vty-4.7.5: A simple terminal UI library

Safe HaskellNone



The inline module provides a limited interface to changing the style of terminal output. The intention is for this interface to be used inline with other output systems.

The changes specified by the InlineM monad are applied to the terminals display attributes. These display attributes effect the display of all following text output to the terminal file descriptor.

For example, in an IO monad the following code with print the text "Not styled. " Followed by the text " Styled! " drawn over a red background and underlined.

      t <- terminal_handle
      putStr "Not styled. "
      put_attr_change t $ do
          back_color red 
          apply_style underline
      putStr " Styled! "
      put_attr_change t $ default_all
      putStrLn "Not styled."
      release_terminal t

put_attr_change outputs the control codes to the terminal device Handle. This is a duplicate of the stdout handle when the terminal_handle was (first) acquired. If stdout has since been changed then putStr, putStrLn, print etc.. will output to a different Handle than put_attr_change

Copyright 2009-2010 Corey O'Connor



back_color :: Color -> InlineM ()Source

Set the background color to the provided Color

fore_color :: Color -> InlineM ()Source

Set the foreground color to the provided Color

apply_style :: Style -> InlineM ()Source

Attempt to change the Style of the following text.

If the terminal does not support the style change no error is produced. The style can still be removed.

remove_style :: Style -> InlineM ()Source

Attempt to remove the specified Style from the display of the following text.

This will fail if apply_style for the given style has not been previously called.

default_all :: InlineM ()Source

Reset the display attributes

put_attr_change :: (Applicative m, MonadIO m) => TerminalHandle -> InlineM () -> m ()Source

Apply the provided display attribute changes to the terminal.

This also flushes the stdout handle.