feat(calendar): Initial import of the CalendarView

src/SamplesApp/UITests.Shared/UITests.Shared.projitems

@@ -989,6 +989,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\CalendarView\CalendarView_Basics.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Canvas\Canvas_With_Outer_Clip.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -4791,6 +4795,9 @@
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Button\Buttons_Native.xaml.cs">
       <DependentUpon>Buttons_Native.xaml</DependentUpon>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\CalendarView\CalendarView_Basics.xaml.cs">
+      <DependentUpon>CalendarView_Basics.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Canvas\Canvas_With_Outer_Clip.xaml.cs">
       <DependentUpon>Canvas_With_Outer_Clip.xaml</DependentUpon>
     </Compile>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/CalendarView/CalendarView_Basics.xaml

@@ -0,0 +1,14 @@
+<Page
+    x:Class="UITests.Windows_UI_Xaml_Controls.CalendarViewTests.CalendarView_Basics"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:UITests.Windows_UI_Xaml_Controls.CalendarViewTests"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+
+    <Grid>
+		<CalendarView />
+	</Grid>
+</Page>

src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/CalendarView/CalendarView_Basics.xaml.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Windows.Foundation;
+using Windows.Foundation.Collections;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Controls.Primitives;
+using Windows.UI.Xaml.Data;
+using Windows.UI.Xaml.Input;
+using Windows.UI.Xaml.Media;
+using Windows.UI.Xaml.Navigation;
+using Uno.UI.Samples.Controls;
+
+// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=234238
+
+namespace UITests.Windows_UI_Xaml_Controls.CalendarViewTests
+{
+	[Sample]
+	public sealed partial class CalendarView_Basics : Page
+	{
+		public CalendarView_Basics()
+		{
+			this.InitializeComponent();
+		}
+	}
+}

src/Uno.UI/DirectUI/BudgetManager.cs

@@ -0,0 +1,64 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+
+
+
+namespace DirectUI
+{
+	partial class BudgetManager
+	{
+		private void Initialize()
+		{
+			//bool success = false;
+
+			//success = QueryPerformanceFrequency(&m_freq);
+
+			//return;
+		}
+
+		private void StoreFrameTime(bool isBeginOfTick)
+		{
+			//bool success = false;
+
+			//if (isBeginOfTick)
+			//{
+			//	m_startFrameTime = success = QueryPerformanceCounter();
+			//}
+			//else
+			//{
+			//	m_endFrameTime = success = QueryPerformanceCounter();
+			//}
+
+			//// does all ARM hardware support this
+			//global::System.Diagnostics.Debug.Assert(success);
+		}
+
+
+		private void GetElapsedMilliSecondsSinceLastUITickImpl(out int returnValue)
+		{
+			//long lTimeCurrent = default;
+			//bool success = false;
+
+			//// todo: switch between end and start time based on whether we trust the tick to be accurate
+
+			//success = QueryPerformanceCounter(lTimeCurrent);
+
+			//if (success)
+			//{
+			//	double elapsedSeconds = (double)(lTimeCurrent.QuadPart - m_endFrameTime.QuadPart) / (double)(m_freq.QuadPart);
+
+			//	returnValue = (int)(elapsedSeconds1000);
+			//}
+			//else
+			//{
+			//	// hardware that doesn't understand QPC?? Very unlikely, but in this case, let's not crash
+			//	// and just return that no time has elapsed. This will trigger people relying on budget to see that they
+			//	// have a lot of budget and atleast not have them encounter a situation where they do not get to perform
+			//	// certain work.
+			//	returnValue = 0;
+			//}
+
+			returnValue = default;
+		}
+	}
+}

src/Uno.UI/DirectUI/BudgetManager.h.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+
+//  Abstract:
+//      Represents budgetmanager to keep the uitick times
+
+#pragma once
+
+
+namespace DirectUI
+{
+	internal partial class BudgetManager
+	{
+		// The default elapsed time before deferring
+		private const int BUDGET_MANAGER_DEFAULT_LIMIT = 40;
+
+		long m_freq;
+		long m_startFrameTime;
+		long m_endFrameTime;
+	}
+}
+

src/Uno.UI/DirectUI/BudgetManager.uno.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Linq;
+
+namespace DirectUI
+{
+	partial class BudgetManager
+	{
+		public int GetElapsedMilliSecondsSinceLastUITick()
+		{
+			throw new NotImplementedException();
+		}
+	}
+}

src/Uno.UI/DirectUI/CalendarConstants.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Linq;
+
+namespace DirectUI
+{
+	internal class CalendarConstants
+	{
+		internal const long s_ticksPerDay = 864000000000L;       // 24 hours, the regular days
+		internal const long s_ticksPerHour = 36000000000L;       // 1 hour for day light saving
+		internal const long s_maxTicksPerDay = s_ticksPerDay + s_ticksPerHour;
+		internal const long s_maxTicksPerMonth = 31 * s_ticksPerDay + s_ticksPerHour;
+		internal const long s_maxTicksPerYear = 366 * s_ticksPerDay + s_ticksPerHour;
+	}
+}

src/Uno.UI/DirectUI/DMManipulationState.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace DirectUI
+{
+	internal enum DMManipulationState
+	{
+		DMManipulationStarting = 1,
+		DMManipulationStarted = 2,
+		DMManipulationDelta = 3,
+		DMManipulationLastDelta = 4,
+		DMManipulationCompleted = 5,
+		ConstantVelocityScrollStarted = 6,
+		ConstantVelocityScrollStopped = 7
+	}
+}

src/Uno.UI/DirectUI/DXamlCore.cs

@@ -0,0 +1,70 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Windows.UI.Core;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+
+namespace DirectUI
+{
+	internal class DXamlCore
+	{
+		private static DXamlCore _current;
+		private ElementSoundPlayerService _elementSoundPlayerServiceNoRef;
+		private BuildTreeService _buildTreeService;
+		private BudgetManager _budgetManager;
+
+		public static DXamlCore GetCurrent()
+			=> _current ?? new DXamlCore();
+
+		public static DXamlCore GetCurrentNoCreate()
+			=> _current ?? new DXamlCore();
+
+		public string GetLocalizedResourceString(string key)
+			=> key;
+
+		public ElementSoundPlayerService GetElementSoundPlayerServiceNoRef()
+			=> _elementSoundPlayerServiceNoRef ??= new ElementSoundPlayerService();
+
+		public BuildTreeService GetBuildTreeService()
+			=> _buildTreeService ??= new BuildTreeService();
+
+		public BudgetManager GetBudgetManager()
+			=> _budgetManager ??= new BudgetManager();
+	}
+
+	internal class BuildTreeService
+	{
+		public void RegisterWork(ITreeBuilder treeBuilder)
+		{
+			treeBuilder.IsRegisteredForCallbacks = true;
+			CoreDispatcher.Main.RunAsync(CoreDispatcherPriority.High, () =>
+			{
+				if (treeBuilder.IsBuildTreeSuspended)
+				{
+					RegisterWork(treeBuilder);
+					return;
+				}
+
+				var workerHasWorkLeft = treeBuilder.BuildTree();
+				if (workerHasWorkLeft)
+				{
+					var workerReRegistered = treeBuilder.IsRegisteredForCallbacks;
+					if (!workerReRegistered)
+					{
+						RegisterWork(treeBuilder);
+					}
+				}
+			});
+		}
+	}
+
+	internal interface ITreeBuilder
+	{
+		public bool IsBuildTreeSuspended { get; }
+
+		public bool IsRegisteredForCallbacks { get; set; }
+
+		public bool BuildTree();
+	}
+}