TreeSelect displays your workspaces or actions in a Tree-like format. You can select the desired workspace/action with the cursor or hjkl keys.

This module is fully configurable and very useful if you like to have a lot of workspaces.

Only the nodes up to the currently selected are displayed. This will be configurable in the near future by changing ts_hidechildren to False, this is not yet implemented.

These imports are used in the following example

import Data.Tree
import XMonad.Actions.TreeSelect
import XMonad.Hooks.WorkspaceHistory
import qualified XMonad.StackSet as W

For selecting Workspaces, you need to define them in a tree structure using Node instead of just a standard list

Here is an example workspace-tree

myWorkspaces :: Forest String
myWorkspaces = [ Node "Browser" [] -- a workspace for your browser
               , Node "Home"       -- for everyday activity's
                   [ Node "1" []   --  with 4 extra sub-workspaces, for even more activity's
                   , Node "2" []
                   , Node "3" []
                   , Node "4" []
                   ]
               , Node "Programming" -- for all your programming needs
                   [ Node "Haskell" []
                   , Node "Docs"    [] -- documentation
                   ]
               ]

Then add it to your workspaces using the toWorkspaces function.

Optionally, if you add workspaceHistoryHook to your logHook you can use the 'o' and 'i' keys to select from previously-visited workspaces

xmonad $ def { ...
             , workspaces = toWorkspaces myWorkspaces
             , logHook = workspaceHistoryHook
             }

After that you still need to bind buttons to treeselectWorkspace to start selecting a workspaces and moving windows

you could bind Mod-f to switch workspace

 , ((modMask, xK_f), treeselectWorkspace myTreeConf myWorkspaces W.greedyView)

and bind Mod-Shift-f to moving the focused windows to a workspace

 , ((modMask .|. shiftMask, xK_f), treeselectWorkspace myTreeConf myWorkspaces W.shift)

The selection menu is very configurable, you can change the font, all colors and the sizes of the boxes.

The default config defined as def

def = TSConfig { ts_hidechildren = True
               , ts_background   = 0xc0c0c0c0
               , ts_font         = "xft:Sans-16"
               , ts_node         = (0xff000000, 0xff50d0db)
               , ts_nodealt      = (0xff000000, 0xff10b8d6)
               , ts_highlight    = (0xffffffff, 0xffff0000)
               , ts_extra        = 0xff000000
               , ts_node_width   = 200
               , ts_node_height  = 30
               , ts_originX      = 0
               , ts_originY      = 0
               , ts_indent       = 80
               , ts_navigate     = defaultNavigation
               }

The Pixel Color format is in the form of 0xaarrggbb

Note that transparency is only supported if you have a window compositor running like compton

Some Examples:

white       = 0xffffffff
black       = 0xff000000
red         = 0xffff0000
green       = 0xff00ff00
blue        = 0xff0000ff
transparent = 0x00000000

Keybindings for navigations can also be modified

This is the definition of defaultNavigation

defaultNavigation :: M.Map (KeyMask, KeySym) (TreeSelect a (Maybe a))
defaultNavigation = M.fromList
    [ ((0, xK_Escape), cancel)
    , ((0, xK_Return), select)
    , ((0, xK_space),  select)
    , ((0, xK_Up),     movePrev)
    , ((0, xK_Down),   moveNext)
    , ((0, xK_Left),   moveParent)
    , ((0, xK_Right),  moveChild)
    , ((0, xK_k),      movePrev)
    , ((0, xK_j),      moveNext)
    , ((0, xK_h),      moveParent)
    , ((0, xK_l),      moveChild)
    , ((0, xK_o),      moveHistBack)
    , ((0, xK_i),      moveHistForward)
    ]

This module can also be used to select any other action