Merge pull request #8990 from Kuldeep-MS/feat/add-hyphen-ligature

Adding AppContext Switch for disabling special character ligatures

Author: Kuldeep-MS

src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/CoreAppContextSwitches.cs

@@ -395,6 +395,21 @@ public static bool EnableHardwareAccelerationInRdp
 
         #endregion
 
+        #region DisableSpecialCharacterLigature
+
+        internal const string DisableSpecialCharacterLigatureSwitchName = "Switch.System.Windows.DisableSpecialCharacterLigature";
+        private static int _disableSpecialCharacterLigature;
+        public static bool DisableSpecialCharacterLigature
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return LocalAppContext.GetCachedSwitchValue(DisableSpecialCharacterLigatureSwitchName, ref _disableSpecialCharacterLigature);
+            }
+        }
+
+        #endregion
+
     }
 #pragma warning restore 436
 }

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/AppContextDefaultValues.cs

@@ -61,6 +61,7 @@ private static void InitializeNetFxSwitchDefaultsForNetCoreRuntime()
             LocalAppContext.DefineSwitchDefault(CoreAppContextSwitches.DoNotUsePresentationDpiCapabilityTier3OrGreaterSwitchName, false);
             LocalAppContext.DefineSwitchDefault(CoreAppContextSwitches.AllowExternalProcessToBlockAccessToTemporaryFilesSwitchName, false);
             LocalAppContext.DefineSwitchDefault(CoreAppContextSwitches.EnableHardwareAccelerationInRdpSwitchName, false);
+            LocalAppContext.DefineSwitchDefault(CoreAppContextSwitches.DisableSpecialCharacterLigatureSwitchName, false);
         }
     }
 #pragma warning restore 436

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/InterOp/HwndTarget.cs

@@ -276,6 +276,7 @@ public HwndTarget(IntPtr hwnd)
                 //      DPI_AWARENESS_CONTEXT (DpiAwarenessContext property)
                 //      Window DPI scale (CurrentDpiScale field)
                 InitializeDpiAwarenessAndDpiScales();
+                CheckAndDisableSpecialCharacterLigature();
 
                 _worldTransform = new MatrixTransform(
                     new Matrix(
@@ -311,6 +312,14 @@ public HwndTarget(IntPtr hwnd)
             }
         }
 
+        /// <summary>
+        /// Disables hyphen ligatures if user has exlicitly wants it
+        /// </summary>
+        private void CheckAndDisableSpecialCharacterLigature()
+        {
+            NativeMethodsSetLastError.LsDisableSpecialCharacterLigature(CoreAppContextSwitches.DisableSpecialCharacterLigature);
+        }
+
         /// <summary>
         /// Ensures the system/primary monitor's DPI scale. Get the process DPI awareness.
         /// </summary>

src/Microsoft.DotNet.Wpf/src/Shared/MS/Win32/NativeMethodsSetLastError.cs

@@ -161,5 +161,8 @@ internal static class NativeMethodsSetLastError
         public static extern IntPtr SetWindowLongPtrWndProc(HandleRef hWnd, int nIndex, NativeMethods.WndProc dwNewLong);
 
 #endif
+
+        [DllImport(PresentationNativeDll, EntryPoint="LsDisableSpecialCharacterLigature")]
+        public static extern void LsDisableSpecialCharacterLigature(bool fDisable);
     }
 }