From de2bfe560a8085630ffe976fd5972ee1e8d03916 Mon Sep 17 00:00:00 2001
From: pskry <peter@skrypalle.dk>
Date: Mon, 16 Nov 2020 17:47:05 +0100
Subject: [PATCH] Enable swapping master- and stack-area

Enables swapping the master- and stack area such that the master-client
appears on the right and the stack-clients appear on the left.

A variable and a toggle-function are introduced to achieve this
behaviour which are set in the config.h:

* The rmaster-variable can be set to 1 to make the right area the
default master-area
* The togglemaster-function can be used to swap the master- and
stack-areas dynamically.
---
 config.def.h |  2 ++
 dwm.c        | 23 ++++++++++++++++++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/config.def.h b/config.def.h
index 1c0b587..1d00282 100644
--- a/config.def.h
+++ b/config.def.h
@@ -3,6 +3,7 @@
 /* appearance */
 static const unsigned int borderpx  = 1;        /* border pixel of windows */
 static const unsigned int snap      = 32;       /* snap pixel */
+static const int rmaster            = 1;        /* 1 means master-area is initially on the right */
 static const int showbar            = 1;        /* 0 means no bar */
 static const int topbar             = 1;        /* 0 means bottom bar */
 static const char *fonts[]          = { "monospace:size=10" };
@@ -78,6 +79,7 @@ static Key keys[] = {
 	{ MODKEY,                       XK_m,      setlayout,      {.v = &layouts[2]} },
 	{ MODKEY,                       XK_space,  setlayout,      {0} },
 	{ MODKEY|ShiftMask,             XK_space,  togglefloating, {0} },
+	{ MODKEY,                       XK_r,      togglermaster,  {0} },
 	{ MODKEY,                       XK_0,      view,           {.ui = ~0 } },
 	{ MODKEY|ShiftMask,             XK_0,      tag,            {.ui = ~0 } },
 	{ MODKEY,                       XK_comma,  focusmon,       {.i = -1 } },
diff --git a/dwm.c b/dwm.c
index 4465af1..a2d118b 100644
--- a/dwm.c
+++ b/dwm.c
@@ -122,6 +122,7 @@ struct Monitor {
 	unsigned int seltags;
 	unsigned int sellt;
 	unsigned int tagset[2];
+	int rmaster;
 	int showbar;
 	int topbar;
 	Client *clients;
@@ -211,6 +212,7 @@ static void tagmon(const Arg *arg);
 static void tile(Monitor *);
 static void togglebar(const Arg *arg);
 static void togglefloating(const Arg *arg);
+static void togglermaster(const Arg *arg);
 static void toggletag(const Arg *arg);
 static void toggleview(const Arg *arg);
 static void unfocus(Client *c, int setfocus);
@@ -636,6 +638,7 @@ createmon(void)
 	m->tagset[0] = m->tagset[1] = 1;
 	m->mfact = mfact;
 	m->nmaster = nmaster;
+	m->rmaster = rmaster;
 	m->showbar = showbar;
 	m->topbar = topbar;
 	m->lt[0] = &layouts[0];
@@ -1681,17 +1684,21 @@ tile(Monitor *m)
 		return;
 
 	if (n > m->nmaster)
-		mw = m->nmaster ? m->ww * m->mfact : 0;
+		mw = m->nmaster
+			? m->ww * (m->rmaster ? 1.0 - m->mfact : m->mfact)
+			: 0;
 	else
 		mw = m->ww;
 	for (i = my = ty = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)
 		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);
+			resize(c, m->rmaster ? m->wx + m->ww - mw : m->wx,
+			       m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
 			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);
+			resize(c, m->rmaster ? m->wx : m->wx + mw, m->wy + ty,
+			       m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
 			ty += HEIGHT(c);
 		}
 }
@@ -1719,6 +1726,16 @@ togglefloating(const Arg *arg)
 	arrange(selmon);
 }
 
+void
+togglermaster(const Arg *arg)
+{
+	selmon->rmaster = !selmon->rmaster;
+	/* now mfact represents the left factor */
+	selmon->mfact = 1.0 - selmon->mfact;
+	if (selmon->lt[selmon->sellt]->arrange)
+		arrange(selmon);
+}
+
 void
 toggletag(const Arg *arg)
 {
-- 
2.31.1