mod-b, toggle on or off the status bar gap

Config.hs

@@ -49,9 +49,9 @@ defaultDelta = 3%100
 defaultWindowsInMaster :: Int
 defaultWindowsInMaster = 1
 
--- Default width of gap at top of screen for a menu bar (e.g. 16)
-defaultMenuGap :: Int
-defaultMenuGap = 0
+-- Default height of gap at top of screen for a menu bar (e.g. 15)
+defaultStatusGap :: Int
+defaultStatusGap = 0 -- 15 for default dzen
 
 -- numlock handling:
 --
@@ -114,6 +114,9 @@ keys = M.fromList $
     , ((modMask              , xK_comma ), sendMessage (IncMasterN 1)) -- @@ Increment the number of windows in the master area
     , ((modMask              , xK_period), sendMessage (IncMasterN (-1))) -- @@ Deincrement the number of windows in the master area
 
+    -- toggle the status bar gap
+    , ((modMask              , xK_b     ), modifyGap (\n -> if n == 0 then defaultStatusGap else 0)) -- @@ Toggle the status bar gap
+
     -- quit, or restart
     , ((modMask .|. shiftMask, xK_q                     ), io (exitWith ExitSuccess)) -- @@ Quit xmonad
     , ((modMask .|. shiftMask .|. controlMask, xK_q     ), restart Nothing True) -- @@ Restart xmonad

Config.hs-boot

@@ -1,4 +1,3 @@
 module Config where
 import Graphics.X11.Xlib.Types (Dimension)
 borderWidth :: Dimension
-defaultMenuGap :: Int

Main.hs

@@ -61,6 +61,7 @@ main = do
         st = XState
             { windowset     = winset
             , layouts       = M.fromList [(w, safeLayouts) | w <- [0 .. W workspaces - 1]]
+            , statusGap     = defaultStatusGap
             , xineScreens   = xinesc
             , dimensions    = (fromIntegral (displayWidth dpy dflt),
                                fromIntegral (displayHeight dpy dflt)) }

Operations.hs

@@ -15,7 +15,7 @@ module Operations where
 
 import XMonad
 import qualified StackSet as W
-import {-# SOURCE #-} Config (borderWidth,defaultMenuGap)
+import {-# SOURCE #-} Config (borderWidth)
 
 import Data.Maybe
 import Data.List            (genericIndex, intersectBy)
@@ -67,6 +67,12 @@ shift n = withFocused hide >> windows (W.shift n)
 view :: WorkspaceId -> X ()
 view = windows . W.view
 
+-- | Modify the size of the status gap at the top of the screen
+modifyGap :: (Int -> Int) -> X ()
+modifyGap f = do modify $ \s -> s { statusGap = max 0 (f (statusGap s)) }
+                 refresh
+
+
 -- | Kill the currently focused client. If we do kill it, we'll get a
 -- delete notify back from X.
 --
@@ -123,7 +129,7 @@ hide w = withDisplay $ \d -> do
 --
 refresh :: X ()
 refresh = do
-    XState { windowset = ws, layouts = fls, xineScreens = xinesc } <- get
+    XState { windowset = ws, layouts = fls, xineScreens = xinesc, statusGap = gap } <- get
     d <- asks display
 
     -- for each workspace, layout the currently visible workspaces
@@ -133,8 +139,8 @@ refresh = do
             Just l = fmap fst $ M.lookup n fls
             Rectangle sx sy sw sh = genericIndex xinesc (W.screen w)
         -- now tile the windows on this workspace
-        rs <- doLayout l (Rectangle sx (sy + fromIntegral defaultMenuGap)
-                                    sw (sh - fromIntegral defaultMenuGap)) (W.index this)
+        rs <- doLayout l (Rectangle sx (sy + fromIntegral gap)
+                                    sw (sh - fromIntegral gap)) (W.index this)
         mapM_ (\(win,rect) -> io (tileWindow d win rect)) rs
 
         -- and raise the focused window if there is one.

XMonad.hs

@@ -40,6 +40,7 @@ data XState = XState
     { windowset         :: !WindowSet           -- ^ workspace list
     , xineScreens       :: ![Rectangle]         -- ^ dimensions of each screen
     , dimensions        :: !(Position,Position) -- ^ dimensions of the screen,
+    , statusGap         :: !Int                 -- ^ width of status bar
                                                 -- used for hiding windows
     , layouts           :: !(M.Map WorkspaceId (Layout, [Layout]))  }
                        -- ^ mapping of workspaces to descriptions of their layouts

util/gapcalc.c

@@ -0,0 +1,70 @@
+/*  gapcalc - calculate height of given font
+ *  Copyright (C) 2007 by Robert Manea  <rob.manea@gmail.com>
+ *
+ *  Compile with: cc -lX11 -o gapcalc gapcalc.c
+ */
+
+#include<stdio.h>
+#include<stdlib.h>
+#include<stdarg.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+void 
+eprint(const char *errstr, ...) {
+    va_list ap;
+
+    va_start(ap, errstr);
+    vfprintf(stderr, errstr, ap);
+    va_end(ap);
+    exit(EXIT_FAILURE);
+}
+
+
+int 
+main(int argc, char *argv[]) {
+    Display *dpy;    
+    XFontStruct *xfont;
+    XFontSet set;
+    char *def, **missing;
+    char *fontstr;
+    int i, n, ascent, descent;
+
+    if(argc < 2)
+        eprint("Usage: gapcalc <font>\n");
+
+    if(!(dpy = XOpenDisplay(0)))
+        eprint("fatal: cannot open display\n");
+
+    fontstr = argv[1];
+    missing = NULL;
+
+    set = XCreateFontSet(dpy, fontstr, &missing, &n, &def);
+    if(missing)
+        XFreeStringList(missing);
+    if(set) {
+        XFontSetExtents *font_extents;
+        XFontStruct **xfonts;
+        char **font_names;
+        ascent = descent = 0;
+        font_extents = XExtentsOfFontSet(set);
+        n = XFontsOfFontSet(set, &xfonts, &font_names);
+        for(i = 0, ascent = 0, descent = 0; i < n; i++) {
+            if(ascent < (*xfonts)->ascent)
+                ascent = (*xfonts)->ascent;
+            if(descent < (*xfonts)->descent)
+                descent = (*xfonts)->descent;
+            xfonts++;
+        }
+    } else if(!set && (xfont = XLoadQueryFont(dpy, fontstr))) {
+        ascent = xfont->ascent;
+        descent = xfont->descent;
+    } else 
+        eprint("fatal: cannot find specified font\n");
+
+    printf("%d\n", ascent + descent + 2);
+
+  
+  return EXIT_SUCCESS;
+}
+