xmonad-contrib/XMonad/Doc/Extending.hs

-----------------------------------------------------------------------------
-- |
-- Module      :  XMonad.Doc.Extending
-- Copyright   :  (C) 2007 Andrea Rossato
-- License     :  BSD3
--
-- Maintainer  :  andrea.rossato@unibz.it
-- Stability   :  unstable
-- Portability :  portable
--
-- This is a module for documenting the xmonad-contrib library and
-- describing how to use it to extend xmonad capabilities.
--
-- While it should not require a deep knowledge of Haskell. this
-- document is intended also for the more advanced users, which
-- requires a reference to some features of Haskell. Still we hope the
-- examples may be useful also for those users who do not Haskell and
-- do not want to start learning it.
--
-- More configuration examples may be fond on the Haskell wiki at this
-- address:
--
-- <http://haskell.org/haskellwiki/Xmonad/Config_archive>
--
-----------------------------------------------------------------------------

module XMonad.Doc.Extending
    (
    -- * The xmonad-contrib library
    -- $library

    -- ** Actions
    -- $actions

    -- ** Configurations
    -- $configs

    -- ** Hooks
    -- $hooks

    -- ** Layouts
    -- $layouts

    -- ** Prompts
    -- $prompts

    -- ** Utilities
    -- $utils

    -- * Extending xmonad
    -- $extending

    -- ** Editing key bindings
    -- $keys

    -- *** Adding key bindings
    -- $keyAdding

    -- *** Removing key bindings
    -- $keyDel

    -- *** Adding and removing key bindings
    -- $keyAddDel

    -- ** Editing the layout hook
    -- $layoutHook

    -- ** Editing the manage hook
    -- $manageHook

    -- ** The log hook and external status bars
    -- $logHook
    ) where

--------------------------------------------------------------------------------
--
--  The XmonadContrib Library
--
--------------------------------------------------------------------------------

{- $library

The xmonad-contrib (xmc) library is a set of extension modules
contributed by xmonad hackers and users, which provide additional
xmonad features.  Examples include various layout modes (tabbed,
spiral, three-column...), prompts, program launchers, the ability to
manipulate windows and workspaces in various ways, alternate
navigation modes, and much more.  There are also \"meta-modules\"
which make it easier to write new modules and extensions.

This is a short overview of the xmonad-contrib modules.  For more
information about any particular module, just click on its name to
view its Haddock documentation; each module should come with extensive
documentation.  If you find a module that could be better documented,
or has incorrect documentation, please report it as a bug
(<http://code.google.com/p/xmonad/issues/list>)!

-}

{- $actions

In the @XMonad.Actions@ namespace you can find modules exporting
various functions that are usually intended to be bound to key
combinations or mouse actions, in order to provide functionality
beyond the standard keybindings provided by xmonad.

See "XMonad.Doc.Extending#Editing_key_bindings" for instructions on how to
edit your key bindings.

* "XMonad.Actions.Commands": running internal xmonad actions
  interactively.

* "XMonad.Actions.ConstrainedResize": an aspect-ratio-constrained
  window resizing mode.

* "XMonad.Actions.CopyWindow": duplicating windows on multiple
  workspaces.

* "XMonad.Actions.CycleWS": move between workspaces.

* "XMonad.Actions.DeManage": cease management of a window without
  unmapping it.

* "XMonad.Actions.DwmPromote": dwm-like master window swapping.

* "XMonad.Actions.DynamicWorkspaces": add and delete workspaces.

* "XMonad.Actions.FindEmptyWorkspace": find an empty workspace.

* "XMonad.Actions.FlexibleManipulate": move\/resize windows without
  warping the mouse.

* "XMonad.Actions.FlexibleResize": resize windows from any corner.

* "XMonad.Actions.FloatKeys": move\/resize floating windows with
  keybindings.

* "XMonad.Actions.FocusNth": focus the nth window on the screen.

* "XMonad.Actions.MouseGestures": bind mouse gestures to actions.

* "XMonad.Actions.RotSlaves": rotate non-master windows.

* "XMonad.Actions.RotView": cycle through non-empty workspaces.

* "XMonad.Actions.SimpleDate": display the date in a popup menu.

* "XMonad.Actions.SinkAll": sink all floating windows.

* "XMonad.Actions.Submap": create key submaps, i.e. the ability to
  bind actions to key sequences rather than being limited to single
  key combinations.

* "XMonad.Actions.SwapWorkspaces": swap workspace tags.

* "XMonad.Actions.TagWindows": tag windows and select by tag.

* "XMonad.Actions.Warp": warp the pointer.

* "XMonad.Actions.WindowBringer": bring windows to you, and you to
  windows.

* "XMonad.Actions.WmiiActions": wmii-style actions.

-}

{- $configs

In the @XMonad.Config@ namespace you can find modules exporting the
configurations used by some of the xmonad and xmonad-contrib
developers.  You can look at them for examples while creating your own
configuration; you can also simply import them and use them as your
own configuration, possibly with some modifications.

-}

{- $hooks

In the @XMonad.Hooks@ namespace you can find modules exporting hooks.

Hooks are actions that xmonad performs when some events occur. The two
most important hooks are:

* 'XMonad.Core.manageHook': this hook is called when a new window
  xmonad must take care of is created. This is a very powerful hook,
  since it let us look at the new window's properties and act
  accordingly. For instance, we can configure xmonad to put windows
  belonging to a given application in the float layer, not to manage
  dock applications, or open them in a given workspace. See
  "XMonad.Doc.Extending#Editing_the_manage_hook" for more information on
  customizing the 'XMonad.Core.manageHook'.

* 'XMonad.Core.logHook': this hook is called when the stack of windows
  managed by xmonad has been changed, by calling the
  'XMonad.Operations.windows' function. For instance
  "XMonad.Hooks.DynamicLog" will produce a string (whose format can be
  configured) to be printed to the standard output. This can be used
  to display some information about the xmonad state in a Status Bar.
  See "XMonad.Doc.Extending#The_log_hook_and_external_status_bars" for more
  information.

-}

{- $layouts

In the @XMonad.Layout@ name space you can find modules exporting
contributed tiling algorithms, such as a tabbed layout, a circle and a
three columns ones, etc.

Other modules provide facilities for combining different layouts, such
as "XMonad.Layout.Combo", or a complete set of layout combinators,
like "XMonad.Layout.LayoutCombinators"

Layouts can be also modified with layout modifiers. A general
interface for writing layout modifiers is implemented in
"XMonad.Layout.LayoutModifier".

For more information on using those modules for customizing your
'XMonad.Core.layoutHook' see "XMonad.Doc.Extending#Editing_the_layout_hook".


-}

{- $prompts

In the @XMonad.Prompt@ name space you can find modules exporting
graphical prompts for getting user input and performing, with it,
different actions.

"XMonad.Prompt" provides a library for easily writing prompts.

These are the available prompts:

* "XMonad.Prompt.Directory"

* "XMonad.Prompt.Layout"

* "XMonad.Prompt.Man"

* "XMonad.Prompt.Shell"

* "XMonad.Prompt.Ssh"

* "XMonad.Prompt.Window"

* "XMonad.Prompt.Workspace"

* "XMonad.Prompt.XMonad"

Usually a prompt is called by some key binding. See
"XMonad.Doc.Extending#Editing_key_bindings" on how to configure xmonad to use
some prompts. The give examples include adding some prompts.

-}

{- $utils

In the @XMonad.Util@ namespace you can find modules exporting various
utility functions that are used by the other modules of the
xmonad-contrib library.

There are also utilities for helping in configuring xmonad or using
external utilities.

A non complete list with a brief description:

* "XMonad.Util.CustomKeys" or "XMonad.Util.EZConfig" can be used to
  configure key bindings (see "XMonad.Doc.Extending#Editing_key_bindings");

* "XMonad.Util.Dzen" "XMonad.Util.Dmenu" provide useful functions for
  running dzen as a xmonad status bar and dmenu as a program launcher;

* "XMonad.Util.XSelection" provide utilities for using the mouse
  selection;

* "XMonad.Util.XUtils" and "XMonad.Util.Font" are libraries for
  accessing Xlib and XFT function in a convenient way.

-}

--------------------------------------------------------------------------------
--
--  Extending Xmonad
--
--------------------------------------------------------------------------------

{- $extending
#Extending_xmonad#

Since the @xmonad.hs@ file is just another Haskell module, you may
import and use any Haskell code or libraries you wish, such as
extensions from the xmonad-contrib library, or other code you write
yourself.

-}

{- $keys
#Editing_key_bindings#

Editing key bindings means changing the 'XMonad.Core.XConfig.keys'
record of the 'XMonad.Core.XConfig' data type, like:

>    main = xmonad defaultConfig { keys = myKeys }

and providing a proper definition of @myKeys@ such as:

>    myKeys x =
>             [ ((modMask x, xK_F12), xmonadPrompt defaultXPConfig)
>             , ((modMask x, xK_F3 ), shellPrompt  defaultXPConfig)
>             ]

Remember that this definition requires importing "Graphics.X11.Xlib",
"XMonad.Prompt", "XMonad.Prompt.Shell", and "XMonad.Prompt.XMonad"

Sometimes, more than completely redefining the key bindings, as we did
above, we may want to add some new bindings, or\/and remove existing
ones.

-}

{- $keyAdding
#Adding_key_bindings#

Adding key bindings can be done in different ways. The type signature
of "XMonad.Core.XConfig.keys" is:

>    keys :: XConfig Layout -> M.Map (ButtonMask,KeySym) (X ())

which means thatm in order to add new bindings you need to create a
'Data.Map.Map' from the list of your new key bindings, you can do that
with 'Data.Map.fromList', and then join this newly created map with
the one of the existing bindings. This can be done with
'Data.Map.union'.

For instance, if you have defined some additional key bindings like
these:

>    myKeys x =
>             [ ((modMask x, xK_F12), xmonadPrompt defaultXPConfig)
>             , ((modMask x, xK_F3 ), shellPrompt  defaultXPConfig)
>             ]

then you create a new key bindings map by joining the default one with
yours:

>    newKeys x  = M.union (keys defaultConfig x) (M.fromList (myKeys x))

Finally you need to update accordingly the default configuration
'XMonad.Core.XConfig.keys' record:

>    main = xmonad defaultConfig { keys = newKeys }


And that's it.

At the end your @~\/.xmonad\/xmonad.hs@ would look like this:


>    module Main (main) where
>
>    import XMonad
>
>    import qualified Data.Map as M
>    import Graphics.X11.Xlib
>    import XMonad.Prompt
>    import XMonad.Prompt.Shell
>    import XMonad.Prompt.XMonad
>
>    main :: IO ()
>    main = xmonad defaultConfig { keys = newKeys }
>
>    newKeys x = M.union (keys defaultConfig x) (M.fromList (myKeys x))
>
>    myKeys x =
>             [ ((modMask x, xK_F12), xmonadPrompt defaultXPConfig)
>             , ((modMask x, xK_F3 ), shellPrompt  defaultXPConfig)
>             ]


Obviously there are other ways of defining @newKeys@. For instance,
you could define it like this:

>    newKeys x = foldr (uncurry M.insert) (keys defaultConfig x) (myKeys x)

An even simpler way to add new key bindings is the use of some of the
utilities provided by the xmonad-contrib library. For instance,
"XMonad.Util.EZConfig" and "XMonad.Util.CustomKeys" both provide
useful functions for editing your key bindings. Look, for instance, at
'XMonad.Util.EZConfig.additionalKeys'.

 -}

{- $keyDel
#Removing_key_bindings#

Removing key bindings requires modifying the binding 'Data.Map.Map'.
This can be done with 'Data.Map.difference' or with 'Data.Map.delete'.

Suppose you wan to get rid of @mod-q@ and @mod-shift-q@. To do this
you just need to define a @newKeys@ as a 'Data.Map.difference' between
the default map and the map of the key bindings you want to remove.

>    newKeys x = M.difference (keys defaultConfig x) (M.fromList $ keysToRemove x)
>
>    keysToRemove :: XConfig Layout ->    [((KeyMask, KeySym),X ())]
>    keysToRemove x =
>             [ ((modMask x              , xK_q ), return ())
>             , ((modMask x .|. shiftMask, xK_q ), return ())
>             ]

As you may see we do not need to define an action for the key bindings
we want to get rid of. We just build a map of keys to remove.

It is also possible to define a list of key bindings and then use
'Data.Map.delete' to remove them from the default key bindings, in
which case we should write something like:

>    newKeys x = foldr M.delete (keys defaultConfig x) (keysToRemove x)
>
>    keysToRemove :: XConfig Layout -> [(KeyMask, KeySym)]
>    keysToRemove x =
>             [ (modMask x              , xK_q )
>             , (modMask x .|. shiftMask, xK_q )
>             ]

Another even simpler possibility is the use of some of the utilities
provided by the xmonad-contrib library. Look, for instance, at
'XMonad.Util.EZConfig.removeKeys'.

-}

{- $keyAddDel
#Adding_and_removing_key_bindings#

Adding and removing key bindings requires to compose the action of
removing and, after that, the action of adding.

This is an example you may find in "XMonad.Config.Arossato":


>    defKeys    = keys defaultConfig
>    delKeys x  = foldr M.delete           (defKeys x) (toRemove x)
>    newKeys x  = foldr (uncurry M.insert) (delKeys x) (toAdd    x)
>    -- remove some of the default key bindings
>    toRemove x =
>        [ (modMask x              , xK_j     )
>        , (modMask x              , xK_k     )
>        , (modMask x              , xK_p     )
>        , (modMask x .|. shiftMask, xK_p     )
>        , (modMask x .|. shiftMask, xK_q     )
>        , (modMask x              , xK_q     )
>        ] ++
>        -- I want modMask .|. shiftMask 1-9 to be free!
>        [(shiftMask .|. modMask x, k) | k <- [xK_1 .. xK_9]]
>    -- These are my personal key bindings
>    toAdd x   =
>        [ ((modMask x              , xK_F12   ), xmonadPrompt defaultXPConfig )
>        , ((modMask x              , xK_F3    ), shellPrompt  defaultXPConfig )
>        ] ++
>        -- Use modMask .|. shiftMask .|. controlMask 1-9 instead
>        [( (m .|. modMask x, k), windows $ f i)
>         | (i, k) <- zip (workspaces x) [xK_1 .. xK_9]
>        ,  (f, m) <- [(W.greedyView, 0), (W.shift, shiftMask .|. controlMask)]
>        ]

You can achieve the same result by using "XMonad.Util.CustomKeys" and,
specifically, 'XMonad.Util.CustomKeys.customKeys'.

-}

{- $layoutHook
#Editing_the_layout_hook#

When you start an application that opens a new window, when you change
the focused window, or move it to another workspace, or change that
workspace's layout, xmonad will use the 'XMonad.Core.layoutHook' for
reordering the visible windows on the visible workspace(s).

Since different layouts may be attached to different workspaces, and
you can change them, xmonad needs to know which one to pick up. In
this sense the layoutHook may be thought as the combination, or the
list, of layouts that xmonad will use for ordering windows on the
screen(s)

The problem is that the layout subsystem is implemented with an
advanced feature of the Haskell programming language: type classes.
This allows us to very easily write new layouts, combine or modify
existing layouts, have some of them with a state, etc. See
"XMonad.Doc.Extending#The_LayoutClass" for more information.

The price we have to pay to get all that for free - which is something
that makes xmonad so powerful with such a ridiculously low number of
lines - is that we cannot simply have a list of layouts as we used to
have before the 0.5 release: a list requires every member to belong to
the same type!

Instead the combination of layouts to be used by xmonad is created
with a specific layout combinator: 'XMonad.Layouts.|||'

Suppose we want a list with the 'XMonad.Layouts.Full', the
'XMonad.Layout.Tabbed.tabbed' and the
'XMonad.Layout.Accordion.Accordion' layouts. First we import, in our
@~\/.xmonad\/xmonad.hs@, all the needed module:

>    import XMonad
>    import XMonad.Layouts
>
>    import XMonad.Layout.Tabbed
>    import XMonad.Layout.Accordion

Then we create the combination of layouts we need:

>    mylayoutHook = Full ||| tabbed shrinkText defaultTConf ||| Accordion


Now, all we need to do is to change the 'XMonad.Core.layoutHook'
record of the 'XMonad.Core.XConfig' data type, like:

>    main = xmonad defaultConfig { layoutHook = mylayoutHook }

Thanks to the new combinator we can apply a layout modifier to the
combination of layouts, instead of applying it to each one. Suppose we
want to use the 'XMonad.Layout.NoBorders.noBorders' layout modifier,
from the "XMonad.Layout.NoBorders" module (which must be imported):

>    mylayoutHook = noBorders (Full ||| tabbed shrinkText defaultTConf ||| Accordion)

Obviously, if we want only the tabbed layout without borders, then we
may write:

>    mylayoutHook = Full ||| noBorders (tabbed shrinkText defaultTConf) ||| Accordion

Our @~\/.xmonad\/xmonad.hs@ will now look like this:

>    import XMonad.Layouts
>
>    import XMonad.Layout.Tabbed
>    import XMonad.Layout.Accordion
>    import XMonad.Layout.NoBorders
>
>    mylayoutHook = Full ||| noBorders (tabbed shrinkText defaultTConf) ||| Accordion
>
>    main = xmonad defaultConfig { layoutHook = mylayoutHook }

That's it!

-}

{- $manageHook
#Editing_the_manage_hook#
TODO: Manage Hook

-}

{- $logHook
#The_log_hook_and_external_status_bars#

TODO: Log Hook

-}