Remove Keys.ShouldInsert (#822)

The method Keys.ShouldInsert was a misguided attempt to avoid inserting
keys where there is no binding but the key really doesn't make sense as
input.

Unfortunately it is just causing more pain and probably wasn't
addressing a serious problem, so I'm removing it.

Fix #798

Author: lzybkr

PSReadLine/KeyBindings.cs

@@ -245,6 +245,9 @@ void SetDefaultWindowsBindings()
                 { Keys.PageDown,               MakeKeyHandler(ScrollDisplayDown,         "ScrollDisplayDown") },
                 { Keys.CtrlPageUp,             MakeKeyHandler(ScrollDisplayUpLine,       "ScrollDisplayUpLine") },
                 { Keys.CtrlPageDown,           MakeKeyHandler(ScrollDisplayDownLine,     "ScrollDisplayDownLine") },
+                { Keys.VolumeDown,             MakeKeyHandler(Ignore,                    "Ignore") },
+                { Keys.VolumeUp,               MakeKeyHandler(Ignore,                    "Ignore") },
+                { Keys.VolumeMute,             MakeKeyHandler(Ignore,                    "Ignore") },
             };
 
             // Some bindings are not available on certain platforms
@@ -334,6 +337,9 @@ void SetDefaultEmacsBindings()
                 { Keys.CtrlAltY,        MakeKeyHandler(YankNthArg,           "YankNthArg") },
                 { Keys.PageUp,          MakeKeyHandler(ScrollDisplayUp,      "ScrollDisplayUp") },
                 { Keys.PageDown,        MakeKeyHandler(ScrollDisplayDown,    "ScrollDisplayDown") },
+                { Keys.VolumeDown,      MakeKeyHandler(Ignore,               "Ignore") },
+                { Keys.VolumeUp,        MakeKeyHandler(Ignore,               "Ignore") },
+                { Keys.VolumeMute,      MakeKeyHandler(Ignore,               "Ignore") },
             };
 
             // Some bindings are not available on certain platforms

PSReadLine/KeyBindings.vi.cs

@@ -86,7 +86,10 @@ private void SetDefaultViBindings()
                 { Keys.ShiftF3,         MakeKeyHandler(CharacterSearchBackward,"CharacterSearchBackward") },
                 { Keys.CtrlAltQuestion, MakeKeyHandler(ShowKeyBindings,        "ShowKeyBindings") },
                 { Keys.CtrlR,           MakeKeyHandler(ViSearchHistoryBackward,"ViSearchHistoryBackward") },
-                { Keys.CtrlS,           MakeKeyHandler(SearchForward,          "SearchForward") }
+                { Keys.CtrlS,           MakeKeyHandler(SearchForward,          "SearchForward") },
+                { Keys.VolumeDown,      MakeKeyHandler(Ignore,                 "Ignore") },
+                { Keys.VolumeUp,        MakeKeyHandler(Ignore,                 "Ignore") },
+                { Keys.VolumeMute,      MakeKeyHandler(Ignore,                 "Ignore") },
             };
 
             // Some bindings are not available on certain platforms
@@ -205,7 +208,10 @@ private void SetDefaultViBindings()
                 { Keys.Minus,           MakeKeyHandler(PreviousHistory,      "PreviousHistory") },
                 { Keys.Period,          MakeKeyHandler(RepeatLastCommand,    "RepeatLastCommand") },
                 { Keys.Semicolon,       MakeKeyHandler(RepeatLastCharSearch, "RepeatLastCharSearch") },
-                { Keys.Comma,           MakeKeyHandler(RepeatLastCharSearchBackwards, "RepeatLastCharSearchBackwards") }
+                { Keys.Comma,           MakeKeyHandler(RepeatLastCharSearchBackwards, "RepeatLastCharSearchBackwards") },
+                { Keys.VolumeDown,      MakeKeyHandler(Ignore,               "Ignore") },
+                { Keys.VolumeUp,        MakeKeyHandler(Ignore,               "Ignore") },
+                { Keys.VolumeMute,      MakeKeyHandler(Ignore,               "Ignore") },
             };
 
             // Some bindings are not available on certain platforms

PSReadLine/Keys.cs

@@ -363,6 +363,9 @@ static ConsoleKeyInfo CtrlAlt(char c)
         public static ConsoleKeyInfo CtrlAltRBracket     = CtrlAlt(']');
         public static ConsoleKeyInfo CtrlAltQuestion     = CtrlAlt('?');
 
+        public static ConsoleKeyInfo VolumeUp   = Key(ConsoleKey.VolumeUp);
+        public static ConsoleKeyInfo VolumeDown = Key(ConsoleKey.VolumeDown);
+        public static ConsoleKeyInfo VolumeMute = Key(ConsoleKey.VolumeMute);
 
         [DllImport("user32.dll")]
         public static extern int VkKeyScan(short wAsciiVal);
@@ -469,6 +472,9 @@ internal static bool IgnoreKeyChar(this ConsoleKeyInfo key)
                 case ConsoleKey.RightArrow:
                 case ConsoleKey.Tab:
                 case ConsoleKey.UpArrow:
+                case ConsoleKey.VolumeUp:
+                case ConsoleKey.VolumeDown:
+                case ConsoleKey.VolumeMute:
                     return true;
             }
 
@@ -560,43 +566,6 @@ internal static int GetNormalizedHashCode(this ConsoleKeyInfo obj)
             return unchecked(((h1 << 5) + h1) ^ h2);
         }
 
-        internal static bool ShouldInsert(this ConsoleKeyInfo key)
-        {
-            var keyChar = key.KeyChar;
-            if (keyChar == '\0') return false;
-            foreach (char c in " `~!@#$%^&*()-_=+[{]}\\|;:'\",<.>/?") {
-                // we always want to insert chars essential to the PowerShell experience
-                if (keyChar == c) { return true; }
-            }
-            if (key.Modifiers != 0)
-            {
-                // We want to ignore control sequences - but distinguishing a control sequence
-                // isn't as simple as it could be because we will get inconsistent modifiers
-                // depending on the OS or keyboard layout.
-                //
-                // Windows will give us the key state even if we didn't care, e.g. it's normal
-                // to see Alt+Control (AltGr) on a Spanish, French, or German keyboard for many normal
-                // characters. So we just ask the OS what mods to expect for a given key.
-                // On non-Windows - anything but Shift is assumed to be a control sequence.
-                ConsoleModifiers expectedMods = default(ConsoleModifiers);
-                if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
-                {
-                    var keyWithMods = WindowsKeyScan(key.KeyChar);
-                    if (keyWithMods.HasValue)
-                    {
-                        expectedMods = keyWithMods.Value.Modifiers;
-                    }
-                }
-                else
-                {
-                    expectedMods = key.Modifiers & ConsoleModifiers.Shift;
-                }
-                return key.Modifiers == expectedMods;
-            }
-
-            return true;
-        }
-
         internal static bool IsUnmodifiedChar(this ConsoleKeyInfo key, char c)
         {
             return key.KeyChar == c &&

PSReadLine/ReadLine.cs

@@ -600,7 +600,7 @@ void ProcessOneKey(ConsoleKeyInfo key, Dictionary<ConsoleKeyInfo, KeyHandler> di
                     handler.Action(key, arg);
                 }
             }
-            else if (!ignoreIfNoAction && key.ShouldInsert())
+            else if (!ignoreIfNoAction)
             {
                 SelfInsert(key, arg);
             }
@@ -848,6 +848,11 @@ private static void Chord(ConsoleKeyInfo? key = null, object arg = null)
             }
         }
 
+        [SuppressMessage("Microsoft.Design", "CA1026:DefaultParametersShouldNotBeUsed")]
+        private static void Ignore(ConsoleKeyInfo? key = null, object arg = null)
+        {
+        }
+
         /// <summary>
         /// Abort current action, e.g. incremental history search.
         /// </summary>

PSReadLine/Replace.vi.cs

@@ -44,7 +44,7 @@ private static void ViReplaceUntilEsc(ConsoleKeyInfo? key, object arg)
                         _singleton.Render();
                     }
                 }
-                else if (nextKey.ShouldInsert())
+                else
                 {
                     if (_singleton._current >= _singleton._buffer.Length)
                     {