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-rw-r--r-- | XMonad/Prompt/Input.hs | 114 |
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diff --git a/XMonad/Prompt/Input.hs b/XMonad/Prompt/Input.hs new file mode 100644 index 0000000..27a0a56 --- /dev/null +++ b/XMonad/Prompt/Input.hs @@ -0,0 +1,114 @@ +----------------------------------------------------------------------------- +-- | +-- Module : XMonad.Prompt.Input +-- Copyright : (c) 2007 Brent Yorgey +-- License : BSD-style (see LICENSE) +-- +-- Maintainer : <byorgey@gmail.com> +-- Stability : unstable +-- Portability : unportable +-- +-- A generic framework for prompting the user for input and passing it +-- along to some other action. +-- +----------------------------------------------------------------------------- + +module XMonad.Prompt.Input ( + -- * Usage + -- $usage + inputPrompt, + inputPromptWithCompl, + (?+) + ) where + +import XMonad.Core +import XMonad.Prompt + +-- $usage +-- +-- To use this module, import it along with "XMonad.Prompt": +-- +-- > import XMonad.Prompt +-- > import XMonad.Prompt.Input +-- +-- This module provides no useful functionality in isolation, but +-- is intended for use in building other actions which require user +-- input. +-- +-- For example, suppose Mr. Big wants a way to easily fire his +-- employees. We'll assume that he already has a function +-- +-- > fireEmployee :: String -> X () +-- +-- which takes as input the name of an employee, and fires them. He +-- just wants a convenient way to provide the input for this function +-- from within xmonad. Here is where the "XMonad.Prompt.Input" module +-- comes into play. He can use the 'inputPrompt' function to create a +-- prompt, and the '?+' operator to compose the prompt with the +-- @fireEmployee@ action, like so: +-- +-- > firingPrompt :: X () +-- > firingPrompt = inputPrompt defaultXPConfig \"Fire\" ?+ fireEmployee +-- +-- If @employees@ contains a list of all his employees, he could also +-- create an autocompleting version, like this: +-- +-- > firingPrompt' = inputPromptWithCompl defaultXPConfig \"Fire\" +-- > (mkComplFunFromList employees) ?+ fireEmployee +-- +-- Now all he has to do is add a keybinding to @firingPrompt@ (or +-- @firingPrompt'@), such as +-- +-- > , ((modMask x .|. controlMask, xK_f), firingPrompt) +-- +-- Now when Mr. Big hits mod-ctrl-f, a prompt will pop up saying +-- \"Fire: \", waiting for him to type the name of someone to fire. +-- If he thinks better of it after hitting mod-ctrl-f and cancels the +-- prompt (e.g. by hitting Esc), the @fireEmployee@ action will not be +-- invoked. +-- +-- (For detailed instructions on editing your key bindings, see +-- "XMonad.Doc.Extending#Editing_key_bindings".) +-- +-- "XMonad.Prompt.Input" is also intended to ease the process of +-- developing other modules which require user input. For an example +-- of a module developed using this functionality, see +-- "XMonad.Prompt.Email", which prompts the user for a recipient, +-- subject, and one-line body, and sends a quick email. + +data InputPrompt = InputPrompt String + +instance XPrompt InputPrompt where + showXPrompt (InputPrompt s) = s ++ ": " + +-- | Given a prompt configuration and some prompt text, create an X +-- action which pops up a prompt waiting for user input, and returns +-- whatever they type. Note that the type of the action is @X +-- (Maybe String)@, which reflects the fact that the user might +-- cancel the prompt (resulting in @Nothing@), or enter an input +-- string @s@ (resulting in @Just s@). +inputPrompt :: XPConfig -> String -> X (Maybe String) +inputPrompt c p = inputPromptWithCompl c p (const (return [])) + +-- | The same as 'inputPrompt', but with a completion function. The +-- type @ComplFunction@ is @String -> IO [String]@, as defined in +-- "XMonad.Prompt". The 'mkComplFunFromList' utility function, also +-- defined in "XMonad.Prompt", is useful for creating such a +-- function from a known list of possibilities. +inputPromptWithCompl :: XPConfig -> String -> ComplFunction -> X (Maybe String) +inputPromptWithCompl c p compl = mkXPromptWithReturn (InputPrompt p) c compl return + + +infixr 1 ?+ + +-- | A combinator for hooking up an input prompt action to a function +-- which can take the result of the input prompt and produce another +-- action. If the user cancels the input prompt, the +-- second function will not be run. +-- +-- The astute student of types will note that this is actually a +-- very general combinator and has nothing in particular to do +-- with input prompts. If you find a more general use for it and +-- want to move it to a different module, be my guest. +(?+) :: (Monad m) => m (Maybe a) -> (a -> m ()) -> m () +x ?+ k = x >>= maybe (return ()) k
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