Adapt QCalendarWidget and QDateTimeEdit to support choice of calendar

[ChangeLog][QtWidgets][QCalendarWidget] Allow choice of calendar, with
Gregorian remaining the default.

[ChangeLog][QtWidgets][QDateTimeEdit] Allow choice of calendar, with
Gregorian remaining the default.

Change-Id: Ia11dd895032393543aee534b177324e643dcfb20
Done-with: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 31 insertions, 19 deletions

diff --git a/src/widgets/widgets/qdatetimeedit.cpp b/src/widgets/widgets/qdatetimeedit.cpp
index 17dc94bba1..31607d77e7 100644
--- a/src/widgets/widgets/qdatetimeedit.cpp
+++ b/src/widgets/widgets/qdatetimeedit.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2019 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtWidgets module of the Qt Toolkit.
@@ -312,6 +312,22 @@ void QDateTimeEdit::setTime(const QTime &time)
 }
 
 
+QCalendar QDateTimeEdit::calendar() const
+{
+    Q_D(const QDateTimeEdit);
+    return d->calendar;
+}
+
+void QDateTimeEdit::setCalendar(QCalendar calendar)
+{
+    Q_D(QDateTimeEdit);
+    // Set invalid date time to prevent runtime crashes on calendar change
+    QDateTime previousValue = d->value.toDateTime();
+    setDateTime(QDateTime());
+    d->setCalendar(calendar);
+    setDateTime(previousValue);
+}
+
 /*!
   \property QDateTimeEdit::minimumDateTime
   \since 4.4
@@ -1344,7 +1360,7 @@ void QDateTimeEdit::stepBy(int steps)
 QString QDateTimeEdit::textFromDateTime(const QDateTime &dateTime) const
 {
     Q_D(const QDateTimeEdit);
-    return locale().toString(dateTime, d->displayFormat);
+    return locale().toString(dateTime, d->displayFormat, d->calendar);
 }
 
 
@@ -1636,7 +1652,7 @@ QDateEdit::~QDateEdit()
 
 
 QDateTimeEditPrivate::QDateTimeEditPrivate()
-    : QDateTimeParser(QVariant::DateTime, QDateTimeParser::DateTimeEdit)
+    : QDateTimeParser(QVariant::DateTime, QDateTimeParser::DateTimeEdit, QCalendar())
 {
     hasHadFocus = false;
     formatExplicitlySet = false;
@@ -1661,10 +1677,6 @@ QDateTimeEditPrivate::QDateTimeEditPrivate()
 #endif
 }
 
-QDateTimeEditPrivate::~QDateTimeEditPrivate()
-{
-}
-
 void QDateTimeEditPrivate::updateTimeSpec()
 {
     minimum = minimum.toDateTime().toTimeSpec(spec);
@@ -2008,8 +2020,7 @@ QDateTime QDateTimeEditPrivate::stepBy(int sectionIndex, int steps, bool test) c
         val = (wrapping ? min + val - max - 1 : max);
     }
 
-
-    const int oldDay = v.date().day();
+    const int oldDay = v.date().day(calendar);
 
     setDigit(v, sectionIndex, val);
     // if this sets year or month it will make
@@ -2028,10 +2039,10 @@ QDateTime QDateTimeEditPrivate::stepBy(int sectionIndex, int steps, bool test) c
             if (steps > 0) {
                 setDigit(v, sectionIndex, min);
                 if (!(sn.type & DaySectionMask) && sections & DateSectionMask) {
-                    const int daysInMonth = v.date().daysInMonth();
-                    if (v.date().day() < oldDay && v.date().day() < daysInMonth) {
+                    const int daysInMonth = v.date().daysInMonth(calendar);
+                    if (v.date().day(calendar) < oldDay && v.date().day(calendar) < daysInMonth) {
                         const int adds = qMin(oldDay, daysInMonth);
-                        v = v.addDays(adds - v.date().day());
+                        v = v.addDays(adds - v.date().day(calendar));
                     }
                 }
 
@@ -2043,10 +2054,10 @@ QDateTime QDateTimeEditPrivate::stepBy(int sectionIndex, int steps, bool test) c
             } else {
                 setDigit(v, sectionIndex, max);
                 if (!(sn.type & DaySectionMask) && sections & DateSectionMask) {
-                    const int daysInMonth = v.date().daysInMonth();
-                    if (v.date().day() < oldDay && v.date().day() < daysInMonth) {
+                    const int daysInMonth = v.date().daysInMonth(calendar);
+                    if (v.date().day(calendar) < oldDay && v.date().day(calendar) < daysInMonth) {
                         const int adds = qMin(oldDay, daysInMonth);
-                        v = v.addDays(adds - v.date().day());
+                        v = v.addDays(adds - v.date().day(calendar));
                     }
                 }
 
@@ -2060,7 +2071,7 @@ QDateTime QDateTimeEditPrivate::stepBy(int sectionIndex, int steps, bool test) c
             setDigit(v, sectionIndex, (steps > 0 ? localmax : localmin));
         }
     }
-    if (!test && oldDay != v.date().day() && !(sn.type & DaySectionMask)) {
+    if (!test && oldDay != v.date().day(calendar) && !(sn.type & DaySectionMask)) {
         // this should not happen when called from stepEnabled
         cachedDay = qMax<int>(oldDay, cachedDay);
     }
@@ -2513,7 +2524,7 @@ void QDateTimeEditPrivate::initCalendarPopup(QCalendarWidget *cw)
 {
     Q_Q(QDateTimeEdit);
     if (!monthCalendar) {
-        monthCalendar = new QCalendarPopup(q, cw);
+        monthCalendar = new QCalendarPopup(q, cw, calendar);
         monthCalendar->setObjectName(QLatin1String("qt_datetimedit_calendar"));
         QObject::connect(monthCalendar, SIGNAL(newDateSelected(QDate)), q, SLOT(setDate(QDate)));
         QObject::connect(monthCalendar, SIGNAL(hidingCalendar(QDate)), q, SLOT(setDate(QDate)));
@@ -2574,8 +2585,8 @@ void QDateTimeEditPrivate::syncCalendarWidget()
     }
 }
 
-QCalendarPopup::QCalendarPopup(QWidget * parent, QCalendarWidget *cw)
-    : QWidget(parent, Qt::Popup)
+QCalendarPopup::QCalendarPopup(QWidget *parent, QCalendarWidget *cw, QCalendar ca)
+    : QWidget(parent, Qt::Popup), calendarSystem(ca)
 {
     setAttribute(Qt::WA_WindowPropagation);
 
@@ -2591,6 +2602,7 @@ QCalendarWidget *QCalendarPopup::verifyCalendarInstance()
 {
     if (calendar.isNull()) {
         QCalendarWidget *cw = new QCalendarWidget(this);
+        cw->setCalendar(calendarSystem);
         cw->setVerticalHeaderFormat(QCalendarWidget::NoVerticalHeader);
 #ifdef QT_KEYPAD_NAVIGATION
         if (QApplicationPrivate::keypadNavigationEnabled())