From 7b578d9f4647d84f79a2e8a46a1c65cbacf8d90b Mon Sep 17 00:00:00 2001
From: Nikita Ivanov <nikita.vyach.ivanov@gmail.com>
Date: Wed, 19 Mar 2025 02:28:46 +0100
Subject: [PATCH] Add menurule to tweak rules at runtime

---
 config.def.h |   2 +
 dwl.c        | 116 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 118 insertions(+)

diff --git a/config.def.h b/config.def.h
index e03a754..77b10ff 100644
--- a/config.def.h
+++ b/config.def.h
@@ -24,6 +24,7 @@ static const Menu menus[] = {
 	/* command                            feed function        action function */
 	{ "wmenu -i -l 10 -p Windows",        menuwinfeed,         menuwinaction    },
 	{ "wmenu -i -p Layouts",              menulayoutfeed,      menulayoutaction },
+	{ "wmenu -i -l 10 -p Rules",          menurulefeed,        menuruleaction },
 };
 
 /* Max amount of dynamically added rules */
@@ -151,6 +152,7 @@ static const Key keys[] = {
 	{ MODKEY,                    XKB_KEY_space,      setlayout,      {0} },
 	{ MODKEY,                    XKB_KEY_o,          menu,           {.v = &menus[0]} },
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_O,          menu,           {.v = &menus[1]} },
+	{ MODKEY,                    XKB_KEY_r,          menu,           {.v = &menus[2]} },
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_space,      togglefloating, {0} },
 	{ MODKEY,                    XKB_KEY_e,         togglefullscreen, {0} },
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_R,          setruleisfloating,{0} },
diff --git a/dwl.c b/dwl.c
index be007d8..df4901f 100644
--- a/dwl.c
+++ b/dwl.c
@@ -316,6 +316,8 @@ static void menuwinfeed(FILE *f);
 static void menuwinaction(char *line);
 static void menulayoutfeed(FILE *f);
 static void menulayoutaction(char *line);
+static void menurulefeed(FILE *f);
+static void menuruleaction(char *line);
 static void monocle(Monitor *m);
 static void motionabsolute(struct wl_listener *listener, void *data);
 static void motionnotify(uint32_t time, struct wlr_input_device *device, double sx,
@@ -1974,6 +1976,120 @@ found:
 	setlayout(&(const Arg){ .v = l });
 }
 
+void
+menurulefeed(FILE *f)
+{
+	Rule t, *p, *r;
+	const char *appid, *title;
+	static char buf[515];
+	Client *c = focustop(selmon);
+	int n, wid = 0, match;
+
+	t = (Rule){ 0 };
+	t.monitor = -1;
+	if (c) {
+		t.id    = client_get_appid(c);
+		t.title = client_get_title(c);
+		appid   = t.id    ? t.id    : broken;
+		title   = t.title ? t.title : broken;
+	}
+
+	for (p = drules; p <= drules + druleslen; p++) {
+		r = (p == drules + druleslen) ? &t : p;
+		n = 0;
+		n += strlen(r->id ? r->id : "NULL");
+		n += strlen(r->title ? r->title : "NULL");
+		n += 3;
+		wid = MAX(wid, n);
+	}
+	wid = MIN(wid, 40);
+
+	for (p = drules; p <= drules + druleslen; p++) {
+		match = 0;
+		/* Check if rule applies to the focused client */
+		if (c && p < drules + druleslen) {
+			match = (!p->title || strstr(title, p->title))
+				&& (!p->id || strstr(appid, p->id));
+			if (match && p->id)
+				t.id = NULL;
+			if (match && p->title)
+				t.title = NULL;
+		}
+		r = (p == drules + druleslen) ? &t : p;
+		if (r == &t && t.id)
+			t.title = NULL;
+		/* Do not suggest to add a new empty rule */
+		if (r == &t && !(t.id || t.title))
+			continue;
+		if (r->id && r->title &&
+				strcmp(r->id, "removedrule") == 0 && strcmp(r->title, "removedrule") == 0)
+			continue;
+		snprintf(buf, LENGTH(buf) - 1, "[%s|%s]",
+			r->id ? r->id : "NULL", r->title ? r->title : "NULL");
+		fprintf(f, "%-*s "
+			" tags:%-4"PRIi32
+			" isfloating:%-2d"
+			" monitor:%-2d"
+			"%s\n", wid, buf,
+			r->tags,
+			r->isfloating,
+			r->monitor,
+			(r == &t) ? "  (NEW)" : match ? "  <" : "");
+	}
+}
+
+void
+menuruleaction(char *line)
+{
+	Rule r, *f;
+	static char appid[256], title[256];
+	int del = 0, end;
+
+	if (line[0] == '-') {
+		del = 1;
+		line++;
+	}
+	end = 0;
+	sscanf(line, "[%255[^|]|%255[^]]]"
+		" tags:%"SCNu32
+		" isfloating:%d"
+		" monitor:%d"
+		"%n", appid, title,
+		&r.tags,
+		&r.isfloating,
+		&r.monitor,
+		&end);
+
+	/* Full line was not parsed, exit */
+	if (!end)
+		return;
+
+	r.id    = (strcmp(appid, "NULL") != 0) ? appid : NULL;
+	r.title = (strcmp(title, "NULL") != 0) ? title : NULL;
+
+	/* Find which rule we are trying to edit */
+	for (f = drules; f < drules + druleslen; f++)
+		if (((!r.title && !f->title) || (r.title && f->title && !strcmp(r.title, f->title)))
+				&& (((!r.id && !f->id) || (r.id && f->id && !strcmp(r.id, f->id)))))
+			goto found;
+
+	if (druleslen >= LENGTH(rules) + RULES_MAX)
+		return; /* No free slots left */
+
+	f = drules + druleslen++;
+	f->id    = r.id    ? strdup(r.id)    : NULL;
+	f->title = r.title ? strdup(r.title) : NULL;
+
+found:
+	if (del) {
+		f->id = f->title = "removedrule";
+		return;
+	}
+	r.id    = f->id;
+	r.title = f->title;
+	*f = r;
+}
+
 void
 monocle(Monitor *m)
 {
-- 
2.49.0