vty-5.22: A simple terminal UI library

Safe HaskellNone



This module provides functions for accessing the current terminal or a specific terminal device.

See also:

  1. Graphics.Vty.Output: This instantiates an abtract interface to the terminal based on the TERM and COLORTERM environment variables.
  2. Graphics.Vty.Output.Interface: Defines the generic interface all terminal modules need to implement.
  3. Graphics.Vty.Output.TerminfoBased: Defines a terminal instance that uses terminfo for all control strings. No attempt is made to change the character set to UTF-8 for these terminals.
  4. Graphics.Vty.Output.XTermColor: This module contains an interface suitable for xterm-like terminals. These are the terminals where TERM begins with xterm. This does use terminfo for as many control codes as possible.


outputForConfig :: Config -> IO Output Source #

Returns an Output for the terminal specified in Config.

The specific Output implementation used is hidden from the API user. All terminal implementations are assumed to perform more, or less, the same. Currently, all implementations use terminfo for at least some terminal specific information.

If a terminal implementation is developed for a terminal without terminfo support then Vty should work as expected on that terminal.

Selection of a terminal is done as follows:

  • If TERM contains "xterm" or "screen", use XTermColor.
  • otherwise use the TerminfoBased driver.

setCursorPos :: MonadIO m => Output -> Int -> Int -> m () Source #

Sets the cursor position to the given output column and row.

This is not necessarially the same as the character position with the same coordinates. Characters can be a variable number of columns in width.

Currently, the only way to set the cursor position to a given character coordinate is to specify the coordinate in the Picture instance provided to outputPicture or refresh.

hideCursor :: MonadIO m => Output -> m () Source #

Hides the cursor.

showCursor :: MonadIO m => Output -> m () Source #

Shows the cursor.