Navigation2D is an xmonad extension that allows easy directional navigation of windows and screens (in a multi-monitor setup).

Navigation2D provides directional navigation (go left, right, up, down) for windows and screens. It treats floating and tiled windows as two separate layers and provides mechanisms to navigate within each layer and to switch between layers. Navigation2D provides three different navigation strategies (see #Technical_Discussion for details): Line navigation and Side navigation feel rather natural but may make it impossible to navigate to a given window from the current window, particularly in the floating layer. Center navigation feels less natural in certain situations but ensures that all windows can be reached without the need to involve the mouse. Another option is to use a Hybrid of the three strategies, automatically choosing whichever first provides a suitable target window. Navigation2D allows different navigation strategies to be used in the two layers and allows customization of the navigation strategy for the tiled layer based on the layout currently in effect.

You can use this module with (a subset of) the following in your ~/.xmonad/xmonad.hs:

import XMonad.Actions.Navigation2D

Then add the configuration of the module to your main function:

main = xmonad $ navigation2D def
                             (xK_Up, xK_Left, xK_Down, xK_Right)
                             [(mod4Mask,               windowGo  ),
                              (mod4Mask .|. shiftMask, windowSwap)]
                             False
              $ def

Alternatively, you can use navigation2DP:

main = xmonad $ navigation2DP def
                              ("<Up>", "<Left>", "<Down>", "<Right>")
                              [("M-",   windowGo  ),
                               ("M-S-", windowSwap)]
                              False
              $ def

That's it. If instead you'd like more control, you can combine withNavigation2DConfig and additionalNav2DKeys or additionalNav2DKeysP:

main = xmonad $ withNavigation2DConfig def
              $ additionalNav2DKeys (xK_Up, xK_Left, xK_Down, xK_Right)
                                    [(mod4Mask,               windowGo  ),
                                     (mod4Mask .|. shiftMask, windowSwap)]
                                    False
              $ additionalNav2DKeys (xK_u, xK_l, xK_d, xK_r)
                                    [(mod4Mask,               screenGo  ),
                                     (mod4Mask .|. shiftMask, screenSwap)]
                                    False
              $ def

Or you can add the configuration of the module to your main function:

main = xmonad $ withNavigation2DConfig def $ def

And specify your keybindings normally:

   -- Switch between layers
   , ((modm,                 xK_space), switchLayer)

   -- Directional navigation of windows
   , ((modm,                 xK_Right), windowGo R False)
   , ((modm,                 xK_Left ), windowGo L False)
   , ((modm,                 xK_Up   ), windowGo U False)
   , ((modm,                 xK_Down ), windowGo D False)

   -- Swap adjacent windows
   , ((modm .|. controlMask, xK_Right), windowSwap R False)
   , ((modm .|. controlMask, xK_Left ), windowSwap L False)
   , ((modm .|. controlMask, xK_Up   ), windowSwap U False)
   , ((modm .|. controlMask, xK_Down ), windowSwap D False)

   -- Directional navigation of screens
   , ((modm,                 xK_r    ), screenGo R False)
   , ((modm,                 xK_l    ), screenGo L False)
   , ((modm,                 xK_u    ), screenGo U False)
   , ((modm,                 xK_d    ), screenGo D False)

   -- Swap workspaces on adjacent screens
   , ((modm .|. controlMask, xK_r    ), screenSwap R False)
   , ((modm .|. controlMask, xK_l    ), screenSwap L False)
   , ((modm .|. controlMask, xK_u    ), screenSwap U False)
   , ((modm .|. controlMask, xK_d    ), screenSwap D False)

   -- Send window to adjacent screen
   , ((modm .|. mod1Mask,    xK_r    ), windowToScreen R False)
   , ((modm .|. mod1Mask,    xK_l    ), windowToScreen L False)
   , ((modm .|. mod1Mask,    xK_u    ), windowToScreen U False)
   , ((modm .|. mod1Mask,    xK_d    ), windowToScreen D False)

For detailed instruction on editing the key binding see:

XMonad.Doc.Extending.

The above should get you started. Here are some finer points:

Navigation2D has the ability to wrap around at screen edges. For example, if you navigated to the rightmost window on the rightmost screen and you continued to go right, this would get you to the leftmost window on the leftmost screen. This feature may be useful for switching between screens that are far apart but may be confusing at least to novice users. Therefore, it is disabled in the above example (e.g., navigation beyond the rightmost window on the rightmost screen is not possible and trying to do so will simply not do anything.) If you want this feature, change all the False values in the above example to True. You could also decide you want wrapping only for a subset of the operations and no wrapping for others.

By default, all layouts use the defaultTiledNavigation strategy specified in the Navigation2DConfig (by default, line navigation is used). To override this behaviour for some layouts, add a pair ("layout name", navigation strategy) to the layoutNavigation list in the Navigation2DConfig, where "layout name" is the string reported by the layout's description method (normally what is shown as the layout name in your status bar). For example, all navigation strategies normally allow only navigation between mapped windows. The first step to overcome this, for example, for the Full layout, is to switch to center navigation for the Full layout:

myNavigation2DConfig = def { layoutNavigation = [("Full", centerNavigation)] }

main = xmonad $ withNavigation2DConfig myNavigation2DConfig
              $ def

The navigation between windows is based on their screen rectangles, which are available and meaningful only for mapped windows. Thus, as already said, the default is to allow navigation only between mapped windows. However, there are layouts that do not keep all windows mapped. One example is the Full layout, which unmaps all windows except the one that has the focus, thereby preventing navigation to any other window in the layout. To make navigation to unmapped windows possible, unmapped windows need to be assigned rectangles to pretend they are mapped, and a natural way to do this for the Full layout is to pretend all windows occupy the full screen and are stacked on top of each other so that only the frontmost one is visible. This can be done as follows:

myNavigation2DConfig = def { layoutNavigation   = [("Full", centerNavigation)]
                           , unmappedWindowRect = [("Full", singleWindowRect)]
                           }

main = xmonad $ withNavigation2DConfig myNavigation2DConfig
              $ def

With this setup, Left/Up navigation behaves like standard focusUp and Right/Down navigation behaves like focusDown, thus allowing navigation between windows in the layout.

In general, each entry in the unmappedWindowRect association list is a pair ("layout description", function), where the function computes a rectangle for each unmapped window from the screen it is on and the window ID. Currently, Navigation2D provides only two functions of this type: singleWindowRect and fullScreenRect.

With per-layout navigation strategies, if different layouts are in effect on different screens in a multi-monitor setup, and different navigation strategies are defined for these active layouts, the most general of these navigation strategies is used across all screens (because Navigation2D does not distinguish between windows on different workspaces), where center navigation is more general than line navigation, as discussed formally under #Technical_Discussion.

There exist two alternatives to Navigation2D: XMonad.Actions.WindowNavigation and XMonad.Layout.WindowNavigation. X.L.WindowNavigation has the advantage of colouring windows to indicate the window that would receive the focus in each navigation direction, but it does not support navigation across multiple monitors, does not support directional navigation of floating windows, and has a very unintuitive definition of which window receives the focus next in each direction. X.A.WindowNavigation does support navigation across multiple monitors but does not provide window colouring while retaining the unintuitive navigational semantics of X.L.WindowNavigation. This makes it very difficult to predict which window receives the focus next. Neither X.A.WindowNavigation nor X.L.WindowNavigation supports directional navigation of screens.

Currently Navigation2D is known not to play nicely with tabbed layouts, but it should work well with any other tiled layout. My hope is to address the incompatibility with tabbed layouts in a future version. The navigation to unmapped windows, for example in a Full layout, by assigning rectangles to unmapped windows is more a workaround than a clean solution. Figuring out how to deal with tabbed layouts may also lead to a more general and cleaner solution to query the layout for a window's rectangle that may make this workaround unnecessary. At that point, the unmappedWindowRect field of the Navigation2DConfig will disappear.

An in-depth discussion of the navigational strategies implemented in Navigation2D, including formal proofs of their properties, can be found at http://www.cs.dal.ca/~nzeh/xmonad/Navigation2D.pdf.