Initial commit

2 files changed, 62 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..e399d2a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,2 @@
+clockoverlay: clockoverlay.c
+	cc clockoverlay.c -o clockoverlay -lX11
diff --git a/clockoverlay.c b/clockoverlay.c
new file mode 100644
index 0000000..88eadbe
--- /dev/null
+++ b/clockoverlay.c
@@ -0,0 +1,60 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/select.h>
+#include <time.h>
+#include <unistd.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+
+static inline unsigned long _RGB(int r, int g, int b)
+{
+	return b + (g << 8) + (r << 16);
+}
+
+int main(void) {	
+	Display *display = XOpenDisplay(NULL);
+	assert(display);
+
+	int fd = ConnectionNumber(display);
+
+	XVisualInfo vinfo;
+	XMatchVisualInfo(display, DefaultScreen(display), 32, TrueColor, &vinfo);
+
+	XSetWindowAttributes attribs;
+	attribs.colormap = XCreateColormap(display, DefaultRootWindow(display), vinfo.visual, AllocNone);
+	attribs.override_redirect = 1;
+	attribs.border_pixel = 0;
+	attribs.background_pixel = 0;
+
+	Window window = XCreateWindow(display, DefaultRootWindow(display), 10, 10, 24 / 2 * 8, 24, 0,
+		vinfo.depth, InputOutput, vinfo.visual,
+		CWColormap | CWOverrideRedirect | CWBorderPixel | CWBackPixel, &attribs);
+	XMapWindow(display, window);
+
+	Font font = XLoadFont(display, "*x24");
+
+	GC ctx = XCreateGC(display, window, 0, NULL);
+	XSetForeground(display, ctx, _RGB(255, 255, 255));
+	XSetFont(display, ctx, font);
+
+	for (;;) {
+		time_t t = time(NULL);
+		struct tm *tm = localtime(&t);
+
+		char buf[9];
+		strftime(buf, 9, "%H:%M:%S", tm);
+		XClearWindow(display, window);
+		XDrawString(display, window, ctx, 0, 24, buf, 8);
+
+		XEvent event;
+		while (XPending(display))
+			XNextEvent(display, &event);
+
+		fd_set set;
+		FD_ZERO(&set);
+		FD_SET(fd, &set);
+		select(fd + 1, &set, NULL, NULL, &(struct timeval) {1, 0});
+	}
+}