From 56f643120f082c9fd609f25e3ad9db6eb435fb89 Mon Sep 17 00:00:00 2001
From: elbachir-one <bachiralfa@gmail.com>
Date: Mon, 24 Jun 2024 22:15:50 +0100
Subject: [PATCH] Inspired by a Reddit post from u/PawarShubham3007
shubham-cpp on github, this patch aiming to make dwm focus on windows
 of the same program.

---
 config.def.h |  4 +++-
 dwm.c        | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/config.def.h b/config.def.h
index 9efa774..fd0dda6 100644
--- a/config.def.h
+++ b/config.def.h
@@ -85,6 +85,8 @@ static const Key keys[] = {
 	{ MODKEY,                       XK_period, focusmon,       {.i = +1 } },
 	{ MODKEY|ShiftMask,             XK_comma,  tagmon,         {.i = -1 } },
 	{ MODKEY|ShiftMask,             XK_period, tagmon,         {.i = +1 } },
+   { MODKEY,                       XK_n,      focussame,      {.i = +1 } },
+   { MODKEY|ShiftMask,             XK_n,      focussame,      {.i = -1 } },
 	TAGKEYS(                        XK_1,                      0)
 	TAGKEYS(                        XK_2,                      1)
 	TAGKEYS(                        XK_3,                      2)
diff --git a/dwm.c b/dwm.c
index 67c6b2b..c657315 100644
--- a/dwm.c
+++ b/dwm.c
@@ -233,6 +233,8 @@ static int xerror(Display *dpy, XErrorEvent *ee);
 static int xerrordummy(Display *dpy, XErrorEvent *ee);
 static int xerrorstart(Display *dpy, XErrorEvent *ee);
 static void zoom(const Arg *arg);
+static void focussame(const Arg *arg);
+static Window lastfocusedwin = None;
 
 /* variables */
 static const char broken[] = "broken";
@@ -786,6 +788,59 @@ expose(XEvent *e)
 		drawbar(m);
 }
 
+void
+focussame(const Arg *arg) {
+    Client *c;
+    XClassHint ch = { NULL, NULL };
+    char *class_name = NULL;
+    int direction = arg->i;
+
+    if (!selmon->sel)
+        return;
+
+    if (!XGetClassHint(dpy, selmon->sel->win, &ch))
+        return;
+    class_name = ch.res_class;
+
+    Client *clients[32];
+    int num_clients = 0;
+    for (c = selmon->clients; c && num_clients < 32; c = c->next) {
+        if (c->tags & selmon->tagset[selmon->seltags] && XGetClassHint(dpy, c->win, &ch)) {
+            if (strcmp(class_name, ch.res_class) == 0)
+                clients[num_clients++] = c;
+            XFree(ch.res_class);
+            XFree(ch.res_name);
+        }
+    }
+
+    Client *target_client = NULL;
+    if (direction == +1) {
+        for (int i = 0; i < num_clients; ++i) {
+            if (clients[i]->win == lastfocusedwin) {
+                target_client = clients[(i + 1) % num_clients];
+                break;
+            }
+        }
+        if (!target_client)
+            target_client = clients[0];
+    } else if (direction == -1) {
+        for (int i = 0; i < num_clients; ++i) {
+            if (clients[i]->win == lastfocusedwin) {
+                target_client = clients[(i - 1 + num_clients) % num_clients];
+                break;
+            }
+        }
+        if (!target_client)
+            target_client = clients[num_clients - 1];
+    }
+
+    if (target_client) {
+        focus(target_client);
+        restack(selmon);
+        lastfocusedwin = target_client->win;
+    }
+}
+
 void
 focus(Client *c)
 {
-- 
2.45.2