Merge branch 'firstweekday' of https://github.com/lanurmi/wxWidgets

Add API for determining the first day of the week and use it in
wxCalendarCtrl.

Closes https://github.com/wxWidgets/wxWidgets/pull/522

include/wx/calctrl.h

@@ -27,7 +27,7 @@
 enum
 {
     // show Sunday as the first day of the week (default)
-    wxCAL_SUNDAY_FIRST               = 0x0000,
+    wxCAL_SUNDAY_FIRST               = 0x0080,
 
     // show Monday as the first day of the week
     wxCAL_MONDAY_FIRST               = 0x0001,
@@ -332,6 +332,9 @@ protected:
 
     // called by EnableHolidayDisplay()
     virtual void RefreshHolidays() { }
+
+    // does the week start on monday based on flags and OS settings?
+    bool WeekStartsOnMonday() const;
 };
 
 // ----------------------------------------------------------------------------

include/wx/datetime.h

@@ -392,6 +392,9 @@ public:
         // returns true if the given year is a leap year in the given calendar
     static bool IsLeapYear(int year = Inv_Year, Calendar cal = Gregorian);
 
+        // acquires the first day of week based on locale and/or OS settings
+    static bool GetFirstWeekDay(WeekDay *firstDay);
+
         // get the century (19 for 1999, 20 for 2000 and -5 for 492 BC)
     static int GetCentury(int year);
 
@@ -1142,6 +1145,9 @@ private:
     // functions
     inline bool IsInStdRange() const;
 
+    // assign the preferred first day of a week to flags, if necessary
+    void UseEffectiveWeekDayFlags(WeekFlags &flags) const;
+
     // the internal representation of the time is the amount of milliseconds
     // elapsed since the origin which is set by convention to the UNIX/C epoch
     // value: the midnight of January 1, 1970 (UTC)

include/wx/generic/calctrlg.h

@@ -202,13 +202,13 @@ private:
     // get the first/last days of the week corresponding to the current style
     wxDateTime::WeekDay GetWeekStart() const
     {
-        return HasFlag(wxCAL_MONDAY_FIRST) ? wxDateTime::Mon
+        return WeekStartsOnMonday() ? wxDateTime::Mon
                                            : wxDateTime::Sun;
     }
 
     wxDateTime::WeekDay GetWeekEnd() const
     {
-        return HasFlag(wxCAL_MONDAY_FIRST) ? wxDateTime::Sun
+        return WeekStartsOnMonday() ? wxDateTime::Sun
                                            : wxDateTime::Sat;
     }