From e61a957ff8b7e14219b5fbaab9da794b722e7874 Mon Sep 17 00:00:00 2001
From: Hai Nguyen <hhai2105@gmail.com>
Date: Fri, 10 Dec 2021 21:45:00 -0500
Subject: [PATCH] add Keychord struct, change keypress() and grabkeys() to be
 able to grab a sequence of keystroke

---
 config.def.h | 67 ++++++++++++++++++++++++++------------------------
 dwm.c        | 69 ++++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 88 insertions(+), 48 deletions(-)

diff --git a/config.def.h b/config.def.h
index a2ac963..15a3e05 100644
--- a/config.def.h
+++ b/config.def.h
@@ -46,11 +46,12 @@ static const Layout layouts[] = {
 
 /* key definitions */
 #define MODKEY Mod1Mask
-#define TAGKEYS(KEY,TAG) \
-	{ MODKEY,                       KEY,      view,           {.ui = 1 << TAG} }, \
-	{ MODKEY|ControlMask,           KEY,      toggleview,     {.ui = 1 << TAG} }, \
-	{ MODKEY|ShiftMask,             KEY,      tag,            {.ui = 1 << TAG} }, \
-	{ MODKEY|ControlMask|ShiftMask, KEY,      toggletag,      {.ui = 1 << TAG} },
+
+#define TAGKEYS(KEY,TAG)												\
+	{1, {{MODKEY, KEY}},								view,           {.ui = 1 << TAG} },	\
+	{1, {{MODKEY|ControlMask, KEY}},					toggleview,     {.ui = 1 << TAG} }, \
+	{1, {{MODKEY|ShiftMask, KEY}},						tag,            {.ui = 1 << TAG} }, \
+	{1, {{MODKEY|ControlMask|ShiftMask, KEY}},			toggletag,      {.ui = 1 << TAG} },
 
 /* helper for spawning shell commands in the pre dwm-5.0 fashion */
 #define SHCMD(cmd) { .v = (const char*[]){ "/bin/sh", "-c", cmd, NULL } }
@@ -59,32 +60,34 @@ static const Layout layouts[] = {
 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 };
+static const char *emacs[]  = { "emacs", NULL };
 
-static Key keys[] = {
-	/* modifier                     key        function        argument */
-	{ MODKEY,                       XK_p,      spawn,          {.v = dmenucmd } },
-	{ MODKEY|ShiftMask,             XK_Return, spawn,          {.v = termcmd } },
-	{ MODKEY,                       XK_b,      togglebar,      {0} },
-	{ MODKEY,                       XK_j,      focusstack,     {.i = +1 } },
-	{ MODKEY,                       XK_k,      focusstack,     {.i = -1 } },
-	{ MODKEY,                       XK_i,      incnmaster,     {.i = +1 } },
-	{ MODKEY,                       XK_d,      incnmaster,     {.i = -1 } },
-	{ MODKEY,                       XK_h,      setmfact,       {.f = -0.05} },
-	{ MODKEY,                       XK_l,      setmfact,       {.f = +0.05} },
-	{ MODKEY,                       XK_Return, zoom,           {0} },
-	{ MODKEY,                       XK_Tab,    view,           {0} },
-	{ MODKEY|ShiftMask,             XK_c,      killclient,     {0} },
-	{ MODKEY,                       XK_t,      setlayout,      {.v = &layouts[0]} },
-	{ MODKEY,                       XK_f,      setlayout,      {.v = &layouts[1]} },
-	{ MODKEY,                       XK_m,      setlayout,      {.v = &layouts[2]} },
-	{ MODKEY,                       XK_space,  setlayout,      {0} },
-	{ MODKEY|ShiftMask,             XK_space,  togglefloating, {0} },
-	{ MODKEY,                       XK_0,      view,           {.ui = ~0 } },
-	{ MODKEY|ShiftMask,             XK_0,      tag,            {.ui = ~0 } },
-	{ MODKEY,                       XK_comma,  focusmon,       {.i = -1 } },
-	{ MODKEY,                       XK_period, focusmon,       {.i = +1 } },
-	{ MODKEY|ShiftMask,             XK_comma,  tagmon,         {.i = -1 } },
-	{ MODKEY|ShiftMask,             XK_period, tagmon,         {.i = +1 } },
+static Keychord keychords[] = {
+	/* Keys        function        argument */
+	{1, {{MODKEY, XK_p}},							spawn,          {.v = dmenucmd } },
+	{1, {{MODKEY|ShiftMask, XK_Return}},			spawn,          {.v = termcmd } },
+	{2, {{MODKEY, XK_e}, {MODKEY, XK_e}},			spawn,          {.v = termcmd } },
+	{1, {{MODKEY, XK_b}},							togglebar,      {0} },
+	{1, {{MODKEY, XK_j}},							focusstack,     {.i = +1 } },
+	{1, {{MODKEY, XK_k}},							focusstack,     {.i = -1 } },
+	{1, {{MODKEY, XK_i}},							incnmaster,     {.i = +1 } },
+	{1, {{MODKEY, XK_d}},							incnmaster,     {.i = -1 } },
+	{1, {{MODKEY, XK_h}},							setmfact,       {.f = -0.05} },
+	{1, {{MODKEY, XK_l}},							setmfact,       {.f = +0.05} },
+	{1, {{MODKEY, XK_Return}},						zoom,           {0} },
+	{1, {{MODKEY, XK_Tab}},							view,           {0} },
+	{1, {{MODKEY|ShiftMask, XK_c}},					killclient,     {0} },
+	{1, {{MODKEY, XK_t}},							setlayout,      {.v = &layouts[0]} },
+	{1, {{MODKEY, XK_f}},							setlayout,      {.v = &layouts[1]} },
+	{1, {{MODKEY, XK_m}},							setlayout,      {.v = &layouts[2]} },
+	{1, {{MODKEY, XK_space}},						setlayout,      {0} },
+	{1, {{MODKEY|ShiftMask, XK_space}},				togglefloating, {0} },
+	{1, {{MODKEY, XK_0}},							view,           {.ui = ~0 } },
+	{1, {{MODKEY|ShiftMask, XK_0}},					tag,            {.ui = ~0 } },
+	{1, {{MODKEY, XK_comma}},						focusmon,       {.i = -1 } },
+	{1, {{MODKEY, XK_period}},						focusmon,       {.i = +1 } },
+	{1, {{MODKEY|ShiftMask, XK_comma}},				tagmon,         {.i = -1 } },
+	{1, {{MODKEY|ShiftMask, XK_period}},			tagmon,         {.i = +1 } },
 	TAGKEYS(                        XK_1,                      0)
 	TAGKEYS(                        XK_2,                      1)
 	TAGKEYS(                        XK_3,                      2)
@@ -92,9 +95,9 @@ static Key keys[] = {
 	TAGKEYS(                        XK_5,                      4)
 	TAGKEYS(                        XK_6,                      5)
 	TAGKEYS(                        XK_7,                      6)
-	TAGKEYS(                        XK_8,                      7)
+	 TAGKEYS(                        XK_8,                      7)
 	TAGKEYS(                        XK_9,                      8)
-	{ MODKEY|ShiftMask,             XK_q,      quit,           {0} },
+	{1, {{MODKEY|ShiftMask, XK_q}},					quit,           {0} },
 };
 
 /* button definitions */
diff --git a/dwm.c b/dwm.c
index 5e4d494..56c4661 100644
--- a/dwm.c
+++ b/dwm.c
@@ -102,9 +102,14 @@ struct Client {
 typedef struct {
 	unsigned int mod;
 	KeySym keysym;
+} Key;
+
+typedef struct {
+	unsigned int n;
+	const Key keys[5];
 	void (*func)(const Arg *);
 	const Arg arg;
-} Key;
+} Keychord;
 
 typedef struct {
 	const char *symbol;
@@ -268,6 +273,7 @@ static Display *dpy;
 static Drw *drw;
 static Monitor *mons, *selmon;
 static Window root, wmcheckwin;
+unsigned int currentkey = 0;
 
 /* configuration, allows nested code to access above variables */
 #include "config.h"
@@ -951,16 +957,16 @@ grabkeys(void)
 {
 	updatenumlockmask();
 	{
-		unsigned int i, j;
+		unsigned int i, k;
 		unsigned int modifiers[] = { 0, LockMask, numlockmask, numlockmask|LockMask };
 		KeyCode code;
 
 		XUngrabKey(dpy, AnyKey, AnyModifier, root);
-		for (i = 0; i < LENGTH(keys); i++)
-			if ((code = XKeysymToKeycode(dpy, keys[i].keysym)))
-				for (j = 0; j < LENGTH(modifiers); j++)
-					XGrabKey(dpy, code, keys[i].mod | modifiers[j], root,
-						True, GrabModeAsync, GrabModeAsync);
+		for (i = 0; i < LENGTH(keychords); i++)
+			if ((code = XKeysymToKeycode(dpy, keychords[i].keys[currentkey].keysym)))
+				for (k = 0; k < LENGTH(modifiers); k++)
+					XGrabKey(dpy, code, keychords[i].keys[currentkey].mod | modifiers[k], root,
+							 True, GrabModeAsync, GrabModeAsync);
 	}
 }
 
@@ -986,17 +992,48 @@ isuniquegeom(XineramaScreenInfo *unique, size_t n, XineramaScreenInfo *info)
 void
 keypress(XEvent *e)
 {
-	unsigned int i;
+	XEvent event = *e;
+	Keychord *keychord;
+	unsigned int ran = 0;
 	KeySym keysym;
 	XKeyEvent *ev;
-
-	ev = &e->xkey;
-	keysym = XKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 0);
-	for (i = 0; i < LENGTH(keys); i++)
-		if (keysym == keys[i].keysym
-		&& CLEANMASK(keys[i].mod) == CLEANMASK(ev->state)
-		&& keys[i].func)
-			keys[i].func(&(keys[i].arg));
+	Keychord *newoptions;
+	Keychord *oldoptions = (Keychord *)malloc(sizeof(keychords));
+
+	memcpy(oldoptions, keychords, sizeof(keychords));
+	size_t numoption = 0;
+	while(!ran){
+		ev = &event.xkey;
+		keysym = XKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 0);
+		newoptions = (Keychord *)malloc(0);
+		numoption = 0;
+		for (keychord = oldoptions; keychord->n != 0 && currentkey < 5; keychord = (Keychord *)((char *)keychord + sizeof(Keychord))){
+			if(keysym == keychord->keys[currentkey].keysym
+			   && CLEANMASK(keychord->keys[currentkey].mod) == CLEANMASK(ev->state)
+			   && keychord->func){
+				if(keychord->n == currentkey +1){
+					keychord->func(&(keychord->arg));
+					ran = 1;
+				}else{
+					numoption++;
+					newoptions = (Keychord *)realloc(newoptions, numoption * sizeof(Keychord));
+					memcpy((char *)newoptions + (numoption -1) * sizeof(Keychord),keychord, sizeof(Keychord));
+				}
+			}
+		}
+		currentkey++;
+		if(numoption == 0)
+			break;
+		grabkeys();
+		while (running && !XNextEvent(dpy, &event) && !ran)
+			if(event.type == KeyPress)
+				break;
+		free(oldoptions);
+		oldoptions = newoptions;
+	}
+	free(newoptions);
+	currentkey = 0;
+	grabkeys();
 }
 
 void
-- 
2.34.1

