[feature] only show the current keyboard layout and follow the changes

[zaza42]

Long story long: The reason I still use xxkb in 2025 is 3 essential things:

1. it shows the flag
2. I can switch with alt-shift
3. very low on resources

I just noticed that IceWM can also display flags instead of text (the manual wasn't clear that you have to copy a file called us.xpm to ~/.icewm/icons for this), so that part is solved.
There are all kinds of input remappers to bind alt-shift to e.g. alt+shift+c, but these consume more resources than the whole icewm. (and this is true for other keyboard indicators that aren't xxkb) And all keyboard switchers can track changes in the xorg keyboard layout, but IceWM can't. Even though the layout has changed, the flag remains the same.

So... what if IceWM just did this: draw the flag (or print the country code in its absence), and that's it.

I should add that I have very little skills with X11 and C, but with the help of an LLM I could create a patch that does just that. I've never made a pull request in my life, so I'll just copy it here first.
@gijsbers , take a look, what do you think?

diff -urNad icewm/src/default.h icewm-OnlyShowLayout/src/default.h
--- icewm/src/default.h	2025-11-25 03:17:11.339754991 +0100
+++ icewm-OnlyShowLayout/src/default.h	2025-11-25 03:18:19.352519366 +0100
@@ -4,6 +4,7 @@
 #include "yconfig.h"
 
 /************************************************************************************************************************************************************/
+XIV(bool, onlyShowLayout,                       false)
 XIV(bool, clickFocus,                           true)
 XIV(bool, focusOnAppRaise,                      false)
 XIV(bool, requestFocusOnAppRaise,               true)
@@ -244,6 +245,7 @@
 #ifdef CFGDEF
 
 cfoption icewm_preferences[] = {
+    OBV("OnlyShowLayout",                       &onlyShowLayout,                "Only show and follow the current keyboard layout"),
     OBV("ClickToFocus",                         &clickFocus,                    "Focus windows by clicking"),
     OBV("FocusOnAppRaise",                      &focusOnAppRaise,               "Focus windows when application requests to raise"),
     OBV("RequestFocusOnAppRaise",               &requestFocusOnAppRaise,        "Request focus (flashing in taskbar) when application requests raise"),
diff -urNad icewm/src/wmapp.cc icewm-OnlyShowLayout/src/wmapp.cc
--- icewm/src/wmapp.cc	2025-11-25 03:17:11.351755126 +0100
+++ icewm-OnlyShowLayout/src/wmapp.cc	2025-11-25 03:50:17.598133365 +0100
@@ -40,6 +40,11 @@
 #include <X11/Xproto.h>
 #include "ywordexp.h"
 #include "intl.h"
+#include <X11/XKBlib.h>
+#include <X11/extensions/XKBstr.h>
+
+static int xkbEventBase = 0;
+static int xkbErrorBase = 0;
 
 char const *ApplicationName("IceWM");
 RebootShutdown rebootOrShutdown = Logout;
@@ -1449,6 +1454,17 @@
 
     registerProtocols2(managerWindow);
 
+    // --- XKB extension enable for following keyboard layouts ---
+    if (onlyShowLayout) {
+       int major = XkbMajorVersion, minor = XkbMinorVersion;
+       if (XkbQueryExtension(xapp->display(), nullptr,
+                             &xkbEventBase, &xkbErrorBase,
+                             &major, &minor)) {
+           XkbSelectEvents(xapp->display(), XkbUseCoreKbd,
+                           XkbStateNotifyMask, XkbStateNotifyMask);
+       }
+    }
+
     initIcons();
     initIconSize();
     WPixRes::initPixmaps(this);
@@ -1663,6 +1679,16 @@
 }
 
 bool YWMApp::filterEvent(const XEvent &xev) {
+    if (onlyShowLayout && xev.type == xkbEventBase) {
+        const XkbEvent* xkbev = reinterpret_cast<const XkbEvent*>(&xev);
+        if (xkbev->any.xkb_type == XkbStateNotify) {
+            int group = xkbev->state.group;
+            if (manager && configKeyboards.nonempty()) {
+                manager->setKeyboard(configKeyboards[group % configKeyboards.getCount()]);
+            }
+            return true;
+        }
+    }
     if (xev.type == SelectionClear) {
         if (xev.xselectionclear.window == managerWindow) {
             manager->unmanageClients();
diff -urNad icewm/src/wmmgr.cc icewm-OnlyShowLayout/src/wmmgr.cc
--- icewm/src/wmmgr.cc	2025-11-25 03:17:11.351755126 +0100
+++ icewm-OnlyShowLayout/src/wmmgr.cc	2025-11-25 03:57:14.878839684 +0100
@@ -590,7 +590,7 @@
             taskBar->moveNext();
         return true;
     } else if (gKeySysKeyboardNext == key) {
-        if (configKeyboards.nonempty())
+        if (!onlyShowLayout && configKeyboards.nonempty())
             setKeyboard((fDefaultKeyboard + 1) % configKeyboards.getCount());
         return true;
     }
@@ -3676,26 +3676,32 @@
 void YWindowManager::setKeyboard(mstring keyboard) {
     if (keyboard != null && keyboard != fCurrentKeyboard) {
         fCurrentKeyboard = keyboard;
-        char program[] = "setxkbmap";
-        csmart path(path_lookup(program));
-        if (path) {
-            wordexp_t exp = {};
-            exp.we_offs = 1;
-            if (wordexp(keyboard, &exp, WRDE_NOCMD | WRDE_DOOFFS) == 0) {
-                exp.we_wordv[0] = program;
-                wmapp->runProgram(path, exp.we_wordv);
-                exp.we_wordv[0] = nullptr;
-                wordfree(&exp);
-            }
+        if (onlyShowLayout) {
             if (taskBar) {
                 taskBar->keyboardUpdate(keyboard);
             }
-        }
-        else if (ONCE) {
-            new YMsgBox(YMsgBox::mbOK,
-                        _("Missing program setxkbmap"),
-                        _("For keyboard switching, please install setxkbmap."),
-                        this, "key");
+        } else {
+            char program[] = "setxkbmap";
+            csmart path(path_lookup(program));
+            if (path) {
+                wordexp_t exp = {};
+                exp.we_offs = 1;
+                if (wordexp(keyboard, &exp, WRDE_NOCMD | WRDE_DOOFFS) == 0) {
+                    exp.we_wordv[0] = program;
+                    wmapp->runProgram(path, exp.we_wordv);
+                    exp.we_wordv[0] = nullptr;
+                    wordfree(&exp);
+                }
+                if (taskBar) {
+                    taskBar->keyboardUpdate(keyboard);
+                }
+            }
+            else if (ONCE) {
+                new YMsgBox(YMsgBox::mbOK,
+                            _("Missing program setxkbmap"),
+                            _("For keyboard switching, please install setxkbmap."),
+                            this, "key");
+            }
         }
     }
 }

Pro 1: I can use alt+shift (which fixes also #721, #632, #622)
Pro 2: no need to call an external binary for changing the layout --> more lightweight. (I'm changing my layout a LOT, even more times in one sentence)
Pro 3: I can rid of using xxkb forever. ;->

[gijsbers]

Icewm does monitor changes to the keyboard and reflects that in the keyboard applet flag.

You can simply get used to some other key combination that includes a proper keysym.

[zaza42]

Icewm does monitor changes to the keyboard and reflects that in the keyboard applet flag.

Then explain this:

You can simply get used to some other key combination that includes a proper keysym.

Yeah, and I can switch to Dvorak layout instead of QWERTY, even though I've been using it for 40 years... I've been using the Alt-Shift combination for 30 years, since the DOS era...
This is practically the only reason why I still need to run xxkb in 2025.
...and now, just for your sake, I've switched the layout from the command line, not by Alt-Shift.

[gijsbers]

You haven't shown your KeyboardLayouts setting. Why not? That is surely relevant. Please follow the manpage examples. You have studied previous issues, hence follow the conclusions.

Icewm provides options to manage keyboard layout, but they are basic. Icewm was built from older X11 libraries, hence it lacks a few more modern features.

We can't incorporate every personal preference. That is an unreasonable expectation.

This topic is wasting my time.

[zaza42]

You haven't shown your KeyboardLayouts setting. Why not? That is surely relevant.

Here you go.
KeyboardLayouts="us", "hu -variant 102_qwerty_dot_dead"

(Just to note: all keyboard indicators were able to follow the layout changes without me having to write a single letter in their config files. They all worked out-of-the-box.)

Icewm provides options to manage keyboard layout, but they are basic. Icewm was built from older X11 libraries, hence it lacks a few more modern features.

I don't think that xxkb, which hasn't been updated in 10 years, would use such new features. I've been using it for 25 years, and it's been working like this ever since.
setxkbmap worked in practically the same way from the days of XFree86, which was back in the last millennium.

We can't incorporate every personal preference. That is an unreasonable expectation.

The strange thing is that all keyboard indicators (including xxkb, gxkb, sbxkb, fbxkb) serve to such niche personal preferences. And all command line keyboard layout switchers are just like that (xkblayout-state, xkb-switch ). What's more, Gnome, KDE, XFCE, Enlightenment, Mate, LXDE, LXQt and polybar are acting in the same way. Even polybar which was designed for DWM. For the god's sake: from DWM to Gnome. In fact, IceWM has the only X11 keyboard indicator I've ever seen that does not track changes in keyboard layouts. Sorry, but I feel like IceWM is driving the wrong way down the highway here, and not everyone else is stupid with their uncommon personal preferences.
IceWM says this about itself: "IceWM originally was designed to emulate the look of Motif, OS/2 Warp 4, OS/2 Warp 3 and Windows 95. " According to Wikipedia: "allow it to imitate the GUI of Windows 95, Windows XP, Windows 7, OS/2, Motif, and other graphical user interfaces." AFAIK Windows 3.1, 95, XP, 7 and OS/2 Warp uses Alt-Shift layout switcher keybinding by default; so you shouldn't be too surprised when users miss this feature in IceWM. Even in the f*king MS-DOS MULTIKEY.EXE, this was the default binding—that's when I got used to it.

This topic is wasting my time.

Yes, I've seen that in other issues (#721, #632, #622 and ...) when someone asked why kbd status doesn't work the same way as in ALL other WM and DE. I repeat: IN ALL OTHER.

[...ok, a few minutes and I calmed down...]

I completely understand if this doesn't fit in your time. That's why I dared to write this little patch, which works with a little hacky solution that you have to set the same things for groups in setxkbmap as in ~/.icewm/preferences as KeyboardLayouts, because the patch only takes the layout number as a basis, it doesn't ask for the name. (That's enough for me anyway, I can live with it. There are bigger redundancies than this in my home system.)
But boy, redundancies... emmm.... well...

21:01:20.128164               21736 <zaza> /usr/bin/setxkbmap us
21:01:20.186600           21737 <zaza> /usr/bin/lksh -c '"/usr/bin/xkbcomp" -w 1 "-R/usr/share/X11/xkb" -xkm "-" -em1 "The XKEYBOARD keymap compiler (xkbcomp) reports:" -emp "> " -eml "Errors from xkbcomp are not fatal to the X server" "/tmp/server-0.xkm"'
21:01:20.225442             21738 <zaza> /usr/bin/xkbcomp -w 1 -R/usr/share/X11/xkb -xkm - -em1 'The XKEYBOARD keymap compiler (xkbcomp) reports:' -emp '> ' -eml 'Errors from xkbcomp are not fatal to the X server' /tmp/server-0.xkm
21:01:20.318787               21739 <zaza> /usr/bin/setxkbmap -query

This is serious, that 4 external binaries need to be run for something that XFree96 already supported in '86... sorry... which XFree86 already supported internally in '96.

21:03:35.612424 xkbcomp(21829) [1000:1000]: +   /tmp
21:03:35.612424 unknown(21829): CWO (deleted)
21:03:35.628818 Xorg(17119) [0:0]: RCO (deleted)
21:03:35.628818 Xorg(17119) [0:0]: D   /tmp

And what is that tempfile? No way! Is this serious? ... And... hey! What is this file doing in my /tmp??? That's not my TMPDIR. IceWM, please...

$ strings /proc/`pidof icewm`/environ|grep -e TMP -e XDG
TMP=/dev/shm/
TMPDIR=/dev/shm/
XDG_CACHE_HOME=/dev/shm/zaza_cache
XDG_TEMPLATES_DIR=/home/zaza/.Templates

Those are my temp folders, please respect it. I said I've calmed down, but this tempfile is really fc*ked up, and that it goes to /tmp. Should I really accept this now that 4 external calling +1 hardcoded tempfile is required to change a single keyboard layout? Which DE or WM does it in a similar way btw? Is this just my little personal preference, not to write temp files every time I switch keyboards?
At this point, I don't really understand what "older X11 libraries" you are talking about, since IceWM does not use libraries for layout switching, but external binaries. (Which can depend on any library, even one that was created yesterday...)

[ .... yet another 5 minutes ... ]

So I'd be glad to patch this so that a KeyboardStatusIndicatorLikeTheRestOfTheWorldDoesIt=1 option can be added to ~/.icewm/preferences , and then it would work exactly as 99% of users assume. (Assuming that 1% of the world uses IceWM.) All I need is to ask Xcb for not only the layout number, but also for the name, and I'm almost done. What do you think of this idea?

[gijsbers]

Thanks for your lengthy explanation.

When I use your KeyboardLayouts setting, then icewm tracks changes in the keyboard status fine. Also when I use setxkbmap on the command line. It is confusing why this doesn't seem to work for you. If it would work the same way for you as it does for me then your patch seems unneeded.

You are right that the Xkb extension, which xxkb uses, seems to be from 1996 and could have been used by icewm as well. However, the programming of the keyboard by xxkb is rather complex. I wonder how many window managers have a similar design. To Marko the use of XGrabKey sufficed. Support for keyboard layout switching was added by me in 2020.

"... and polybar are acting in the same way." in what way?

IceWM has the only X11 keyboard indicator I've ever seen that does not track changes in keyboard layouts.

As I said, that surprises me. Sofar you seem to be the only one.

I don't see the need for a new option as it seems to work fine here. The question is why not on your computer. I can't reproduce your issue with your settings, why not?

[gijsbers]

Maybe this: can you succeed in getting the taskbar to track your KB changes by issueing the setxkbmap commands that icewm uses by hand on the command line?