 namespace QXlsx {
 
@@ -62,6 +64,30 @@ QColor fromARGBString(const QString &c)
     return color;
 }
 
+double datetimeToNumber(const QDateTime &dt, bool is1904)
+{
+    //Note, for number 0, Excel2007 shown as 1900-1-0, which should be 1899-12-31
+    QDateTime epoch(is1904 ? QDate(1904, 1, 1): QDate(1899, 12, 31), QTime(0,0), Qt::UTC);
+
+    double excel_time = epoch.msecsTo(dt) / (1000*60*60*24.0);
+    if (!is1904 && excel_time > 59) {//31+28
+        //Account for Excel erroneously treating 1900 as a leap year.
+        excel_time += 1;
+    }
+    return excel_time;
+}
+
+QDateTime datetimeFromNumber(double num, bool is1904)
+{
+    if (!is1904 && num > 60)
+        num = num - 1;
+
+    qint64 msecs = static_cast<qint64>(num * 1000*60*60*24.0);
+    QDateTime epoch(is1904 ? QDate(1904, 1, 1): QDate(1899, 12, 31), QTime(0,0), Qt::UTC);
+
+    return epoch.addMSecs(msecs);
+}
+
 QPoint xl_cell_to_rowcol(const QString &cell_str)
 {
     if (cell_str.isEmpty())

src/xlsx/xlsxutility_p.h

@@ -30,12 +30,15 @@ class QPoint;
 class QString;
 class QStringList;
 class QColor;
+class QDateTime;
 
 namespace QXlsx {
 
 XLSX_AUTOTEST_EXPORT int intPow(int x, int p);
 XLSX_AUTOTEST_EXPORT QStringList splitPath(const QString &path);
 XLSX_AUTOTEST_EXPORT QColor fromARGBString(const QString &c);
+XLSX_AUTOTEST_EXPORT double datetimeToNumber(const QDateTime &dt, bool is1904=false);
+XLSX_AUTOTEST_EXPORT QDateTime datetimeFromNumber(double num, bool is1904=false);
 
 XLSX_AUTOTEST_EXPORT QPoint xl_cell_to_rowcol(const QString &cell_str);
 XLSX_AUTOTEST_EXPORT QString xl_col_to_name(int col_num);

src/xlsx/xlsxworkbook.cpp

@@ -51,7 +51,7 @@ WorkbookPrivate::WorkbookPrivate(Workbook *q) :
 
     strings_to_numbers_enabled = false;
     date1904 = false;
-    defaultDateFormat = QStringLiteral("dd/mm/yyyy hh:mm");
+    defaultDateFormat = QStringLiteral("yyyy-mm-ddThh:mm:ss");
     activesheet = 0;
     firstsheet = 0;
     table_count = 0;
@@ -74,12 +74,15 @@ bool Workbook::isDate1904() const
     return d->date1904;
 }
 
-/*
+/*!
   Excel for Windows uses a default epoch of 1900 and Excel
   for Mac uses an epoch of 1904. However, Excel on either
   platform will convert automatically between one system
- and the other. QtXlsxWriter stores dates in the 1900 format
+  and the other. Qt Xlsx stores dates in the 1900 format
   by default.
+
+  \note This function should be called before any date/time
+  has been written.
 */
 void Workbook::setDate1904(bool date1904)
 {
@@ -310,7 +313,7 @@ QByteArray Workbook::saveToXmlData()
 
 QSharedPointer<Workbook> Workbook::loadFromXmlFile(QIODevice *device)
 {
-    Workbook *book = new Workbook;
+    QSharedPointer<Workbook> book(new Workbook);
 
     XmlStreamReader reader(device);
     while(!reader.atEnd()) {
@@ -321,10 +324,14 @@ QSharedPointer<Workbook> Workbook::loadFromXmlFile(QIODevice *device)
                  QString sheetName = attributes.value(QLatin1String("name")).toString();
                  QString rId = attributes.value(QLatin1String("r:id")).toString();
                  book->d_func()->sheetNameIdPairList.append(QPair<QString, QString>(sheetName, rId));
+             } else if (reader.name() == QLatin1String("workbookPr")) {
+                QXmlStreamAttributes attrs = reader.attributes();
+                if (attrs.hasAttribute(QLatin1String("date1904")))
+                    book->d_ptr->date1904 = true;
              }
          }
     }
-    return QSharedPointer<Workbook>(book);
+    return book;
 }
 
 QSharedPointer<Workbook> Workbook::loadFromXmlData(const QByteArray &data)

src/xlsx/xlsxworksheet.cpp

@@ -423,7 +423,10 @@ int Worksheet::writeDateTime(int row, int column, const QDateTime &dt, Format *f
         format = d->workbook->createFormat();
         format->setNumberFormat(d->workbook->defaultDateFormat());
     }
-    d->cellTable[row][column] = QSharedPointer<Cell>(new Cell(dt, Cell::DateTime, format));
+
+    double value = datetimeToNumber(dt, d->workbook->isDate1904());
+
+    d->cellTable[row][column] = QSharedPointer<Cell>(new Cell(value, Cell::Number, format));
     d->workbook->styles()->addFormat(format);
 
     return 0;
@@ -729,23 +732,11 @@ void WorksheetPrivate::writeCellData(XmlStreamWriter &writer, int row, int col,
             writer.writeAttribute(QStringLiteral("t"), QStringLiteral("str"));
         writer.writeTextElement(QStringLiteral("f"), cell->formula());
         writer.writeTextElement(QStringLiteral("v"), cell->value().toString());
-    } else if (cell->dataType() == Cell::ArrayFormula) {
-
     } else if (cell->dataType() == Cell::Boolean) {
         writer.writeAttribute(QStringLiteral("t"), QStringLiteral("b"));
         writer.writeTextElement(QStringLiteral("v"), cell->value().toBool() ? QStringLiteral("1") : QStringLiteral("0"));
     } else if (cell->dataType() == Cell::Blank) {
         //Ok, empty here.
-    } else if (cell->dataType() == Cell::DateTime) {
-        QDateTime epoch(QDate(1899, 12, 31));
-        if (workbook->isDate1904())
-            epoch = QDateTime(QDate(1904, 1, 1));
-        qint64 delta = epoch.msecsTo(cell->value().toDateTime());
-        double excel_time = delta / (1000*60*60*24);
-        //Account for Excel erroneously treating 1900 as a leap year.
-        if (!workbook->isDate1904() && excel_time > 59)
-            excel_time += 1;
-        writer.writeTextElement(QStringLiteral("v"), QString::number(excel_time, 'g', 15));
     }
     writer.writeEndElement(); //c
 }

tests/auto/utility/tst_utilitytest.cpp

@@ -25,6 +25,7 @@
 #include "private/xlsxutility_p.h"
 #include <QString>
 #include <QtTest>
+#include <QDateTime>
 
 class UtilityTest : public QObject
 {
@@ -39,6 +40,12 @@ private Q_SLOTS:
 
     void test_rowcol_to_cell();
     void test_rowcol_to_cell_data();
+
+    void test_datetimeToNumber_data();
+    void test_datetimeToNumber();
+
+    void test_datetimeFromNumber_data();
+    void test_datetimeFromNumber();
 };
 
 UtilityTest::UtilityTest()
@@ -101,6 +108,55 @@ void UtilityTest::test_rowcol_to_cell_data()
     QTest::newRow("...") << 1048576 << 16384 << false << false << "XFE1048577";
 }
 
+void UtilityTest::test_datetimeToNumber_data()
+{
+    QTest::addColumn<QDateTime>("dt");
+    QTest::addColumn<bool>("is1904");
+    QTest::addColumn<double>("num");
+
+    //Note, for number 0, Excel2007 shown as 1900-1-0, which should be 1899-12-31
+    QTest::newRow("0") << QDateTime(QDate(1899, 12, 31), QTime(0,0), Qt::UTC) << false << 0.0;
+    QTest::newRow("1.25") << QDateTime(QDate(1900, 1, 1), QTime(6, 0), Qt::UTC) << false << 1.25;
+    QTest::newRow("59") << QDateTime(QDate(1900, 2, 28), QTime(0, 0), Qt::UTC) << false << 59.0;
+    QTest::newRow("61") << QDateTime(QDate(1900, 3, 1), QTime(0, 0), Qt::UTC) << false << 61.0;
+
+    QTest::newRow("1904: 0") << QDateTime(QDate(1904, 1, 1), QTime(0,0), Qt::UTC) << true << 0.0;
+    QTest::newRow("1904: 1.25") << QDateTime(QDate(1904, 1, 2), QTime(6, 0), Qt::UTC) << true << 1.25;
+}
+
+void UtilityTest::test_datetimeToNumber()
+{
+    QFETCH(QDateTime, dt);
+    QFETCH(bool, is1904);
+    QFETCH(double, num);
+
+    QCOMPARE(QXlsx::datetimeToNumber(dt, is1904), num);
+}
+
+void UtilityTest::test_datetimeFromNumber_data()
+{
+    QTest::addColumn<QDateTime>("dt");
+    QTest::addColumn<bool>("is1904");
+    QTest::addColumn<double>("num");
+
+    QTest::newRow("0") << QDateTime(QDate(1899, 12, 31), QTime(0,0), Qt::UTC) << false << 0.0;
+    QTest::newRow("1.25") << QDateTime(QDate(1900, 1, 1), QTime(6, 0), Qt::UTC) << false << 1.25;
+    QTest::newRow("59") << QDateTime(QDate(1900, 2, 28), QTime(0,0), Qt::UTC) << false << 59.0;
+    QTest::newRow("61") << QDateTime(QDate(1900, 3, 1), QTime(0,0), Qt::UTC) << false << 61.0;
+
+    QTest::newRow("1904: 0") << QDateTime(QDate(1904, 1, 1), QTime(0,0), Qt::UTC) << true << 0.0;
+    QTest::newRow("1904: 1.25") << QDateTime(QDate(1904, 1, 2), QTime(6, 0), Qt::UTC) << true << 1.25;
+}
+
+void UtilityTest::test_datetimeFromNumber()
+{
+    QFETCH(QDateTime, dt);
+    QFETCH(bool, is1904);
+    QFETCH(double, num);
+
+    QCOMPARE(QXlsx::datetimeFromNumber(num, is1904), dt);
+}
+
 QTEST_APPLESS_MAIN(UtilityTest)
 
 #include "tst_utilitytest.moc"