1 files changed, 50 insertions, 0 deletions
diff --git a/components/keyboard_indicators.c b/components/keyboard_indicators.c
new file mode 100755
index 0000000..5f62bb7
--- /dev/null
+++ b/components/keyboard_indicators.c
@@ -0,0 +1,50 @@
+/* See LICENSE file for copyright and license details. */
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <X11/Xlib.h>
+
+#include "../slstatus.h"
+#include "../util.h"
+
+/*
+ * fmt consists of uppercase or lowercase 'c' for caps lock and/or 'n' for num
+ * lock, each optionally followed by '?', in the order of indicators desired.
+ * If followed by '?', the letter with case preserved is included in the output
+ * if the corresponding indicator is on.  Otherwise, the letter is always
+ * included, lowercase when off and uppercase when on.
+ */
+const char *
+keyboard_indicators(const char *fmt)
+{
+	Display *dpy;
+	XKeyboardState state;
+	size_t fmtlen, i, n;
+	int togglecase, isset;
+	char key;
+
+	if (!(dpy = XOpenDisplay(NULL))) {
+		warn("XOpenDisplay: Failed to open display");
+		return NULL;
+	}
+	XGetKeyboardControl(dpy, &state);
+	XCloseDisplay(dpy);
+
+	fmtlen = strnlen(fmt, 4);
+	for (i = n = 0; i < fmtlen; i++) {
+		key = tolower(fmt[i]);
+		if (key != 'c' && key != 'n')
+			continue;
+
+		togglecase = (i + 1 >= fmtlen || fmt[i + 1] != '?');
+		isset = (state.led_mask & (1 << (key == 'n')));
+
+		if (togglecase)
+			buf[n++] = isset ? toupper(key) : key;
+		else if (isset)
+			buf[n++] = fmt[i];
+	}
+
+	buf[n] = 0;
+	return buf;
+}