Adding swallow patch

README.md

@@ -15,7 +15,7 @@ Refer to [https://dwm.suckless.org/](https://dwm.suckless.org/) for details on t
 
 ### Changelog:
 
-2019-10-22 - Added ispermanent patch
+2019-10-22 - Added ispermanent and swallow patches
 
 2019-10-16 - Introduced [flexipatch-finalizer](https://github.com/bakkeby/flexipatch-finalizer)
 
@@ -244,6 +244,11 @@ Refer to [https://dwm.suckless.org/](https://dwm.suckless.org/) for details on t
    - [sticky](https://dwm.suckless.org/patches/sticky/)
       - adds toggleable keyboard shortcut to make a client 'sticky', i.e. visible on all tags
 
+   - [swallow](https://dwm.suckless.org/patches/swallow/)
+      - this patch adds "window swallowing" to dwm as known from Plan 9's windowing system rio
+      - clients marked with isterminal in config.h swallow a window opened by any child process, e.g. running xclock in a terminal
+      - closing the xclock window restores the terminal window in the current position
+
    - [switchcol](https://dwm.suckless.org/patches/switchcol/)
       - allows you to switch focus between the master and stack columns using a single keybinding
 

config.def.h

@@ -186,66 +186,130 @@ static const Rule rules[] = {
 	 *	WM_NAME(STRING) = title
 	 *	WM_WINDOW_ROLE(STRING) = role
 	 */
-	#if WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH
+	#if WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    switchtag    iscentered   isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,           0,           0,          0,         -1 }
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    switchtag    iscentered   isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    switchtag    iscentered   isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    switchtag    iscentered   isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    iscentered   isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           0,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,           0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    iscentered   isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           0,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    iscentered   isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           0,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    iscentered   isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           0,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    switchtag    isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    switchtag    isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    switchtag    isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    switchtag    isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      1,           0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     switchtag    iscentered   isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            1,           0,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     switchtag    iscentered   isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       0,            1,           0,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,           0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     switchtag    iscentered   isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            1,           0,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     switchtag    iscentered   isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       0,            1,           0,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,           -1 },
-	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      role        instance    title         tags mask    isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           0,          0,         -1 },
+	#elif WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      role        instance    title         tags mask    isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       NULL,         0,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       NULL,         1 << 8,      0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     switchtag    isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            1,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     switchtag    isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       0,            1,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     switchtag    isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            1,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     switchtag    isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       0,            1,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       1,           0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     iscentered   isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            0,           1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     iscentered   isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       0,            0,           1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,           0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     iscentered   isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            0,           1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && CENTER_PATCH && !ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     iscentered   isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       0,            0,           1,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,           -1 },
-	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     isfloating   ispermanent  isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            1,           0,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,           0,          0,         -1 },
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && ISPERMANENT_PATCH && !SWALLOW_PATCH
 	/* class      instance    title       tags mask     isfloating   ispermanent  monitor */
 	{ "Gimp",     NULL,       NULL,       0,            1,           0,           -1 },
 	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,           -1 },
+	#elif !WINDOWROLERULE_PATCH && !SWITCHTAG_PATCH && !CENTER_PATCH && !ISPERMANENT_PATCH && SWALLOW_PATCH
+	/* class      instance    title       tags mask     isfloating   isterminal  noswallow  monitor */
+	{ "Gimp",     NULL,       NULL,       0,            1,           0,          0,         -1 },
+	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           0,          0,         -1 },
 	#else
 	/* class      instance    title       tags mask     isfloating   monitor */
 	{ "Gimp",     NULL,       NULL,       0,            1,           -1 },

config.mk

@@ -23,9 +23,12 @@ FREETYPEINC = /usr/include/freetype2
 # Uncomment this for the mdpcontrol patch / MDPCONTROL_PATCH
 #LMPDCLIENT = -lmpdclient
 
+# Uncomment this for the swallow patch / SWALLOW_PATCH
+#LXCBLIBS = -lX11-xcb -lxcb -lxcb-res
+
 # includes and libs
 INCS = -I${X11INC} -I${FREETYPEINC}
-LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS} -lXrender ${LMPDCLIENT}
+LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS} -lXrender ${LMPDCLIENT} ${LXCBLIBS}
 
 
 # flags

dwm.c

@@ -162,11 +162,18 @@ struct Client {
 	#if ISPERMANENT_PATCH
 	int ispermanent;
 	#endif // ISPERMANENT_PATCH
+	#if SWALLOW_PATCH
+	int isterminal, noswallow;
+	pid_t pid;
+	#endif // SWALLOW_PATCH
 	#if STICKY_PATCH
 	int issticky;
 	#endif // STICKY_PATCH
 	Client *next;
 	Client *snext;
+	#if SWALLOW_PATCH
+	Client *swallowing;
+	#endif // SWALLOW_PATCH
 	Monitor *mon;
 	Window win;
 };
@@ -263,6 +270,10 @@ typedef struct {
 	#if ISPERMANENT_PATCH
 	int ispermanent;
 	#endif // ISPERMANENT_PATCH
+	#if SWALLOW_PATCH
+	int isterminal;
+	int noswallow;
+	#endif // SWALLOW_PATCH
 	int monitor;
 } Rule;
 
@@ -477,6 +488,10 @@ applyrules(Client *c)
 			#if ISPERMANENT_PATCH
 			c->ispermanent = r->ispermanent;
 			#endif // ISPERMANENT_PATCH
+			#if SWALLOW_PATCH
+			c->isterminal = r->isterminal;
+			c->noswallow = r->noswallow;
+			#endif // SWALLOW_PATCH
 			c->isfloating = r->isfloating;
 			c->tags |= r->tags;
 			for (m = mons; m && m->num != r->monitor; m = m->next);
@@ -1193,6 +1208,10 @@ destroynotify(XEvent *e)
 
 	if ((c = wintoclient(ev->window)))
 		unmanage(c, 1);
+	#if SWALLOW_PATCH
+	else if ((c = swallowingclient(ev->window)))
+		unmanage(c->swallowing, 1);
+	#endif // SWALLOW_PATCH
 	#if SYSTRAY_PATCH
 	else if (showsystray && (c = wintosystrayicon(ev->window))) {
 		removesystrayicon(c);
@@ -1871,11 +1890,17 @@ void
 manage(Window w, XWindowAttributes *wa)
 {
 	Client *c, *t = NULL;
+	#if SWALLOW_PATCH
+	Client *term = NULL;
+	#endif // SWALLOW_PATCH
 	Window trans = None;
 	XWindowChanges wc;
 
 	c = ecalloc(1, sizeof(Client));
 	c->win = w;
+	#if SWALLOW_PATCH
+	c->pid = winpid(w);
+	#endif // SWALLOW_PATCH
 	/* geometry */
 	c->x = c->oldx = wa->x;
 	c->y = c->oldy = wa->y;
@@ -1893,6 +1918,9 @@ manage(Window w, XWindowAttributes *wa)
 	} else {
 		c->mon = selmon;
 		applyrules(c);
+		#if SWALLOW_PATCH
+		term = termforwin(c);
+		#endif // SWALLOW_PATCH
 	}
 
 	if (c->x + WIDTH(c) > c->mon->mx + c->mon->mw)
@@ -1986,6 +2014,10 @@ manage(Window w, XWindowAttributes *wa)
 	#else
 	XMapWindow(dpy, c->win);
 	#endif // AWESOMEBAR_PATCH
+	#if SWALLOW_PATCH
+	if (term)
+		swallow(term, c);
+	#endif // SWALLOW_PATCH
 	focus(NULL);
 }
 
@@ -3105,6 +3137,22 @@ unmanage(Client *c, int destroyed)
 	Monitor *m = c->mon;
 	XWindowChanges wc;
 
+	#if SWALLOW_PATCH
+	if (c->swallowing) {
+		unswallow(c);
+		return;
+	}
+
+	Client *s = swallowingclient(c->win);
+	if (s) {
+		free(s->swallowing);
+		s->swallowing = NULL;
+		arrange(m);
+		focus(NULL);
+		return;
+	}
+	#endif // SWALLOW_PATCH
+
 	detach(c);
 	detachstack(c);
 	if (!destroyed) {
@@ -3119,6 +3167,10 @@ unmanage(Client *c, int destroyed)
 		XUngrabServer(dpy);
 	}
 	free(c);
+	#if SWALLOW_PATCH
+	if (s)
+		return;
+	#endif // SWALLOW_PATCH
 	focus(NULL);
 	updateclientlist();
 	arrange(m);
@@ -3627,6 +3679,10 @@ main(int argc, char *argv[])
 		fputs("warning: no locale support\n", stderr);
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("dwm: cannot open display");
+	#if SWALLOW_PATCH
+	if (!(xcon = XGetXCBConnection(dpy)))
+		die("dwm: cannot get xcb connection\n");
+	#endif // SWALLOW_PATCH
 	checkotherwm();
 	#if XRDB_PATCH
 	XrmInitialize();

patch/include.c

@@ -90,6 +90,9 @@
 #if SYSTRAY_PATCH
 #include "systray.c"
 #endif
+#if SWALLOW_PATCH
+#include "swallow.c"
+#endif // SWALLOW_PATCH
 #if SWITCHCOL_PATCH
 #include "switchcol.c"
 #endif

patch/include.h

@@ -90,6 +90,9 @@
 #if SYSTRAY_PATCH
 #include "systray.h"
 #endif
+#if SWALLOW_PATCH
+#include "swallow.h"
+#endif // SWALLOW_PATCH
 #if SWITCHCOL_PATCH
 #include "switchcol.h"
 #endif

patch/swallow.c

@@ -0,0 +1,149 @@
+#include <X11/Xlib-xcb.h>
+#include <xcb/res.h>
+
+static xcb_connection_t *xcon;
+
+void
+swallow(Client *p, Client *c)
+{
+	if (c->noswallow || c->isterminal)
+		return;
+
+	detach(c);
+	detachstack(c);
+
+	setclientstate(c, WithdrawnState);
+	XUnmapWindow(dpy, p->win);
+
+	p->swallowing = c;
+	c->mon = p->mon;
+
+	Window w = p->win;
+	p->win = c->win;
+	c->win = w;
+	updatetitle(p);
+	arrange(p->mon);
+	XMoveResizeWindow(dpy, p->win, p->x, p->y, p->w, p->h);
+	configure(p);
+	updateclientlist();
+}
+
+void
+unswallow(Client *c)
+{
+	c->win = c->swallowing->win;
+
+	free(c->swallowing);
+	c->swallowing = NULL;
+
+	updatetitle(c);
+	arrange(c->mon);
+	XMapWindow(dpy, c->win);
+	XMoveResizeWindow(dpy, c->win, c->x, c->y, c->w, c->h);
+	configure(c);
+	setclientstate(c, NormalState);
+}
+
+pid_t
+winpid(Window w)
+{
+	pid_t result = 0;
+
+	xcb_res_client_id_spec_t spec = {0};
+	spec.client = w;
+	spec.mask = XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID;
+
+	xcb_generic_error_t *e = NULL;
+	xcb_res_query_client_ids_cookie_t c = xcb_res_query_client_ids(xcon, 1, &spec);
+	xcb_res_query_client_ids_reply_t *r = xcb_res_query_client_ids_reply(xcon, c, &e);
+
+	if (!r)
+		return (pid_t)0;
+
+	xcb_res_client_id_value_iterator_t i = xcb_res_query_client_ids_ids_iterator(r);
+	for (; i.rem; xcb_res_client_id_value_next(&i)) {
+		spec = i.data->spec;
+		if (spec.mask & XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID) {
+			uint32_t *t = xcb_res_client_id_value_value(i.data);
+			result = *t;
+			break;
+		}
+	}
+
+	free(r);
+
+	if (result == (pid_t)-1)
+		result = 0;
+	return result;
+}
+
+pid_t
+getparentprocess(pid_t p)
+{
+	unsigned int v = 0;
+
+#ifdef __linux__
+	FILE *f;
+	char buf[256];
+	snprintf(buf, sizeof(buf) - 1, "/proc/%u/stat", (unsigned)p);
+
+	if (!(f = fopen(buf, "r")))
+		return 0;
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-result"
+	fscanf(f, "%*u %*s %*c %u", &v);
+#pragma GCC diagnostic pop
+	fclose(f);
+#endif /* __linux__ */
+
+	return (pid_t)v;
+}
+
+int
+isdescprocess(pid_t p, pid_t c)
+{
+	while (p != c && c != 0)
+		c = getparentprocess(c);
+
+	return (int)c;
+}
+
+Client *
+termforwin(const Client *w)
+{
+	Client *c;
+	Monitor *m;
+
+	if (!w->pid || w->isterminal)
+		return NULL;
+
+	c = selmon->sel;
+	if (c && c->isterminal && !c->swallowing && c->pid && isdescprocess(c->pid, w->pid))
+		return c;
+
+	for (m = mons; m; m = m->next) {
+		for (c = m->clients; c; c = c->next) {
+			if (c->isterminal && !c->swallowing && c->pid && isdescprocess(c->pid, w->pid))
+				return c;
+		}
+	}
+
+	return NULL;
+}
+
+Client *
+swallowingclient(Window w)
+{
+	Client *c;
+	Monitor *m;
+
+	for (m = mons; m; m = m->next) {
+		for (c = m->clients; c; c = c->next) {
+			if (c->swallowing && c->swallowing->win == w)
+				return c;
+		}
+	}
+
+	return NULL;
+}

patch/swallow.h

@@ -0,0 +1,5 @@
+static pid_t getparentprocess(pid_t p);
+static int isdescprocess(pid_t p, pid_t c);
+static Client *swallowingclient(Window w);
+static Client *termforwin(const Client *c);
+static pid_t winpid(Window w);

patches.h

@@ -377,6 +377,14 @@
  */
 #define SYSTRAY_PATCH 0
 
+/* This patch adds "window swallowing" to dwm as known from Plan 9's windowing system rio.
+ * Clients marked with isterminal in config.h swallow a window opened by any child process,
+ * e.g. running xclock in a terminal. Closing the xclock window restores the terminal window
+ * in the current position.
+ * https://dwm.suckless.org/patches/swallow/
+ */
+#define SWALLOW_PATCH 0
+
 /* Switch focus between the master and stack columns using a single keybinding.
  * https://dwm.suckless.org/patches/switchcol/
  */