From 49b0da41f1f28a60cf216f5bffecc0ce1ea1ec9c Mon Sep 17 00:00:00 2001
From: nate zhou <gnuunixchad@outlook.com>
Date: Mon, 23 Mar 2026 00:50:54 +0800
Subject: [PATCH] shifttag with filtering occupied/unoccupied tags support

---
 config.def.h |  8 +++++
 shifttag.c   | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 shifttag.c

diff --git a/config.def.h b/config.def.h
index 8a6eda0..2377fa5 100644
--- a/config.def.h
+++ b/config.def.h
@@ -118,6 +118,8 @@ static const enum libinput_config_tap_button_map button_map = LIBINPUT_CONFIG_TA
 static const char *termcmd[] = { "foot", NULL };
 static const char *menucmd[] = { "wmenu-run", NULL };
 
+#include "shifttag.c"
+
 static const Key keys[] = {
 	/* Note that Shift changes certain key codes: 2 -> at, etc. */
 	/* modifier                  key                  function          argument */
@@ -131,6 +133,12 @@ static const Key keys[] = {
 	{ MODKEY,                    XKB_KEY_l,           setmfact,         {.f = +0.05f} },
 	{ MODKEY,                    XKB_KEY_Return,      zoom,             {0} },
 	{ MODKEY,                    XKB_KEY_Tab,         view,             {0} },
+	{ MODKEY,                    XKB_KEY_apostrophe,  shifttag_occupied,   { .i = 1 } },
+	{ MODKEY,                    XKB_KEY_semicolon,   shifttag_occupied,   { .i = -1 } },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_quotedbl,    shifttag,            { .i = 1 } },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_colon,       shifttag,            { .i = -1 } },
+	{ MODKEY|WLR_MODIFIER_CTRL,  XKB_KEY_apostrophe,  shifttag_unoccupied, { .i = 1 } },
+	{ MODKEY|WLR_MODIFIER_CTRL,  XKB_KEY_semicolon,   shifttag_unoccupied, { .i = -1 } },
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_c,           killclient,       {0} },
 	{ MODKEY,                    XKB_KEY_t,           setlayout,        {.v = &layouts[0]} },
 	{ MODKEY,                    XKB_KEY_f,           setlayout,        {.v = &layouts[1]} },
diff --git a/shifttag.c b/shifttag.c
new file mode 100644
index 0000000..5aeee00
--- /dev/null
+++ b/shifttag.c
@@ -0,0 +1,99 @@
+// "arg->i" stores the number of tags to shift right (positive value)
+//          or left (negative value)
+
+static uint32_t
+get_occupied_tags(Monitor *m)
+{
+	uint32_t occupied = 0;
+	Client *c;
+	wl_list_for_each(c, &clients, link) {
+		if (c->mon == m)
+			occupied |= c->tags;
+	}
+	return occupied & TAGMASK;
+}
+
+static uint32_t
+find_next_tag(uint32_t current_tag, int direction, bool skip_unoccupied, bool skip_occupied)
+{
+	uint32_t occupied = get_occupied_tags(selmon);
+	uint32_t start = current_tag;
+	uint32_t test_tag = current_tag;
+	uint32_t new_tag = current_tag;
+	int count = 0;
+
+	if (!skip_unoccupied && !skip_occupied) {
+		if (direction > 0) {
+			new_tag = (current_tag << 1) | (current_tag >> (TAGCOUNT - 1));
+		} else {
+			new_tag = (current_tag >> 1) | (current_tag << (TAGCOUNT - 1));
+		}
+		return new_tag & TAGMASK;
+	}
+
+	do {
+		if (direction > 0) {
+			if (test_tag << 1 && (test_tag << 1) <= TAGMASK)
+				test_tag = test_tag << 1;
+			else
+				test_tag = 1;
+		} else {
+			if (test_tag >> 1)
+				test_tag = test_tag >> 1;
+			else
+				test_tag = 1 << (TAGCOUNT - 1);
+		}
+
+		int is_occupied = (occupied & test_tag) != 0;
+		int should_select = (skip_unoccupied && is_occupied) ||
+							(skip_occupied && !is_occupied);
+
+		if (should_select) {
+			new_tag = test_tag;
+			break;
+		}
+		count++;
+	} while (test_tag != start && count < TAGCOUNT);
+
+	return new_tag;
+}
+
+static void
+shifttag_with_filter(const Arg *arg, bool skip_unoccupied, bool skip_occupied)
+{
+	Arg a;
+	if (!selmon)
+		return;
+
+	uint32_t occupied = get_occupied_tags(selmon);
+	if (skip_unoccupied && !skip_occupied && occupied == 0)
+		return;
+	if (skip_occupied && !skip_unoccupied && (occupied == TAGMASK))
+		return;
+
+	uint32_t curseltags = selmon->tagset[selmon->seltags];
+	uint32_t nextseltags = find_next_tag(curseltags, arg->i, skip_unoccupied, skip_occupied);
+
+	if (nextseltags != curseltags) {
+		a.i = nextseltags;
+		view(&a);
+	}
+}
+
+void
+shifttag(const Arg *arg)
+{
+	shifttag_with_filter(arg, false, false);
+}
+
+void
+shifttag_occupied(const Arg *arg)
+{
+	shifttag_with_filter(arg, true, false);
+}
+
+void
+shifttag_unoccupied(const Arg *arg)
+{
+	shifttag_with_filter(arg, false, true);
+}
-- 
2.53.0