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

@@ -22,38 +22,28 @@ internal static bool IsScreenReaderActive()
         }
 
         private static bool IsAnyWindowsScreenReaderEnabled() {
-            // The supposedly official way to check for a screen reader on
-            // Windows is SystemParametersInfo(SPI_GETSCREENREADER, ...) but it
-            // doesn't detect the in-box Windows Narrator and is otherwise known
-            // to be problematic.
+            // The official way to check for a screen reader on Windows is
+            // SystemParametersInfo(SPI_GETSCREENREADER, ...) but it 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
+            // 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 Windows Narrator using the NarratorRunning mutex
+            // 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"))
                 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)
-            {
-                if (PlatformWindows.IsLibraryLoaded(library))
-                    return true;
-            }
-
             return false;
         }
 

PSReadLine/PlatformWindows.cs

@@ -92,28 +92,6 @@ 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);