components/keyboard_indicators.c
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/* See LICENSE file for copyright and license details. */
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.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;
}