Add new WrapLayout and StaggeredLayout controls

Microsoft.Toolkit.Uwp.SampleApp/Microsoft.Toolkit.Uwp.SampleApp.csproj

@@ -125,7 +125,7 @@
       <Version>6.1.0-build.6</Version>
     </PackageReference>
     <PackageReference Include="Microsoft.UI.Xaml">
-      <Version>2.2.190917002</Version>
+      <Version>2.3.200213001</Version>
     </PackageReference>
     <PackageReference Include="Monaco.Editor">
       <Version>0.7.0-alpha</Version>

Microsoft.Toolkit.Uwp.UI.Controls.Layout/Microsoft.Toolkit.Uwp.UI.Controls.Layout.csproj

@@ -0,0 +1,31 @@
+<Project Sdk="MSBuild.Sdk.Extras">
+
+  <PropertyGroup>
+    <TargetFramework>uap10.0.18362</TargetFramework>
+    <TargetPlatformVersion Condition="'$(TargetPlatformVersion)' == '' ">10.0.18362.0</TargetPlatformVersion>
+    <Title>Windows Community Toolkit Layout</Title>
+    <Description>
+      This library provides XAML layout controls. It is part of the Windows Community Toolkit.
+    </Description>
+    <RootNamespace>Microsoft.Toolkit.Uwp.UI.Controls</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <None Include="VisualStudioToolsManifest.xml" Pack="true" PackagePath="tools" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.UI.Xaml" Version="2.3.200213001" />
+  </ItemGroup>
+
+  <Import Project="$(MSBuildSDKExtrasTargets)" Condition="Exists('$(MSBuildSDKExtrasTargets)')" />
+
+  <!-- https://weblogs.asp.net/rweigelt/disable-warnings-in-generated-c-files-of-uwp-app -->
+  <Target Name="PragmaWarningDisablePrefixer" AfterTargets="MarkupCompilePass2">
+    <ItemGroup>
+      <GeneratedCSFiles Include="**\*.g.cs;**\*.g.i.cs" />
+    </ItemGroup>
+    <Message Text="CSFiles: @(GeneratedCSFiles->'&quot;%(Identity)&quot;')" />
+    <Exec Command="for %%f in (@(GeneratedCSFiles->'&quot;%(Identity)&quot;')) do echo #pragma warning disable &gt; %%f.temp &amp;&amp; type %%f &gt;&gt; %%f.temp &amp;&amp; move /y %%f.temp %%f &gt; NUL" />
+  </Target>
+</Project>

Microsoft.Toolkit.Uwp.UI.Controls.Layout/Microsoft.Toolkit.Uwp.UI.Controls.Layout.csproj.DotSettings

@@ -0,0 +1,3 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+
+</wpf:ResourceDictionary>

Microsoft.Toolkit.Uwp.UI.Controls.Layout/Properties/AssemblyInfo.cs

@@ -0,0 +1,12 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Resources;
+using System.Runtime.CompilerServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: InternalsVisibleTo("UnitTests")]
+[assembly: NeutralResourcesLanguage("en-US")]

Microsoft.Toolkit.Uwp.UI.Controls.Layout/Properties/Microsoft.Windows.Toolkit.UI.Controls.Layout.rd.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Directives xmlns="http://schemas.microsoft.com/netfx/2013/01/metadata">
+  <Library Name="Microsoft.Toolkit.Uwp.UI.Controls.Layout">
+  </Library>
+</Directives>

Microsoft.Toolkit.Uwp.UI.Controls.Layout/StaggeredLayout/StaggeredColumnLayout.cs

@@ -0,0 +1,26 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+
+namespace Microsoft.Toolkit.Uwp.UI.Controls
+{
+    [System.Diagnostics.DebuggerDisplay("Count = {Count}, Height = {Height}")]
+    internal class StaggeredColumnLayout : List<StaggeredItem>
+    {
+        public double Height { get; private set; }
+
+        public new void Add(StaggeredItem item)
+        {
+            Height = item.Top + item.Height;
+            base.Add(item);
+        }
+
+        public new void Clear()
+        {
+            Height = 0;
+            base.Clear();
+        }
+    }
+}

Microsoft.Toolkit.Uwp.UI.Controls.Layout/StaggeredLayout/StaggeredItem.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using Microsoft.UI.Xaml.Controls;
+using Windows.Foundation;
+using Windows.UI.Xaml;
+
+namespace Microsoft.Toolkit.Uwp.UI.Controls
+{
+    internal class StaggeredItem
+    {
+        public StaggeredItem(int index)
+        {
+            this.Index = index;
+        }
+
+        public double Top { get; internal set; }
+
+        public double Height { get; internal set; }
+
+        public int Index { get; }
+    }
+}