Add setters to BDate and BCalendarView

* BDate setters don't perform any validation, use with caution.
* BCalendarView setters do perform validation checks, and will adjust
the day so it fits the requested month or year.
* Add tests for the BCalendarView setters.

headers/os/support/DateTime.h

@@ -119,6 +119,10 @@ public:
 			int32				Month() const;
 			int32				Difference(const BDate& date) const;
 
+			void				SetDay(int32 day);
+			void				SetMonth(int32 month);
+			void				SetYear(int32 year);
+
 			int32				DayOfWeek() const;
 			int32				DayOfYear() const;
 

headers/private/shared/CalendarView.h

@@ -79,8 +79,12 @@ public:
 	virtual	BSize				PreferredSize();
 
 			int32				Day() const;
-			int32				Year() const;
 			int32				Month() const;
+			int32				Year() const;
+
+			bool				SetDay(int32 day);
+			bool				SetMonth(int32 month);
+			bool				SetYear(int32 year);
 
 			BDate				Date() const;
 			bool				SetDate(const BDate& date);

src/kits/shared/CalendarView.cpp

@@ -530,6 +530,57 @@ BCalendarView::Month() const
 }
 
 
+bool
+BCalendarView::SetDay(int32 day)
+{
+	BDate date = Date();
+	date.SetDay(day);
+	if (!date.IsValid())
+		return false;
+	SetDate(date);
+	return true;
+}
+
+
+bool
+BCalendarView::SetMonth(int32 month)
+{
+	if (month < 1 || month > 12)
+		return false;
+	BDate date = Date();
+	int32 oldDay = date.Day();
+
+	date.SetMonth(month);
+	date.SetDay(1); // make sure the date is valid
+
+	// We must make sure that the day in month fits inside the new month.
+	if (oldDay > date.DaysInMonth())
+		date.SetDay(date.DaysInMonth());
+	else
+		date.SetDay(oldDay);
+	SetDate(date);
+	return true;
+}
+
+
+bool
+BCalendarView::SetYear(int32 year)
+{
+	BDate date = Date();
+
+	// This can fail when going from 29 feb. on a leap year to a non-leap year.
+	if (date.Month() == 2 && date.Day() == 29 && !date.IsLeapYear(year))
+		date.SetDay(28);
+
+	// TODO we should also handle the "hole" at the switch between Julian and
+	// Gregorian calendars, which will result in an invalid date.
+
+	date.SetYear(year);
+	SetDate(date);
+	return true;
+}
+
+
 BDate
 BCalendarView::Date() const
 {

src/kits/support/DateTime.cpp

@@ -769,6 +769,27 @@ BDate::Difference(const BDate& date) const
 }
 
 
+void
+BDate::SetDay(int32 day)
+{
+	fDay = day;
+}
+
+
+void
+BDate::SetMonth(int32 month)
+{
+	fMonth = month;
+}
+
+
+void
+BDate::SetYear(int32 year)
+{
+	fYear = year;
+}
+
+
 /*!
 	Returns the week number of the date, if the date is invalid it will return
 	B_ERROR. Please note that this function does only work within the Gregorian

src/tests/kits/shared/CalendarViewTest.cpp

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2014, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include "CalendarViewTest.h"
+
+#include <CalendarView.h>
+
+#include <cppunit/TestCaller.h>
+#include <cppunit/TestSuite.h>
+
+
+using namespace BPrivate;
+
+
+CalendarViewTest::CalendarViewTest()
+{
+}
+
+
+CalendarViewTest::~CalendarViewTest()
+{
+}
+
+
+void
+CalendarViewTest::TestSetters()
+{
+	BCalendarView view("test");
+
+	NextSubTest();
+	view.SetDate(2004, 2, 29);
+	CPPUNIT_ASSERT_EQUAL(2004, view.Year());
+	CPPUNIT_ASSERT_EQUAL(2, view.Month());
+	CPPUNIT_ASSERT_EQUAL(29, view.Day());
+
+	NextSubTest();
+	// Moving from leap year to leap year on 29 feb. must not change day
+	view.SetYear(2008);
+	CPPUNIT_ASSERT_EQUAL(2008, view.Year());
+	CPPUNIT_ASSERT_EQUAL(2, view.Month());
+	CPPUNIT_ASSERT_EQUAL(29, view.Day());
+
+	NextSubTest();
+	// Moving from leap year to non-leap year on 29 feb. must go back to 28
+	view.SetYear(2014);
+	CPPUNIT_ASSERT_EQUAL(2014, view.Year());
+	CPPUNIT_ASSERT_EQUAL(2, view.Month());
+	CPPUNIT_ASSERT_EQUAL(28, view.Day());
+
+	NextSubTest();
+	view.SetDate(2014, 8, 31);
+	CPPUNIT_ASSERT_EQUAL(2014, view.Year());
+	CPPUNIT_ASSERT_EQUAL(8, view.Month());
+	CPPUNIT_ASSERT_EQUAL(31, view.Day());
+
+	NextSubTest();
+	// Moving to month with less days should adjust day
+	view.SetMonth(2);
+	CPPUNIT_ASSERT_EQUAL(2014, view.Year());
+	CPPUNIT_ASSERT_EQUAL(2, view.Month());
+	CPPUNIT_ASSERT_EQUAL(28, view.Day());
+}
+
+
+/*static*/ void
+CalendarViewTest::AddTests(BTestSuite& parent)
+{
+	CppUnit::TestSuite& suite = *new CppUnit::TestSuite("CalendarViewTest");
+
+	suite.addTest(new CppUnit::TestCaller<CalendarViewTest>(
+		"CalendarViewTest::TestSetters", &CalendarViewTest::TestSetters));
+
+	parent.addTest("CalendarViewTest", &suite);
+}

src/tests/kits/shared/CalendarViewTest.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2014, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef CALENDAR_VIEW_TEST_H
+#define CALENDAR_VIEW_TEST_H
+
+
+#include <TestCase.h>
+#include <TestSuite.h>
+
+
+class CalendarViewTest : public BTestCase {
+public:
+								CalendarViewTest();
+	virtual						~CalendarViewTest();
+
+			void				TestSetters();
+
+	static	void				AddTests(BTestSuite& suite);
+};
+
+
+#endif	// CALENDAR_VIEW_TEST_H

src/tests/kits/shared/SharedTestAddon.cpp

@@ -7,6 +7,7 @@
 #include <TestSuite.h>
 #include <TestSuiteAddon.h>
 
+#include "CalendarViewTest.h"
 #include "NaturalCompareTest.h"
 
 
@@ -15,6 +16,7 @@ getTestSuite()
 {
 	BTestSuite* suite = new BTestSuite("Shared");
 
+	CalendarViewTest::AddTests(*suite);
 	NaturalCompareTest::AddTests(*suite);
 
 	return suite;