XMonad.Actions.WindowGo: add a runOrRaise module for Joseph Garvin with the help of Spencer Janssen

XMonad/Actions/WindowGo.hs

@@ -0,0 +1,75 @@
+{- --------------------------------------------------------------------------
+|
+Module      :  XMonad.Actions.WindowGo
+License     :  Public domain
+
+Maintainer  :  <gwern0@gmail.com>
+Stability   :  unstable
+Portability :  unportable
+
+Defines a few simple operations for raising windows based on XMonad's Query
+Monad, such as runOrRaise.
+
+----------------------------------------------------------------------------- -}
+
+module XMonad.Actions.WindowGo (
+                 -- * Usage
+                 -- $usage
+                 raise,
+                 runOrRaise,
+                 raiseMaybe,
+                 module XMonad.ManageHook
+                ) where
+
+import XMonad (Query(), X(), withWindowSet, spawn, runQuery, focus)
+import Control.Monad (filterM)
+import qualified XMonad.StackSet as W (allWindows)
+import XMonad.ManageHook
+
+-- $usage
+--
+-- Import the module into your @~\/.xmonad\/xmonad.hs@:
+--
+-- > import XMonad.Actions.WindowGo
+--
+-- and define appropriate key bindings:
+--
+-- > , ((modMask x .|. shiftMask, xK_g     ), raise (className =? "Firefox-bin"))
+-- > , ((modMask x .|. shiftMask, xK_b     ), runOrRaise "mozilla-firefox" (className =? "Firefox-bin"))
+--
+-- For detailed instructions on editing your key bindings, see
+-- "XMonad.Doc.Extending#Editing_key_bindings".
+
+-- | 'action' is an executable to be run via 'spawn' if the Window cannot be found.
+--   Presumably this executable is the same one that you were looking for.
+runOrRaise :: String -> Query Bool -> X ()
+runOrRaise action = raiseMaybe $ spawn action
+
+-- | See 'raiseMaybe'. If the Window can't be found, quietly give up and do nothing.
+raise :: Query Bool -> X ()
+raise = raiseMaybe $ return ()
+
+{- | raiseMaybe: this queries all Windows based on a boolean provided by the
+   user. Currently, there are three such useful booleans defined in
+   XMonad.ManageHook: title, resource, className. Each one tests based pretty
+   much as you would think. ManageHook also defines several operators, the most
+   useful of which is (=?). So a useful test might be finding a Window whose
+   class is Firefox. Firefox declares the class "Firefox-bin", so you'd want to
+   pass in a boolean like '(className =? "Firefox-bin")'.
+   If the boolean returns True on one or more windows, then XMonad will quickly
+   make visible the first result. If no Window meets the criteria, then the
+   first argument comes into play.
+
+   The first argument is an arbitrary IO function which will be executed if the
+   tests fail. This is what enables runOrRaise to use raiseMaybe: it simply runs
+   the desired program if it isn't found. But you don't have to do that. Maybe
+   you want to do nothing if the search fails (the definition of 'raise'), or
+   maybe you want to write to a log file, or call some prompt function, or
+   something crazy like that. This hook gives you that flexibility.
+-}
+raiseMaybe :: X () -> Query Bool -> X ()
+raiseMaybe f thatUserQuery = withWindowSet $ \s -> do
+    maybeResult <- filterM (runQuery thatUserQuery) (W.allWindows s)
+    case maybeResult of
+      [] -> f
+      (x:_)  -> focus x

xmonad-contrib.cabal

@@ -81,6 +81,7 @@ library
                         XMonad.Actions.SwapWorkspaces
                         XMonad.Actions.TagWindows
                         XMonad.Actions.Warp
+                        XMonad.Actions.WindowGo
                         XMonad.Actions.WindowBringer
                         XMonad.Actions.WmiiActions
                         XMonad.Config.Sjanssen