Win32 magic to properly identify left and right keys.

src/Windows/Avalonia.Win32/Input/KeyInterop.cs

@@ -2,7 +2,6 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using System.Collections.Generic;
-using System.Text;
 using Avalonia.Input;
 using Avalonia.Win32.Interop;
 
@@ -364,33 +363,80 @@ namespace Avalonia.Win32.Input
             { 254, Key.OemClear },
         };
 
-        public static Key KeyFromVirtualKey(int virtualKey, int flags)
+        /// <summary>
+        /// Indicates whether the key is an extended key, such as the right-hand ALT and CTRL keys.
+        /// According to https://docs.microsoft.com/en-us/windows/win32/inputdev/wm-keydown.
+        /// </summary>
+        private static bool IsExtended(int keyData)
         {
-            s_keyFromVirtualKey.TryGetValue(virtualKey, out var result);
-
-            // Indicates whether the key is an extended key, such as the right-hand ALT and CTRL keys.
-            // According to https://docs.microsoft.com/en-us/windows/win32/inputdev/wm-keydown.
             const int extendedMask = 1 << 24;
-            bool isExtended = (flags & extendedMask) != 0;
 
-            if (isExtended)
+            return (keyData & extendedMask) != 0;
+        }
+
+        private static int GetVirtualKey(int virtualKey, int keyData)
+        {
+            // Adapted from https://github.com/dotnet/wpf/blob/master/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/InterOp/HwndKeyboardInputProvider.cs.
+
+            if (virtualKey == (int)UnmanagedMethods.VirtualKeyStates.VK_SHIFT)
             {
-                return result switch
+                // Bits from 16 to 23 represent scan code.
+                const int scanCodeMask = 0xFF0000;
+
+                var scanCode = (keyData & scanCodeMask) >> 16;
+
+                virtualKey = (int)UnmanagedMethods.MapVirtualKey((uint)scanCode, (uint)UnmanagedMethods.MapVirtualKeyMapTypes.MAPVK_VSC_TO_VK_EX);
+
+                if (virtualKey == 0)
                 {
-                    Key.LeftAlt => Key.RightAlt,
-                    Key.LeftCtrl => Key.RightCtrl,
-                    Key.LeftShift => Key.RightShift,
-                    _ => result
-                };
+                    virtualKey = (int)UnmanagedMethods.VirtualKeyStates.VK_LSHIFT;
+                }
             }
 
+            if (virtualKey == (int)UnmanagedMethods.VirtualKeyStates.VK_MENU)
+            {
+                bool isRight = IsExtended(keyData);
+
+                if (isRight)
+                {
+                    virtualKey = (int)UnmanagedMethods.VirtualKeyStates.VK_RMENU;
+                }
+                else
+                {
+                    virtualKey = (int)UnmanagedMethods.VirtualKeyStates.VK_LMENU;
+                }
+            }
+            
+            if (virtualKey == (int)UnmanagedMethods.VirtualKeyStates.VK_CONTROL)
+            {
+                bool isRight = IsExtended(keyData);
+
+                if (isRight)
+                {
+                    virtualKey = (int)UnmanagedMethods.VirtualKeyStates.VK_RCONTROL;
+                }
+                else
+                {
+                    virtualKey = (int)UnmanagedMethods.VirtualKeyStates.VK_LCONTROL;
+                }
+            }
+
+            return virtualKey;
+        }
+
+        public static Key KeyFromVirtualKey(int virtualKey, int keyData)
+        {
+            virtualKey = GetVirtualKey(virtualKey, keyData);
+
+            s_keyFromVirtualKey.TryGetValue(virtualKey, out var result);
+
             return result;
         }
 
         public static int VirtualKeyFromKey(Key key)
         {
-            int result;
-            s_virtualKeyFromKey.TryGetValue(key, out result);
+            s_virtualKeyFromKey.TryGetValue(key, out var result);
+
             return result;
         }
     }

src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs

@@ -241,6 +241,170 @@ namespace Avalonia.Win32.Interop
             MK_XBUTTON2 = 0x0040
         }
 
+        public enum VirtualKeyStates : int
+        {
+            VK_LBUTTON = 0x01,
+            VK_RBUTTON = 0x02,
+            VK_CANCEL = 0x03,
+            VK_MBUTTON = 0x04,
+            VK_XBUTTON1 = 0x05,
+            VK_XBUTTON2 = 0x06,
+            VK_BACK = 0x08,
+            VK_TAB = 0x09,
+            VK_CLEAR = 0x0C,
+            VK_RETURN = 0x0D,
+            VK_SHIFT = 0x10,
+            VK_CONTROL = 0x11,
+            VK_MENU = 0x12,
+            VK_PAUSE = 0x13,
+            VK_CAPITAL = 0x14,
+            VK_KANA = 0x15,
+            VK_HANGEUL = 0x15,
+            VK_HANGUL = 0x15,
+            VK_JUNJA = 0x17,
+            VK_FINAL = 0x18,
+            VK_HANJA = 0x19,
+            VK_KANJI = 0x19,
+            VK_ESCAPE = 0x1B,
+            VK_CONVERT = 0x1C,
+            VK_NONCONVERT = 0x1D,
+            VK_ACCEPT = 0x1E,
+            VK_MODECHANGE = 0x1F,
+            VK_SPACE = 0x20,
+            VK_PRIOR = 0x21,
+            VK_NEXT = 0x22,
+            VK_END = 0x23,
+            VK_HOME = 0x24,
+            VK_LEFT = 0x25,
+            VK_UP = 0x26,
+            VK_RIGHT = 0x27,
+            VK_DOWN = 0x28,
+            VK_SELECT = 0x29,
+            VK_PRINT = 0x2A,
+            VK_EXECUTE = 0x2B,
+            VK_SNAPSHOT = 0x2C,
+            VK_INSERT = 0x2D,
+            VK_DELETE = 0x2E,
+            VK_HELP = 0x2F,
+            VK_LWIN = 0x5B,
+            VK_RWIN = 0x5C,
+            VK_APPS = 0x5D,
+            VK_SLEEP = 0x5F,
+            VK_NUMPAD0 = 0x60,
+            VK_NUMPAD1 = 0x61,
+            VK_NUMPAD2 = 0x62,
+            VK_NUMPAD3 = 0x63,
+            VK_NUMPAD4 = 0x64,
+            VK_NUMPAD5 = 0x65,
+            VK_NUMPAD6 = 0x66,
+            VK_NUMPAD7 = 0x67,
+            VK_NUMPAD8 = 0x68,
+            VK_NUMPAD9 = 0x69,
+            VK_MULTIPLY = 0x6A,
+            VK_ADD = 0x6B,
+            VK_SEPARATOR = 0x6C,
+            VK_SUBTRACT = 0x6D,
+            VK_DECIMAL = 0x6E,
+            VK_DIVIDE = 0x6F,
+            VK_F1 = 0x70,
+            VK_F2 = 0x71,
+            VK_F3 = 0x72,
+            VK_F4 = 0x73,
+            VK_F5 = 0x74,
+            VK_F6 = 0x75,
+            VK_F7 = 0x76,
+            VK_F8 = 0x77,
+            VK_F9 = 0x78,
+            VK_F10 = 0x79,
+            VK_F11 = 0x7A,
+            VK_F12 = 0x7B,
+            VK_F13 = 0x7C,
+            VK_F14 = 0x7D,
+            VK_F15 = 0x7E,
+            VK_F16 = 0x7F,
+            VK_F17 = 0x80,
+            VK_F18 = 0x81,
+            VK_F19 = 0x82,
+            VK_F20 = 0x83,
+            VK_F21 = 0x84,
+            VK_F22 = 0x85,
+            VK_F23 = 0x86,
+            VK_F24 = 0x87,
+            VK_NUMLOCK = 0x90,
+            VK_SCROLL = 0x91,
+            VK_OEM_NEC_EQUAL = 0x92,
+            VK_OEM_FJ_JISHO = 0x92,
+            VK_OEM_FJ_MASSHOU = 0x93,
+            VK_OEM_FJ_TOUROKU = 0x94,
+            VK_OEM_FJ_LOYA = 0x95,
+            VK_OEM_FJ_ROYA = 0x96,
+            VK_LSHIFT = 0xA0,
+            VK_RSHIFT = 0xA1,
+            VK_LCONTROL = 0xA2,
+            VK_RCONTROL = 0xA3,
+            VK_LMENU = 0xA4,
+            VK_RMENU = 0xA5,
+            VK_BROWSER_BACK = 0xA6,
+            VK_BROWSER_FORWARD = 0xA7,
+            VK_BROWSER_REFRESH = 0xA8,
+            VK_BROWSER_STOP = 0xA9,
+            VK_BROWSER_SEARCH = 0xAA,
+            VK_BROWSER_FAVORITES = 0xAB,
+            VK_BROWSER_HOME = 0xAC,
+            VK_VOLUME_MUTE = 0xAD,
+            VK_VOLUME_DOWN = 0xAE,
+            VK_VOLUME_UP = 0xAF,
+            VK_MEDIA_NEXT_TRACK = 0xB0,
+            VK_MEDIA_PREV_TRACK = 0xB1,
+            VK_MEDIA_STOP = 0xB2,
+            VK_MEDIA_PLAY_PAUSE = 0xB3,
+            VK_LAUNCH_MAIL = 0xB4,
+            VK_LAUNCH_MEDIA_SELECT = 0xB5,
+            VK_LAUNCH_APP1 = 0xB6,
+            VK_LAUNCH_APP2 = 0xB7,
+            VK_OEM_1 = 0xBA,
+            VK_OEM_PLUS = 0xBB,
+            VK_OEM_COMMA = 0xBC,
+            VK_OEM_MINUS = 0xBD,
+            VK_OEM_PERIOD = 0xBE,
+            VK_OEM_2 = 0xBF,
+            VK_OEM_3 = 0xC0,
+            VK_OEM_4 = 0xDB,
+            VK_OEM_5 = 0xDC,
+            VK_OEM_6 = 0xDD,
+            VK_OEM_7 = 0xDE,
+            VK_OEM_8 = 0xDF,
+            VK_OEM_AX = 0xE1,
+            VK_OEM_102 = 0xE2,
+            VK_ICO_HELP = 0xE3,
+            VK_ICO_00 = 0xE4,
+            VK_PROCESSKEY = 0xE5,
+            VK_ICO_CLEAR = 0xE6,
+            VK_PACKET = 0xE7,
+            VK_OEM_RESET = 0xE9,
+            VK_OEM_JUMP = 0xEA,
+            VK_OEM_PA1 = 0xEB,
+            VK_OEM_PA2 = 0xEC,
+            VK_OEM_PA3 = 0xED,
+            VK_OEM_WSCTRL = 0xEE,
+            VK_OEM_CUSEL = 0xEF,
+            VK_OEM_ATTN = 0xF0,
+            VK_OEM_FINISH = 0xF1,
+            VK_OEM_COPY = 0xF2,
+            VK_OEM_AUTO = 0xF3,
+            VK_OEM_ENLW = 0xF4,
+            VK_OEM_BACKTAB = 0xF5,
+            VK_ATTN = 0xF6,
+            VK_CRSEL = 0xF7,
+            VK_EXSEL = 0xF8,
+            VK_EREOF = 0xF9,
+            VK_PLAY = 0xFA,
+            VK_ZOOM = 0xFB,
+            VK_NONAME = 0xFC,
+            VK_PA1 = 0xFD,
+            VK_OEM_CLEAR = 0xFE
+        }
+
         public enum WindowActivate
         {
             WA_INACTIVE,
@@ -581,6 +745,14 @@ namespace Avalonia.Win32.Interop
             WM_DISPATCH_WORK_ITEM = WM_USER,
         }
 
+        public enum MapVirtualKeyMapTypes : uint
+        {
+            MAPVK_VK_TO_VSC = 0x00,
+            MAPVK_VSC_TO_VK = 0x01,
+            MAPVK_VK_TO_CHAR = 0x02,
+            MAPVK_VSC_TO_VK_EX = 0x03,
+        }
+
         public enum BitmapCompressionMode : uint
         {
             BI_RGB = 0,
@@ -756,6 +928,9 @@ namespace Avalonia.Win32.Interop
         [DllImport("user32.dll")]
         public static extern bool GetKeyboardState(byte[] lpKeyState);
 
+        [DllImport("user32.dll", EntryPoint = "MapVirtualKeyW")]
+        public static extern uint MapVirtualKey(uint uCode, uint uMapType);
+
         [DllImport("user32.dll", EntryPoint = "GetMessageW")]
         public static extern sbyte GetMessage(out MSG lpMsg, IntPtr hWnd, uint wMsgFilterMin, uint wMsgFilterMax);