From f7fe24e29a99628f6a68149e920d7ee8b0bdbc54 Mon Sep 17 00:00:00 2001
From: Dariusz Komosinski <darek.komosinski@gmail.com>
Date: Sun, 15 May 2022 12:09:09 +0200
Subject: [PATCH 1/2] Remove event handler allocations done in a loop from
 CalendarItem.

---
 .../Calendar/CalendarItem.cs                  | 33 ++++++++++++-------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/src/Avalonia.Controls/Calendar/CalendarItem.cs b/src/Avalonia.Controls/Calendar/CalendarItem.cs
index c44994f92f..32fdaceacb 100644
--- a/src/Avalonia.Controls/Calendar/CalendarItem.cs
+++ b/src/Avalonia.Controls/Calendar/CalendarItem.cs
@@ -7,6 +7,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
+using Avalonia.Collections.Pooled;
 using Avalonia.Controls.Metadata;
 using Avalonia.Data;
 using Avalonia.Input;
@@ -172,13 +173,13 @@ namespace Avalonia.Controls.Primitives
             if (MonthView != null)
             {
                 var childCount = Calendar.RowsPerMonth + Calendar.RowsPerMonth * Calendar.ColumnsPerMonth;
-                var children = new List<IControl>(childCount);
+                using var children = new PooledList<IControl>(childCount);
 
                 for (int i = 0; i < Calendar.RowsPerMonth; i++)
                 {
                     if (_dayTitleTemplate != null)
                     {
-                        var cell = _dayTitleTemplate.Build();
+                        var cell = (Control) _dayTitleTemplate.Build();
                         cell.DataContext = string.Empty;
                         cell.SetValue(Grid.RowProperty, 0);
                         cell.SetValue(Grid.ColumnProperty, i);
@@ -186,11 +187,16 @@ namespace Avalonia.Controls.Primitives
                     }
                 }
 
+                EventHandler<PointerPressedEventArgs> cellMouseLeftButtonDown = Cell_MouseLeftButtonDown;
+                EventHandler<PointerReleasedEventArgs> cellMouseLeftButtonUp = Cell_MouseLeftButtonUp;
+                EventHandler<PointerEventArgs> cellMouseEnter = Cell_MouseEnter;
+                EventHandler<RoutedEventArgs> cellClick = Cell_Click;
+
                 for (int i = 1; i < Calendar.RowsPerMonth; i++)
                 {
                     for (int j = 0; j < Calendar.ColumnsPerMonth; j++)
                     {
-                        CalendarDayButton cell = new CalendarDayButton();
+                        var cell = new CalendarDayButton();
 
                         if (Owner != null)
                         {
@@ -198,10 +204,10 @@ namespace Avalonia.Controls.Primitives
                         }
                         cell.SetValue(Grid.RowProperty, i);
                         cell.SetValue(Grid.ColumnProperty, j);
-                        cell.CalendarDayButtonMouseDown += Cell_MouseLeftButtonDown;
-                        cell.CalendarDayButtonMouseUp += Cell_MouseLeftButtonUp;
-                        cell.PointerEnter += Cell_MouseEnter;
-                        cell.Click += Cell_Click;
+                        cell.CalendarDayButtonMouseDown += cellMouseLeftButtonDown;
+                        cell.CalendarDayButtonMouseUp += cellMouseLeftButtonUp;
+                        cell.PointerEnter += cellMouseEnter;
+                        cell.Click += cellClick;
                         children.Add(cell);
                     }
                 }
@@ -214,12 +220,15 @@ namespace Avalonia.Controls.Primitives
                 var childCount = Calendar.RowsPerYear * Calendar.ColumnsPerYear;
                 var children = new List<IControl>(childCount);
 
-                CalendarButton month;
+                EventHandler<PointerPressedEventArgs> monthCalendarButtonMouseDown = Month_CalendarButtonMouseDown;
+                EventHandler<PointerReleasedEventArgs> monthCalendarButtonMouseUp = Month_CalendarButtonMouseUp;
+                EventHandler<PointerEventArgs> monthMouseEnter = Month_MouseEnter;
+
                 for (int i = 0; i < Calendar.RowsPerYear; i++)
                 {
                     for (int j = 0; j < Calendar.ColumnsPerYear; j++)
                     {
-                        month = new CalendarButton();
+                        var month = new CalendarButton();
 
                         if (Owner != null)
                         {
@@ -227,9 +236,9 @@ namespace Avalonia.Controls.Primitives
                         }
                         month.SetValue(Grid.RowProperty, i);
                         month.SetValue(Grid.ColumnProperty, j);
-                        month.CalendarLeftMouseButtonDown += Month_CalendarButtonMouseDown;
-                        month.CalendarLeftMouseButtonUp += Month_CalendarButtonMouseUp;
-                        month.PointerEnter += Month_MouseEnter;
+                        month.CalendarLeftMouseButtonDown += monthCalendarButtonMouseDown;
+                        month.CalendarLeftMouseButtonUp += monthCalendarButtonMouseUp;
+                        month.PointerEnter += monthMouseEnter;
                         children.Add(month);
                     }
                 }

From 646cefa8cce8b3cf0b4a519ee6b352c62832383e Mon Sep 17 00:00:00 2001
From: Dariusz Komosinski <darek.komosinski@gmail.com>
Date: Sun, 15 May 2022 12:12:54 +0200
Subject: [PATCH 2/2] Enable test that was skipped for two years.

---
 tests/Avalonia.Controls.UnitTests/CalendarTests.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/Avalonia.Controls.UnitTests/CalendarTests.cs b/tests/Avalonia.Controls.UnitTests/CalendarTests.cs
index 95ddd211da..13c6638308 100644
--- a/tests/Avalonia.Controls.UnitTests/CalendarTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/CalendarTests.cs
@@ -15,7 +15,7 @@ namespace Avalonia.Controls.UnitTests
                 first.Day == second.Day;
         }
 
-        [Fact(Skip ="FIX ME ASAP")]
+        [Fact]
         public void SelectedDatesChanged_Should_Fire_When_SelectedDate_Set()
         {
             bool handled = false;