Revert to system parameter screen reader check on Windows

That algorithm doesn't work for a non-windowed app like PowerShell.

Author: andyleejordan

PSReadLine/Accessibility.cs

@@ -22,7 +22,7 @@ internal static bool IsScreenReaderActive()
             }
 
             // TODO: Support Linux per https://code.visualstudio.com/docs/configure/accessibility/accessibility
-                return false;
+            return false;
         }
 
         private static bool IsAnyWindowsScreenReaderEnabled()
@@ -32,31 +32,25 @@ private static bool IsAnyWindowsScreenReaderEnabled()
             // doesn't detect the in-box Windows Narrator and is otherwise known
             // to be problematic.
             //
-            // The following is adapted from the Electron project, under the MIT License.
-            // Hence this is also how VS Code detects screenreaders.
-            // See: https://github.com/electron/electron/pull/39988
-
-            // Check for Windows Narrator using the NarratorRunning mutex
-            if (PlatformWindows.IsMutexPresent("NarratorRunning"))
+            // Unfortunately, the alternative method used by Electron and
+            // Chromium, where the relevant screen reader libraries (modules)
+            // are checked for does not work in the context of PowerShell
+            // because it relies on those applications injecting themselves into
+            // the app. Which they do not because it's not a windowed app, so
+            // we're stuck using the known-to-be-buggy way.
+            bool spiScreenReader = false;
+            PlatformWindows.SystemParametersInfo(PlatformWindows.SPI_GETSCREENREADER, 0, ref spiScreenReader, 0);
+            if (spiScreenReader)
+            {
                 return true;
+            }
 
-            // Check for various screen reader libraries
-            string[] screenReaderLibraries = {
-                // NVDA
-                "nvdaHelperRemote.dll",
-                // JAWS
-                "jhook.dll",
-                // Window-Eyes
-                "gwhk64.dll", 
-                "gwmhook.dll",
-                // ZoomText
-                "AiSquared.Infuser.HookLib.dll"
-            };
-
-            foreach (string library in screenReaderLibraries)
+            // At least we can correctly check for Windows Narrator using the
+            // NarratorRunning mutex (which is mostly not broken with
+            // PSReadLine, as it were).
+            if (PlatformWindows.IsMutexPresent("NarratorRunning"))
             {
-                if (PlatformWindows.IsLibraryLoaded(library))
-                    return true;
+                return true;
             }
 
             return false;

PSReadLine/PlatformWindows.cs

@@ -94,28 +94,6 @@ internal static bool IsMutexPresent(string name)
         }
     }
 
-    [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
-    [return: MarshalAs(UnmanagedType.Bool)]
-    internal static extern bool GetModuleHandleEx(uint dwFlags, string lpModuleName, out IntPtr phModule);
-
-    internal static bool IsLibraryLoaded(string name)
-    {
-        // Prevents the reference count for the module being incremented.
-        const uint GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT = 0x00000002;
-        try
-        {
-            bool retValue = GetModuleHandleEx(
-                GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, 
-                name, 
-                out IntPtr phModule);
-            return phModule != IntPtr.Zero;
-        }
-        catch
-        {
-            return false;
-        }
-    }
-
     [DllImport("kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
     static extern bool SetConsoleCtrlHandler(BreakHandler handlerRoutine, bool add);