vty/CHANGELOG.md

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](https://github.com/jtdaugherty/vty/issues/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 <path>" 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