Generalize new workspace addition functions to support arbitrary insertion.

Ignore-this: 9f8c14b5aa9d398b3f167da0af1a8650

The current DynamicWorkspaces module only supports adding new workspaces
at the start of the list of workspaces. This means when binding workspaces
to keys based on the position in the list, key bindings can change
as workspaces are added in removed in a far more destructive way than
necessary. Instead, supporting appending and arbitrary insertion allows
the user to determine where the new workspace should be added.

This patch is a straight generalization of the addHiddenWorkspace' function.
Rather than always using `(:)` to insert the new workspace into the list
of workspaces, this patches causes it to use an arbitrary list insertion
function instead. A few new functions are added to prevent breakage of
external code while exported functions are left unchanged.

List of new functions:
  appendWorkspace
  appendWorkspacePrompt
  addWorkspaceAt
  addHiddenWorkspaceAt

Existing functions were modified to call their generalized brethren where possible
without changing functionality. This patch should not change behavior for any
existing users of this module.

darcs-hash:20141219002309-8d489-1a2c5cacb9724bd185836691027d1aefb8a799d5.gz

1 files changed, 32 insertions, 8 deletions

diff --git a/XMonad/Actions/DynamicWorkspaces.hs b/XMonad/Actions/DynamicWorkspaces.hs
index fc73542..6b2d050 100644
--- a/XMonad/Actions/DynamicWorkspaces.hs
+++ b/XMonad/Actions/DynamicWorkspaces.hs
@@ -16,12 +16,14 @@ module XMonad.Actions.DynamicWorkspaces (
                                          -- * Usage
                                          -- $usage
                                          addWorkspace, addWorkspacePrompt,
+                                         appendWorkspace, appendWorkspacePrompt,
+                                         addWorkspaceAt,
                                          removeWorkspace,
                                          removeWorkspaceByTag,
                                          removeEmptyWorkspace,
                                          removeEmptyWorkspaceAfter,
                                          removeEmptyWorkspaceAfterExcept,
-                                         addHiddenWorkspace,
+                                         addHiddenWorkspace, addHiddenWorkspaceAt,
                                          withWorkspace,
                                          selectWorkspace, renameWorkspace,
                                          renameWorkspaceByName,
@@ -63,6 +65,7 @@ import Control.Monad (when)
 -- "XMonad.Actions.CopyWindow", 'windows', 'shift', and 'XPConfig'.
 
 
+
 mkCompl :: [String] -> String -> IO [String]
 mkCompl l s = return $ filter (\x -> take (length s) x == s) l
 
@@ -108,20 +111,41 @@ selectWorkspace conf = workspacePrompt conf $ \w ->
 --   workspace with the given name already exists; then switch to the
 --   newly created workspace.
 addWorkspace :: String -> X ()
-addWorkspace newtag = addHiddenWorkspace newtag >> windows (greedyView newtag)
+addWorkspace = addWorkspaceAt (:)
+
+-- | Same as addWorkspace, but adds the workspace to the end of the list of workspaces
+appendWorkspace :: String -> X()
+appendWorkspace = addWorkspaceAt (flip (++) . return)
+
+-- | Adds a new workspace with the given name to the current list of workspaces.
+--   This function allows the user to pass a function that inserts an element
+--   into a list at an arbitrary spot.
+addWorkspaceAt :: (WindowSpace -> [WindowSpace] -> [WindowSpace]) -> String -> X ()
+addWorkspaceAt add newtag = addHiddenWorkspaceAt add newtag >> windows (greedyView newtag)
 
 -- | Prompt for the name of a new workspace, add it if it does not
 --   already exist, and switch to it.
 addWorkspacePrompt :: XPConfig -> X ()
 addWorkspacePrompt conf = mkXPrompt (Wor "New workspace name: ") conf (const (return [])) addWorkspace
 
+-- | Prompt for the name of a new workspace, appending it to the end of the list of workspaces 
+--   if it does not already exist, and switch to it.
+appendWorkspacePrompt :: XPConfig -> X ()
+appendWorkspacePrompt conf = mkXPrompt (Wor "New workspace name: ") conf (const (return [])) appendWorkspace
+
 -- | Add a new hidden workspace with the given name, or do nothing if
---   a workspace with the given name already exists.
-addHiddenWorkspace :: String -> X ()
-addHiddenWorkspace newtag =
+--   a workspace with the given name already exists. Takes a function to insert
+--   the workspace at an arbitrary spot in the list.
+addHiddenWorkspaceAt :: (WindowSpace -> [WindowSpace] -> [WindowSpace]) -> String -> X ()
+addHiddenWorkspaceAt add newtag =
   whenX (gets (not . tagMember newtag . windowset)) $ do
     l <- asks (layoutHook . config)
-    windows (addHiddenWorkspace' newtag l)
+    windows (addHiddenWorkspace' add newtag l)
+
+-- | Add a new hidden workspace with the given name, or do nothing if
+--   a workspace with the given name already exists.
+addHiddenWorkspace :: String -> X ()
+addHiddenWorkspace = addHiddenWorkspaceAt (:)
 
 -- | Remove the current workspace if it contains no windows.
 removeEmptyWorkspace :: X ()
@@ -166,8 +190,8 @@ isEmpty t = do wsl <- gets $ workspaces . windowset
                let mws = find (\ws -> tag ws == t) wsl
                return $ maybe True (isNothing . stack) mws
 
-addHiddenWorkspace' :: i -> l -> StackSet i l a sid sd -> StackSet i l a sid sd
-addHiddenWorkspace' newtag l s@(StackSet { hidden = ws }) = s { hidden = Workspace newtag l Nothing:ws }
+addHiddenWorkspace' :: (Workspace i l a -> [Workspace i l a] -> [Workspace i l a]) -> i -> l -> StackSet i l a sid sd -> StackSet i l a sid sd
+addHiddenWorkspace' add newtag l s@(StackSet { hidden = ws }) = s { hidden = add (Workspace newtag l Nothing) ws }
 
 -- | Remove the hidden workspace with the given tag from the StackSet, if
 --   it exists. All the windows in that workspace are moved to the current