Apply swallow-20200522-7accbcf

For the sake of builds, and patches these two should be
the same

config.def.h

@@ -2,7 +2,9 @@
 
 /* appearance */
 static const unsigned int borderpx  = 1;        /* border pixel of windows */
+static const unsigned int gappx     = 5;        /* gaps between windows */
 static const unsigned int snap      = 32;       /* snap pixel */
+static const int swallowfloating    = 0;        /* 1 means swallow floating windows by default */
 static const int showbar            = 1;        /* 0 means no bar */
 static const int topbar             = 1;        /* 0 means bottom bar */
 static const char *fonts[]          = { "monospace:size=10" };
@@ -26,9 +28,11 @@ static const Rule rules[] = {
 	 *	WM_CLASS(STRING) = instance, class
 	 *	WM_NAME(STRING) = title
 	 */
-	/* class      instance    title       tags mask     isfloating   monitor */
+	/* class     instance  title           tags mask  isfloating  isterminal  noswallow  monitor */
-	{ "Gimp",     NULL,       NULL,       0,            1,           -1 },
+	{ "Gimp",    NULL,     NULL,           0,         1,          0,           0,        -1 },
-	{ "Firefox",  NULL,       NULL,       1 << 8,       0,           -1 },
+	{ "Firefox", NULL,     NULL,           1 << 8,    0,          0,          -1,        -1 },
+	{ "st",      NULL,     NULL,           0,         0,          1,          -1,        -1 },
+	{ NULL,      NULL,     "Event Tester", 0,         1,          0,           1,        -1 }, /* xev */
 };
 
 /* layout(s) */
@@ -85,6 +89,9 @@ static Key keys[] = {
 	{ MODKEY,                       XK_period, focusmon,       {.i = +1 } },
 	{ MODKEY|ShiftMask,             XK_comma,  tagmon,         {.i = -1 } },
 	{ MODKEY|ShiftMask,             XK_period, tagmon,         {.i = +1 } },
+	{ MODKEY,                       XK_minus,  setgaps,        {.i = -1 } },
+	{ MODKEY,                       XK_equal,  setgaps,        {.i = +1 } },
+	{ MODKEY|ShiftMask,             XK_equal,  setgaps,        {.i = 0  } },
 	TAGKEYS(                        XK_1,                      0)
 	TAGKEYS(                        XK_2,                      1)
 	TAGKEYS(                        XK_3,                      2)

config.h

@@ -0,0 +1 @@
+config.def.h

config.mk

@@ -22,7 +22,7 @@ FREETYPEINC = /usr/include/freetype2
 
 # includes and libs
 INCS = -I${X11INC} -I${FREETYPEINC}
-LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS}
+LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS} -lX11-xcb -lxcb -lxcb-res
 
 # flags
 CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_C_SOURCE=200809L -DVERSION=\"${VERSION}\" ${XINERAMAFLAGS}

dwm.1

@@ -140,6 +140,16 @@ View all windows with any tag.
 .B Mod1\-Control\-[1..n]
 Add/remove all windows with nth tag to/from the view.
 .TP
+.B Mod1\--
+Decrease the gaps around windows.
+.TP
+.B Mod1\-=
+Increase the gaps around windows.
+.TP
+.B Mod1\-Shift-=
+Reset the gaps around windows to
+.BR 0 .
+.TP
 .B Mod1\-Shift\-q
 Quit dwm.
 .SS Mouse commands

dwm.c

@@ -40,6 +40,8 @@
 #include <X11/extensions/Xinerama.h>
 #endif /* XINERAMA */
 #include <X11/Xft/Xft.h>
+#include <X11/Xlib-xcb.h>
+#include <xcb/res.h>
 
 #include "drw.h"
 #include "util.h"
@@ -92,9 +94,11 @@ struct Client {
 	int basew, baseh, incw, inch, maxw, maxh, minw, minh;
 	int bw, oldbw;
 	unsigned int tags;
-	int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen;
+	int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen, isterminal, noswallow;
+	pid_t pid;
 	Client *next;
 	Client *snext;
+	Client *swallowing;
 	Monitor *mon;
 	Window win;
 };
@@ -119,6 +123,7 @@ struct Monitor {
 	int by;               /* bar geometry */
 	int mx, my, mw, mh;   /* screen size */
 	int wx, wy, ww, wh;   /* window area  */
+	int gappx;            /* gaps between windows */
 	unsigned int seltags;
 	unsigned int sellt;
 	unsigned int tagset[2];
@@ -138,6 +143,8 @@ typedef struct {
 	const char *title;
 	unsigned int tags;
 	int isfloating;
+	int isterminal;
+	int noswallow;
 	int monitor;
 } Rule;
 
@@ -200,6 +207,7 @@ static void sendmon(Client *c, Monitor *m);
 static void setclientstate(Client *c, long state);
 static void setfocus(Client *c);
 static void setfullscreen(Client *c, int fullscreen);
+static void setgaps(const Arg *arg);
 static void setlayout(const Arg *arg);
 static void setmfact(const Arg *arg);
 static void setup(void);
@@ -235,9 +243,16 @@ static int xerrordummy(Display *dpy, XErrorEvent *ee);
 static int xerrorstart(Display *dpy, XErrorEvent *ee);
 static void zoom(const Arg *arg);
 
+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);
+
 /* variables */
 static const char broken[] = "broken";
 static char stext[256];
+static int scanner;
 static int screen;
 static int sw, sh;           /* X display screen geometry width, height */
 static int bh, blw = 0;      /* bar geometry */
@@ -269,6 +284,8 @@ static Drw *drw;
 static Monitor *mons, *selmon;
 static Window root, wmcheckwin;
 
+static xcb_connection_t *xcon;
+
 /* configuration, allows nested code to access above variables */
 #include "config.h"
 
@@ -286,6 +303,7 @@ applyrules(Client *c)
 	XClassHint ch = { NULL, NULL };
 
 	/* rule matching */
+	c->noswallow = -1;
 	c->isfloating = 0;
 	c->tags = 0;
 	XGetClassHint(dpy, c->win, &ch);
@@ -298,6 +316,8 @@ applyrules(Client *c)
 		&& (!r->class || strstr(class, r->class))
 		&& (!r->instance || strstr(instance, r->instance)))
 		{
+			c->isterminal = r->isterminal;
+			c->noswallow  = r->noswallow;
 			c->isfloating = r->isfloating;
 			c->tags |= r->tags;
 			for (m = mons; m && m->num != r->monitor; m = m->next);
@@ -414,6 +434,61 @@ attachstack(Client *c)
 	c->mon->stack = c;
 }
 
+void
+swallow(Client *p, Client *c)
+{
+	Client *s;
+
+	if (c->noswallow > 0 || c->isterminal)
+		return;
+	if (c->noswallow < 0 && !swallowfloating && c->isfloating)
+		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;
+
+	XChangeProperty(dpy, c->win, netatom[NetClientList], XA_WINDOW, 32, PropModeReplace,
+		(unsigned char *) &(p->win), 1);
+
+	updatetitle(p);
+	s = scanner ? c : p;
+	XMoveResizeWindow(dpy, p->win, s->x, s->y, s->w, s->h);
+	arrange(p->mon);
+	configure(p);
+	updateclientlist();
+}
+
+void
+unswallow(Client *c)
+{
+	c->win = c->swallowing->win;
+
+	free(c->swallowing);
+	c->swallowing = NULL;
+
+	XDeleteProperty(dpy, c->win, netatom[NetClientList]);
+
+	/* unfullscreen the client */
+	setfullscreen(c, 0);
+	updatetitle(c);
+	arrange(c->mon);
+	XMapWindow(dpy, c->win);
+	XMoveResizeWindow(dpy, c->win, c->x, c->y, c->w, c->h);
+	setclientstate(c, NormalState);
+	focus(NULL);
+	arrange(c->mon);
+}
+
 void
 buttonpress(XEvent *e)
 {
@@ -631,6 +706,8 @@ configurerequest(XEvent *e)
 Monitor *
 createmon(void)
 {
+	Bool gappx = True;
+
 	Monitor *m;
 
 	m = ecalloc(1, sizeof(Monitor));
@@ -639,6 +716,7 @@ createmon(void)
 	m->nmaster = nmaster;
 	m->showbar = showbar;
 	m->topbar = topbar;
+	m->gappx = gappx;
 	m->lt[0] = &layouts[0];
 	m->lt[1] = &layouts[1 % LENGTH(layouts)];
 	strncpy(m->ltsymbol, layouts[0].symbol, sizeof m->ltsymbol);
@@ -653,6 +731,9 @@ destroynotify(XEvent *e)
 
 	if ((c = wintoclient(ev->window)))
 		unmanage(c, 1);
+
+	else if ((c = swallowingclient(ev->window)))
+		unmanage(c->swallowing, 1);
 }
 
 void
@@ -1018,12 +1099,13 @@ killclient(const Arg *arg)
 void
 manage(Window w, XWindowAttributes *wa)
 {
-	Client *c, *t = NULL;
+	Client *c, *t = NULL, *term = NULL;
 	Window trans = None;
 	XWindowChanges wc;
 
 	c = ecalloc(1, sizeof(Client));
 	c->win = w;
+	c->pid = winpid(w);
 	/* geometry */
 	c->x = c->oldx = wa->x;
 	c->y = c->oldy = wa->y;
@@ -1038,6 +1120,7 @@ manage(Window w, XWindowAttributes *wa)
 	} else {
 		c->mon = selmon;
 		applyrules(c);
+		term = termforwin(c);
 	}
 
 	if (c->x + WIDTH(c) > c->mon->mx + c->mon->mw)
@@ -1074,6 +1157,8 @@ manage(Window w, XWindowAttributes *wa)
 	c->mon->sel = c;
 	arrange(c->mon);
 	XMapWindow(dpy, c->win);
+	if (term)
+		swallow(term, c);
 	focus(NULL);
 }
 
@@ -1384,7 +1469,9 @@ run(void)
 void
 scan(void)
 {
+	scanner = 1;
 	unsigned int i, num;
+	char swin[256];
 	Window d1, d2, *wins = NULL;
 	XWindowAttributes wa;
 
@@ -1395,6 +1482,8 @@ scan(void)
 				continue;
 			if (wa.map_state == IsViewable || getstate(wins[i]) == IconicState)
 				manage(wins[i], &wa);
+			else if (gettextprop(wins[i], netatom[NetClientList], swin, sizeof swin))
+				manage(wins[i], &wa);
 		}
 		for (i = 0; i < num; i++) { /* now the transients */
 			if (!XGetWindowAttributes(dpy, wins[i], &wa))
@@ -1406,6 +1495,7 @@ scan(void)
 		if (wins)
 			XFree(wins);
 	}
+	scanner = 0;
 }
 
 void
@@ -1498,6 +1588,16 @@ setfullscreen(Client *c, int fullscreen)
 	}
 }
 
+void
+setgaps(const Arg *arg)
+{
+	if ((arg->i == 0) || (selmon->gappx + arg->i < 0))
+		selmon->gappx = 0;
+	else
+		selmon->gappx += arg->i;
+	arrange(selmon);
+}
+
 void
 setlayout(const Arg *arg)
 {
@@ -1684,18 +1784,18 @@ tile(Monitor *m)
 	if (n > m->nmaster)
 		mw = m->nmaster ? m->ww * m->mfact : 0;
 	else
-		mw = m->ww;
+		mw = m->ww - m->gappx;
-	for (i = my = ty = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)
+	for (i = 0, my = ty = m->gappx, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)
 		if (i < m->nmaster) {
-			h = (m->wh - my) / (MIN(n, m->nmaster) - i);
+			h = (m->wh - my) / (MIN(n, m->nmaster) - i) - m->gappx;
-			resize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
+			resize(c, m->wx + m->gappx, m->wy + my, mw - (2*c->bw) - m->gappx, h - (2*c->bw), 0);
-			if (my + HEIGHT(c) < m->wh)
+			if (my + HEIGHT(c) + m->gappx < m->wh)
-				my += HEIGHT(c);
+				my += HEIGHT(c) + m->gappx;
 		} else {
-			h = (m->wh - ty) / (n - i);
+			h = (m->wh - ty) / (n - i) - m->gappx;
-			resize(c, m->wx + mw, m->wy + ty, m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
+			resize(c, m->wx + mw + m->gappx, m->wy + ty, m->ww - mw - (2*c->bw) - 2*m->gappx, h - (2*c->bw), 0);
-			if (ty + HEIGHT(c) < m->wh)
+			if (ty + HEIGHT(c) + m->gappx < m->wh)
-				ty += HEIGHT(c);
+				ty += HEIGHT(c) + m->gappx;
 		}
 }
 
@@ -1768,6 +1868,20 @@ unmanage(Client *c, int destroyed)
 	Monitor *m = c->mon;
 	XWindowChanges wc;
 
+	if (c->swallowing) {
+		unswallow(c);
+		return;
+	}
+
+	Client *s = swallowingclient(c->win);
+	if (s) {
+		free(s->swallowing);
+		s->swallowing = NULL;
+		arrange(m);
+		focus(NULL);
+		return;
+	}
+
 	detach(c);
 	detachstack(c);
 	if (!destroyed) {
@@ -1782,9 +1896,12 @@ unmanage(Client *c, int destroyed)
 		XUngrabServer(dpy);
 	}
 	free(c);
-	focus(NULL);
+
-	updateclientlist();
+	if (!s) {
-	arrange(m);
+		arrange(m);
+		focus(NULL);
+		updateclientlist();
+	}
 }
 
 void
@@ -2047,6 +2164,110 @@ view(const Arg *arg)
 	arrange(selmon);
 }
 
+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;
+
+#if defined(__linux__)
+	FILE *f;
+	char buf[256];
+	snprintf(buf, sizeof(buf) - 1, "/proc/%u/stat", (unsigned)p);
+
+	if (!(f = fopen(buf, "r")))
+		return (pid_t)0;
+
+	if (fscanf(f, "%*u %*s %*c %u", (unsigned *)&v) != 1)
+		v = (pid_t)0;
+	fclose(f);
+#elif defined(__FreeBSD__)
+	struct kinfo_proc *proc = kinfo_getproc(p);
+	if (!proc)
+		return (pid_t)0;
+
+	v = proc->ki_ppid;
+	free(proc);
+#endif
+	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;
+
+	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;
+}
+
 Client *
 wintoclient(Window w)
 {
@@ -2138,6 +2359,8 @@ main(int argc, char *argv[])
 		fputs("warning: no locale support\n", stderr);
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("dwm: cannot open display");
+	if (!(xcon = XGetXCBConnection(dpy)))
+		die("dwm: cannot get xcb connection\n");
 	checkotherwm();
 	setup();
 #ifdef __OpenBSD__