Graphics.Vty.Config

Vty supports a configuration file format and associated Config data type. The Config can be provided to mkVty to customize the application's use of Vty.

Lines in config files that fail to parse are ignored. Later entries take precedence over earlier ones.

Debug

debugLog

Format:

 "debugLog" string

The value of the environment variable VTY_DEBUG_LOG is equivalent to a debugLog entry at the end of the last config file.

Input Processing

map

Format:

 "map" term string key modifier_list
 where
     key := KEsc | KChar Char | KBS ... (same as Key)
     modifier_list := "[" modifier+ "]"
     modifier := MShift | MCtrl | MMeta | MAlt
     term := "_" | string

E.g., if the contents are

 map _       "\ESC[B"    KUp   []
 map _       "\ESC[1;3B" KDown [MAlt]
 map "xterm" "\ESC[D"    KLeft []

Then the bytes "\ESC[B" will result in the KUp event on all terminals. The bytes "\ESC[1;3B" will result in the event KDown with the MAlt modifier on all terminals. The bytes "\ESC[D" will result in the KLeft event when TERM is xterm.

If a debug log is requested then vty will output the current input table to the log in the above format. A workflow for using this is to set VTY_DEBUG_LOG. Run the application. Check the debug log for incorrect mappings. Add corrected mappings to $HOME.vtyconfig.

Unicode Character Width Maps

widthMap

Format:

 "widthMap" string string

E.g.,

  widthMap "xterm" "/home/user/.vty/xterm_map.dat"

This directive specifies the path to a Unicode character width map (the second argument) that should be loaded and used when the value of TERM matches the first argument. Unicode character width maps can be produced either by running the provided binary vty-build-width-table or by calling the library routine buildUnicodeWidthTable. The mkVty function will use these configuration settings to attempt to load and install the specified width map. See the documentation for mkVty for details.

Documentation

type InputMap = [(Maybe String, String, Event)]

Mappings from input bytes to event in the order specified. Later entries take precedence over earlier in the case multiple entries have the same byte string.

data Config

A Vty configuration.

Constructors

Config

Fields

• vmin :: Maybe Int

  The default is 1 character.

• vtime :: Maybe Int

  The default is 100 milliseconds, 0.1 seconds.

• mouseMode :: Maybe Bool

  The default is False.

• bracketedPasteMode :: Maybe Bool

  The default is False.

• debugLog :: Maybe FilePath

  Debug information is appended to this file if not Nothing.

• inputMap :: InputMap

  The (input byte, output event) pairs extend the internal input table of VTY and the table from terminfo.

  See Graphics.Vty.Config module documentation for documentation of the map directive.

• inputFd :: Maybe Fd

  The input file descriptor to use. The default is stdInput

• outputFd :: Maybe Fd

  The output file descriptor to use. The default is stdOutput

• termName :: Maybe String

  The terminal name used to look up terminfo capabilities. The default is the value of the TERM environment variable.

• termWidthMaps :: [(String, FilePath)]

  Terminal width map files.

• allowCustomUnicodeWidthTables :: Maybe Bool

  Whether to permit custom Unicode width table loading by mkVty. Just False indicates that table loading should not be performed. Other values permit table loading.

  If a table load is attempted and fails, information about the failure will be logged to the debug log if the configuration specifies one. If no custom table is loaded (or if a load fails), the built-in character width table will be used.

Instances

Eq Config

Defined in Graphics.Vty.Config

Methods

(==) :: Config -> Config -> Bool

(/=) :: Config -> Config -> Bool

Show Config

Defined in Graphics.Vty.Config

Methods

showsPrec :: Int -> Config -> ShowS

show :: Config -> String

showList :: [Config] -> ShowS

Semigroup Config

Defined in Graphics.Vty.Config

Methods

(<>) :: Config -> Config -> Config

sconcat :: NonEmpty Config -> Config

stimes :: Integral b => b -> Config -> Config

Monoid Config

Defined in Graphics.Vty.Config

Methods

mempty :: Config

mappend :: Config -> Config -> Config

mconcat :: [Config] -> Config

data VtyConfigurationError

Type of errors that can be thrown when configuring VTY

Constructors

VtyMissingTermEnvVar

TERM environment variable not set

Instances

Eq VtyConfigurationError

Defined in Graphics.Vty.Config

Methods

(==) :: VtyConfigurationError -> VtyConfigurationError -> Bool

(/=) :: VtyConfigurationError -> VtyConfigurationError -> Bool

Show VtyConfigurationError

Defined in Graphics.Vty.Config

Methods

showsPrec :: Int -> VtyConfigurationError -> ShowS

show :: VtyConfigurationError -> String

showList :: [VtyConfigurationError] -> ShowS

Exception VtyConfigurationError

Defined in Graphics.Vty.Config

Methods

toException :: VtyConfigurationError -> SomeException

fromException :: SomeException -> Maybe VtyConfigurationError

displayException :: VtyConfigurationError -> String

userConfig :: IO Config

Load a configuration from vtyConfigPath and $VTY_CONFIG_FILE.

overrideEnvConfig :: IO Config

standardIOConfig :: IO Config

Configures VTY using defaults suitable for terminals. This function can raise VtyConfigurationError.

runParseConfig :: String -> ByteString -> Config

parseConfigFile :: FilePath -> IO Config

defaultConfig :: Config

getTtyEraseChar :: Fd -> IO (Maybe Char)

Get the "erase" character for the terminal attached to the specified file descriptor. This is the character configured by 'stty erase'. If the call to tcgetattr fails, this will return Nothing. Otherwise it will return the character that has been configured to indicate the canonical mode ERASE behavior. That character can then be added to the table of strings that we interpret to mean Backspace.

For more details, see:

• https://www.gnu.org/software/libc/manual/html_node/Canonical-or-Not.html
• https://www.gsp.com/cgi-bin/man.cgi?section=1&topic=stty
• https://github.com/matterhorn-chat/matterhorn/issues/565

currentTerminalName :: IO (Maybe String)

vtyConfigPath :: IO FilePath

widthTableFilename :: String -> String

vtyDataDirectory :: IO FilePath

terminalWidthTablePath :: IO (Maybe FilePath)

vtyConfigFileEnvName :: String

data ConfigUpdateResult

Constructors

ConfigurationCreated

ConfigurationModified

ConfigurationConflict String

ConfigurationRedundant

Instances

Eq ConfigUpdateResult

Defined in Graphics.Vty.Config

Methods

(==) :: ConfigUpdateResult -> ConfigUpdateResult -> Bool

(/=) :: ConfigUpdateResult -> ConfigUpdateResult -> Bool

Show ConfigUpdateResult

Defined in Graphics.Vty.Config

Methods

showsPrec :: Int -> ConfigUpdateResult -> ShowS

show :: ConfigUpdateResult -> String

showList :: [ConfigUpdateResult] -> ShowS

addConfigWidthMap

Arguments

:: FilePath

The configuration file path of the configuration to modify or create.

-> String

The TERM value for the widthMap directive.

-> FilePath

The width table file path for the directive.

-> IO ConfigUpdateResult

Add a widthMap directive to the Vty configuration file at the specified path.

If the configuration path refers to a configuration that already contains the directive for the specified map and terminal type, the configuration file will not be modified. If the file does not contain the directive, it will be appended to the file.

If the configuration path does not exist, a new configuration file will be created and any directories in the path will also be created.

This returns True if the configuration was created or modified and False otherwise. This does not handle exceptions raised by file or directory permissions issues.