Merge pull request unoplatform#15234 from Youssef1313/calendarview-in…

…finite-loop2 fix: Fix CalendarView infinite loop
ramezgerges · Feb 7, 2024 · 9bb910a · 9bb910a
2 parents db94c92 + 62d492e
commit 9bb910a
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Showing 4 changed files with 24 additions and 6 deletions.
diff --git a/src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Controls/Given_CalendarView.cs b/src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Controls/Given_CalendarView.cs
@@ -22,6 +22,16 @@ namespace Uno.UI.RuntimeTests.Tests.Windows_UI_Xaml_Controls;
 [RunsOnUIThread]
 public class Given_CalendarView
 {
+	[TestMethod]
+	public async Task When_MinDate_Has_Different_Offset()
+	{
+		var calendarView = new CalendarView();
+		calendarView.MinDate = new DateTimeOffset(new DateTime(2010, 1, 1, 22, 0, 0), TimeSpan.Zero);
+		calendarView.MaxDate = new DateTimeOffset(new DateTime(2010, 1, 31), TimeSpan.FromHours(2));
+
+		await UITestHelper.Load(calendarView);
+	}
+
 #if __WASM__
 	[TestMethod]
 	public async Task When_ItemCornerRadius()

diff --git a/src/Uno.UI.Tests/Windows_Globalization/When_Calendar.cs b/src/Uno.UI.Tests/Windows_Globalization/When_Calendar.cs
@@ -26,7 +26,7 @@ public void When_DateTimeOffset_Is_Next_Day_If_Converted_To_Utc()
 			var comparer = new DirectUI.DateComparer();
 			comparer.SetCalendarForComparison(calendar);
 			var result = comparer.CompareDay(offset, new DateTimeOffset(year: 2023, month: 5, day: 1, hour: 4, minute: 0, second: 0, TimeSpan.FromHours(0)));
-			Assert.AreEqual(0, result);
+			Assert.AreEqual(1, result);
 		}
 
 		[TestMethod]

diff --git a/src/Uno.UI/DirectUI/DateComparer.cs b/src/Uno.UI/DirectUI/DateComparer.cs
@@ -103,7 +103,14 @@ private int CompareDate(
 
 			global::System.Diagnostics.Debug.Assert(m_spCalendar is { });
 
-			long delta = lhs.ToUniversalTime().Ticks - rhs.ToUniversalTime().Ticks;
+			// Uno specific: In WinUI, wf::DateTime is a struct that only has "UniversalTime" field.
+			// So, we need to call ToUniversalTime here.
+			// Failure to do so can cause issues when comparing dates like 2024/01/01 10:00:00 PM UTC+2 and 2024/01/02 12:00:00 AM UTC
+			// Both dates should be equal, but getUnit will return 1 and 2 indicating that the first date is smaller.
+			lhs = lhs.ToUniversalTime();
+			rhs = rhs.ToUniversalTime();
+
+			long delta = lhs.Ticks - rhs.Ticks;
 			if (delta < 0)
 			{
 				delta = -delta;

diff --git a/src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarViewGeneratorHost.cs b/src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarViewGeneratorHost.cs
@@ -281,7 +281,7 @@ internal void ComputeSize()
 		{
 			int index = 0;
 
-			m_lastVisitedDateAndIndex.first = Owner.MinDate;
+			m_lastVisitedDateAndIndex.first = Owner.MinDate.ToUniversalTime();
 			m_lastVisitedDateAndIndex.second = 0;
 
 			global::System.Diagnostics.Debug.Assert(!Owner.DateComparer.LessThan(Owner.MaxDate, Owner.MinDate));
@@ -332,10 +332,10 @@ internal DateTime GetDateAt(uint index)
 
 			pCalendar.SetDateTime(m_lastVisitedDateAndIndex.first);
 			AddUnits((int)(index) - m_lastVisitedDateAndIndex.second);
-			date = pCalendar.GetDateTime();
+			date = pCalendar.GetDateTime().ToUniversalTime();
 			m_lastVisitedDateAndIndex.first = date;
 			m_lastVisitedDateAndIndex.second = (int)(index);
-			var pDate = date; // .ToUniversalTime() - UNO
+			var pDate = date;
 
 			return pDate;
 		}
@@ -350,7 +350,8 @@ internal DateTime GetDateAt(uint index)
 		internal int CalculateOffsetFromMinDate(DateTime date)
 		{
 			var pIndex = 0;
-			DateTime estimatedDate = m_lastVisitedDateAndIndex.first; //.ToUniversalTime(); - UNO
+			DateTime estimatedDate = m_lastVisitedDateAndIndex.first.ToUniversalTime();
+
 			var pCalendar = GetCalendar();
 			global::System.Diagnostics.Debug.Assert(m_lastVisitedDateAndIndex.second != -1);