Add SVG Thumbnail Provider for Windows Explorer (#5048)

* Add SVG Thumbnail Provider

* Some cleanup

* Small settings changes

* Update PowerToys.sln

Remove Any CPU entries

* Fix project configuration issues

* Fix bad merge

* Update output path for SVG thumbnail provider

* Sync with latest

src/modules/previewpane/common/PreviewHandlerCommon.csproj

@@ -103,6 +103,8 @@
     <Compile Include="cominterop\IPreviewHandler.cs" />
     <Compile Include="cominterop\IPreviewHandlerFrame.cs" />
     <Compile Include="cominterop\IPreviewHandlerVisuals.cs" />
+    <Compile Include="cominterop\IThumbnailProvider.cs" />
+    <Compile Include="cominterop\IViewObject.cs" />
     <Compile Include="cominterop\LOGFONT.cs" />
     <Compile Include="cominterop\MSG.cs" />
     <Compile Include="cominterop\RECT.cs" />
@@ -125,6 +127,7 @@
     <Compile Include="handlers\StreamBasedPreviewHandler.cs" />
     <Compile Include="examplehandler\TestCustomHandler.cs" />
     <Compile Include="Utilities\StreamWrapper.cs" />
+    <Compile Include="Utilities\SvgPreviewHandlerHelper.cs" />
   </ItemGroup>
   <ItemGroup>
     <AdditionalFiles Include="..\..\..\codeAnalysis\StyleCop.json">

src/modules/previewpane/common/Utilities/SvgPreviewHandlerHelper.cs

@@ -0,0 +1,66 @@
+// 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.Collections.Generic;
+using System.Linq;
+using System.Xml.Linq;
+
+namespace Common.Utilities
+{
+    /// <summary>
+    /// Helper utilities for Svg Preview Handler.
+    /// </summary>
+    public class SvgPreviewHandlerHelper
+    {
+        /// <summary>
+        /// Dictionary of elements in lower case that are blocked from Svg for preview pane.
+        /// Reference for list of Svg Elements: https://developer.mozilla.org/en-US/docs/Web/SVG/Element.
+        /// </summary>
+        private static Dictionary<string, bool> blockedElementsName = new Dictionary<string, bool>
+        {
+            { "script", true },
+            { "image", true },
+            { "feimage", true },
+        };
+
+        /// <summary>
+        /// Check if any of the blocked elements present in Svg.
+        /// </summary>
+        /// <param name="svgData">Input Svg.</param>
+        /// <returns>Returns true in case any of the blocked element is present otherwise false.</returns>
+        public static bool CheckBlockedElements(string svgData)
+        {
+            bool foundBlockedElement = false;
+            if (string.IsNullOrWhiteSpace(svgData))
+            {
+                return foundBlockedElement;
+            }
+
+            // Check if any of the blocked element is present. If failed to parse or iterate over Svg return default false.
+            // No need to throw because all the external content and script are blocked on the Web Browser Control itself.
+            try
+            {
+                var doc = XDocument.Parse(svgData);
+                var elements = doc.Descendants().ToList();
+                foreach (XElement element in elements)
+                {
+                    var elementName = element?.Name?.LocalName?.ToLower();
+                    if (elementName != null && blockedElementsName.ContainsKey(elementName))
+                    {
+                        foundBlockedElement = true;
+
+                        // No need to iterate further since we are displaying info bar with condition of atleast one occurrence of blocked element is present.
+                        break;
+                    }
+                }
+            }
+            catch (Exception)
+            {
+            }
+
+            return foundBlockedElement;
+        }
+    }
+}

src/modules/previewpane/common/cominterop/IThumbnailProvider.cs

@@ -0,0 +1,47 @@
+// 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.Runtime.InteropServices;
+
+namespace Common.ComInterlop
+{
+    /// <summary>
+    /// Specifies the alpha type of the image.
+    /// </summary>
+    public enum WTS_ALPHATYPE : int
+    {
+        /// <summary>
+        /// he bitmap is an unknown format. The Shell tries nonetheless to detect whether the image has an alpha channel.
+        /// </summary>
+        WTSAT_UNKNOWN = 0,
+
+        /// <summary>
+        /// The bitmap is an RGB image without alpha. The alpha channel is invalid and the Shell ignores it.
+        /// </summary>
+        WTSAT_RGB = 1,
+
+        /// <summary>
+        /// The bitmap is an ARGB image with a valid alpha channel.
+        /// </summary>
+        WTSAT_ARGB = 2,
+    }
+
+    /// <summary>
+    /// Exposes methods for thumbnail provider.
+    /// </summary>
+    [ComImport]
+    [Guid("e357fccd-a995-4576-b01f-234630154e96")]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    public interface IThumbnailProvider
+    {
+        /// <summary>
+        /// Gets a thumbnail image and alpha type.
+        /// </summary>
+        /// <param name="cx">The maximum thumbnail size, in pixels.</param>
+        /// <param name="phbmp">When this method returns, contains a pointer to the thumbnail image handle.</param>
+        /// <param name="pdwAlpha">When this method returns, contains a pointer to one of the values from the WTS_ALPHATYPE enumeration.</param>
+        void GetThumbnail(uint cx, out IntPtr phbmp, out WTS_ALPHATYPE pdwAlpha);
+    }
+}

src/modules/previewpane/common/cominterop/IViewObject.cs

@@ -0,0 +1,33 @@
+// 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.Runtime.InteropServices;
+
+namespace Common.ComInterlop
+{
+    /// <summary>
+    /// Enables an object to display itself directly without passing a data object to the caller.
+    /// </summary>
+    [ComImport]
+    [Guid("0000010D-0000-0000-C000-000000000046")]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    public interface IViewObject
+    {
+        /// <summary>
+        /// Draws a representation of an object onto the specified device context.
+        /// </summary>
+        /// <param name="dwAspect">Specifies the aspect to be drawn, that is, how the object is to be represented.</param>
+        /// <param name="lindex">Portion of the object that is of interest for the draw operation.</param>
+        /// <param name="pvAspect">Pointer to additional information in a DVASPECTINFO structure that enables drawing optimizations depending on the aspect specified.</param>
+        /// <param name="ptd">Pointer to the DVTARGETDEVICE structure that describes the device for which the object is to be rendered.</param>
+        /// <param name="hdcTargetDev">Information context for the target device indicated by the ptd parameter from which the object can extract device metrics and test the device's capabilities.</param>
+        /// <param name="hdcDraw">Device context on which to draw. For a windowless object, the hdcDraw parameter should be in MM_TEXT mapping mode with its logical coordinates matching the client coordinates of the containing window.</param>
+        /// <param name="lprcBounds">Pointer to a RECTL structure specifying the rectangle on hdcDraw and in which the object should be drawn.</param>
+        /// <param name="lprcWBounds">If hdcDraw is a metafile device context, pointer to a RECTL structure specifying the bounding rectangle in the underlying metafile.</param>
+        /// <param name="pfnContinue">Pointer to a callback function that the view object should call periodically during a lengthy drawing operation to determine whether the operation should continue or be canceled.</param>
+        /// <param name="dwContinue">Value to pass as a parameter to the function pointed to by the pfnContinue parameter.</param>
+        void Draw([MarshalAs(UnmanagedType.U4)] uint dwAspect, int lindex, IntPtr pvAspect, [In] IntPtr ptd, IntPtr hdcTargetDev, IntPtr hdcDraw, [MarshalAs(UnmanagedType.Struct)] ref RECT lprcBounds, [In] IntPtr lprcWBounds, IntPtr pfnContinue, [MarshalAs(UnmanagedType.U4)] uint dwContinue);
+    }
+}