3 files changed, 101 insertions, 2 deletions
diff --git a/xmonad/.gitignore b/xmonad/.gitignore
index 48adae9..4e800a7 100644
--- a/xmonad/.gitignore
+++ b/xmonad/.gitignore
@@ -1 +1,2 @@
 /xmonad.hs
+/xmonad-autofocus-output
diff --git a/xmonad/Makefile b/xmonad/Makefile
index 4003b95..2265823 100644
--- a/xmonad/Makefile
+++ b/xmonad/Makefile
@@ -3,7 +3,7 @@ include ../common.mk
 
 XINITRC_ORDER = 80
 
-install:
+install: xmonad-autofocus-output
 	$(CHECK_INSTALLED) xwallpaper
 	$(CHECK_INSTALLED) xcman
 	$(CHECK_INSTALLED) pdeath
@@ -18,6 +18,11 @@ install:
 	test ! -d ~/.xmonad/xmonad.hs
 	ln -sf -- ~/.dotfiles/xmonad/xmonad.hs ~/.xmonad/xmonad.hs
 	make xmonad.hs
+	mkdir -p ~/.local/bin
+	ln -sf -- ~/.dotfiles/xmonad/xmonad-autofocus-output ~/.local/bin
+
+xmonad-autofocus-output: xmonad-autofocus-output.c
+	$(CC) -o $@ $@.c -Wall -s -lX11 -lXtst
 
 include xmonad.mk
 
@@ -30,6 +35,6 @@ uninstall:
 	-make clean
 
 clean:
-	-rm -f xmonad.hs
+	-rm -f xmonad.hs xmonad-autofocus-output
 
 .PHONY: install uninstall clean
diff --git a/xmonad/xmonad-autofocus-output.c b/xmonad/xmonad-autofocus-output.c
new file mode 100644
index 0000000..853e18b
--- /dev/null
+++ b/xmonad/xmonad-autofocus-output.c
@@ -0,0 +1,93 @@
+/* -lX11 -lXtst */
+#include <sys/select.h>
+#include <errno.h>
+#include <stdio.h>
+
+#define XK_MISCELLANY
+#define XK_LATIN1
+#include <X11/Xlib.h>
+#include <X11/keysymdef.h>
+#include <X11/extensions/XTest.h>
+
+static Display *disp;
+static KeyCode mod, key[2];
+
+static inline int
+get_output(int x, int y)
+{
+	return x < 1920;
+}
+
+static inline void
+set_output(int output)
+{
+	XTestFakeKeyEvent(disp, mod, 1, 0);
+	XTestFakeKeyEvent(disp, key[output], 1, 0);
+	XTestFakeKeyEvent(disp, key[output], 0, 0);
+	XTestFakeKeyEvent(disp, mod, 0, 0);
+	XFlush(disp);
+}
+
+int
+main(int argc, char *argv[])
+{
+	int fd, scrn;
+	Window root;
+	fd_set fds;
+	XEvent ev;
+	int output, prev_output = -1;
+
+	XSetLocaleModifiers("");
+	if (!(disp = XOpenDisplay(NULL))) {
+		fprintf(stderr, "%s: cannot open display\n", *argv);
+		return 1;
+	}
+
+	fd = XConnectionNumber(disp);
+	scrn = XDefaultScreen(disp);
+	root = XRootWindow(disp, scrn);
+	XSelectInput(disp, root, PointerMotionMask | EnterWindowMask);
+	XSync(disp, False);
+
+	mod = XKeysymToKeycode(disp, XK_Super_L);
+	key[0] = XKeysymToKeycode(disp, XK_W);
+	key[1] = XKeysymToKeycode(disp, XK_E);
+
+	for (;;) {
+		FD_ZERO(&fds);
+		FD_SET(fd, &fds);
+
+		if (select(fd + 1, &fds, NULL, NULL, NULL) < 0) {
+			if (errno == EINTR)
+				continue;
+			perror(*argv);
+			return 1;
+		}
+
+		if (!FD_ISSET(fd, &fds))
+			continue;
+
+		while (XPending(disp)) {
+			XNextEvent(disp, &ev);
+			if (XFilterEvent(&ev, None))
+				continue;
+			switch (ev.type) {
+			case MotionNotify:
+				output = get_output(ev.xmotion.x_root, ev.xmotion.y_root);
+				if (output == prev_output)
+					continue;
+				prev_output = output;
+				set_output(output);
+				break;
+			case EnterNotify:
+				prev_output = -1;
+				break;
+			default:
+				break;
+			}
+		}
+	}
+
+	return 0;
+	(void) argc;
+}