518 lookup system def before user def

OneMore/Helpers/Office/Word.cs

@@ -4,12 +4,10 @@
 
 namespace River.OneMoreAddIn.Helpers.Office
 {
-	using Microsoft.Win32;
 	using System;
 	using System.IO;
 	using System.Linq;
 	using System.Runtime.InteropServices;
-	using System.Text;
 	using System.Xml.Linq;
 	using MSWord = Microsoft.Office.Interop.Word;
 
@@ -245,33 +243,29 @@ public void ResolveAttachmentRefs(string docPath, XElement root, bool embedded)
 		{
 			var ext = Path.GetExtension(target);
 
-			var application = GetApplication(ext);
-			if (!string.IsNullOrEmpty(application))
+			var association = RegistryHelper.GetAssociation(ext);
+			if (association != null)
 			{
-				object progID = GetProgID(ext);
-				if (!string.IsNullOrEmpty(progID as string))
-				{
-					selection.Text = String.Empty;
-
-					object filename = target;
-					object linkToFile = !embedded;
-					object displayAsIcon = true;
-					object iconIndex = 0;
-					object iconFilename = application;
-					object iconLabel = Path.GetFileName(target);
-
-					selection.InlineShapes.AddOLEObject(
-						progID,
-						ref filename,
-						ref linkToFile,
-						ref displayAsIcon,
-						ref iconFilename,
-						ref iconIndex,
-						ref iconLabel
-						);
-
-					return;
-				}
+				selection.Text = String.Empty;
+
+				object filename = target;
+				object linkToFile = !embedded;
+				object displayAsIcon = true;
+				object iconIndex = association.IconIndex;
+				object iconFilename = association.IconFilename;
+				object iconLabel = Path.GetFileName(target);
+
+				selection.InlineShapes.AddOLEObject(
+					association.ProgID,
+					ref filename,
+					ref linkToFile,
+					ref displayAsIcon,
+					ref iconFilename,
+					ref iconIndex,
+					ref iconLabel
+					);
+
+				return;
 			}
 
 			// get a well-formed URL but also decode it so avoid encoding problems
@@ -283,48 +277,5 @@ ref iconLabel
 			object uri = System.Web.HttpUtility.UrlDecode(new Uri(target).AbsoluteUri);
 			word.Selection.Hyperlinks.Add(range, ref uri);
 		}
-
-
-		private string GetApplication(string ext)
-		{
-			string application = null;
-
-			// fetch length of output buffer
-			uint length = 0;
-			uint ret = Native.AssocQueryString(
-				Native.AssocF.None, Native.AssocStr.Executable, ext, null, null, ref length);
-
-			if (ret == 1) // expect S_FALSE
-			{
-				// fill buffer with executable path
-				var buffer = new StringBuilder((int)length); // long enough for zero-term
-				ret = Native.AssocQueryString(
-					Native.AssocF.None, Native.AssocStr.Executable, ext, null, buffer, ref length);
-
-				if (ret == 0) // expect S_OK
-				{
-					application = buffer.ToString();
-				}
-			}
-
-			return application;
-		}
-
-
-		private string GetProgID(string ext)
-		{
-			string progID = null;
-
-			using (var key = Registry.CurrentUser.OpenSubKey(
-				$@"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\{ext}\UserChoice"))
-			{
-				if (key != null)
-				{
-					progID = key.GetValue("ProgID") as string;
-				}
-			}
-
-			return progID;
-		}
 	}
 }

OneMore/Helpers/RegistryHelper.cs

@@ -0,0 +1,197 @@
+//************************************************************************************************
+// Copyright © 2022 Steven M Cohn.  All rights reserved.
+//************************************************************************************************
+
+namespace River.OneMoreAddIn.Helpers
+{
+	using Microsoft.Win32;
+	using System;
+	using System.Linq;
+	using System.Text;
+	using System.Text.RegularExpressions;
+
+
+	internal class FileAssociation
+	{
+		public string ProgID { get; set; }
+		public string Application { get; set; }
+		public string DefaultExt { get; set; }
+		public string IconFilename { get; set; }
+		public int IconIndex { get; set; }
+	}
+
+
+	internal static class RegistryHelper
+	{
+		/// <summary>
+		/// Load the registered application details for a given file extension.
+		/// </summary>
+		/// <param name="ext">A file extension string similar to ".txt"</param>
+		/// <returns>A FileAssociation instance or null if not found</returns>
+		public static FileAssociation GetAssociation(string ext)
+		{
+			var application = GetApplication(ext);
+			if (application == null)
+			{
+				return null;
+			}
+
+			var association = LookupAssociation(ext, application);
+			if (association != null)
+			{
+				return association;
+			}
+
+			var progID = GetUserChoiceProgID(ext);
+			if (progID != null)
+			{
+				association = new FileAssociation
+				{
+					Application = application,
+					ProgID = progID,
+					DefaultExt = ext,
+					IconFilename = application,
+					IconIndex = 0
+				};
+			}
+
+			return association;
+		}
+
+
+		private static string GetApplication(string ext)
+		{
+			string application = null;
+
+			// fetch length of output buffer
+			uint length = 0;
+			uint ret = Native.AssocQueryString(
+				Native.AssocF.None, Native.AssocStr.Executable, ext, null, null, ref length);
+
+			if (ret == 1) // expect S_FALSE
+			{
+				// fill buffer with executable path
+				var buffer = new StringBuilder((int)length); // long enough for zero-term
+				ret = Native.AssocQueryString(
+					Native.AssocF.None, Native.AssocStr.Executable, ext, null, buffer, ref length);
+
+				if (ret == 0) // expect S_OK
+				{
+					application = buffer.ToString();
+				}
+			}
+
+			return application;
+		}
+
+
+		private static FileAssociation LookupAssociation(string ext, string application)
+		{
+			using (var key = Registry.ClassesRoot.OpenSubKey("CLSID"))
+			{
+				foreach (var classNames in key.GetSubKeyNames())
+				{
+					using (var classKey = key.OpenSubKey(classNames))
+					{
+						var association = GetDetails(classKey, ext, application);
+						if (association != null)
+						{
+							return association;
+						}
+					}
+				}
+			}
+
+			return null;
+		}
+
+
+		private static FileAssociation GetDetails(RegistryKey key, string ext, string application)
+		{
+			var names = key.GetSubKeyNames();
+			if (names.Contains("VersionIndependentProgID") &&
+				names.Contains("DefaultExtension") &&
+				names.Contains("DefaultIcon") &&
+				(names.Contains("InprocServer32") || names.Contains("LocalServer32"))
+				)
+			{
+				var association = new FileAssociation
+				{
+					ProgID = (string)key.GetValue(string.Empty)
+				};
+
+				if (!string.IsNullOrEmpty(association.ProgID))
+				{
+					association.DefaultExt = GetDefaultValue(key, "DefaultExtension");
+
+					if (string.IsNullOrEmpty(association.DefaultExt) ||
+						!Regex.IsMatch(association.DefaultExt, $@"\{ext}\b?"))
+					{
+						return null;
+					}
+
+					association.Application = GetDefaultValue(key, "InprocServer32");
+					if (string.IsNullOrEmpty(association.Application))
+					{
+						association.Application = GetDefaultValue(key, "LocalServer32");
+					}
+
+					if (!string.IsNullOrEmpty(association.Application) &&
+						association.Application.Equals(application, StringComparison.InvariantCultureIgnoreCase))
+					{
+						var defaultIcon = GetDefaultValue(key, "DefaultIcon");
+						var matches = Regex.Matches(defaultIcon, @"([^,]+),(\d+)");
+						if (matches.Count > 0)
+						{
+							association.IconFilename = matches[0].Groups[1].Value;
+							if (int.TryParse(matches[0].Groups[2].Value, out var iconIndex))
+							{
+								association.IconIndex = iconIndex;
+							}
+						}
+						else
+						{
+							association.IconFilename = association.Application;
+							association.IconIndex = 0;
+						}
+
+						return association;
+					}
+				}
+			}
+
+			return null;
+		}
+
+
+		private static string GetDefaultValue(RegistryKey key, string name)
+		{
+			using (var subkey = key.OpenSubKey(name))
+			{
+				if (subkey != null)
+				{
+					return (string)subkey.GetValue(string.Empty);
+				}
+			}
+
+			return null;
+		}
+
+
+		private static string GetUserChoiceProgID(string ext)
+		{
+			string progID = null;
+			using (var key = Registry.CurrentUser.OpenSubKey(
+				$@"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\{ext}\UserChoice"))
+			{
+				if (key != null)
+				{
+					progID = (string)key.GetValue("ProgID");
+				}
+			}
+
+			return progID;
+		}
+
+	}
+}

OneMore/OneMore.csproj

@@ -444,6 +444,7 @@
     <Compile Include="Helpers\Office\Models\OutlookTaskFolders.cs" />
     <Compile Include="Helpers\Office\Models\OutlookTasks.cs" />
     <Compile Include="Helpers\Office\Outlook.cs" />
+    <Compile Include="Helpers\RegistryHelper.cs" />
     <Compile Include="Helpers\SingleThreaded.cs" />
     <Compile Include="Helpers\SynchronizationContextAwaiter.cs" />
     <Compile Include="Commands\Tools\Updater\IUpdateReport.cs" />