Safe Haskell	Safe-Inferred
Language	Haskell2010

Graphics.Vty

Description

Vty provides interfaces for both terminal input and terminal output.

Input to the terminal is provided to the Vty application as a sequence of Events.
Output is provided to Vty by the application in the form of a Picture. A Picture is one or more layers of Images. Image values can be built by the various constructors in Graphics.Vty.Image. Output can be syled using Attr (attribute) values in the Graphics.Vty.Attributes module.

Vty uses threads internally, so programs made with Vty need to be compiled with the threaded runtime using the GHC -threaded option.

 import Graphics.Vty

 main = do
     cfg <- standardIOConfig
     vty <- mkVty cfg
     let line0 = string (defAttr ` withForeColor ` green) "first line"
         line1 = string (defAttr ` withBackColor ` blue) "second line"
         img = line0 <-> line1
         pic = picForImage img
     update vty pic
     e <- nextEvent vty
     shutdown vty
     print ("Last event was: " ++ show e)

Synopsis

data Vty = Vty {
- update :: Picture -> IO ()
- nextEvent :: IO Event
- nextEventNonblocking :: IO (Maybe Event)
- inputIface :: Input
- outputIface :: Output
- refresh :: IO ()
- shutdown :: IO ()
- isShutdown :: IO Bool
}
mkVty :: Config -> IO Vty
setWindowTitle :: Vty -> String -> IO ()
data Mode
- = Mouse
- | BracketedPaste
- | Focus
- | Hyperlink
module Graphics.Vty.Config
module Graphics.Vty.Input
module Graphics.Vty.Output
module Graphics.Vty.Output.Interface
module Graphics.Vty.Picture
module Graphics.Vty.Image
module Graphics.Vty.Attributes

Documentation

data Vty Source #

A Vty value represents a handle to the Vty library that the application must create in order to use Vty.

The use of Vty typically follows this process:

Initialize vty with mkVty (this takes control of the terminal).
Use update to display a picture.
Use nextEvent to get the next input event.
Depending on the event, go to 2 or 5.
Shutdown vty and restore the terminal state with shutdown. At this point the Vty handle cannot be used again.

Operations on Vty handles are not thread-safe.

Constructors

Vty

Fields

update :: Picture -> IO ()
Outputs the given Picture.
nextEvent :: IO Event
Return the next Event or block until one becomes available.
nextEventNonblocking :: IO (Maybe Event)
Non-blocking version of nextEvent.
inputIface :: Input
The input interface. See Input.
outputIface :: Output
The output interface. See Output.
refresh :: IO ()
Refresh the display. If other programs output to the terminal and mess up the display then the application might want to force a refresh using this function.
shutdown :: IO ()
Clean up after vty. A call to this function is necessary to cleanly restore the terminal state before application exit. The above methods will throw an exception if executed after this is executed. Idempotent.
isShutdown :: IO Bool

mkVty :: Config -> IO Vty Source #

Create a Vty handle. At most one handle should be created at a time for a given terminal device.

The specified configuration is added to the the configuration loaded by userConfig with the userConfig configuration taking precedence. See Graphics.Vty.Config.

For most applications mkVty defaultConfig is sufficient.

setWindowTitle :: Vty -> String -> IO () Source #

Set the terminal window title string.

This function emits an Xterm-compatible escape sequence that we anticipate will work for essentially all modern terminal emulators. Ideally we'd use a terminal capability for this, but there does not seem to exist a termcap for setting window titles. If you find that this function does not work for a given terminal emulator, please report the issue.

For details, see:

https://tldp.org/HOWTO/Xterm-Title-3.html

data Mode Source #

Modal terminal features that can be enabled and disabled.

Constructors

Mouse	Mouse mode (whether the terminal is configured to provide mouse input events)
BracketedPaste	Paste mode (whether the terminal is configured to provide events on OS pastes)
Focus	Focus-in/focus-out events (whether the terminal is configured to provide events on focus change)
Hyperlink	Hyperlink mode via the `withURL` attribute modifier (see https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda). Note that this may not work gracefully in all terminal emulators so be sure to test this mode with the terminals you intend to support. It is off by default.

Instances

Instances details

Read Mode Source #
Instance details Defined in Graphics.Vty.Output.Interface Methods readsPrec :: Int -> ReadS Mode # readList :: ReadS [Mode] # readPrec :: ReadPrec Mode # readListPrec :: ReadPrec [Mode] #
Show Mode Source #
Instance details Defined in Graphics.Vty.Output.Interface Methods showsPrec :: Int -> Mode -> ShowS # show :: Mode -> String # showList :: [Mode] -> ShowS #
Eq Mode Source #
Instance details Defined in Graphics.Vty.Output.Interface Methods (==) :: Mode -> Mode -> Bool # (/=) :: Mode -> Mode -> Bool #

module Graphics.Vty.Config

module Graphics.Vty.Input

module Graphics.Vty.Output

module Graphics.Vty.Output.Interface

module Graphics.Vty.Picture

module Graphics.Vty.Image

module Graphics.Vty.Attributes