consolidate some of the ugliness into a separate file

Similar to Linux kernel approach, encapsulate some of the uglier
conditional compilation into inline functions in header files.

The goal is to make dwl.c more attractive to people who embrace the
suckless philosophy - simple, short, hackable, and easy to understand.
We want dwm users to feel comfortable here, not scare them off.  Plus,
if we do this right, the main dwl.c code should require only minimal
changes once XWayland is no longer a necessary evil.

According to `cloc`, this also brings dwl.c down below 2000 lines of
non-blank, non-comment code.

3 files changed, 200 insertions, 127 deletions

diff --git a/client.h b/client.h
new file mode 100644
index 0000000..f4735c2
--- /dev/null
+++ b/client.h
@@ -0,0 +1,163 @@
+/*
+ * Attempt to consolidate unavoidable suck into one file, away from dwl.c.  This
+ * file is not meant to be pretty.  We use a .h file with static inline
+ * functions instead of a separate .c module, or function pointers like sway, so
+ * that they will simply compile out if the chosen #defines leave them unused.
+ */
+
+/* Leave this function first; it's used in the others */
+static inline int
+client_is_x11(Client *c)
+{
+#ifdef XWAYLAND
+	return c->type == X11Managed || c->type == X11Unmanaged;
+#else
+	return 0;
+#endif
+}
+
+/* The others */
+static inline void
+client_activate_surface(struct wlr_surface *s, int activated)
+{
+#ifdef XWAYLAND
+	if (wlr_surface_is_xwayland_surface(s)) {
+		wlr_xwayland_surface_activate(
+				wlr_xwayland_surface_from_wlr_surface(s), activated);
+		return;
+	}
+#endif
+	if (wlr_surface_is_xdg_surface(s))
+		wlr_xdg_toplevel_set_activated(
+				wlr_xdg_surface_from_wlr_surface(s), activated);
+}
+
+static inline void
+client_for_each_surface(Client *c, wlr_surface_iterator_func_t fn, void *data)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		wlr_surface_for_each_surface(c->surface.xwayland->surface,
+				fn, data);
+		return;
+	}
+#endif
+	wlr_xdg_surface_for_each_surface(c->surface.xdg, fn, data);
+}
+
+static inline const char *
+client_get_appid(Client *c)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c))
+		return c->surface.xwayland->class;
+#endif
+	return c->surface.xdg->toplevel->app_id;
+}
+
+static inline void
+client_get_geometry(Client *c, struct wlr_box *geom)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		geom->x = c->surface.xwayland->x;
+		geom->y = c->surface.xwayland->y;
+		geom->width = c->surface.xwayland->width;
+		geom->height = c->surface.xwayland->height;
+		return;
+	}
+#endif
+	wlr_xdg_surface_get_geometry(c->surface.xdg, geom);
+}
+
+static inline const char *
+client_get_title(Client *c)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c))
+		return c->surface.xwayland->title;
+#endif
+	return c->surface.xdg->toplevel->title;
+}
+
+static inline int
+client_is_float_type(Client *c)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c))
+		for (size_t i = 0; i < c->surface.xwayland->window_type_len; i++)
+			if (c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeDialog] ||
+					c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeSplash] ||
+					c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeToolbar] ||
+					c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeUtility])
+				return 1;
+#endif
+	return 0;
+}
+
+static inline int
+client_is_unmanaged(Client *c)
+{
+#ifdef XWAYLAND
+	return c->type == X11Unmanaged;
+#endif
+	return 0;
+}
+
+static inline void
+client_send_close(Client *c)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		wlr_xwayland_surface_close(c->surface.xwayland);
+		return;
+	}
+#endif
+	wlr_xdg_toplevel_send_close(c->surface.xdg);
+}
+
+static inline void
+client_set_fullscreen(Client *c, int fullscreen)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		wlr_xwayland_surface_set_fullscreen(c->surface.xwayland, fullscreen);
+		return;
+	}
+#endif
+	wlr_xdg_toplevel_set_fullscreen(c->surface.xdg, fullscreen);
+}
+
+static inline uint32_t
+client_set_size(Client *c, uint32_t width, uint32_t height)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c)) {
+		wlr_xwayland_surface_configure(c->surface.xwayland,
+				c->geom.x, c->geom.y, width, height);
+		return 0;
+	}
+#endif
+	return wlr_xdg_toplevel_set_size(c->surface.xdg, width, height);
+}
+
+static inline struct wlr_surface *
+client_surface(Client *c)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c))
+		return c->surface.xwayland->surface;
+#endif
+	return c->surface.xdg->surface;
+}
+
+static inline struct wlr_surface *
+client_surface_at(Client *c, double cx, double cy, double *sx, double *sy)
+{
+#ifdef XWAYLAND
+	if (client_is_x11(c))
+		return wlr_surface_surface_at(c->surface.xwayland->surface,
+				cx, cy, sx, sy);
+#endif
+	return wlr_xdg_surface_surface_at(c->surface.xdg, cx, cy, sx, sy);
+}
diff --git a/config.mk b/config.mk
index d84f14d..9a886cc 100644
--- a/config.mk
+++ b/config.mk
@@ -2,7 +2,7 @@
 PREFIX = /usr/local
 
 # Default compile flags (overridable by environment)
-CFLAGS ?= -g -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare -Wno-error=unused-function -Wdeclaration-after-statement
+CFLAGS ?= -g -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare -Wno-unused-function -Wno-unused-variable -Wdeclaration-after-statement
 
 # Uncomment to build XWayland support
-#CFLAGS += -DXWAYLAND
+CFLAGS += -DXWAYLAND
diff --git a/dwl.c b/dwl.c
index c4fb02e..fa6379a 100644
--- a/dwl.c
+++ b/dwl.c
@@ -58,11 +58,6 @@
 #define END(A)                  ((A) + LENGTH(A))
 #define TAGMASK                 ((1 << LENGTH(tags)) - 1)
 #define ROUND(X)                ((int)((X)+0.5))
-#ifdef XWAYLAND
-#define WLR_SURFACE(C)          ((C)->type != XDGShell ? (C)->surface.xwayland->surface : (C)->surface.xdg->surface)
-#else
-#define WLR_SURFACE(C)          ((C)->surface.xdg->surface)
-#endif
 
 /* enums */
 enum { CurNormal, CurMove, CurResize }; /* cursor */
@@ -93,14 +88,8 @@ typedef struct {
 	struct wl_list slink;
 	union {
 		struct wlr_xdg_surface *xdg;
-#ifdef XWAYLAND
 		struct wlr_xwayland_surface *xwayland;
-#endif
 	} surface;
-#ifdef XWAYLAND
-	struct wl_listener activate;
-	struct wl_listener configure;
-#endif
 	struct wl_listener commit;
 	struct wl_listener map;
 	struct wl_listener unmap;
@@ -110,6 +99,8 @@ typedef struct {
 	Monitor *mon;
 #ifdef XWAYLAND
 	unsigned int type;
+	struct wl_listener activate;
+	struct wl_listener configure;
 #endif
 	int bw;
 	unsigned int tags;
@@ -326,10 +317,8 @@ static struct wlr_virtual_keyboard_manager_v1 *virtual_keyboard_mgr;
 
 static struct wlr_cursor *cursor;
 static struct wlr_xcursor_manager *cursor_mgr;
-#ifdef XWAYLAND
 static struct wlr_xcursor *xcursor;
 static struct wlr_xcursor_manager *xcursor_mgr;
-#endif
 
 static struct wlr_seat *seat;
 static struct wl_list keyboards;
@@ -366,7 +355,6 @@ static void configurex11(struct wl_listener *listener, void *data);
 static void createnotifyx11(struct wl_listener *listener, void *data);
 static Atom getatom(xcb_connection_t *xc, const char *name);
 static void renderindependents(struct wlr_output *output, struct timespec *now);
-static void updatewindowtype(Client *c);
 static void xwaylandready(struct wl_listener *listener, void *data);
 static Client *xytoindependent(double x, double y);
 static struct wl_listener new_xwayland_surface = {.notify = createnotifyx11};
@@ -378,6 +366,9 @@ static Atom netatom[NetLast];
 /* configuration, allows nested code to access above variables */
 #include "config.h"
 
+/* attempt to encapsulate suck into one file */
+#include "client.h"
+
 /* compile-time check if all tags fit into an unsigned int bit array. */
 struct NumTags { char limitexceeded[LENGTH(tags) > 31 ? -1 : 1]; };
 
@@ -462,20 +453,11 @@ applyrules(Client *c)
 	unsigned int i, newtags = 0;
 	const Rule *r;
 	Monitor *mon = selmon, *m;
-#ifdef XWAYLAND
-	if (c->type != XDGShell) {
-		updatewindowtype(c);
-		appid = c->surface.xwayland->class;
-		title = c->surface.xwayland->title;
-	} else
-#endif
-	{
-		appid = c->surface.xdg->toplevel->app_id;
-		title = c->surface.xdg->toplevel->title;
-	}
-	if (!appid)
+
+	c->isfloating = client_is_float_type(c);
+	if (!(appid = client_get_appid(c)))
 		appid = broken;
-	if (!title)
+	if (!(title = client_get_title(c)))
 		title = broken;
 
 	for (r = rules; r < END(rules); r++) {
@@ -1107,13 +1089,7 @@ setfullscreen(Client *c, int fullscreen)
 {
 	c->isfullscreen = fullscreen;
 	c->bw = (1 - fullscreen) * borderpx;
-
-#ifdef XWAYLAND
-	if (c->type == X11Managed)
-		wlr_xwayland_surface_set_fullscreen(c->surface.xwayland, fullscreen);
-	else
-#endif
-		wlr_xdg_toplevel_set_fullscreen(c->surface.xdg, fullscreen);
+	client_set_fullscreen(c, fullscreen);
 
 	if (fullscreen) {
 		c->prevx = c->geom.x;
@@ -1166,7 +1142,7 @@ focusclient(Client *c, int lift)
 		wl_list_insert(&stack, &c->slink);
 	}
 
-	if (c && WLR_SURFACE(c) == old)
+	if (c && client_surface(c) == old)
 		return;
 
 	/* Put the new client atop the focus stack and select its monitor */
@@ -1177,21 +1153,13 @@ focusclient(Client *c, int lift)
 	}
 
 	/* Deactivate old client if focus is changing */
-	if (old && (!c || WLR_SURFACE(c) != old)) {
-		if (wlr_surface_is_xdg_surface(old))
-			wlr_xdg_toplevel_set_activated(
-					wlr_xdg_surface_from_wlr_surface(old), 0);
-#ifdef XWAYLAND
-		else if (wlr_surface_is_xwayland_surface(old))
-			wlr_xwayland_surface_activate(
-					wlr_xwayland_surface_from_wlr_surface(old), 0);
-#endif
+	if (old && (!c || client_surface(c) != old)) {
 		/* If an overlay is focused, don't focus or activate the client,
 		 * but only update its position in fstack to render its border with focuscolor
 		 * and focus it after the overlay is closed.
 		 * It's probably pointless to check if old is a layer surface
 		 * since it can't be anything else at this point. */
-		else if (wlr_surface_is_layer_surface(old)) {
+		if (wlr_surface_is_layer_surface(old)) {
 			struct wlr_layer_surface_v1 *wlr_layer_surface =
 				wlr_layer_surface_v1_from_wlr_surface(old);
 
@@ -1200,6 +1168,8 @@ focusclient(Client *c, int lift)
 						wlr_layer_surface->current.layer == ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY
 						))
 				return;
+		} else {
+			client_activate_surface(old, 0);
 		}
 	}
 
@@ -1211,16 +1181,11 @@ focusclient(Client *c, int lift)
 
 	/* Have a client, so focus its top-level wlr_surface */
 	kb = wlr_seat_get_keyboard(seat);
-	wlr_seat_keyboard_notify_enter(seat, WLR_SURFACE(c),
+	wlr_seat_keyboard_notify_enter(seat, client_surface(c),
 			kb->keycodes, kb->num_keycodes, &kb->modifiers);
 
 	/* Activate the new client */
-#ifdef XWAYLAND
-	if (c->type != XDGShell)
-		wlr_xwayland_surface_activate(c->surface.xwayland, 1);
-	else
-#endif
-		wlr_xdg_toplevel_set_activated(c->surface.xdg, 1);
+	client_activate_surface(client_surface(c), 1);
 }
 
 void
@@ -1390,13 +1355,7 @@ killclient(const Arg *arg)
 	Client *sel = selclient();
 	if (!sel)
 		return;
-
-#ifdef XWAYLAND
-	if (sel->type != XDGShell)
-		wlr_xwayland_surface_close(sel->surface.xwayland);
-	else
-#endif
-		wlr_xdg_toplevel_send_close(sel->surface.xdg);
+	client_send_close(sel);
 }
 
 void
@@ -1413,32 +1372,20 @@ mapnotify(struct wl_listener *listener, void *data)
 	/* Called when the surface is mapped, or ready to display on-screen. */
 	Client *c = wl_container_of(listener, c, map), *oldfocus = selclient();
 
-#ifdef XWAYLAND
-	if (c->type == X11Unmanaged) {
+	if (client_is_unmanaged(c)) {
 		/* Insert this independent into independents lists. */
 		wl_list_insert(&independents, &c->link);
 		return;
 	}
-#endif
 
 	/* Insert this client into client lists. */
 	wl_list_insert(&clients, &c->link);
 	wl_list_insert(&fstack, &c->flink);
 	wl_list_insert(&stack, &c->slink);
 
-#ifdef XWAYLAND
-	if (c->type != XDGShell) {
-		c->geom.x = c->surface.xwayland->x;
-		c->geom.y = c->surface.xwayland->y;
-		c->geom.width = c->surface.xwayland->width + 2 * c->bw;
-		c->geom.height = c->surface.xwayland->height + 2 * c->bw;
-	} else
-#endif
-	{
-		wlr_xdg_surface_get_geometry(c->surface.xdg, &c->geom);
-		c->geom.width += 2 * c->bw;
-		c->geom.height += 2 * c->bw;
-	}
+	client_get_geometry(c, &c->geom);
+	c->geom.width += 2 * c->bw;
+	c->geom.height += 2 * c->bw;
 
 	/* Set initial monitor, tags, floating status, and focus */
 	applyrules(c);
@@ -1527,16 +1474,8 @@ motionnotify(uint32_t time)
 	}
 #endif
 	else if ((c = xytoclient(cursor->x, cursor->y))) {
-#ifdef XWAYLAND
-		if (c->type != XDGShell)
-			surface = wlr_surface_surface_at(c->surface.xwayland->surface,
-					cursor->x - c->geom.x - c->bw,
-					cursor->y - c->geom.y - c->bw, &sx, &sy);
-		else
-#endif
-			surface = wlr_xdg_surface_surface_at(c->surface.xdg,
-					cursor->x - c->geom.x - c->bw,
-					cursor->y - c->geom.y - c->bw, &sx, &sy);
+		surface = client_surface_at(c, cursor->x - c->geom.x - c->bw,
+				cursor->y - c->geom.y - c->bw, &sx, &sy);
 	}
 	else if ((surface = xytolayersurface(&selmon->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
 					cursor->x, cursor->y, &sx, &sy)))
@@ -1672,7 +1611,7 @@ pointerfocus(Client *c, struct wlr_surface *surface, double sx, double sy,
 
 	/* Use top level surface if nothing more specific given */
 	if (c && !surface)
-		surface = WLR_SURFACE(c);
+		surface = client_surface(c);
 
 	/* If surface is NULL, clear pointer focus */
 	if (!surface) {
@@ -1695,14 +1634,9 @@ pointerfocus(Client *c, struct wlr_surface *surface, double sx, double sy,
 	 * of its surfaces, and make keyboard focus follow if desired. */
 	wlr_seat_pointer_notify_enter(seat, surface, sx, sy);
 
-	if (!c)
+	if (!c || client_is_unmanaged(c))
 		return;
 
-#if XWAYLAND
-	if (c->type == X11Unmanaged)
-		return;
-#endif
-
 	if (sloppyfocus && !internal_call)
 		focusclient(c, 0);
 }
@@ -1789,7 +1723,7 @@ renderclients(Monitor *m, struct timespec *now)
 					output_layout, m->wlr_output, &c->geom))
 			continue;
 
-		surface = WLR_SURFACE(c);
+		surface = client_surface(c);
 		ox = c->geom.x, oy = c->geom.y;
 		wlr_output_layout_output_coords(output_layout, m->wlr_output,
 				&ox, &oy);
@@ -1819,12 +1753,7 @@ renderclients(Monitor *m, struct timespec *now)
 		rdata.when = now;
 		rdata.x = c->geom.x + c->bw;
 		rdata.y = c->geom.y + c->bw;
-#ifdef XWAYLAND
-		if (c->type != XDGShell)
-			wlr_surface_for_each_surface(c->surface.xwayland->surface, render, &rdata);
-		else
-#endif
-			wlr_xdg_surface_for_each_surface(c->surface.xdg, render, &rdata);
+		client_for_each_surface(c, render, &rdata);
 	}
 }
 
@@ -1861,7 +1790,7 @@ rendermon(struct wl_listener *listener, void *data)
 	/* Do not render if any XDG clients have an outstanding resize. */
 	wl_list_for_each(c, &stack, slink) {
 		if (c->resize) {
-			wlr_surface_send_frame_done(WLR_SURFACE(c), &now);
+			wlr_surface_send_frame_done(client_surface(c), &now);
 			render = 0;
 		}
 	}
@@ -1915,15 +1844,8 @@ resize(Client *c, int x, int y, int w, int h, int interact)
 	c->geom.height = h;
 	applybounds(c, bbox);
 	/* wlroots makes this a no-op if size hasn't changed */
-#ifdef XWAYLAND
-	if (c->type != XDGShell)
-		wlr_xwayland_surface_configure(c->surface.xwayland,
-				c->geom.x, c->geom.y,
-				c->geom.width - 2 * c->bw, c->geom.height - 2 * c->bw);
-	else
-#endif
-		c->resize = wlr_xdg_toplevel_set_size(c->surface.xdg,
-				c->geom.width - 2 * c->bw, c->geom.height - 2 * c->bw);
+	c->resize = client_set_size(c, c->geom.width - 2 * c->bw,
+			c->geom.height - 2 * c->bw);
 }
 
 void
@@ -2059,13 +1981,13 @@ setmon(Client *c, Monitor *m, unsigned int newtags)
 
 	/* TODO leave/enter is not optimal but works */
 	if (oldmon) {
-		wlr_surface_send_leave(WLR_SURFACE(c), oldmon->wlr_output);
+		wlr_surface_send_leave(client_surface(c), oldmon->wlr_output);
 		arrange(oldmon);
 	}
 	if (m) {
 		/* Make sure window actually overlaps with the monitor */
 		applybounds(c, &m->m);
-		wlr_surface_send_enter(WLR_SURFACE(c), m->wlr_output);
+		wlr_surface_send_enter(client_surface(c), m->wlr_output);
 		c->tags = newtags ? newtags : m->tagset[m->seltags]; /* assign tags of target monitor */
 		arrange(m);
 	}
@@ -2389,10 +2311,9 @@ unmapnotify(struct wl_listener *listener, void *data)
 	/* Called when the surface is unmapped, and should no longer be shown. */
 	Client *c = wl_container_of(listener, c, unmap);
 	wl_list_remove(&c->link);
-#ifdef XWAYLAND
-	if (c->type == X11Unmanaged)
+	if (client_is_unmanaged(c))
 		return;
-#endif
+
 	setmon(c, NULL, 0);
 	wl_list_remove(&c->flink);
 	wl_list_remove(&c->slink);
@@ -2608,17 +2529,6 @@ renderindependents(struct wlr_output *output, struct timespec *now)
 }
 
 void
-updatewindowtype(Client *c)
-{
-	for (size_t i = 0; i < c->surface.xwayland->window_type_len; i++)
-		if (c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeDialog] ||
-				c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeSplash] ||
-				c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeToolbar] ||
-				c->surface.xwayland->window_type[i] == netatom[NetWMWindowTypeUtility])
-			c->isfloating = 1;
-}
-
-void
 xwaylandready(struct wl_listener *listener, void *data)
 {
 	struct wlr_xcursor *xcursor;