Adding xkb patch as per request #111

config.def.h

@@ -483,6 +483,9 @@ static const BarRule barrules[] = {
 	#elif BAR_STATUS_PATCH
 	{ 'A',      0,     BAR_ALIGN_RIGHT,  width_status,            draw_status,            click_status,            "status" },
 	#endif // BAR_STATUS2D_PATCH | BAR_STATUSCMD_PATCH
+	#if XKB_PATCH
+	{  0,       0,     BAR_ALIGN_RIGHT,  width_xkb,               draw_xkb,               click_xkb,               "xkb" },
+	#endif // XKB_PATCH
 	#if BAR_FLEXWINTITLE_PATCH
 	{ -1,       0,     BAR_ALIGN_NONE,   width_flexwintitle,      draw_flexwintitle,      click_flexwintitle,      "flexwintitle" },
 	#elif BAR_TABGROUPS_PATCH
@@ -660,6 +663,14 @@ static const Layout layouts[] = {
 };
 #endif // FLEXTILE_DELUXE_LAYOUT
 
+#if XKB_PATCH
+/* xkb frontend */
+static const char *xkb_layouts[]  = {
+	"en",
+	"ru",
+};
+#endif // XKB_PATCH
+
 /* key definitions */
 #define MODKEY Mod1Mask
 #if COMBO_PATCH && SWAPTAGS_PATCH && TAGOTHERMONITOR_PATCH

dwm.c

@@ -55,6 +55,10 @@
 #include <pango/pango.h>
 #endif // BAR_PANGO_PATCH
 
+#if XKB_PATCH
+#include <X11/XKBlib.h>
+#endif // XKB_PATCH
+
 #if SPAWNCMD_PATCH
 #include <assert.h>
 #include <libgen.h>
@@ -217,6 +221,9 @@ enum {
 	ClkWinTitle,
 	ClkClientWin,
 	ClkRootWin,
+	#if XKB_PATCH
+	ClkXKB,
+	#endif // XKB_PATCH
 	ClkLast
 }; /* clicks */
 
@@ -303,6 +310,16 @@ typedef struct {
 	const Arg arg;
 } Button;
 
+#if XKB_PATCH
+typedef struct XkbInfo XkbInfo;
+struct XkbInfo {
+	XkbInfo *next;
+	XkbInfo *prev;
+	int group;
+	Window w;
+};
+#endif // XKB_PATCH
+
 typedef struct Client Client;
 struct Client {
 	char name[256];
@@ -367,6 +384,9 @@ struct Client {
 	#if IPC_PATCH
 	ClientState prevstate;
 	#endif // IPC_PATCH
+	#if XKB_PATCH
+	XkbInfo *xkb;
+	#endif // XKB_PATCH
 };
 
 typedef struct {
@@ -496,9 +516,16 @@ typedef struct {
 	const char *floatpos;
 	#endif // FLOATPOS_PATCH
 	int monitor;
+	#if XKB_PATCH
+	int xkb_layout;
+	#endif // XKB_PATCH
 } Rule;
 
+#if XKB_PATCH
+#define RULE(...) { .monitor = -1, .xkb_layout = -1, ##__VA_ARGS__ },
+#else
 #define RULE(...) { .monitor = -1, ##__VA_ARGS__ },
+#endif // XKB_PATCH
 
 /* Cross patch compatibility rule macro helper macros */
 #define FLOATING , .isfloating = 1
@@ -688,6 +715,9 @@ static char rawestext[1024];
 #endif // BAR_STATUS2D_PATCH | BAR_STATUSCMD_PATCH
 #endif // BAR_EXTRASTATUS_PATCH
 
+#if XKB_PATCH
+static int xkbEventType = 0;
+#endif // XKB_PATCH
 static int screen;
 static int sw, sh;           /* X display screen geometry width, height */
 static int bh;               /* bar geometry */
@@ -877,6 +907,10 @@ applyrules(Client *c)
 				}
 			}
 			#endif // SWITCHTAG_PATCH
+			#if XKB_PATCH
+			if (r->xkb_layout > -1)
+				c->xkb->group = r->xkb_layout;
+			#endif // XKB_PATCH
 			#if ONLY_ONE_RULE_MATCH_PATCH
 			break;
 			#endif // ONLY_ONE_RULE_MATCH_PATCH
@@ -2246,6 +2280,13 @@ manage(Window w, XWindowAttributes *wa)
 	c->cfact = 1.0;
 	#endif // CFACTS_PATCH
 	updatetitle(c);
+
+	#if XKB_PATCH
+	/* Setting current xkb state must be before applyrules */
+	if (!(c->xkb = findxkb(c->win)))
+		c->xkb = createxkb(c->win);
+	#endif // XKB_PATCH
+
 	if (XGetTransientForHint(dpy, w, &trans) && (t = wintoclient(trans))) {
 		c->mon = t->mon;
 		c->tags = t->tags;
@@ -3018,9 +3059,20 @@ run(void)
 	XEvent ev;
 	/* main event loop */
 	XSync(dpy, False);
-	while (running && !XNextEvent(dpy, &ev))
+	while (running && !XNextEvent(dpy, &ev)) {
+
+		#if XKB_PATCH
+		/* Unfortunately the xkbEventType is not constant hence it can't be part of the
+		 * normal event handler below */
+		if (ev.type == xkbEventType) {
+			xkbeventnotify(&ev);
+			continue;
+		}
+		#endif // XKB_PATCH
+
 		if (handler[ev.type])
 			handler[ev.type](&ev); /* call handler */
+	}
 }
 #endif // IPC_PATCH
 
@@ -3198,6 +3250,9 @@ setfocus(Client *c)
 		XChangeProperty(dpy, root, netatom[NetActiveWindow],
 			XA_WINDOW, 32, PropModeReplace,
 			(unsigned char *) &(c->win), 1);
+		#if XKB_PATCH
+		XkbLockGroup(dpy, XkbUseCoreKbd, c->xkb->group);
+		#endif // XKB_PATCH
 	}
 	#if BAR_SYSTRAY_PATCH
 	sendevent(c->win, wmatom[WMTakeFocus], NoEventMask, wmatom[WMTakeFocus], CurrentTime, 0, 0, 0);
@@ -3381,6 +3436,9 @@ setup(void)
 {
 	int i;
 	XSetWindowAttributes wa;
+	#if XKB_PATCH
+	XkbStateRec xkbstate;
+	#endif // XKB_PATCH
 	Atom utf8string;
 
 	/* clean up any zombies immediately */
@@ -3553,6 +3611,17 @@ setup(void)
 		|LeaveWindowMask|StructureNotifyMask|PropertyChangeMask;
 	XChangeWindowAttributes(dpy, root, CWEventMask|CWCursor, &wa);
 	XSelectInput(dpy, root, wa.event_mask);
+
+	#if XKB_PATCH
+	/* get xkb extension info, events and current state */
+	if (!XkbQueryExtension(dpy, NULL, &xkbEventType, NULL, NULL, NULL))
+		fputs("warning: can not query xkb extension\n", stderr);
+	XkbSelectEventDetails(dpy, XkbUseCoreKbd, XkbStateNotify,
+	                      XkbAllStateComponentsMask, XkbGroupStateMask);
+	XkbGetState(dpy, XkbUseCoreKbd, &xkbstate);
+	xkbGlobal.group = xkbstate.locked_group;
+	#endif // XKB_PATCH
+
 	grabkeys();
 	focus(NULL);
 	#if IPC_PATCH
@@ -4034,6 +4103,9 @@ unmanage(Client *c, int destroyed)
 	unsigned int switchtag = c->switchtag;
 	#endif // SWITCHTAG_PATCH
 	XWindowChanges wc;
+	#if XKB_PATCH
+	XkbInfo *xkb;
+	#endif // XKB_PATCH
 
 	#if SWALLOW_PATCH
 	if (c->swallowing) {
@@ -4064,6 +4136,19 @@ unmanage(Client *c, int destroyed)
 		XSetErrorHandler(xerror);
 		XUngrabServer(dpy);
 	}
+	#if XKB_PATCH
+	else {
+		xkb = findxkb(c->win);
+		if (xkb != NULL) {
+			if (xkb->prev)
+				xkb->prev->next = xkb->next;
+			if (xkb->next)
+				xkb->next->prev = xkb->prev;
+			free(xkb);
+		}
+	}
+	#endif // XKB_PATCH
+
 	free(c);
 	#if SWALLOW_PATCH
 	if (s)

patch/include.c

@@ -298,6 +298,9 @@
 #if ZOOMSWAP_PATCH
 #include "zoomswap.c"
 #endif
+#if XKB_PATCH
+#include "xkb.c"
+#endif
 #if XRDB_PATCH && !BAR_VTCOLORS_PATCH
 #include "xrdb.c"
 #endif

patch/include.h

@@ -294,6 +294,9 @@
 #if ZOOMSWAP_PATCH
 #include "zoomswap.h"
 #endif
+#if XKB_PATCH
+#include "xkb.h"
+#endif
 #if XRDB_PATCH && !BAR_VTCOLORS_PATCH
 #include "xrdb.h"
 #endif

patch/ipc.c

@@ -9,6 +9,15 @@ handlexevent(struct epoll_event *ev)
 		XEvent ev;
 		while (running && XPending(dpy)) {
 			XNextEvent(dpy, &ev);
+			#if XKB_PATCH
+			/* Unfortunately the xkbEventType is not constant hence it can't be part of the
+			 * normal event handler below */
+			if (ev.type == xkbEventType) {
+				xkbeventnotify(&ev);
+				continue;
+			}
+			#endif // XKB_PATCH
+
 			if (handler[ev.type]) {
 				handler[ev.type](&ev); /* call handler */
 				ipc_send_events(mons, &lastselmon, selmon);

patch/xkb.c

@@ -0,0 +1,67 @@
+static XkbInfo xkbGlobal;
+static XkbInfo *xkbSaved = NULL;
+
+static XkbInfo *
+createxkb(Window w)
+{
+	XkbInfo *xkb;
+
+	xkb = malloc(sizeof *xkb);
+	if (xkb == NULL)
+		die("fatal: could not malloc() %u bytes\n", sizeof *xkb);
+	xkb->group = xkbGlobal.group;
+	xkb->w = w;
+	xkb->next = xkbSaved;
+	if (xkbSaved != NULL)
+		xkbSaved->prev = xkb;
+	xkb->prev = NULL;
+	xkbSaved = xkb;
+
+	return xkb;
+}
+
+XkbInfo *
+findxkb(Window w)
+{
+	XkbInfo *xkb;
+	for (xkb = xkbSaved; xkb != NULL; xkb = xkb->next)
+		if (xkb->w == w)
+			return xkb;
+	return NULL;
+}
+
+void
+xkbeventnotify(XEvent *e)
+{
+	XkbEvent *ev;
+
+	ev = (XkbEvent *) e;
+	switch (ev->any.xkb_type) {
+	case XkbStateNotify:
+		xkbGlobal.group = ev->state.locked_group;
+		if (selmon != NULL && selmon->sel != NULL)
+			selmon->sel->xkb->group = xkbGlobal.group;
+		drawbars();
+		break;
+	}
+}
+
+/* xkb bar module */
+int
+width_xkb(Bar *bar, BarArg *a)
+{
+	return TEXTW(xkb_layouts[xkbGlobal.group]);
+}
+
+int
+draw_xkb(Bar *bar, BarArg *a)
+{
+	drw_text(drw, a->x, a->y, a->w, a->h, lrpad / 2, xkb_layouts[xkbGlobal.group], 0, False);
+	return 1;
+}
+
+int
+click_xkb(Bar *bar, Arg *arg, BarArg *a)
+{
+	return ClkXKB;
+}

patch/xkb.h

@@ -0,0 +1,7 @@
+static XkbInfo *createxkb(Window w);
+static XkbInfo *findxkb(Window w);
+static void xkbeventnotify(XEvent *e);
+
+static int width_xkb(Bar *bar, BarArg *a);
+static int draw_xkb(Bar *bar, BarArg *a);
+static int click_xkb(Bar *bar, Arg *arg, BarArg *a);

patches.def.h

@@ -1105,6 +1105,13 @@
  */
 #define WINVIEW_PATCH 0
 
+/* Remember keyboard layout per client.
+ * It is recommended that you configure xkb before using this patch as described in
+ * https://www.x.org/archive/X11R7.5/doc/input/XKB-Config.html
+ * https://dwm.suckless.org/patches/xkb/
+ */
+#define XKB_PATCH 0
+
 /* Allows dwm to read colors from xrdb (.Xresources) during runtime. Compatible with
  * the float border color, awesomebar, urgentborder and titlecolor patches.
  * https://dwm.suckless.org/patches/xrdb/