6.0

This release marks the beginning of multi-platform support in Vty. Getting to this point involved removing Unix-specific functionality from Vty and moving it to a new package, vty-unix. Windows support is now provided via a vty-windows package. Another new package, vty-crossplatform, is provided as a convenience for applications that want to support both Unix and Windows platforms automatically at build time. See the migration guide below for details on how to upgrade.

Migration guide for 6.0

To upgrade to this version of Vty, most people will only need to take a few steps:

1. Add a package dependency on vty-unix, vty-windows, or vty-crossplatform, depending on the desired level of platform support. For example, if an application only supports Unix systems, it should depend on vty-unix. But if an application is intended to work anywhere Vty works, then vty-crossplatform is the best choice.
2. Import mkVty from the platform package in step (1). (mkVty was removed from the vty package and is now the responsibility of each platform package.) Imports are as follows:
   • vty-unix: Graphics.Vty.Platform.Unix
   • vty-windows: Graphics.Vty.Platform.Windows
   • vty-crossplatform: Graphics.Vty.CrossPlatform
3. Maintain any existing package dependency on vty; the core library abstractions, types, and functions are still obtained from vty itself. The platform packages do not re-export the core library's modules.
4. If desired, call Graphics.Vty.Config.userConfig to load the Vty user configuration since this step is no longer automatic.

For applications using more of Vty's API than just the basic initialization and rendering API, the full change list is provided below. For people who want to write their own Vty platform package like vty-unix, see PLATFORM-HOWTO.md.

Detailed change list for 6.0

• Package changes:
  • The following modules got added to the vty library:
    • Graphics.Vty.UnicodeWidthTable.Main
  • The following modules got moved to vty-unix:
    • Data.Terminfo.Eval
    • Data.Terminfo.Parse
  • The following modules got moved to vty-unix into the Graphics.Vty.Platform.Unix module namespace (previously Graphics.Vty):
    • Graphics.Vty.Input.Classify
    • Graphics.Vty.Input.Classify.Parse
    • Graphics.Vty.Input.Classify.Types
    • Graphics.Vty.Input.Focus
    • Graphics.Vty.Input.Loop
    • Graphics.Vty.Input.Mouse
    • Graphics.Vty.Input.Paste
    • Graphics.Vty.Input.Terminfo
    • Graphics.Vty.Output.TerminfoBased
    • Graphics.Vty.Output.XTermColor
  • The following modules were removed entirely (with contents migrated elsewhere as needed):
    • Graphics.Vty.Inline.Unsafe
    • Graphics.Vty.Output.Interface (migrated to Graphics.Vty.Output)
  • Removed library dependencies on the following packages:
    • ansi-terminal
    • containers
    • terminfo
    • transformers
    • unix
  • The following executables were moved to other packages:
    • vty-build-width-table (moved to vty-unix as vty-unix-build-width-table)
    • vty-mode-demo (moved to vty-crossplatform)
• API changes:
  • Graphics.Vty.mkVty moved to the vty-unix package's Graphics.Vty.Platform.Unix module.
  • Added Graphics.Vty.mkVtyFromPair for platform packages to construct Vty handles.
  • The contents of the Graphics.Vty.Output.Interface module were merged into Graphics.Vty.Output.
  • The vty-build-width-table tool was removed from the vty package, but its core functionality is now exposed as a library for platform packages to use to provide platform-specific tools using Graphics.Vty.UnicodeWidthTable.Main and a new tool by the same name was added to the vty-unix package.
  • Graphics.Vty.Events: the InternalEvent type's ResumeAfterSignal constructor was renamed to ResumeAfterInterrupt to be a bit more abstract and platform-agnostic.
  • Removed the following lenses for fields of the Input type:
    • eventChannel (was for _eventChannel which was then renamed to eventChannel)
    • configRef (was for _configRef which was then renamed to configRef)
  • The Output record type got a new field, setOutputWindowTitle.
  • The Input record type got a new field, inputLogMsg :: String -> IO (), for logging to the Vty log.
  • Graphics.Vty.Config now exposes VtyUserConfig instead of Config. Many of its fields were Unix-specific and were consequently moved to the UnixSettings type in vty-unix.
  • The VtyUserConfig type's fields got a config field name prefix.
• Behavior changes:
  • Since vty no longer implements mkVty, the Vty user configuration is no longer implicitly loaded by Vty-based applications. Instead, it is now up to the applications to call Graphics.Vty.Config.userConfig to load any user-provided configuration.
  • Vty no longer implicitly attempts to load configured Unicode width tables. It is now the responsibility of the platform packages (such as vty-unix) and/or applications to load tables via Graphics.Vty.UnicodeWidthTable.IO and install them via Graphics.Vty.UnicodeWidthTable.Install.
• Changes to demonstration programs:
  • EventEcho, ModeDemo, and Rogue demo programs moved to the vty-crossplatform package.
• Changes to tests:
  • Where appropriate, some test programs and test cases were moved to vty-unix or vty-crossplatform.

5.39

Package changes:

• Now builds with mtl-2.3.*.

Bug fixes:

• Fixed a long-standing issue where unused input on stdin could cause a memory error and a crash when Vty was being initialized. (#266)

5.38

This release includes numerous API changes, although none of them should break your programs. If so, please open a ticket on the Vty issue tracker.

Package changes:

• Support mtl 2.3 (thanks Daniel Firth)
• The test and example collections got completely overhauled to clean up bit rot.
  • Moved example programs into examples/ under a new vty-examples package.
  • Moved test suite programs out of vty.cabal and into tests/ under a new vty-tests package.
  • Cleaned up all build-depends lists in all three packages to remove unused deps.
  • Consolidated the test suite library modules into the vty-tests library to avoid redundant compilation.
  • Added build.sh to build everything in the development process to help ensure that examples and tests don't get forgotten.
  • Removeed lots of stale/unused modules in old test/ directory.
• Got vty-examples building again and resolved various warnings and issues.

API changes:

• All modules got explicit export lists. Prior to this release, many modules exported everything they contained, making it difficult to know what was really intended to be part of the public API. The new export lists should contain everything that applications need; the risk of breakage exists but should be minor. Please open a ticket if you were using something that is no longer exported. It might be that it was never supposed to be exported to begin with, or it might be just something we need to export once again.
• Moved the attributeControl function from Graphics.Vty.Input.Loop to Graphics.Vty.Input.
• Removed the Graphics.Vty.Image.DisplayText alias for Text.
• Unified the Image cropping constructors (thanks Fraser Tweedale)

5.37

• The Xterm backend is now used when TERM matches rxvt or tmux.
• PictureToSpans now uses error, not fail, to avoid dependence on soon-to-be-removed MonadFail instance for ST (#248)

5.36

• Raised microlens upper bound to allow building with 0.4.13.
• Replaced incomplete Show output for Picture with a derived instance; derived Show for Cursor and Background, too.

5.35.1

Bug fixes:

• Fixed a build issue with a test program.

5.35

New features:

• Add support for 24-bit color (thanks @u-quark). This change updates Vty to look at the COLORTERM environment variable that is conventionally used to advertise support for truecolor escape sequences. The change also updates the Vty demo to demonstrate 24-bit colors. This change also adds a new data type, ColorMode, to represent the color mode in use, as well as an Output interface field, outputColorMode, to track the active color mode and use it to clamp emitted color escape sequences to the active color range.

API changes:

• All types in Graphics.Vty.Input.Events now have strict constructor fields.
• Internal events are now wrapped in a new InternalEvent type to improve how signal handling is done. This change modifies the Input type's event channel API to produce InternalEvents, not Events. The new InternalEvent either wraps Event with the InputEvent constructor (the previous behavior) or indicates that Vty resumed after handling a signal using the ResumeAfterSignal constructor. This change avoids the previous use of EvResize with lazy exception arguments as a sentinel value for ResumeAfterSignal.

Other enhancements:

• Bracketed paste parsing performance has been greatly improved thanks to benchmarking and optimization work by @iphydf. As part of that work, Vty now uses bytestrings rather than Strings internally when parsing input to look for events.
• The \b value is now interpreted as KBS (thanks @vglfr)

5.34

API changes:

• Added an NFData instance for Event (thanks Mario Lang)
• Removed Monoid and Semigroup instances for Attr and MaybeDefault. This change removed the instances because they were misbehaved; merging Attr and MaybeDefault values with these instances resulted in field value losses. For example, before this change,

(defAttr `withForeColor` blue) <> (defAttr `withBackColor` green)

would result in just

   (defAttr `withBackColor` green)

because the instances were designed to favor the right-hand arguments' fields even if they had not been explicitly set (a consequence of the MaybeDefault Semigroup instance). While that behavior was sensible specifically in the context of Graphics.Vty.Inline, it wasn't a useful user-facing API and it made for surprising instance behavior. Since there is actually no good way to handle this in a Semigroup instance for Attr -- some choices have to be made about how to merge two attributes' foreground colors, and that won't be much better than what we had -- the instance was just removed.

5.33

API changes:

• The Cursor type got a new PositionOnly constructor for cursor placement without visibility.

Package changes:

• Relaxed upper bound for random
• Updated microlens bounds to allow 0.4.12

Other improvements:

• Various hlint-driven improvements (thanks Willem Van Onsem)
• The implementation of color240 was improved (thanks (Willem Van Onsem)

5.32

New features:

• Meta-PageUp and Meta-PageDown are now supported (#193)
• Added supportsItalics and supportsStrikethrough functions to check for feature support in terminfo

Bug fixes:

• Detect utf-8 mode in LANG regardless of case (thanks Emeka Nkurumeh)

5.31

New features and API changes:

• Added support for strikethrough mode. This change adds a new strikethrough Style value and uses the smxx and rmxx Terminfo capabilities to activate and deactivate strikethrough mode, respectively. If the terminfo does not report those capabilities, this style is ignored.
• Output: added the setDisplayBounds field to set the output dimensions of the output handle; added an implementation of this for the TerminfoBased backend.

Other changes:

• The C prototype for vty_c_get_window_size in gwinsz.h was fixed.

5.30

New features:

• Added Graphics.Vty.setWindowTitle to emit an escape sequence to set the window title, provide the terminal emulator accepts Xterm-style title sequences. For details, see: https://tldp.org/HOWTO/Xterm-Title-3.html

5.29

API changes:

• The Input type got a new field, 'restoreInputState'. This field allows the end user to have direct access to the logic needed to restore the terminal's input state flags. Prior to having this field, this state restoration logic could only be invoked as part of calling 'shutdownInput', but since that function does other things (like killing threads) it is not advisable to call it repeatedly (which is necessary in the use case this change is intended to support). This can be called directly to restore the input state flags as needed, although this is not required if 'shutdown' (or 'shutdownInput') is called.

Other changes:

• attributeControl: explicitly enable the ICRNL terminal mode flag (see #187 and c572ad).

5.28.2

Bug fixes:

• Added a package dependency on semigroups for the vty-build-width-table tool on older GHCs (#185)

5.28.1

Bug fixes:

• installUnicodeWidthTable: use throwIO, not throw

5.28

This release improves Vty's support for multi-column Unicode characters and provides greater compatibility with a wider array of terminal emulators. The following sections summarize the relevant changes, but an overview of the new functionality is motivated and detailed in the new "Multi-Column Character Support" README section. For historical context, please also consider reading over #175.

API changes:

• New modules were added:
  • Graphics.Vty.UnicodeWidthTable.Types
  • Graphics.Vty.UnicodeWidthTable.IO
  • Graphics.Vty.UnicodeWidthTable.Query
  • Graphics.Vty.UnicodeWidthTable.Install
• The Config type got a new field, allowCustomUnicodeWidthTables, that controls whether mkVty will attempt to load a Unicode width table if specified in the configuration.

Configuration file changes:

• A new syntax was added to support specifying Unicode width tables on a per-TERM basis. The syntax is widthMap <TERM> <PATH>. See the documentation for Graphics.Vty.Config for details. Since prior versions of this library will silently ignore any configuration file lines they cannot parse, this change to user configuration files is at least non-breaking for older versions of Vty.

Other changes:

• The mkVty function now automatically attempts to load a custom Unicode width table if one is specified in the configuration, provided allowCustomUnicodeWidthTables is not set to Just False. See the documentation for Graphics.Vty.mkVty for details.
• Vty now includes a command line tool, vty-build-width-table, that queries the terminal emulator to construct a custom Unicode width table and optionally update the Vty configuration file to use it. Programs that want to use that tool's functionality may also do so via the API exposed in the various modules listed above.

5.27

• Added Graphics.Vty.Config.getTtyEraseChar to support querying the kernel for the current terminal's settings to obtain the character assigned by the stty erase command. That can then be added to the Vty configuration's input map to map to KBS (backspace) if desired.

5.26

• Resolved various import warnings (thanks @glguy)
• Removed the MonadIO constraint from the Output type's fields and removed MonadFail uses (PR #177, thanks @glguy)
• Clarified documentation for ANSI colors (thanks Colby Jenn)
• Graphics.Vty.Attributes no longer re-exports Graphics.Vty.Attributes.Color
• The Graphics.Vty.Attributes.Color module is now exposed (thanks Colby Jenn)
• Raised upper bound for microlens to 0.4.12 (thanks Artyom Kazak)
• Changed from using System.Posix.Env.getEnv to System.Environment.lookupEnv (thanks Jonathan Osser)
• Added Graphics.Vty.Image functions for dealing with character width computations on Text values instead of Strings:
  • safeWctwidth
  • safeWctlwidth
  • wctwidth
  • wctlwidth

5.25.1

• Avoided a conflict with a Microlens 0.4.10 operator and added an upper bound on Microlens of 0.4.11.

5.25

• The Vty type got a new field, isShutdown, that returns whether the Vty handle has had its 'shutdown' function called (thanks Ian Jeffries)
• Vty's shutdown function is now thread-safe.

5.24.1

• The "shutdown" method of Vty handles is now idempotent (#159)

5.24

• Add Generic and NFData instances for some types
• Image: remove custom Show instance, add derived Show and Read instances
• Updated Travis build settings (thanks Eric Mertens)

5.23.1

• Fixed a bug where italics did not combine properly with other display modes (#155, thanks Eric Mertens)

5.23

• Added support for italicized output when terminfo supports it. This takes the form of a new Style, "italic". Note that most terminfo descriptors do not report capabilities for italics, so support for this will be very spotty.
• Updateed text/string function documentation to indicate that escapes are not permitted in their inputs.

5.22

• Added Graphics.Vty.Attributes.Color240.color240CodeToRGB function (thanks Brent Carmer)
• Added nextEventNonblocking function (field) to Vty type (#87)

5.21

• Picture and Background now provide Eq instances (thanks Jaro Reinders)
• #145: vty builds with microlens 0.4.9 (thanks Daniel Wagner)
• #142: note requirement of threaded RTS

5.20

API changes:

• Split up Monoid instances into Monoid and Semigroup for newer GHCs (thanks Ryan Scott)

5.19.1

API changes:

• Cursor now provides an Eq instance (thanks Jaro Reinders)

5.19

API changes:

• URL hyperlinking (via 'withURL') is now optional and disabled by default due to poor support on some common terminals. A new 'Mode' constructor, 'Hyperlink', has been added to enable this feature. To change the hyperlinking mode, use 'setMode' on the 'outputIface' of a Vty handle.

5.18.1

Bug fixes:

• Reset the hyperlink state on line endings to avoid run-on hyperlinks

5.18

API changes:

• Added support for hyperlinking attributes (thanks Getty Ritter). This change adds a new Attr field for containing the hyperlink to apply, as per https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda

5.17.1

• withStyle now ignores zero arguments, leaving attribute styles untouched if the input style is the null style

5.17

API changes:

• Add support for terminal focus events. This change adds a new mode usable with setMode, Focus, that requests that the terminal send events on focus lose/gain. This change also adds two new Event constructors, EvLostFocus and EvGainedFocus.
• No longer enable UTF8 mouse event encoding. This encoding was not working properly with Terminal.app, and using the other modes (SGR, etc.) work.
• Graphics.Vty.Attributes: escape backticks in Haddock comment (fixes #131)

5.16

API changes:

• Added support for mouse wheel events while in mouse mode. The Button type got two new constructors as a result: BScrollUp and BScrollDown. Thanks to doublescale@tutanota.com for this contribution!

Bug fixes:

• charFill now clamps negative arguments to zero (thanks Eric Mertens!)

5.15.1

Package changes:

• Documentation files are now marked accordingly (thanks Michal Suchánek)

Bug fixes:

• translateX/Y: fix negative translations

5.15

Package changes:

• Discontinued support for GHC versions prior to 7.10.1.
• Removed instructions and configuration for Stack builds since they are no longer supported.
• Clarified README mention of (lack of) Windows support (contributors wanted, though!)
• Removed dependency on data-default (see below).

API changes:

• Moved color definitions from Attributes to Color module.
• In lieu of data-default (Default) instances for Attr and Config, use 'defAttr' and the new 'defaultConfig' (or 'mempty') instead of 'def'.
• Graphics.Vty.Output no longer re-exports Graphics.Vty.Output.Interface.
• Removed Graphics.Vty.Prelude module and moved DisplayRegion and its accessors to Graphics.Vty.Image.
• Graphics.Vty.Image no longer re-exports Graphics.Vty.Attributes.
• Graphics.Vty.Picture no longer re-exports Graphics.Vty.Image.

5.14

• addMaybeClippedJoin: instead of raising an exception when the join is totally clipped, just reduce the clip amount and continue
• addMaybeClipped: skip blit of joins when their primary dimension is zero
• 'string' and related text functions no longer treat an empty string as an empty image (thanks Chris Penner). This means that now it is possible to use 'str ""' as a non-empty image with height 1.

5.13

• Reverted changes in 5.12 due to disagreements between terminal emulators and utf8proc; for more details, please see the ticket discussion at https://github.com/coreyoconnor/vty/issues/115

5.12

• Replaced 'wcwidth' with a call to the utf8proc library's character width function, which is much more up to date (by several Unicode versions) and returns the right width for a much larger set of characters.
• Added a bundled version of the utf8proc C library.

5.11.3

• Fix mouse event offsets in mouse-up events

5.11.2

• Mouse events were modified so that the upper-left corner of the window is (0,0) rather than (1,1).

5.11.1

• Add Generic instance for Image
• nextEvent: stop trying to refresh on a resize event (fixes segfault on refresh with normal cursor positioning mode)
• Remove redundant clause from clipForCharWidth (thanks Eric Mertens)
• Update maintainer

5.11

• Vty now raises a VtyConfigurationError exception when the TERM evironment variable is missing (thanks Eric Mertens)
• Graphics.Vty.Config got an explicit export list to avoid accidentally exporting internal types (thanks Eric Mertens)

5.10

• Add absolute cursor positioning mode AbsoluteCursor to Cursor. This mode provides greater control over cursor positioning by bypassing the logical positioning provided by default. Rather than positioning the cursor by looking at the widths of characters involved, this constructor lets you provide a physical row and column instead. This is useful in more sophisticated programs. (thanks Eric Mertens)
• Added a new Generic-derived config parser (thanks Eric Mertens)
• Fixed the MShift case in the configuration file parser (thanks Eric Mertens)
• Fixed wcwidth import and matched safeWcswidth to its documented behavior. Previously vty_mk_wcwidth was being imported with the wrong type causing the -1 return value to be mapped to the wrong Int value. Additionally safeWcswidth was using the unsafe character width function and only ensuring that the final result was non-negative. (thanks Eric Mertens)

5.9.1

• Vty now only emits UTF8 charset sequences in terminals without a preexisting UTF8 declaration to avoid emitting garbage sequences (fixes #89)

5.9

• Added new Output methods supportsBell and ringTerminalBell to find out whether the output device has an audio bell and to ring it (see #102)

5.8.1

• Fixed "refresh" to work as advertised (see #104)

5.8

• API change: EvPaste input event now provides paste data as a raw ByteString rather than a String to allow the application to decode how best to decode it

5.7.1

• ModeDemo: added an explicit Control.Applicative import for older GHCs

5.7

• Mouse and paste modes are now off by default.
• The Config type got new fields: mouseMode and bracketedPasteMode. These determine whether these modes are enabled initially (for terminals that support them).
• Added a Mode type for modal terminal features (mouse events, bracketed paste mode) that is used with new Output interface functions:
  • supportsMode :: Mode -> Bool tells whether the device supports a mode
  • setMode :: Mode -> Bool -> IO () turns a mode on or off
  • getModeStatus :: Mode -> IO Bool tells you whether a mode is on or off
• Added a new demo program, ModeDemo.hs, to demonstrate usage of modes

5.6

• Added support for normal and extended mouse modes in Xterm-like terminals via the MouseDown and MouseUp Event constructors
• Added support for bracketed paste mode in Xterm-like terminals via the EvPaste event constructor
• Added derived Show instances for Event and Button (thanks Felix Hirn)
• Now TERM values containing "screen" will automatically use the XtermColor driver rather than just TerminfoBased

5.5.0

• Replaced lens dependency with microlens, microlens-mtl, microlens-th dependencies. Issue #90
  • Thanks Jonathan Daugherty
• Cabal corrections.
  • Thanks Lennart Spitzner

5.4.0

• Changed eventChannel of Graphics.Vty.Input from Chan to TChan. This enables clients to query if there are no pending events. The Graphics.Vty interface nextEvent is unchanged. Clients that use eventChannel directly will require updating. https://github.com/coreyoconnor/vty/issues/60

5.3.1

• Reverted cabal file to depend on Cabal >= 1.18 instead of 1.20 due to possibly breaking this on reasonable GHC versions

5.3

• Upgraded QuickCheck dependency to 2.7
• The standard IO Config (standardIOConfig) was overriding any provided application config. In addition, the inputFd and outputFd could not be changed if mkVty was used. Fixed.
• Correct handling of display attributes at end of line. The output attributes are set to default at the end of content for the line and at the start of a new line. Previously the current attribute would extend to the next start of content. This was odd to reason about and was the cause of https://github.com/coreyoconnor/vty/issues/76 IIRC Yi requires the old behavior to display the selection region correctly.
• shutdown of the input thread is now performed using killThread and synchronization on an MVar. For correct handling of the terminal read vmin and vtime the read must be a blocking read on an OS thread. This places a threadWaitRead, which will be interrupted by the killThread, prior to the uninterruptable read. An alternative would be to re-import the read foreign call as interruptable.

5.2.11

• deepseq bounds increased for tests.
• Clean up warnings when compiling on 7.10
  • Thanks Eric Mertens
• Avoid discarding input bytes after multi-byte encoded codepoint
  • Thanks Eric Mertens

5.2.10

• "str" now returns EmptyImage for empty strings to match behavior of other string-like Image constructors (fixes #74)
  • Thanks Jonathan Daugherty

5.2.9

• dependency version bumps
  • https://github.com/coreyoconnor/vty/pull/71
  • https://github.com/coreyoconnor/vty/pull/70
• Correct/Simplify the example code
  • Thanks glguy
  • https://github.com/coreyoconnor/vty/pull/69

5.2.8

• blaze-builder, lens, utf8-string version constraint bump
  • Thanks glguy
  • https://github.com/coreyoconnor/vty/pull/67
• Do not differentiate based on TERM_PROGRAM
  • https://github.com/coreyoconnor/vty/issues/68

5.2.7

• lens and deepseq constraint bump + misc
  • Thanks ethercrow
  • https://github.com/coreyoconnor/vty/pull/66

5.2.6

• lens constraint bump
  • Thanks alexander-b!
  • https://github.com/coreyoconnor/vty/pull/64

5.2.5

• lens and random version constraint bump.
  • Thanks RyanGlScott!
  • https://github.com/coreyoconnor/vty/pull/62

5.2.4

• removed -fpic from cc-options. No longer required.
  • https://github.com/coreyoconnor/vty/issues/61
  • https://ghc.haskell.org/trac/ghc/ticket/9657
  • Thanks Fuuzetsu!

5.2.3

• evaluate/compile the input parsing table once instead of each keystroke.
  • https://github.com/coreyoconnor/vty/pull/59
  • Thanks ethercrow!

5.2.2

• When looking at input for an event, don't look too deep.
  • https://github.com/coreyoconnor/vty/pull/57
  • Thanks ethercrow!

5.2.1

• Bump upper version bound for lens to 4.5. Thanks markus1189!

5.2.0

• Config structure now specifies file descriptor to use. The default is stdInput and stdOutput file descriptors. Previously Vty used stdInput for input and the follow code for output:
  • hDuplicate stdout >>= handleToFd >>= (hSetBuffering NoBuffering)
  • the difference was required by Vty.Inline. Now, Vty.Inline uses the Config structure options to acheive the same effect.
• removed: derivedVtime, derivedVmin, inputForCurrentTerminal, inputForNameAndIO, outputForCurrentTerminal, outputForNameAndIO
• added: inputForConfig, outputForConfig
• updates to vty-rogue from jtdaugherty. Thanks!
• the oldest version of GHC tested to support vty is 7.6.2.
• the oldest version of GHC that vty compiles under is 7.4.2

5.1.4

• merged https://github.com/coreyoconnor/vty/pull/51 thanks trofi!

5.1.1

• merged https://github.com/coreyoconnor/vty/pull/48 thanks sjmielke!
• jtdaugherty resolved a number of compiler warnings. Thanks!

5.1.0

• vmin and vtime can be specified however the application requires. See Graphics.Vty.Config.
• fixed the processing of input when vmin is set > 1.

5.0.0

• The naming convention now matches:
  • http://www.haskell.org/haskellwiki/Programming_guidelines#Naming_Conventions
• all projects using vty for input must be compiled with -threaded. Please notify vty author if this is not acceptable.
• mkVtyEscDelay has been removed. Use "mkVty def". Which initialized vty with the default configuration.
• input handling changes
  • KASCII is now KChar
  • KPN5 is now KCenter
  • tests exist.
  • Applications can add to the input tables by setting inputMap of the Config. See Graphics.Vty.Config
  • Users can define input table extensions that will apply to all vty applications. See Graphics.Vty.Config
  • terminal timing is now handled by selecting an appropriate VTIME. Previously this was implemented within Vty itself. This reduced complexity in vty but provides a different meta key behavior and implies a requirement on -threaded.
  • The time vty will wait to verify an ESC byte means a single ESC key is the singleEscPeriod of the Input Config structure.
• removed the typeclass based terminal and display context interface in favor of a data structure of properties interface.
• renamed the Terminal interface to Output
• The default picture for an image now uses the "clear" background. This background fills background spans with spaces or just ends the line.
  • Previously the background defaulted to the space character. This causes issues copying text from a text editor. The text would end up with extra spaces at the end of the line.
• Layer support
  • Each layer is an image.
  • The layers for a picture are a list of images.
  • The first image is the top-most layer. The images are ordered from top to bottom.
  • The transparent areas for a layer are the backgroundFill areas. backgroundFill is added to pad images when images of different sizes are joined.
  • If the background is clear there is no background layer.
  • If there is a background character then the bottom layer is the background layer.
  • emptyPicture is a Picture with no layers and no cursor
  • addToTop and addToBottom add a layer to the top and bottom of the given Picture.
• compatibility improvements:
  • terminfo based terminals with no cursor support are silently accepted. The cursor visibility changes in the Picture will have no effect.
  • alternate (setf/setb) color maps supported. Though colors beyond the first 8 are just a guess.
  • added "rgbColor" for easy support of RGB specified colors.
  • Both applications and users can add to the mapping used to translate from input bytes to events.
• Additional information about input and output process can be appended to a debug log
  • Set environment variable VTY_DEBUG_LOG to path of debug log
  • Or use "debugLog " config directive
  • Or set 'debugLog' property of the Config provided to mkVty.
  • examples moved to vty-examples package. See test directory for cabal file.
    • vty-interactive-terminal-test
      • interactive test. Useful for building a bug report for vty's author.
      • test/interactive_terminal_test.hs
    • vty-event-echo
      • view a input event log for vty. Example of interacting with user.
      • test/EventEcho.hs
    • vty-rogue
      • The start of a rogue-like game. Example of layers and image build operations.
      • test/Rogue.hs
    • vty-benchmark
      • benchmarks vty. A series of tests that push random pictures to the terminal. The random pictures are generated using QuickCheck. The same generators used in the automated tests.
      • test/benchmark.hs

  4.7.0.0

  API changes:

  • Added Graphics.Vty.Image.crop: Ensure an image is no larger than the specified size.
  • Added Graphics.Vty.Image.pad: Ensure an image is no smaller than the specified size.
  • Added Graphics.Vty.Image.translate: Offset an image.
  • Thanks Ben Boeckel MathStuf@gmail.com for these features.

  4.2.1.0

  API changes:

  • Attr record accessor fore_color changed to attr_fore_color
  • Attr record accessor back_color changed to attr_back_color
  • Attr record accessor style changed to attr_style
  • Added an "inline" display attribute changing DSL:
    • put_attr_change applies a display attribute change immediately to a terminal
    • For instance, can be used to change the display attrbiutes of text output via putStrLn and putStr. EX: "put_attr_change $ back_color red" will set the background color to red.
    • Changes do not apply to a Picture output via output_picture.
    • See Graphics.Vty.Inline
  • Moved all IO actions into any monad an instance of MonadIO

  4.0.0.1

  • binding for mk_wcswidth was incorrect. Most platforms just magically worked due to coincidence.

  4.0.0

  API changes:

  • "getSize" has been removed. Use "terminal vty >>= display_bounds" where "vty" is an instance of the Vty data structure.
  • added a "terminal" field to the Vty data structure. Accesses the TerminalHandle associated with the Vty instance.
  • Graphics.Vty.Types has undergone a number of changes. Summary:
    • Partitioned into Graphics.Vty.Attributes for display attributes. Graphics.Vty.Image for image combinators. Graphics.Vty.Picture for final picture construction.
  • Graphics.Vty.Attributes:
    • "setFG" and "setBG" are now "with_fore_color" and "with_back_color"
    • All other "set.." equations similarly replaced.
    • "attr" is now "def_attr", short for "default display attributes" Also added a "current_attr" for "currently applied display attributes"
  • Graphics.Vty.Image:
    • "horzcat" is now "horiz_cat"
    • "vertcat" is now "vert_cat"
    • "renderBS" is now "utf8_bytestring"
    • "renderChar" is now "char"
    • "renderFill" is now "char_fill"
    • added a "utf8_string" and "string" (AKA "iso_10464_string") for UTF-8 encoded Strings and ISO-10464 encoded Strings. String literals in GHC have an ISO-10464 runtime representation.
  • Graphics.Vty.Picture:
    • exports Graphics.Vty.Image
    • "pic" is now "pic_for_image"
    • added API for setting background fill pattern.
  • Completely rewritten output backend.
    • Efficient, scanline style output span generator. Has not been fully optimized, but good enough.
    • The details required to display the desired picture on a terminal are well encapsulated.
    • Terminfo based display terminal implementation. With specialized derivitives for xterm, Terminal.app, and iTerm.app.
      • Attempts to robustly handle even terminals that don't support all display attributes.
      • I've tested the following terminals with success: iTerm.app, Terminal.app, xterm, rxvt, mlterm, Eterm, gnome-terminal, konsole, screen, linux vty. Hopefully you will be as successfull.
    • Improved unicode support. Double wide characters will display as expected.
  • 256 color support. See Graphics.Vty.Attributes.Color240. The actual output color is adjusted according to the number of colors the terminal supports.
  • The Graphics.Vty.Image combinators no longer require matching dimensions to arguments. Unspecified areas are filled in with a user-customizable background pattern. See Graphics.Vty.Picture.
  • output images are always cropped to display size.
  • Significant code coverage by QuickCheck tests. An interactive test for those final properties that couldn't be automatically verified.

  Issues resolved:

  • "gnome terminal displays non-basic attributes as strikethrough"
    • http://trac.haskell.org/vty/ticket/14
  • "Multi-byte characters are not displayed correctly on update"
    • http://trac.haskell.org/vty/ticket/10
  • "Redraw does not handle rendering a line that extends beyond screen width characters"
    • http://trac.haskell.org/vty/ticket/13
  • "The <|> and <-> combinators should be more forgiving of mismatched dimensions"
    • http://trac.haskell.org/vty/ticket/9
  • "256-color support"
    • http://trac.haskell.org/vty/ticket/19