Don’t hard-code escape sequences

Instead of hard-coding VT100-compatible escape sequences, parse the
system terminfo database and read escape sequences from it. This is
both more flexible (it should work well on more terminals) and more
efficient (it won’t insert padding on terminals that don’t need it).

1 files changed, 544 insertions, 0 deletions

diff --git a/goldfishterm/terminfo.h b/goldfishterm/terminfo.h
new file mode 100644
index 0000000..9452468
--- /dev/null
+++ b/goldfishterm/terminfo.h
@@ -0,0 +1,544 @@
+// Copyright 2021 Benjamin Barenblat
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+// Terminfo entries and the terminfo database.
+
+#ifndef EC_GOLDFISHTERM_TERMINFO_H_
+#define EC_GOLDFISHTERM_TERMINFO_H_
+
+#include <stdint.h>
+
+#include <istream>
+#include <string>
+#include <vector>
+
+#include "third_party/abseil/absl/strings/string_view.h"
+#include "third_party/abseil/absl/types/optional.h"
+
+namespace goldfishterm {
+
+// Boolean terminal capabilities. See terminfo(5) for full documentation.
+enum class BooleanCapability {
+  kAutoLeftMargin = 0,
+  kAutoRightMargin = 1,
+  kNoEscCtlc = 2,
+  kCeolStandoutGlitch = 3,
+  kEatNewlineGlitch = 4,
+  kEraseOverstrike = 5,
+  kGenericType = 6,
+  kHardCopy = 7,
+  kHasMetaKey = 8,
+  kHasStatusLine = 9,
+  kInsertNullGlitch = 10,
+  kMemoryAbove = 11,
+  kMemoryBelow = 12,
+  kMoveInsertMode = 13,
+  kMoveStandoutMode = 14,
+  kOverStrike = 15,
+  kStatusLineEscOk = 16,
+  kDestTabsMagicSmso = 17,
+  kTildeGlitch = 18,
+  kTransparentUnderline = 19,
+  kXonXoff = 20,
+  kNeedsXonXoff = 21,
+  kPrtrSilent = 22,
+  kHardCursor = 23,
+  kNonRevRmcup = 24,
+  kNoPadChar = 25,
+  kNonDestScrollRegion = 26,
+  kCanChange = 27,
+  kBackColorErase = 28,
+  kHueLightnessSaturation = 29,
+  kColAddrGlitch = 30,
+  kCrCancelsMicroMode = 31,
+  kHasPrintWheel = 32,
+  kRowAddrGlitch = 33,
+  kSemiAutoRightMargin = 34,
+  kCpiChangesRes = 35,
+  kLpiChangesRes = 36,
+};
+
+// Numeric terminal capabilities. See terminfo(5) for full documentation.
+enum class NumericCapability {
+  kColumns = 0,
+  kInitTabs = 1,
+  kLines = 2,
+  kLinesOfMemory = 3,
+  kMagicCookieGlitch = 4,
+  kPaddingBaudRate = 5,
+  kVirtualTerminal = 6,
+  kWidthStatusLine = 7,
+  kNumLabels = 8,
+  kLabelHeight = 9,
+  kLabelWidth = 10,
+  kMaxAttributes = 11,
+  kMaximumWindows = 12,
+  kMaxColors = 13,
+  kMaxPairs = 14,
+  kNoColorVideo = 15,
+  kBufferCapacity = 16,
+  kDotVertSpacing = 17,
+  kDotHorzSpacing = 18,
+  kMaxMicroAddress = 19,
+  kMaxMicroJump = 20,
+  kMicroColSize = 21,
+  kMicroLineSize = 22,
+  kNumberOfPins = 23,
+  kOutputResChar = 24,
+  kOutputResLine = 25,
+  kOutputResHorzInch = 26,
+  kOutputResVertInch = 27,
+  kPrintRate = 28,
+  kWideCharSize = 29,
+  kButtons = 30,
+  kBitImageEntwining = 31,
+  kBitImageType = 32,
+};
+
+// String terminal capabilities. See terminfo(5) for full documentation.
+enum class StringCapability {
+  kBackTab = 0,
+  kBell = 1,
+  kCarriageReturn = 2,
+  kChangeScrollRegion = 3,
+  kClearAllTabs = 4,
+  kClearScreen = 5,
+  kClrEol = 6,
+  kClrEos = 7,
+  kColumnAddress = 8,
+  kCommandCharacter = 9,
+  kCursorAddress = 10,
+  kCursorDown = 11,
+  kCursorHome = 12,
+  kCursorInvisible = 13,
+  kCursorLeft = 14,
+  kCursorMemAddress = 15,
+  kCursorNormal = 16,
+  kCursorRight = 17,
+  kCursorToLl = 18,
+  kCursorUp = 19,
+  kCursorVisible = 20,
+  kDeleteCharacter = 21,
+  kDeleteLine = 22,
+  kDisStatusLine = 23,
+  kDownHalfLine = 24,
+  kEnterAltCharsetMode = 25,
+  kEnterBlinkMode = 26,
+  kEnterBoldMode = 27,
+  kEnterCaMode = 28,
+  kEnterDeleteMode = 29,
+  kEnterDimMode = 30,
+  kEnterInsertMode = 31,
+  kEnterSecureMode = 32,
+  kEnterProtectedMode = 33,
+  kEnterReverseMode = 34,
+  kEnterStandoutMode = 35,
+  kEnterUnderlineMode = 36,
+  kEraseChars = 37,
+  kExitAltCharsetMode = 38,
+  kExitAttributeMode = 39,
+  kExitCaMode = 40,
+  kExitDeleteMode = 41,
+  kExitInsertMode = 42,
+  kExitStandoutMode = 43,
+  kExitUnderlineMode = 44,
+  kFlashScreen = 45,
+  kFormFeed = 46,
+  kFromStatusLine = 47,
+  kInit1string = 48,
+  kInit2string = 49,
+  kInit3string = 50,
+  kInitFile = 51,
+  kInsertCharacter = 52,
+  kInsertLine = 53,
+  kInsertPadding = 54,
+  kKeyBackspace = 55,
+  kKeyCatab = 56,
+  kKeyClear = 57,
+  kKeyCtab = 58,
+  kKeyDc = 59,
+  kKeyDl = 60,
+  kKeyDown = 61,
+  kKeyEic = 62,
+  kKeyEol = 63,
+  kKeyEos = 64,
+  kKeyF0 = 65,
+  kKeyF1 = 66,
+  kKeyF10 = 67,
+  kKeyF2 = 68,
+  kKeyF3 = 69,
+  kKeyF4 = 70,
+  kKeyF5 = 71,
+  kKeyF6 = 72,
+  kKeyF7 = 73,
+  kKeyF8 = 74,
+  kKeyF9 = 75,
+  kKeyHome = 76,
+  kKeyIc = 77,
+  kKeyIl = 78,
+  kKeyLeft = 79,
+  kKeyLl = 80,
+  kKeyNpage = 81,
+  kKeyPpage = 82,
+  kKeyRight = 83,
+  kKeySf = 84,
+  kKeySr = 85,
+  kKeyStab = 86,
+  kKeyUp = 87,
+  kKeypadLocal = 88,
+  kKeypadXmit = 89,
+  kLabF0 = 90,
+  kLabF1 = 91,
+  kLabF10 = 92,
+  kLabF2 = 93,
+  kLabF3 = 94,
+  kLabF4 = 95,
+  kLabF5 = 96,
+  kLabF6 = 97,
+  kLabF7 = 98,
+  kLabF8 = 99,
+  kLabF9 = 100,
+  kMetaOff = 101,
+  kMetaOn = 102,
+  kNewline = 103,
+  kPadChar = 104,
+  kParmDch = 105,
+  kParmDeleteLine = 106,
+  kParmDownCursor = 107,
+  kParmIch = 108,
+  kParmIndex = 109,
+  kParmInsertLine = 110,
+  kParmLeftCursor = 111,
+  kParmRightCursor = 112,
+  kParmRindex = 113,
+  kParmUpCursor = 114,
+  kPkeyKey = 115,
+  kPkeyLocal = 116,
+  kPkeyXmit = 117,
+  kPrintScreen = 118,
+  kPrtrOff = 119,
+  kPrtrOn = 120,
+  kRepeatChar = 121,
+  kReset1string = 122,
+  kReset2string = 123,
+  kReset3string = 124,
+  kResetFile = 125,
+  kRestoreCursor = 126,
+  kRowAddress = 127,
+  kSaveCursor = 128,
+  kScrollForward = 129,
+  kScrollReverse = 130,
+  kSetAttributes = 131,
+  kSetTab = 132,
+  kSetWindow = 133,
+  kTab = 134,
+  kToStatusLine = 135,
+  kUnderlineChar = 136,
+  kUpHalfLine = 137,
+  kInitProg = 138,
+  kKeyA1 = 139,
+  kKeyA3 = 140,
+  kKeyB2 = 141,
+  kKeyC1 = 142,
+  kKeyC3 = 143,
+  kPrtrNon = 144,
+  kCharPadding = 145,
+  kAcsChars = 146,
+  kPlabNorm = 147,
+  kKeyBtab = 148,
+  kEnterXonMode = 149,
+  kExitXonMode = 150,
+  kEnterAmMode = 151,
+  kExitAmMode = 152,
+  kXonCharacter = 153,
+  kXoffCharacter = 154,
+  kEnaAcs = 155,
+  kLabelOn = 156,
+  kLabelOff = 157,
+  kKeyBeg = 158,
+  kKeyCancel = 159,
+  kKeyClose = 160,
+  kKeyCommand = 161,
+  kKeyCopy = 162,
+  kKeyCreate = 163,
+  kKeyEnd = 164,
+  kKeyEnter = 165,
+  kKeyExit = 166,
+  kKeyFind = 167,
+  kKeyHelp = 168,
+  kKeyMark = 169,
+  kKeyMessage = 170,
+  kKeyMove = 171,
+  kKeyNext = 172,
+  kKeyOpen = 173,
+  kKeyOptions = 174,
+  kKeyPrevious = 175,
+  kKeyPrint = 176,
+  kKeyRedo = 177,
+  kKeyReference = 178,
+  kKeyRefresh = 179,
+  kKeyReplace = 180,
+  kKeyRestart = 181,
+  kKeyResume = 182,
+  kKeySave = 183,
+  kKeySuspend = 184,
+  kKeyUndo = 185,
+  kKeySbeg = 186,
+  kKeyScancel = 187,
+  kKeyScommand = 188,
+  kKeyScopy = 189,
+  kKeyScreate = 190,
+  kKeySdc = 191,
+  kKeySdl = 192,
+  kKeySelect = 193,
+  kKeySend = 194,
+  kKeySeol = 195,
+  kKeySexit = 196,
+  kKeySfind = 197,
+  kKeyShelp = 198,
+  kKeyShome = 199,
+  kKeySic = 200,
+  kKeySleft = 201,
+  kKeySmessage = 202,
+  kKeySmove = 203,
+  kKeySnext = 204,
+  kKeySoptions = 205,
+  kKeySprevious = 206,
+  kKeySprint = 207,
+  kKeySredo = 208,
+  kKeySreplace = 209,
+  kKeySright = 210,
+  kKeySrsume = 211,
+  kKeySsave = 212,
+  kKeySsuspend = 213,
+  kKeySundo = 214,
+  kReqForInput = 215,
+  kKeyF11 = 216,
+  kKeyF12 = 217,
+  kKeyF13 = 218,
+  kKeyF14 = 219,
+  kKeyF15 = 220,
+  kKeyF16 = 221,
+  kKeyF17 = 222,
+  kKeyF18 = 223,
+  kKeyF19 = 224,
+  kKeyF20 = 225,
+  kKeyF21 = 226,
+  kKeyF22 = 227,
+  kKeyF23 = 228,
+  kKeyF24 = 229,
+  kKeyF25 = 230,
+  kKeyF26 = 231,
+  kKeyF27 = 232,
+  kKeyF28 = 233,
+  kKeyF29 = 234,
+  kKeyF30 = 235,
+  kKeyF31 = 236,
+  kKeyF32 = 237,
+  kKeyF33 = 238,
+  kKeyF34 = 239,
+  kKeyF35 = 240,
+  kKeyF36 = 241,
+  kKeyF37 = 242,
+  kKeyF38 = 243,
+  kKeyF39 = 244,
+  kKeyF40 = 245,
+  kKeyF41 = 246,
+  kKeyF42 = 247,
+  kKeyF43 = 248,
+  kKeyF44 = 249,
+  kKeyF45 = 250,
+  kKeyF46 = 251,
+  kKeyF47 = 252,
+  kKeyF48 = 253,
+  kKeyF49 = 254,
+  kKeyF50 = 255,
+  kKeyF51 = 256,
+  kKeyF52 = 257,
+  kKeyF53 = 258,
+  kKeyF54 = 259,
+  kKeyF55 = 260,
+  kKeyF56 = 261,
+  kKeyF57 = 262,
+  kKeyF58 = 263,
+  kKeyF59 = 264,
+  kKeyF60 = 265,
+  kKeyF61 = 266,
+  kKeyF62 = 267,
+  kKeyF63 = 268,
+  kClrBol = 269,
+  kClearMargins = 270,
+  kSetLeftMargin = 271,
+  kSetRightMargin = 272,
+  kLabelFormat = 273,
+  kSetClock = 274,
+  kDisplayClock = 275,
+  kRemoveClock = 276,
+  kCreateWindow = 277,
+  kGotoWindow = 278,
+  kHangup = 279,
+  kDialPhone = 280,
+  kQuickDial = 281,
+  kTone = 282,
+  kPulse = 283,
+  kFlashHook = 284,
+  kFixedPause = 285,
+  kWaitTone = 286,
+  kUser0 = 287,
+  kUser1 = 288,
+  kUser2 = 289,
+  kUser3 = 290,
+  kUser4 = 291,
+  kUser5 = 292,
+  kUser6 = 293,
+  kUser7 = 294,
+  kUser8 = 295,
+  kUser9 = 296,
+  kOrigPair = 297,
+  kOrigColors = 298,
+  kInitializeColor = 299,
+  kInitializePair = 300,
+  kSetColorPair = 301,
+  kSetForeground = 302,
+  kSetBackground = 303,
+  kChangeCharPitch = 304,
+  kChangeLinePitch = 305,
+  kChangeResHorz = 306,
+  kChangeResVert = 307,
+  kDefineChar = 308,
+  kEnterDoublewideMode = 309,
+  kEnterDraftQuality = 310,
+  kEnterItalicsMode = 311,
+  kEnterLeftwardMode = 312,
+  kEnterMicroMode = 313,
+  kEnterNearLetterQuality = 314,
+  kEnterNormalQuality = 315,
+  kEnterShadowMode = 316,
+  kEnterSubscriptMode = 317,
+  kEnterSuperscriptMode = 318,
+  kEnterUpwardMode = 319,
+  kExitDoublewideMode = 320,
+  kExitItalicsMode = 321,
+  kExitLeftwardMode = 322,
+  kExitMicroMode = 323,
+  kExitShadowMode = 324,
+  kExitSubscriptMode = 325,
+  kExitSuperscriptMode = 326,
+  kExitUpwardMode = 327,
+  kMicroColumnAddress = 328,
+  kMicroDown = 329,
+  kMicroLeft = 330,
+  kMicroRight = 331,
+  kMicroRowAddress = 332,
+  kMicroUp = 333,
+  kOrderOfPins = 334,
+  kParmDownMicro = 335,
+  kParmLeftMicro = 336,
+  kParmRightMicro = 337,
+  kParmUpMicro = 338,
+  kSelectCharSet = 339,
+  kSetBottomMargin = 340,
+  kSetBottomMarginParm = 341,
+  kSetLeftMarginParm = 342,
+  kSetRightMarginParm = 343,
+  kSetTopMargin = 344,
+  kSetTopMarginParm = 345,
+  kStartBitImage = 346,
+  kStartCharSetDef = 347,
+  kStopBitImage = 348,
+  kStopCharSetDef = 349,
+  kSubscriptCharacters = 350,
+  kSuperscriptCharacters = 351,
+  kTheseCauseCr = 352,
+  kZeroMotion = 353,
+  kCharSetNames = 354,
+  kKeyMouse = 355,
+  kMouseInfo = 356,
+  kReqMousePos = 357,
+  kGetMouse = 358,
+  kSetAForeground = 359,
+  kSetABackground = 360,
+  kPkeyPlab = 361,
+  kDeviceType = 362,
+  kCodeSetInit = 363,
+  kSet0DesSeq = 364,
+  kSet1DesSeq = 365,
+  kSet2DesSeq = 366,
+  kSet3DesSeq = 367,
+  kSetLrMargin = 368,
+  kSetTbMargin = 369,
+  kBitImageRepeat = 370,
+  kBitImageNewline = 371,
+  kBitImageCarriageReturn = 372,
+  kColorNames = 373,
+  kDefineBitImageRegion = 374,
+  kEndBitImageRegion = 375,
+  kSetColorBand = 376,
+  kSetPageLength = 377,
+  kDisplayPcChar = 378,
+  kEnterPcCharsetMode = 379,
+  kExitPcCharsetMode = 380,
+  kEnterScancodeMode = 381,
+  kExitScancodeMode = 382,
+  kPcTermOptions = 383,
+  kScancodeEscape = 384,
+  kAltScancodeEsc = 385,
+  kEnterHorizontalHlMode = 386,
+  kEnterLeftHlMode = 387,
+  kEnterLowHlMode = 388,
+  kEnterRightHlMode = 389,
+  kEnterTopHlMode = 390,
+  kEnterVerticalHlMode = 391,
+  kSetAAttributes = 392,
+  kSetPglenInch = 393,
+};
+
+// An entry from the terminfo database.
+//
+// This class is thread-safe.
+class TerminfoEntry final {
+ public:
+  // Looks up a terminfo entry in the system terminfo database. Throws
+  // std::runtime_error if no valid system entry exists for the specified
+  // terminal.
+  //
+  // This function is thread-hostile (it inspects the environment).
+  static TerminfoEntry FromSystemDatabase(absl::string_view terminal_name);
+
+  // Parses an entry from binary data. Throws std::runtime_error if the data are
+  // invalid.
+  explicit TerminfoEntry(std::istream&);
+
+  TerminfoEntry(const TerminfoEntry&) noexcept = default;
+  TerminfoEntry& operator=(const TerminfoEntry&) noexcept = default;
+  TerminfoEntry(TerminfoEntry&&) noexcept = default;
+  TerminfoEntry& operator=(TerminfoEntry&&) noexcept = default;
+
+  const std::string& name() const noexcept { return names_[0]; }
+  const std::vector<std::string>& names() const noexcept { return names_; }
+
+  bool get(BooleanCapability) const noexcept;
+  absl::optional<int> get(NumericCapability) const noexcept;
+  const absl::optional<std::string>& get(StringCapability) const noexcept;
+
+ private:
+  std::vector<std::string> names_;
+  std::vector<int8_t> booleans_;
+  std::vector<int32_t> numbers_;
+  std::vector<absl::optional<std::string>> strings_;
+};
+
+}  // namespace goldfishterm
+
+#endif  // EC_GOLDFISHTERM_TERMINFO_H_