QTimeZone - Define new class and api

Implement the new QTimeZone class based on the Olsen Time Zone ID's.

This is the base implementation and does not include the Platform
backends which are implemented separately.

This change does include a default UTC backed to be used if no Platform
backend is available, i.e. if QT_NO_SYSTEMLOCALE is set and ICU is not
configured.  This backend also provides a default set of time zones in
the standard "UTC+00:00" offset format that are guaranteed to always
exist regardless of the Platform backend.

This change includes conversion functions between the Olsen ID's and
Windows ID's using a conversion table based on Unicode CLDR data.
This is implemented for all platforms for scenarios such as a Linux
program needing to communicate with a Windows Exchange Server using
the Windows ID.

The CLDR conversion table is included under the UNICODE license, see
http://unicode.org/copyright.html for details.

[ChangeLog][QtCore][QTimeZone] Added new QTimeZone class to support
time tone calculations using the host platform time zone database
and the Olsen time zone ID's.

Change-Id: Ibb417d08cf2663a0979d2be855d2c6ad6ad01509
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/src/corelib/tools/qtimezone.h b/src/corelib/tools/qtimezone.h
new file mode 100644
index 0000000000..5eeb22f8f3
--- /dev/null
+++ b/src/corelib/tools/qtimezone.h
@@ -0,0 +1,162 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 John Layt <jlayt@kde.org>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 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 the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#ifndef QTIMEZONE_H
+#define QTIMEZONE_H
+
+#include <QtCore/qsharedpointer.h>
+#include <QtCore/qlocale.h>
+#include <QtCore/qdatetime.h>
+
+QT_BEGIN_NAMESPACE
+
+class QTimeZonePrivate;
+
+class Q_CORE_EXPORT QTimeZone
+{
+public:
+    enum TimeType {
+        StandardTime = 0,
+        DaylightTime = 1,
+        GenericTime = 2
+    };
+
+    enum NameType {
+        DefaultName = 0,
+        LongName = 1,
+        ShortName = 2,
+        OffsetName = 3
+    };
+
+    struct OffsetData {
+        QString abbreviation;
+        QDateTime atUtc;
+        int offsetFromUtc;
+        int standardTimeOffset;
+        int daylightTimeOffset;
+    };
+    typedef QVector<OffsetData> OffsetDataList;
+
+    QTimeZone();
+    explicit QTimeZone(const QByteArray &olsenId);
+    QTimeZone(int offsetSeconds);
+    QTimeZone(const QByteArray &zoneId, int offsetSeconds, const QString &name,
+              const QString &abbreviation, QLocale::Country country = QLocale::AnyCountry,
+              const QString &comment = QString());
+    QTimeZone(const QTimeZone &other);
+    ~QTimeZone();
+
+    QTimeZone &operator=(const QTimeZone &other);
+ #ifdef Q_COMPILER_RVALUE_REFS
+    QTimeZone &operator=(QTimeZone &&other) { std::swap(d, other.d); return *this; }
+#endif
+
+    bool operator==(const QTimeZone &other) const;
+    bool operator!=(const QTimeZone &other) const;
+
+    bool isValid() const;
+
+    QByteArray id() const;
+    QLocale::Country country() const;
+    QString comment() const;
+
+    QString displayName(const QDateTime &atDateTime,
+                        QTimeZone::NameType nameType = QTimeZone::DefaultName,
+                        const QLocale &locale = QLocale()) const;
+    QString displayName(QTimeZone::TimeType timeType,
+                        QTimeZone::NameType nameType = QTimeZone::DefaultName,
+                        const QLocale &locale = QLocale()) const;
+    QString abbreviation(const QDateTime &atDateTime) const;
+
+    int offsetFromUtc(const QDateTime &atDateTime) const;
+    int standardTimeOffset(const QDateTime &atDateTime) const;
+    int daylightTimeOffset(const QDateTime &atDateTime) const;
+
+    bool hasDaylightTime() const;
+    bool isDaylightTime(const QDateTime &atDateTime) const;
+
+    OffsetData offsetData(const QDateTime &forDateTime) const;
+
+    bool hasTransitions() const;
+    OffsetData nextTransition(const QDateTime &afterDateTime) const;
+    OffsetData previousTransition(const QDateTime &beforeDateTime) const;
+    OffsetDataList transitions(const QDateTime &fromDateTime, const QDateTime &toDateTime) const;
+
+    static QByteArray systemTimeZoneId();
+
+    static bool isTimeZoneIdAvailable(const QByteArray &olsenId);
+
+    static QList<QByteArray> availableTimeZoneIds();
+    static QList<QByteArray> availableTimeZoneIds(QLocale::Country country);
+    static QList<QByteArray> availableTimeZoneIds(int offsetSeconds);
+
+    static QByteArray olsenIdToWindowsId(const QByteArray &olsenId);
+    static QByteArray windowsIdToDefaultOlsenId(const QByteArray &windowsId);
+    static QByteArray windowsIdToDefaultOlsenId(const QByteArray &windowsId,
+                                                QLocale::Country country);
+    static QList<QByteArray> windowsIdToOlsenIds(const QByteArray &windowsId);
+    static QList<QByteArray> windowsIdToOlsenIds(const QByteArray &windowsId,
+                                                 QLocale::Country country);
+
+private:
+    QTimeZone(QTimeZonePrivate &dd);
+#ifndef QT_NO_DATASTREAM
+    friend Q_CORE_EXPORT QDataStream &operator<<(QDataStream &ds, const QTimeZone &tz);
+#endif
+    friend class QTimeZonePrivate;
+    QSharedDataPointer<QTimeZonePrivate> d;
+};
+
+Q_DECLARE_TYPEINFO(QTimeZone::OffsetData, Q_MOVABLE_TYPE);
+
+#ifndef QT_NO_DATASTREAM
+Q_CORE_EXPORT QDataStream &operator<<(QDataStream &ds, const QTimeZone &tz);
+Q_CORE_EXPORT QDataStream &operator>>(QDataStream &ds, QTimeZone &tz);
+#endif
+
+#ifndef QT_NO_DEBUG_STREAM
+Q_CORE_EXPORT QDebug operator<<(QDebug dbg, const QTimeZone &tz);
+#endif
+
+QT_END_NAMESPACE
+
+#endif // QTIMEZONE_H