[FileExplorer] StlThumbnailProvider (#15568)

* Adds StlThumbnailProvider

* Spell checker fixes

* Adds missing changes

* Attempts to fix alpha background issue

* Adds missing dependency references

* Upgrades .NET Core 3.1 to .NET 5

* Updates Helix Toolkit to fix .net5 compatibility

* Return null bitmap If STL model is empty

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -48,6 +48,7 @@ body:
       - PowerRename
       - PowerToys Run
       - Shortcut Guide
+      - STL Thumbnail
       - SVG Preview
       - SVG Thumbnail
       - Settings

.github/actions/spell-check/excludes.txt

@@ -26,6 +26,7 @@ ignore$
 \.pdf$
 \.PNG$
 \.png$
+\.stl$
 \.woff$
 \.zip$
 ^doc/devdocs/akaLinks\.md$

.github/actions/spell-check/expect.txt

@@ -1103,6 +1103,7 @@ LPVOID
 LPW
 lpwndpl
 LPWSTR
+LReader
 LRESULT
 lshift
 lstrcmp
@@ -1397,6 +1398,7 @@ outsettings
 OVERLAPPEDWINDOW
 overlaywindow
 Overridable
+Oversampling
 OWNDC
 PACL
 PAINTSTRUCT
@@ -1861,6 +1863,7 @@ STEPIT
 stgm
 STGMEDIUM
 sticpl
+stl
 stoi
 stol
 stoll

.pipelines/ESRPSigning_core.json

@@ -57,6 +57,8 @@
                 "modules\\FileExplorerPreview\\PowerToys.PdfThumbnailProvider.comhost.dll",
                 "modules\\FileExplorerPreview\\PowerToys.powerpreview.dll",
                 "modules\\FileExplorerPreview\\PowerToys.PreviewHandlerCommon.dll",
+                "modules\\FileExplorerPreview\\PowerToys.StlThumbnailProvider.dll",
+                "modules\\FileExplorerPreview\\PowerToys.StlThumbnailProvider.comhost.dll",
                 "modules\\FileExplorerPreview\\PowerToys.SvgPreviewHandler.dll",
                 "modules\\FileExplorerPreview\\PowerToys.SvgPreviewHandler.comhost.dll",
                 "modules\\FileExplorerPreview\\PowerToys.SvgThumbnailProvider.dll",
@@ -165,6 +167,8 @@
                 "NLog.dll",
                 "HtmlAgilityPack.dll",
                 "Markdig.Signed.dll",
+                "HelixToolkit.dll",
+                "HelixToolkit.Core.Wpf.dll",
                 "Mages.Core.dll",
                 "JetBrains.Annotations.dll",
                 "ICSharpCode.SharpZipLib.dll",

.pipelines/ci/templates/build-powertoys-steps.yml

@@ -103,6 +103,7 @@ steps:
     testAssemblyVer2: |
       **\UnitTests-GcodeThumbnailProvider.dll
       **\UnitTests-SvgThumbnailProvider.dll
+      **\UnitTests-StlThumbnailProvider.dll
       **\UnitTests-PdfThumbnailProvider.dll
       **\Settings.UI.UnitTests.dll
       **\UnitTests-MarkdownPreviewHandler.dll

PowerToys.sln

@@ -390,6 +390,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Community.PowerToys.Run.Plu
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "MousePointerCrosshair", "src\modules\MouseUtils\MousePointerCrosshair\MousePointerCrosshair.vcxproj", "{EAE14C0E-7A6B-45DA-9080-A7D8C077BA6E}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "StlThumbnailProvider", "src\modules\previewpane\StlThumbnailProvider\StlThumbnailProvider.csproj", "{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "UnitTests-StlThumbnailProvider", "src\modules\previewpane\UnitTests-StlThumbnailProvider\UnitTests-StlThumbnailProvider.csproj", "{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|x64 = Debug|x64
@@ -1053,6 +1057,18 @@ Global
 		{EAE14C0E-7A6B-45DA-9080-A7D8C077BA6E}.Release|x64.ActiveCfg = Release|x64
 		{EAE14C0E-7A6B-45DA-9080-A7D8C077BA6E}.Release|x64.Build.0 = Release|x64
 		{EAE14C0E-7A6B-45DA-9080-A7D8C077BA6E}.Release|x86.ActiveCfg = Release|x64
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}.Debug|x64.ActiveCfg = Debug|x64
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}.Debug|x64.Build.0 = Debug|x64
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}.Debug|x86.ActiveCfg = Debug|x64
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}.Release|x64.ActiveCfg = Release|x64
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}.Release|x64.Build.0 = Release|x64
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}.Release|x86.ActiveCfg = Release|x64
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}.Debug|x64.ActiveCfg = Debug|x64
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}.Debug|x64.Build.0 = Debug|x64
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}.Debug|x86.ActiveCfg = Debug|x64
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}.Release|x64.ActiveCfg = Release|x64
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}.Release|x64.Build.0 = Release|x64
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}.Release|x86.ActiveCfg = Release|x64
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -1181,6 +1197,8 @@ Global
 		{48A0A19E-A0BE-4256-ACF8-CC3B80291AF9} = {60CD2D4F-C3B9-4897-9821-FCA5098B41CE}
 		{9F94B303-5E21-4364-9362-64426F8DB932} = {4AFC9975-2456-4C70-94A4-84073C1CED93}
 		{EAE14C0E-7A6B-45DA-9080-A7D8C077BA6E} = {322566EF-20DC-43A6-B9F8-616AF942579A}
+		{F7C8C0F1-5431-4347-89D0-8E5354F93CF2} = {2F305555-C296-497E-AC20-5FA1B237996A}
+		{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC} = {2F305555-C296-497E-AC20-5FA1B237996A}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {C3A2F9D1-7930-4EF4-A6FC-7EE0A99821D0}

installer/PowerToysSetup/Product.wxs

@@ -877,6 +877,13 @@
                 <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.GcodeThumbnailProvider.comhost.dll" />
                 <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.GcodeThumbnailProvider.runtimeconfig.json" />
                 <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.GcodeThumbnailProvider.deps.json" />
+                <!-- File to include dll for Stl Thumbnail Provider -->
+                <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.StlThumbnailProvider.dll" />
+                <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.StlThumbnailProvider.comhost.dll" />
+                <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.StlThumbnailProvider.runtimeconfig.json" />
+                <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\PowerToys.StlThumbnailProvider.deps.json" />
+                <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\HelixToolkit.dll" />
+                <File Source="$(var.BinX64Dir)modules\FileExplorerPreview\HelixToolkit.Core.Wpf.dll" />
             </Component>
         </DirectoryRef>
 

src/common/utils/modulesRegistry.h

@@ -106,6 +106,20 @@ inline registry::ChangeSet getGcodeThumbnailHandlerChangeSet(const std::wstring
                                   L".gcode");
 }
 
+inline registry::ChangeSet getStlThumbnailHandlerChangeSet(const std::wstring installationDir, const bool perUser)
+{
+    using namespace registry::shellex;
+    return generatePreviewHandler(PreviewHandlerType::thumbnail,
+                                  perUser,
+                                  L"{8BC8AFC2-4E7C-4695-818E-8C1FFDCEA2AF}",
+                                  get_std_product_version(),
+                                  (fs::path{ installationDir } / LR"d(modules\FileExplorerPreview\PowerToys.StlThumbnailProvider.comhost.dll)d").wstring(),
+                                  registry::DOTNET_COMPONENT_CATEGORY_CLSID,
+                                  L"Microsoft.PowerToys.ThumbnailHandler.Stl.StlThumbnailProvider",
+                                  L"Stl Thumbnail Provider",
+                                  L".stl");
+}
+
 inline std::vector<registry::ChangeSet> getAllModulesChangeSets(const std::wstring installationDir)
 {
     constexpr bool PER_USER = true;
@@ -115,5 +129,6 @@ inline std::vector<registry::ChangeSet> getAllModulesChangeSets(const std::wstri
              getGcodePreviewHandlerChangeSet(installationDir, PER_USER),
              getSvgThumbnailHandlerChangeSet(installationDir, PER_USER),
              getPdfThumbnailHandlerChangeSet(installationDir, PER_USER),
-             getGcodeThumbnailHandlerChangeSet(installationDir, PER_USER) };
+             getGcodeThumbnailHandlerChangeSet(installationDir, PER_USER),
+             getStlThumbnailHandlerChangeSet(installationDir, PER_USER) };
 }

src/modules/previewpane/StlThumbnailProvider/StlThumbnailProvider.cs

@@ -0,0 +1,145 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.ComTypes;
+using System.Windows;
+using System.Windows.Media;
+using System.Windows.Media.Media3D;
+using Common.ComInterlop;
+using Common.Utilities;
+using HelixToolkit.Wpf;
+using Bitmap = System.Drawing.Bitmap;
+
+namespace Microsoft.PowerToys.ThumbnailHandler.Stl
+{
+    /// <summary>
+    /// Stl Thumbnail Provider.
+    /// </summary>
+    [Guid("8BC8AFC2-4E7C-4695-818E-8C1FFDCEA2AF")]
+    [ClassInterface(ClassInterfaceType.None)]
+    [ComVisible(true)]
+    public class StlThumbnailProvider : IInitializeWithStream, IThumbnailProvider
+    {
+        /// <summary>
+        /// Gets the stream object to access file.
+        /// </summary>
+        public IStream Stream { get; private set; }
+
+        /// <summary>
+        ///  The maximum dimension (width or height) thumbnail we will generate.
+        /// </summary>
+        private const uint MaxThumbnailSize = 10000;
+
+        /// <summary>
+        /// Loads the Stl model into a Viewport3D and renders a bitmap of it.
+        /// </summary>
+        /// <param name="stream">The Stream instance for the Stl content.</param>
+        /// <param name="cx">The maximum thumbnail size, in pixels.</param>
+        /// <returns>A thumbnail rendered from the Stl model.</returns>
+        public static Bitmap GetThumbnail(Stream stream, uint cx)
+        {
+            if (cx > MaxThumbnailSize || stream == null || stream.Length == 0)
+            {
+                return null;
+            }
+
+            Bitmap thumbnail = null;
+
+            var stlReader = new StLReader
+            {
+                DefaultMaterial = new DiffuseMaterial(new SolidColorBrush(Color.FromRgb(255, 201, 36))),
+            };
+
+            var model = stlReader.Read(stream);
+
+            if (model.Bounds == Rect3D.Empty)
+            {
+                return null;
+            }
+
+            var viewport = new System.Windows.Controls.Viewport3D();
+
+            viewport.Measure(new Size(cx, cx));
+            viewport.Arrange(new Rect(0, 0, cx, cx));
+
+            var modelVisual = new ModelVisual3D()
+            {
+                Transform = new RotateTransform3D(new AxisAngleRotation3D(new Vector3D(0, 0, 1), 180)),
+            };
+            viewport.Children.Add(modelVisual);
+            viewport.Children.Add(new DefaultLights());
+
+            var perspectiveCamera = new PerspectiveCamera
+            {
+                Position = new Point3D(1, 2, 1),
+                LookDirection = new Vector3D(-1, -2, -1),
+                UpDirection = new Vector3D(0, 0, 1),
+                FieldOfView = 20,
+                NearPlaneDistance = 0.1,
+                FarPlaneDistance = double.PositiveInfinity,
+            };
+            viewport.Camera = perspectiveCamera;
+
+            modelVisual.Content = model;
+
+            perspectiveCamera.ZoomExtents(viewport);
+
+            var bitmapExporter = new BitmapExporter
+            {
+                Background = new SolidColorBrush(Colors.Transparent),
+                OversamplingMultiplier = 1,
+            };
+
+            var bitmapStream = new MemoryStream();
+
+            bitmapExporter.Export(viewport, bitmapStream);
+
+            bitmapStream.Position = 0;
+
+            thumbnail = new Bitmap(bitmapStream);
+
+            return thumbnail;
+        }
+
+        /// <inheritdoc/>
+        public void Initialize(IStream pstream, uint grfMode)
+        {
+            // Ignore the grfMode always use read mode to access the file.
+            this.Stream = pstream;
+        }
+
+        /// <inheritdoc/>
+        public void GetThumbnail(uint cx, out IntPtr phbmp, out WTS_ALPHATYPE pdwAlpha)
+        {
+            phbmp = IntPtr.Zero;
+            pdwAlpha = WTS_ALPHATYPE.WTSAT_UNKNOWN;
+
+            if (cx == 0 || cx > MaxThumbnailSize)
+            {
+                return;
+            }
+
+            using (var stream = new ReadonlyStream(this.Stream as IStream))
+            {
+                using (var memStream = new MemoryStream())
+                {
+                    stream.CopyTo(memStream);
+
+                    memStream.Position = 0;
+
+                    using (Bitmap thumbnail = GetThumbnail(memStream, cx))
+                    {
+                        if (thumbnail != null && thumbnail.Size.Width > 0 && thumbnail.Size.Height > 0)
+                        {
+                            phbmp = thumbnail.GetHbitmap(System.Drawing.Color.Transparent);
+                            pdwAlpha = WTS_ALPHATYPE.WTSAT_ARGB;
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

src/modules/previewpane/StlThumbnailProvider/StlThumbnailProvider.csproj

@@ -0,0 +1,65 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Platforms>x64</Platforms>
+    <UseWindowsForms>true</UseWindowsForms>
+    <ProjectGuid>{F7C8C0F1-5431-4347-89D0-8E5354F93CF2}</ProjectGuid>
+    <RootNamespace>Microsoft.PowerToys.ThumbnailHandler.Stl</RootNamespace>
+    <AssemblyName>PowerToys.StlThumbnailProvider</AssemblyName>
+    <AssemblyTitle>PowerToys.StlThumbnailProvider</AssemblyTitle>
+    <AssemblyDescription>PowerToys StlPreviewHandler</AssemblyDescription>
+    <AssemblyCompany>Microsoft Corporation</AssemblyCompany>
+    <AssemblyCopyright>Copyright (C) 2020 Microsoft Corporation</AssemblyCopyright>
+    <AssemblyProduct>PowerToys</AssemblyProduct>
+    <TargetFramework>net5.0-windows</TargetFramework>
+    <EnableComHosting>true</EnableComHosting>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <Company>Microsoft Corporation</Company>
+    <Product>PowerToys</Product>
+    <NeutralLanguage>en-US</NeutralLanguage>
+    <Description>PowerToys StlPreviewHandler</Description>
+    <Copyright>Copyright (C) 2020 Microsoft Corporation</Copyright>
+    <OutputPath>$(SolutionDir)$(Platform)\$(Configuration)\modules\FileExplorerPreview\</OutputPath>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
+    <AppendRuntimeIdentifierToOutputPath>false</AppendRuntimeIdentifierToOutputPath>
+    <UseWPF>true</UseWPF>
+    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+  </PropertyGroup>
+
+  <Import Project="..\..\..\Version.props" />
+
+  <ItemGroup>
+    <PackageReference Include="HelixToolkit" Version="2.20.1" />
+    <PackageReference Include="HelixToolkit.Core.Wpf" Version="2.20.1" />
+    <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.CodeAnalysis.VersionCheckAnalyzer" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.CodeQuality.Analyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NetCore.Analyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NetFramework.Analyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="StyleCop.Analyzers" Version="1.1.118">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\..\..\codeAnalysis\GlobalSuppressions.cs" Link="GlobalSuppressions.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\common\ManagedTelemetry\Telemetry\ManagedTelemetry.csproj" />
+    <ProjectReference Include="..\Common\PreviewHandlerCommon.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <AdditionalFiles Include="..\..\..\codeAnalysis\StyleCop.json">
+      <Link>StyleCop.json</Link>
+    </AdditionalFiles>
+  </ItemGroup>
+</Project>

src/modules/previewpane/UnitTests-StlThumbnailProvider/StlThumbnailProviderTests.cs

@@ -0,0 +1,111 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Drawing;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.ComTypes;
+using Common.ComInterlop;
+using Microsoft.PowerToys.STATestExtension;
+using Microsoft.PowerToys.ThumbnailHandler.Stl;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Moq;
+
+namespace StlThumbnailProviderUnitTests
+{
+    [STATestClass]
+    public class StlThumbnailProviderTests
+    {
+        [TestMethod]
+        public void GetThumbnailValidStreamStl()
+        {
+            // Act
+            var file = File.ReadAllBytes("HelperFiles/sample.stl");
+
+            StlThumbnailProvider provider = new StlThumbnailProvider();
+
+            provider.Initialize(GetMockStream(file), 0);
+
+            provider.GetThumbnail(256, out IntPtr bitmap, out WTS_ALPHATYPE alphaType);
+
+            Assert.IsTrue(bitmap != IntPtr.Zero);
+            Assert.IsTrue(alphaType == WTS_ALPHATYPE.WTSAT_ARGB);
+        }
+
+        [TestMethod]
+        public void GetThumbnailInValidSizeStl()
+        {
+            // Act
+            var file = File.ReadAllBytes("HelperFiles/sample.stl");
+
+            StlThumbnailProvider provider = new StlThumbnailProvider();
+
+            provider.Initialize(GetMockStream(file), 0);
+
+            provider.GetThumbnail(0, out IntPtr bitmap, out WTS_ALPHATYPE alphaType);
+
+            Assert.IsTrue(bitmap == IntPtr.Zero);
+            Assert.IsTrue(alphaType == WTS_ALPHATYPE.WTSAT_UNKNOWN);
+        }
+
+        [TestMethod]
+        public void GetThumbnailToBigStl()
+        {
+            // Act
+            var file = File.ReadAllBytes("HelperFiles/sample.stl");
+
+            StlThumbnailProvider provider = new StlThumbnailProvider();
+
+            provider.Initialize(GetMockStream(file), 0);
+
+            provider.GetThumbnail(10001, out IntPtr bitmap, out WTS_ALPHATYPE alphaType);
+
+            Assert.IsTrue(bitmap == IntPtr.Zero);
+            Assert.IsTrue(alphaType == WTS_ALPHATYPE.WTSAT_UNKNOWN);
+        }
+
+        [TestMethod]
+        public void CheckNoStlEmptyStreamShouldReturnNullBitmap()
+        {
+            using (var stream = new MemoryStream())
+            {
+                Bitmap thumbnail = StlThumbnailProvider.GetThumbnail(stream, 256);
+                Assert.IsTrue(thumbnail == null);
+            }
+        }
+
+        [TestMethod]
+        public void CheckNoStlNullStreamShouldReturnNullBitmap()
+        {
+            Bitmap thumbnail = StlThumbnailProvider.GetThumbnail(null, 256);
+            Assert.IsTrue(thumbnail == null);
+        }
+
+        private static IStream GetMockStream(byte[] sourceArray)
+        {
+            var streamMock = new Mock<IStream>();
+            int bytesRead = 0;
+
+            streamMock
+                .Setup(x => x.Read(It.IsAny<byte[]>(), It.IsAny<int>(), It.IsAny<IntPtr>()))
+                .Callback<byte[], int, IntPtr>((buffer, countToRead, bytesReadPtr) =>
+                {
+                    int actualCountToRead = Math.Min(sourceArray.Length - bytesRead, countToRead);
+                    if (actualCountToRead > 0)
+                    {
+                        Array.Copy(sourceArray, bytesRead, buffer, 0, actualCountToRead);
+                        Marshal.WriteInt32(bytesReadPtr, actualCountToRead);
+                        bytesRead += actualCountToRead;
+                    }
+                    else
+                    {
+                        Marshal.WriteInt32(bytesReadPtr, 0);
+                    }
+                });
+
+            return streamMock.Object;
+        }
+    }
+}

src/modules/previewpane/UnitTests-StlThumbnailProvider/UnitTests-StlThumbnailProvider.csproj

@@ -0,0 +1,78 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Platforms>x64</Platforms>
+    <AssemblyTitle>UnitTests-StlThumbnailProvider</AssemblyTitle>
+    <AssemblyDescription>PowerToys UnitTests-StlThumbnailProvider</AssemblyDescription>
+    <AssemblyCompany>Microsoft Corporation</AssemblyCompany>
+    <AssemblyCopyright>Copyright (C) 2020 Microsoft Corporation</AssemblyCopyright>
+    <AssemblyProduct>PowerToys</AssemblyProduct>
+    <AssemblyTitle>UnitTests-StlThumbnailProvider</AssemblyTitle>
+    <Company>Microsoft Corporation</Company>
+    <Product>PowerToys</Product>
+    <NeutralLanguage>en-US</NeutralLanguage>
+    <Description>PowerToys UnitTests-StlThumbnailProvider</Description>
+    <Copyright>Copyright (C) 2021 Microsoft Corporation</Copyright>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <ProjectGuid>{F1F6B6B6-9F18-4A17-8B5C-97DF552C53DC}</ProjectGuid>
+    <RootNamespace>StlThumbnailProviderUnitTests</RootNamespace>
+    <TargetFramework>net5.0-windows10.0.18362.0</TargetFramework>
+    <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+    <ReferencePath>$(ProgramFiles)\Common Files\microsoft shared\VSTT\$(VisualStudioVersion)\UITestExtensionPackages</ReferencePath>
+    <IsCodedUITest>False</IsCodedUITest>
+    <TestProjectType>UnitTest</TestProjectType>
+  </PropertyGroup>
+
+  <Import Project="..\..\..\Version.props" />
+
+  <ItemGroup>
+    <None Remove="HelperFiles\sample.stl" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Castle.Core" Version="4.4.1" />
+    <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.CodeAnalysis.VersionCheckAnalyzer" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.CodeQuality.Analyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NetCore.Analyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NetFramework.Analyzers" Version="3.3.0">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="Moq" Version="4.16.1" />
+    <PackageReference Include="MSTest.TestAdapter" Version="2.2.3" />
+    <PackageReference Include="MSTest.TestFramework" Version="2.2.3" />
+    <PackageReference Include="StyleCop.Analyzers" Version="1.1.118">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="5.0.0" />
+    <PackageReference Include="System.Threading.Tasks.Extensions" Version="4.5.4" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Common\PreviewHandlerCommon.csproj" />
+    <ProjectReference Include="..\StlThumbnailProvider\StlThumbnailProvider.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\..\..\codeAnalysis\GlobalSuppressions.cs" Link="GlobalSuppressions.cs" />
+    <Compile Include="..\STATestClassAttribute.cs" Link="STATestClassAttribute.cs" />
+    <Compile Include="..\STATestMethodAttribute.cs" Link="STATestMethodAttribute.cs" />
+    <AdditionalFiles Include="..\..\..\codeAnalysis\StyleCop.json">
+      <Link>StyleCop.json</Link>
+    </AdditionalFiles>
+  </ItemGroup>
+  <ItemGroup>
+    <Content Include="HelperFiles\sample.stl">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+</Project>

src/modules/previewpane/powerpreview/CLSID.h

@@ -40,6 +40,9 @@ const CLSID CLSID_GcodePreviewHandler = { 0xec52dea8, 0x7c9f, 0x4130, { 0xa7, 0x
 // BFEE99B4-B74D-4348-BCA5-E757029647FF
 const GUID CLSID_GcodeThumbnailProvider = { 0xbfee99b4, 0xb74d, 0x4348, { 0xbc, 0xa5, 0xe7, 0x57, 0x02, 0x96, 0x47, 0xff } };
 
+// 8BC8AFC2-4E7C-4695-818E-8C1FFDCEA2AF
+const GUID CLSID_StlThumbnailProvider = { 0x8bc8afc2, 0x4e7c, 0x4695, { 0x81, 0x8e, 0x8c, 0x1f, 0xfd, 0xce, 0xa2, 0xaf } };
+ 
 // Pairs of NativeClsid vs ManagedClsid used for preview handlers.
 const std::vector<std::pair<CLSID, CLSID>> NativeToManagedClsid({ 
     { CLSID_SHIMActivateMdPreviewHandler, CLSID_MdPreviewHandler },

src/modules/previewpane/powerpreview/Resources.resx

@@ -186,4 +186,7 @@
   <data name="Prevpane_Gcode_Settings_Displayname" xml:space="preserve">
     <value>G-code Previewer</value>
   </data>
+  <data name="Stl_Thumbnail_Provider_Settings_Description" xml:space="preserve">
+    <value>Stl Thumbnail Provider</value>
+  </data>
 </root>

src/modules/previewpane/powerpreview/powerpreview.cpp

@@ -54,6 +54,10 @@ PowerPreviewModule::PowerPreviewModule() :
                                       .settingDescription = GET_RESOURCE_STRING(IDS_GCODE_THUMBNAIL_PROVIDER_SETTINGS_DESCRIPTION),
                                       .registryChanges = getGcodeThumbnailHandlerChangeSet(installationDir, installPerUser) });
 
+    m_fileExplorerModules.push_back({ .settingName = L"stl-thumbnail-toggle-setting",
+                                      .settingDescription = GET_RESOURCE_STRING(IDS_STL_THUMBNAIL_PROVIDER_SETTINGS_DESCRIPTION),
+                                      .registryChanges = getStlThumbnailHandlerChangeSet(installationDir, installPerUser) });
+
     try
     {
         PowerToysSettings::PowerToyValues settings =

src/settings-ui/Settings.UI.Library/PowerPreviewProperties.cs

@@ -131,6 +131,23 @@ namespace Microsoft.PowerToys.Settings.UI.Library
             }
         }
 
+        private bool enableStlThumbnail = true;
+
+        [JsonPropertyName("stl-thumbnail-toggle-setting")]
+        [JsonConverter(typeof(BoolPropertyJsonConverter))]
+        public bool EnableStlThumbnail
+        {
+            get => enableStlThumbnail;
+            set
+            {
+                if (value != enableStlThumbnail)
+                {
+                    LogTelemetryEvent(value);
+                    enableStlThumbnail = value;
+                }
+            }
+        }
+
         public PowerPreviewProperties()
         {
         }

src/settings-ui/Settings.UI.Library/ViewModels/PowerPreviewViewModel.cs

@@ -53,6 +53,7 @@ namespace Microsoft.PowerToys.Settings.UI.Library.ViewModels
             _gcodeRenderIsEnabled = Settings.Properties.EnableGcodePreview;
             _pdfThumbnailIsEnabled = Settings.Properties.EnablePdfThumbnail;
             _gcodeThumbnailIsEnabled = Settings.Properties.EnableGcodeThumbnail;
+            _stlThumbnailIsEnabled = Settings.Properties.EnableStlThumbnail;
         }
 
         private bool _svgRenderIsEnabled;
@@ -62,6 +63,7 @@ namespace Microsoft.PowerToys.Settings.UI.Library.ViewModels
         private bool _svgThumbnailIsEnabled;
         private bool _pdfThumbnailIsEnabled;
         private bool _gcodeThumbnailIsEnabled;
+        private bool _stlThumbnailIsEnabled;
 
         public bool SVGRenderIsEnabled
         {
@@ -189,6 +191,24 @@ namespace Microsoft.PowerToys.Settings.UI.Library.ViewModels
             }
         }
 
+        public bool STLThumbnailIsEnabled
+        {
+            get
+            {
+                return _stlThumbnailIsEnabled;
+            }
+
+            set
+            {
+                if (value != _stlThumbnailIsEnabled)
+                {
+                    _stlThumbnailIsEnabled = value;
+                    Settings.Properties.EnableStlThumbnail = value;
+                    RaisePropertyChanged();
+                }
+            }
+        }
+
         public string GetSettingsSubPath()
         {
             return _settingsConfigFileFolder + "\\" + ModuleName;

src/settings-ui/Settings.UI.UnitTests/ViewModelTests/PowerPreview.cs

@@ -63,6 +63,7 @@ namespace ViewModelTests
             Assert.AreEqual(originalSettings.Properties.EnableSvgThumbnail, viewModel.SVGThumbnailIsEnabled);
             Assert.AreEqual(originalSettings.Properties.EnablePdfThumbnail, viewModel.PDFThumbnailIsEnabled);
             Assert.AreEqual(originalSettings.Properties.EnableGcodeThumbnail, viewModel.GCODEThumbnailIsEnabled);
+            Assert.AreEqual(originalSettings.Properties.EnableStlThumbnail, viewModel.STLThumbnailIsEnabled);
 
             // Verify that the stub file was used
             var expectedCallCount = 2;  // once via the view model, and once by the test (GetSettings<T>)
@@ -141,6 +142,24 @@ namespace ViewModelTests
             viewModel.GCODEThumbnailIsEnabled = true;
         }
 
+        [TestMethod]
+        public void STLThumbnailIsEnabledShouldPrevHandlerWhenSuccessful()
+        {
+            // Assert
+            Func<string, int> sendMockIPCConfigMSG = msg =>
+            {
+                SndModuleSettings<SndPowerPreviewSettings> snd = JsonSerializer.Deserialize<SndModuleSettings<SndPowerPreviewSettings>>(msg);
+                Assert.IsTrue(snd.PowertoysSetting.FileExplorerPreviewSettings.Properties.EnableStlThumbnail);
+                return 0;
+            };
+
+            // arrange
+            PowerPreviewViewModel viewModel = new PowerPreviewViewModel(SettingsRepository<PowerPreviewSettings>.GetInstance(mockPowerPreviewSettingsUtils.Object), SettingsRepository<GeneralSettings>.GetInstance(mockGeneralSettingsUtils.Object), sendMockIPCConfigMSG, PowerPreviewSettings.ModuleName);
+
+            // act
+            viewModel.STLThumbnailIsEnabled = true;
+        }
+
         [TestMethod]
         public void MDRenderIsEnabledShouldPrevHandlerWhenSuccessful()
         {

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -632,6 +632,10 @@
     <value>Enable SVG (.svg) thumbnails</value>
     <comment>Do you want this feature on / off</comment>
   </data>
+  <data name="FileExplorerPreview_ToggleSwitch_STL_Thumbnail.Header" xml:space="preserve">
+    <value>Enable STL (.stl) thumbnails</value>
+    <comment>Do you want this feature on / off</comment>
+  </data>
   <data name="FileExplorerPreview_ToggleSwitch_PDF_Thumbnail.Header" xml:space="preserve">
     <value>Enable PDF (.pdf) thumbnails</value>
     <comment>Do you want this feature on / off</comment>

src/settings-ui/Settings.UI/Views/PowerPreviewPage.xaml

@@ -77,6 +77,13 @@
                                           x:Uid="ToggleSwitch"/>
                         </controls:Setting.ActionContent>
                     </controls:Setting>
+
+                  <controls:Setting x:Uid="FileExplorerPreview_ToggleSwitch_STL_Thumbnail" Icon="&#xF158;">
+                      <controls:Setting.ActionContent>
+                          <ToggleSwitch IsOn="{x:Bind Mode=TwoWay, Path=ViewModel.STLThumbnailIsEnabled}"
+                                        x:Uid="ToggleSwitch"/>
+                      </controls:Setting.ActionContent>
+                  </controls:Setting>
                 </controls:SettingsGroup>
                 
             </StackPanel>

tools/BugReportTool/BugReportTool/RegistryUtils.cpp

@@ -19,6 +19,7 @@ namespace
     { HKEY_CLASSES_ROOT, L"CLSID\\{ec52dea8-7c9f-4130-a77b-1737d0418507}" },
     { HKEY_CLASSES_ROOT, L"CLSID\\{BCC13D15-9720-4CC4-8371-EA74A274741E}" },
     { HKEY_CLASSES_ROOT, L"CLSID\\{BFEE99B4-B74D-4348-BCA5-E757029647FF}" },
+    { HKEY_CLASSES_ROOT, L"CLSID\\{8BC8AFC2-4E7C-4695-818E-8C1FFDCEA2AF}" },
     { HKEY_CLASSES_ROOT, L"CLSID\\{51B4D7E5-7568-4234-B4BB-47FB3C016A69}\\InprocServer32" },
     { HKEY_CLASSES_ROOT, L"CLSID\\{0440049F-D1DC-4E46-B27B-98393D79486B}" },
     { HKEY_CLASSES_ROOT, L"AllFileSystemObjects\\ShellEx\\ContextMenuHandlers\\PowerRenameExt" },
@@ -29,7 +30,8 @@ namespace
     { HKEY_CLASSES_ROOT, L".pdf\\shellex\\{8895b1c6-b41f-4c1c-a562-0d564250836f}" },
     { HKEY_CLASSES_ROOT, L".pdf\\shellex\\{E357FCCD-A995-4576-B01F-234630154E96}" },
     { HKEY_CLASSES_ROOT, L".gcode\\shellex\\{8895b1c6-b41f-4c1c-a562-0d564250836f}" },
-    { HKEY_CLASSES_ROOT, L".gcode\\shellex\\{E357FCCD-A995-4576-B01F-234630154E96}" }
+    { HKEY_CLASSES_ROOT, L".gcode\\shellex\\{E357FCCD-A995-4576-B01F-234630154E96}" },
+    { HKEY_CLASSES_ROOT, L".stl\\shellex\\{E357FCCD-A995-4576-B01F-234630154E96}" }
     };
 
     vector<tuple<HKEY, wstring, wstring>> registryValues = {