implement enough of the fdo specs to be able to write desktop menu files

to the appropriate system or local user directory

Utility/FreeDesktop.hs

@@ -0,0 +1,94 @@
+{- Freedesktop.org specifications
+ -
+ - http://standards.freedesktop.org/basedir-spec/latest/
+ - http://standards.freedesktop.org/desktop-entry-spec/latest/
+ - http://standards.freedesktop.org/menu-spec/latest/
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Utility.DesktopMenu (
+	DesktopEntry,	
+	genDesktopEntry,
+	buildDesktopMenuFile,
+	writeDesktopMenuFile,
+	userDesktopMenuFilePath,
+	systemDesktopMenuFilePath		
+) where
+
+import Utility.Exception
+import Utility.Directory
+import Utility.Path
+
+import System.IO
+import System.Environment
+import System.Directory
+import System.FilePath
+import Data.List
+import Data.String.Utils
+
+type DesktopEntry = [(Key, Value)]
+
+type Key = String
+
+data Value = StringV String | BoolV Bool | NumericV Float | ListV [Value]
+
+toString :: Value -> String
+toString (StringV s) = s
+toString (BoolV b)
+	| b = "true"
+	| otherwise = "false"
+toString(NumericV f) = show f
+toString (ListV l)
+	| null l = ""
+	| otherwise = (intercalate ";" $ map (escapesemi . toString) l) ++ ";"
+	where
+		escapesemi = join "\\;" . split ";"
+
+genDesktopEntry :: String -> String -> Bool -> FilePath -> FilePath -> [String] -> DesktopEntry
+genDesktopEntry name comment terminal program icon categories =
+	[ item "Encoding" StringV "UTF-8"
+	, item "Type" StringV "Application"
+	, item "Version" NumericV 1.0
+	, item "Name" StringV name
+	, item "Comment" StringV comment
+	, item "Terminal" BoolV terminal
+	, item "Exec" StringV program
+	, item "Icon" StringV icon
+	, item "Categories" ListV (map StringV categories)
+	]
+	where
+		item x c y = (x, c y)
+
+buildDesktopMenuFile :: DesktopEntry -> String
+buildDesktopMenuFile d = unlines ("[Desktop Entry]" : map keyvalue d) ++ "\n"
+	where
+		keyvalue (k, v) = k ++ "=" ++ toString v
+
+writeDesktopMenuFile :: DesktopEntry -> String -> IO ()
+writeDesktopMenuFile d file = do
+	createDirectoryIfMissing True (parentDir file)
+	writeFile file $ buildDesktopMenuFile d
+
+userDesktopMenuFilePath :: String -> IO FilePath
+userDesktopMenuFilePath basename = do
+	datadir <- userDataDir
+	return $ datadir </> "applications" </> basename
+
+systemDesktopMenuFilePath :: String -> FilePath
+systemDesktopMenuFilePath basename = "/usr/share/applications" </> basename
+
+userDataDir :: IO FilePath
+userDataDir = do
+	dir <- xdgEnv "DATA_HOME" =<< myHomeDir
+	return $ dir </> ".local" </> "share"
+
+userConfigDir :: IO FilePath
+userConfigDir = do
+	dir <- xdgEnv "DATA_HOME" =<< myHomeDir
+	return $ dir </> ".config"
+
+xdgEnv :: String -> String -> IO String
+xdgEnv envbase def = catchDefaultIO (getEnv $ "XDG_" ++ envbase) def