Made statusbar clickable

Many users new to dwm find themselves caught out by being kicked out to the login manager (dwm crashing) when they open 50+ clients for demonstration purposes. The number of clients reported varies depending on the resolution of the monitor.

The cause of this is due to how the default tile layout calculates the height of the next client based on the position of the previous client. Because clients have a minimum size the (ty) position can exceed that of the window height, resulting in (m->wh - ty) becoming negative. The negative height stored as an unsigned int results in a very large height ultimately resulting in dwm crashing.

This patch adds safeguards to prevent the ty and my positions from exceeding that of the window height.

config.def.h

@@ -59,6 +59,10 @@ static char dmenumon[2] = "0"; /* component of dmenucmd, manipulated in spawn()
 static const char *dmenucmd[] = { "dmenu_run", "-m", dmenumon, "-fn", dmenufont, "-nb", col_gray1, "-nf", col_gray3, "-sb", col_cyan, "-sf", col_gray4, NULL };
 static const char *termcmd[]  = { "st", NULL };
 
+/* commands spawned when clicking statusbar, the mouse button pressed is exported as BUTTON */
+static char *statuscmds[] = { "notify-send Mouse$BUTTON" };
+static char *statuscmd[] = { "/bin/sh", "-c", NULL, NULL };
+
 static Key keys[] = {
 	/* modifier                     key        function        argument */
 	{ MODKEY,                       XK_p,      spawn,          {.v = dmenucmd } },
@@ -103,7 +107,9 @@ static Button buttons[] = {
 	{ ClkLtSymbol,          0,              Button1,        setlayout,      {0} },
 	{ ClkLtSymbol,          0,              Button3,        setlayout,      {.v = &layouts[2]} },
 	{ ClkWinTitle,          0,              Button2,        zoom,           {0} },
-	{ ClkStatusText,        0,              Button2,        spawn,          {.v = termcmd } },
+	{ ClkStatusText,        0,              Button1,        spawn,          {.v = statuscmd } },
+	{ ClkStatusText,        0,              Button2,        spawn,          {.v = statuscmd } },
+	{ ClkStatusText,        0,              Button3,        spawn,          {.v = statuscmd } },
 	{ ClkClientWin,         MODKEY,         Button1,        movemouse,      {0} },
 	{ ClkClientWin,         MODKEY,         Button2,        togglefloating, {0} },
 	{ ClkClientWin,         MODKEY,         Button3,        resizemouse,    {0} },

config.mk

@@ -25,7 +25,7 @@ INCS = -I${X11INC} -I${FREETYPEINC}
 LIBS = -L${X11LIB} -lX11 ${XINERAMALIBS} ${FREETYPELIBS}
 
 # flags
-CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_C_SOURCE=2 -DVERSION=\"${VERSION}\" ${XINERAMAFLAGS}
+CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_POSIX_C_SOURCE=200809L -DVERSION=\"${VERSION}\" ${XINERAMAFLAGS}
 #CFLAGS   = -g -std=c99 -pedantic -Wall -O0 ${INCS} ${CPPFLAGS}
 CFLAGS   = -std=c99 -pedantic -Wall -Wno-deprecated-declarations -Os ${INCS} ${CPPFLAGS}
 LDFLAGS  = ${LIBS}

dwm.c

@@ -156,6 +156,7 @@ static void clientmessage(XEvent *e);
 static void configure(Client *c);
 static void configurenotify(XEvent *e);
 static void configurerequest(XEvent *e);
+static void copyvalidchars(char *text, char *rawtext);
 static Monitor *createmon(void);
 static void destroynotify(XEvent *e);
 static void detach(Client *c);
@@ -169,6 +170,7 @@ static void focus(Client *c);
 static void focusin(XEvent *e);
 static void focusmon(const Arg *arg);
 static void focusstack(const Arg *arg);
+static Atom getatomprop(Client *c, Atom prop);
 static int getrootptr(int *x, int *y);
 static long getstate(Window w);
 static int gettextprop(Window w, Atom atom, char *text, unsigned int size);
@@ -237,6 +239,9 @@ static void zoom(const Arg *arg);
 /* variables */
 static const char broken[] = "broken";
 static char stext[256];
+static char rawstext[256];
+static int statuscmdn;
+static char lastbutton[] = "-";
 static int screen;
 static int sw, sh;           /* X display screen geometry width, height */
 static int bh, blw = 0;      /* bar geometry */
@@ -421,6 +426,7 @@ buttonpress(XEvent *e)
 	Client *c;
 	Monitor *m;
 	XButtonPressedEvent *ev = &e->xbutton;
+	*lastbutton = '0' + ev->button;
 
 	click = ClkRootWin;
 	/* focus monitor if necessary */
@@ -439,9 +445,26 @@ buttonpress(XEvent *e)
 			arg.ui = 1 << i;
 		} else if (ev->x < x + blw)
 			click = ClkLtSymbol;
-		else if (ev->x > selmon->ww - TEXTW(stext))
+		else if (ev->x > (x = selmon->ww - TEXTW(stext) + lrpad)) {
 			click = ClkStatusText;
-		else
+
+			char *text = rawstext;
+			int i = -1;
+			char ch;
+			statuscmdn = 0;
+			while (text[++i]) {
+				if ((unsigned char)text[i] < ' ') {
+					ch = text[i];
+					text[i] = '\0';
+					x += TEXTW(text) - lrpad;
+					text[i] = ch;
+					text += i+1;
+					i = -1;
+					if (x >= ev->x) break;
+					if (ch <= LENGTH(statuscmds)) statuscmdn = ch - 1;
+				}
+			}
+		} else
 			click = ClkWinTitle;
 	} else if ((c = wintoclient(ev->window))) {
 		focus(c);
@@ -627,6 +650,19 @@ configurerequest(XEvent *e)
 	XSync(dpy, False);
 }
 
+void
+copyvalidchars(char *text, char *rawtext)
+{
+	int i = -1, j = 0;
+
+	while(rawtext[++i]) {
+		if ((unsigned char)rawtext[i] >= ' ') {
+			text[j++] = rawtext[i];
+		}
+	}
+	text[j] = '\0';
+}
+
 Monitor *
 createmon(void)
 {
@@ -695,7 +731,7 @@ dirtomon(int dir)
 void
 drawbar(Monitor *m)
 {
-	int x, w, sw = 0;
+	int x, w, tw = 0;
 	int boxs = drw->fonts->h / 9;
 	int boxw = drw->fonts->h / 6 + 2;
 	unsigned int i, occ = 0, urg = 0;
@@ -704,8 +740,8 @@ drawbar(Monitor *m)
 	/* draw status first so it can be overdrawn by tags later */
 	if (m == selmon) { /* status is only drawn on selected monitor */
 		drw_setscheme(drw, scheme[SchemeNorm]);
-		sw = TEXTW(stext) - lrpad + 2; /* 2px right padding */
-		drw_text(drw, m->ww - sw, 0, sw, bh, 0, stext, 0);
+		tw = TEXTW(stext) - lrpad + 2; /* 2px right padding */
+		drw_text(drw, m->ww - tw, 0, tw, bh, 0, stext, 0);
 	}
 
 	for (c = m->clients; c; c = c->next) {
@@ -728,7 +764,7 @@ drawbar(Monitor *m)
 	drw_setscheme(drw, scheme[SchemeNorm]);
 	x = drw_text(drw, x, 0, w, bh, lrpad / 2, m->ltsymbol, 0);
 
-	if ((w = m->ww - sw - x) > bh) {
+	if ((w = m->ww - tw - x) > bh) {
 		if (m->sel) {
 			drw_setscheme(drw, scheme[m == selmon ? SchemeSel : SchemeNorm]);
 			drw_text(drw, x, 0, w, bh, lrpad / 2, m->sel->name, 0);
@@ -1520,7 +1556,7 @@ setmfact(const Arg *arg)
 	if (!arg || !selmon->lt[selmon->sellt]->arrange)
 		return;
 	f = arg->f < 1.0 ? arg->f + selmon->mfact : arg->f - 1.0;
-	if (f < 0.1 || f > 0.9)
+	if (f < 0.05 || f > 0.95)
 		return;
 	selmon->mfact = f;
 	arrange(selmon);
@@ -1641,6 +1677,10 @@ spawn(const Arg *arg)
 {
 	if (arg->v == dmenucmd)
 		dmenumon[0] = '0' + selmon->num;
+	else if (arg->v == statuscmd) {
+		statuscmd[2] = statuscmds[statuscmdn];
+		setenv("BUTTON", lastbutton, 1);
+	}
 	if (fork() == 0) {
 		if (dpy)
 			close(ConnectionNumber(dpy));
@@ -1688,11 +1728,13 @@ tile(Monitor *m)
 		if (i < m->nmaster) {
 			h = (m->wh - my) / (MIN(n, m->nmaster) - i);
 			resize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
-			my += HEIGHT(c);
+			if (my + HEIGHT(c) < m->wh)
+				my += HEIGHT(c);
 		} else {
 			h = (m->wh - ty) / (n - i);
 			resize(c, m->wx + mw, m->wy + ty, m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
-			ty += HEIGHT(c);
+			if (ty + HEIGHT(c) < m->wh)
+				ty += HEIGHT(c);
 		}
 }
 
@@ -1987,8 +2029,10 @@ updatesizehints(Client *c)
 void
 updatestatus(void)
 {
-	if (!gettextprop(root, XA_WM_NAME, stext, sizeof(stext)))
+	if (!gettextprop(root, XA_WM_NAME, rawstext, sizeof(rawstext)))
 		strcpy(stext, "dwm-"VERSION);
+	else
+		copyvalidchars(stext, rawstext);
 	drawbar(selmon);
 }