move TerminalFormatStrings to a separate file

src/libraries/System.Console/src/System.Console.csproj

@@ -158,6 +158,7 @@
   <!-- Unix -->
   <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\ConsolePal.Unix.cs" />
+    <Compile Include="System\ConsolePal.TerminalFormatStrings.cs" />
     <Compile Include="$(CommonPath)System\Console\ConsoleUtils.cs"
              Link="Common\System\Console\ConsoleUtils.cs" />
     <Compile Include="System\TermInfo.cs" />

src/libraries/System.Console/src/System/ConsolePal.TerminalFormatStrings.cs

@@ -0,0 +1,256 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using System.Diagnostics;
+
+namespace System;
+
+internal static partial class ConsolePal
+{
+    /// <summary>Provides format strings and related information for use with the current terminal.</summary>
+    internal sealed class TerminalFormatStrings
+    {
+        /// <summary>Gets the lazily-initialized terminal information for the terminal.</summary>
+        public static TerminalFormatStrings Instance { get { return s_instance.Value; } }
+        private static readonly Lazy<TerminalFormatStrings> s_instance = new Lazy<TerminalFormatStrings>(() => new TerminalFormatStrings(TermInfo.DatabaseFactory.ReadActiveDatabase()));
+
+        /// <summary>The format string to use to change the foreground color.</summary>
+        public readonly string? Foreground;
+        /// <summary>The format string to use to change the background color.</summary>
+        public readonly string? Background;
+        /// <summary>The format string to use to reset the foreground and background colors.</summary>
+        public readonly string? Reset;
+        /// <summary>The maximum number of colors supported by the terminal.</summary>
+        public readonly int MaxColors;
+        /// <summary>The number of columns in a format.</summary>
+        public readonly int Columns;
+        /// <summary>The number of lines in a format.</summary>
+        public readonly int Lines;
+        /// <summary>The format string to use to make cursor visible.</summary>
+        public readonly string? CursorVisible;
+        /// <summary>The format string to use to make cursor invisible</summary>
+        public readonly string? CursorInvisible;
+        /// <summary>The format string to use to set the window title.</summary>
+        public readonly string? Title;
+        /// <summary>The format string to use for an audible bell.</summary>
+        public readonly string? Bell;
+        /// <summary>The format string to use to clear the terminal.</summary>
+        public readonly string? Clear;
+        /// <summary>The format string to use to set the position of the cursor.</summary>
+        public readonly string? CursorAddress;
+        /// <summary>The format string to use to move the cursor to the left.</summary>
+        public readonly string? CursorLeft;
+        /// <summary>The format string to use to clear to the end of line.</summary>
+        public readonly string? ClrEol;
+        /// <summary>The ANSI-compatible string for the Cursor Position report request.</summary>
+        /// <remarks>
+        /// This should really be in user string 7 in the terminfo file, but some terminfo databases
+        /// are missing it.  As this is defined to be supported by any ANSI-compatible terminal,
+        /// we assume it's available; doing so means CursorTop/Left will work even if the terminfo database
+        /// doesn't contain it (as appears to be the case with e.g. screen and tmux on Ubuntu), at the risk
+        /// of outputting the sequence on some terminal that's not compatible.
+        /// </remarks>
+        public const string CursorPositionReport = "\x1B[6n";
+        /// <summary>
+        /// The dictionary of keystring to ConsoleKeyInfo.
+        /// Only some members of the ConsoleKeyInfo are used; in particular, the actual char is ignored.
+        /// </summary>
+        public readonly Dictionary<ReadOnlyMemory<char>, ConsoleKeyInfo> KeyFormatToConsoleKey =
+            new Dictionary<ReadOnlyMemory<char>, ConsoleKeyInfo>(new ReadOnlyMemoryContentComparer());
+
+        /// <summary> Max key length </summary>
+        public readonly int MaxKeyFormatLength;
+        /// <summary> Min key length </summary>
+        public readonly int MinKeyFormatLength;
+        /// <summary>The ANSI string used to enter "application" / "keypad transmit" mode.</summary>
+        public readonly string? KeypadXmit;
+
+        public TerminalFormatStrings(TermInfo.Database? db)
+        {
+            if (db == null)
+                return;
+
+            KeypadXmit = db.GetString(TermInfo.WellKnownStrings.KeypadXmit);
+            Foreground = db.GetString(TermInfo.WellKnownStrings.SetAnsiForeground);
+            Background = db.GetString(TermInfo.WellKnownStrings.SetAnsiBackground);
+            Reset = db.GetString(TermInfo.WellKnownStrings.OrigPairs) ?? db.GetString(TermInfo.WellKnownStrings.OrigColors);
+            Bell = db.GetString(TermInfo.WellKnownStrings.Bell);
+            Clear = db.GetString(TermInfo.WellKnownStrings.Clear);
+            Columns = db.GetNumber(TermInfo.WellKnownNumbers.Columns);
+            Lines = db.GetNumber(TermInfo.WellKnownNumbers.Lines);
+            CursorVisible = db.GetString(TermInfo.WellKnownStrings.CursorVisible);
+            CursorInvisible = db.GetString(TermInfo.WellKnownStrings.CursorInvisible);
+            CursorAddress = db.GetString(TermInfo.WellKnownStrings.CursorAddress);
+            CursorLeft = db.GetString(TermInfo.WellKnownStrings.CursorLeft);
+            ClrEol = db.GetString(TermInfo.WellKnownStrings.ClrEol);
+
+            Title = GetTitle(db);
+
+            Debug.WriteLineIf(db.GetString(TermInfo.WellKnownStrings.CursorPositionReport) != CursorPositionReport,
+                "Getting the cursor position will only work if the terminal supports the CPR sequence," +
+                "but the terminfo database does not contain an entry for it.");
+
+            int maxColors = db.GetNumber(TermInfo.WellKnownNumbers.MaxColors);
+            MaxColors = // normalize to either the full range of all ANSI colors, just the dark ones, or none
+                maxColors >= 16 ? 16 :
+                maxColors >= 8 ? 8 :
+                0;
+
+            AddKey(db, TermInfo.WellKnownStrings.KeyF1, ConsoleKey.F1);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF2, ConsoleKey.F2);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF3, ConsoleKey.F3);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF4, ConsoleKey.F4);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF5, ConsoleKey.F5);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF6, ConsoleKey.F6);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF7, ConsoleKey.F7);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF8, ConsoleKey.F8);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF9, ConsoleKey.F9);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF10, ConsoleKey.F10);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF11, ConsoleKey.F11);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF12, ConsoleKey.F12);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF13, ConsoleKey.F13);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF14, ConsoleKey.F14);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF15, ConsoleKey.F15);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF16, ConsoleKey.F16);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF17, ConsoleKey.F17);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF18, ConsoleKey.F18);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF19, ConsoleKey.F19);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF20, ConsoleKey.F20);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF21, ConsoleKey.F21);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF22, ConsoleKey.F22);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF23, ConsoleKey.F23);
+            AddKey(db, TermInfo.WellKnownStrings.KeyF24, ConsoleKey.F24);
+            AddKey(db, TermInfo.WellKnownStrings.KeyBackspace, ConsoleKey.Backspace);
+            AddKey(db, TermInfo.WellKnownStrings.KeyBackTab, ConsoleKey.Tab, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeyBegin, ConsoleKey.Home);
+            AddKey(db, TermInfo.WellKnownStrings.KeyClear, ConsoleKey.Clear);
+            AddKey(db, TermInfo.WellKnownStrings.KeyDelete, ConsoleKey.Delete);
+            AddKey(db, TermInfo.WellKnownStrings.KeyDown, ConsoleKey.DownArrow);
+            AddKey(db, TermInfo.WellKnownStrings.KeyEnd, ConsoleKey.End);
+            AddKey(db, TermInfo.WellKnownStrings.KeyEnter, ConsoleKey.Enter);
+            AddKey(db, TermInfo.WellKnownStrings.KeyHelp, ConsoleKey.Help);
+            AddKey(db, TermInfo.WellKnownStrings.KeyHome, ConsoleKey.Home);
+            AddKey(db, TermInfo.WellKnownStrings.KeyInsert, ConsoleKey.Insert);
+            AddKey(db, TermInfo.WellKnownStrings.KeyLeft, ConsoleKey.LeftArrow);
+            AddKey(db, TermInfo.WellKnownStrings.KeyPageDown, ConsoleKey.PageDown);
+            AddKey(db, TermInfo.WellKnownStrings.KeyPageUp, ConsoleKey.PageUp);
+            AddKey(db, TermInfo.WellKnownStrings.KeyPrint, ConsoleKey.Print);
+            AddKey(db, TermInfo.WellKnownStrings.KeyRight, ConsoleKey.RightArrow);
+            AddKey(db, TermInfo.WellKnownStrings.KeyScrollForward, ConsoleKey.PageDown, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeyScrollReverse, ConsoleKey.PageUp, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeySBegin, ConsoleKey.Home, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeySDelete, ConsoleKey.Delete, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeySHome, ConsoleKey.Home, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeySelect, ConsoleKey.Select);
+            AddKey(db, TermInfo.WellKnownStrings.KeySLeft, ConsoleKey.LeftArrow, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeySPrint, ConsoleKey.Print, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeySRight, ConsoleKey.RightArrow, shift: true, alt: false, control: false);
+            AddKey(db, TermInfo.WellKnownStrings.KeyUp, ConsoleKey.UpArrow);
+            AddPrefixKey(db, "kLFT", ConsoleKey.LeftArrow);
+            AddPrefixKey(db, "kRIT", ConsoleKey.RightArrow);
+            AddPrefixKey(db, "kUP", ConsoleKey.UpArrow);
+            AddPrefixKey(db, "kDN", ConsoleKey.DownArrow);
+            AddPrefixKey(db, "kDC", ConsoleKey.Delete);
+            AddPrefixKey(db, "kEND", ConsoleKey.End);
+            AddPrefixKey(db, "kHOM", ConsoleKey.Home);
+            AddPrefixKey(db, "kNXT", ConsoleKey.PageDown);
+            AddPrefixKey(db, "kPRV", ConsoleKey.PageUp);
+
+            if (KeyFormatToConsoleKey.Count > 0)
+            {
+                MaxKeyFormatLength = int.MinValue;
+                MinKeyFormatLength = int.MaxValue;
+
+                foreach (KeyValuePair<ReadOnlyMemory<char>, ConsoleKeyInfo> entry in KeyFormatToConsoleKey)
+                {
+                    if (entry.Key.Length > MaxKeyFormatLength)
+                    {
+                        MaxKeyFormatLength = entry.Key.Length;
+                    }
+                    if (entry.Key.Length < MinKeyFormatLength)
+                    {
+                        MinKeyFormatLength = entry.Key.Length;
+                    }
+                }
+            }
+        }
+
+        private static string GetTitle(TermInfo.Database db)
+        {
+            // Try to get the format string from tsl/fsl and use it if they're available
+            string? tsl = db.GetString(TermInfo.WellKnownStrings.ToStatusLine);
+            string? fsl = db.GetString(TermInfo.WellKnownStrings.FromStatusLine);
+            if (tsl != null && fsl != null)
+            {
+                return tsl + "%p1%s" + fsl;
+            }
+
+            string term = db.Term;
+            if (term == null)
+            {
+                return string.Empty;
+            }
+
+            if (term.StartsWith("xterm", StringComparison.Ordinal)) // normalize all xterms to enable easier matching
+            {
+                term = "xterm";
+            }
+
+            switch (term)
+            {
+                case "aixterm":
+                case "dtterm":
+                case "linux":
+                case "rxvt":
+                case "xterm":
+                    return "\x1B]0;%p1%s\x07";
+                case "cygwin":
+                    return "\x1B];%p1%s\x07";
+                case "konsole":
+                    return "\x1B]30;%p1%s\x07";
+                case "screen":
+                    return "\x1Bk%p1%s\x1B";
+                default:
+                    return string.Empty;
+            }
+        }
+
+        private void AddKey(TermInfo.Database db, TermInfo.WellKnownStrings keyId, ConsoleKey key)
+        {
+            AddKey(db, keyId, key, shift: false, alt: false, control: false);
+        }
+
+        private void AddKey(TermInfo.Database db, TermInfo.WellKnownStrings keyId, ConsoleKey key, bool shift, bool alt, bool control)
+        {
+            ReadOnlyMemory<char> keyFormat = db.GetString(keyId).AsMemory();
+            if (!keyFormat.IsEmpty)
+                KeyFormatToConsoleKey[keyFormat] = new ConsoleKeyInfo('\0', key, shift, alt, control);
+        }
+
+        private void AddPrefixKey(TermInfo.Database db, string extendedNamePrefix, ConsoleKey key)
+        {
+            AddKey(db, extendedNamePrefix + "3", key, shift: false, alt: true,  control: false);
+            AddKey(db, extendedNamePrefix + "4", key, shift: true,  alt: true,  control: false);
+            AddKey(db, extendedNamePrefix + "5", key, shift: false, alt: false, control: true);
+            AddKey(db, extendedNamePrefix + "6", key, shift: true,  alt: false, control: true);
+            AddKey(db, extendedNamePrefix + "7", key, shift: false, alt: false, control: true);
+        }
+
+        private void AddKey(TermInfo.Database db, string extendedName, ConsoleKey key, bool shift, bool alt, bool control)
+        {
+            ReadOnlyMemory<char> keyFormat = db.GetExtendedString(extendedName).AsMemory();
+            if (!keyFormat.IsEmpty)
+                KeyFormatToConsoleKey[keyFormat] = new ConsoleKeyInfo('\0', key, shift, alt, control);
+        }
+    }
+
+    private sealed class ReadOnlyMemoryContentComparer : IEqualityComparer<ReadOnlyMemory<char>>
+    {
+        public bool Equals(ReadOnlyMemory<char> x, ReadOnlyMemory<char> y) =>
+            x.Span.SequenceEqual(y.Span);
+
+        public int GetHashCode(ReadOnlyMemory<char> obj) =>
+            string.GetHashCode(obj.Span);
+    }
+}