bsps.c

   1 #define _BSD_SOURCE
   2
   3 #include <fcntl.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <signal.h>
  11 #include <xcb/xcb.h>
  12 #include <xcb/xcb_event.h>
  13 #include <xcb/xcb_icccm.h>
  14 #include <xcb/xcb_ewmh.h>
  15 #include <cairo/cairo.h>
  16 #include "bsps.h"
  17
  18 #define MAX(A, B)         ((A) > (B) ? (A) : (B))
  19
  20 #define FIFO_PATH  "BSPWM_FIFO"
  21 #define NO_VALUE   " "
  22 #define NAME_SEP   "\0"
  23 #define FONT_FAMILY "sans-serif"
  24 #define FONT_SIZE   11
  25 #define HORIZONTAL_PADDING  9
  26
  27 typedef enum {
  28     false,
  29     true
  30 } bool;
  31
  32 char *desktop_name;
  33 char *window_title;
  34 char *font_family ;
  35 int font_size = FONT_SIZE;
  36 char external_infos[BUFSIZ] = NO_VALUE;
  37 xcb_window_t curwin;
  38
  39 char *fifo_path;
  40 int fifo_fd, dpy_fd, sel_fd;
  41
  42 xcb_connection_t *dpy;
  43 xcb_ewmh_connection_t ewmh;
  44 xcb_screen_t *screen;
  45 int default_screen;
  46
  47 uint16_t screen_width;
  48 unsigned int horizontal_padding = HORIZONTAL_PADDING;
  49
  50
  51 bool running;
  52
  53 double text_width(char *s)
  54 {
  55     int w;
  56     cairo_surface_t *surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, 1, 1);
  57     cairo_t *cr = cairo_create(surface);
  58     cairo_text_extents_t te;
  59     cairo_select_font_face(cr, font_family, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
  60     cairo_set_font_size(cr, font_size);
  61     cairo_text_extents(cr, s, &te);
  62     w = te.x_advance;
  63     cairo_destroy(cr);
  64     cairo_surface_destroy(surface);
  65     /* fprintf(stderr, "%s\n", cairo_status_to_string(cairo_status(cr))); */
  66     return w;
  67 }
  68
  69 void handle_signal(int sig)
  70 {
  71     if (sig == SIGTERM || sig == SIGINT || sig == SIGHUP)
  72         running = false;
  73 }
  74
  75 void update_window_title(void)
  76 {
  77     xcb_window_t win;
  78     xcb_ewmh_get_utf8_strings_reply_t ewmh_txt_prop;
  79     xcb_icccm_get_text_property_reply_t icccm_txt_prop;
  80     uint32_t values[] = {XCB_EVENT_MASK_PROPERTY_CHANGE};
  81     uint32_t values_reset[] = {XCB_EVENT_MASK_NO_EVENT};
  82
  83     free(window_title);
  84     ewmh_txt_prop.strings = NULL;
  85     icccm_txt_prop.name = NULL;
  86
  87     if (xcb_ewmh_get_active_window_reply(&ewmh, xcb_ewmh_get_active_window(&ewmh, default_screen), &win, NULL) == 1
  88             && (xcb_ewmh_get_wm_name_reply(&ewmh, xcb_ewmh_get_wm_name(&ewmh, win), &ewmh_txt_prop, NULL) == 1
  89                 || xcb_icccm_get_wm_name_reply(dpy, xcb_icccm_get_wm_name(dpy, win), &icccm_txt_prop, NULL) == 1)) {
  90         if (ewmh_txt_prop.strings != NULL)
  91             window_title = strdup(ewmh_txt_prop.strings);
  92         else if (icccm_txt_prop.name != NULL)
  93             window_title = strdup(icccm_txt_prop.name);
  94         else
  95             window_title = strdup(NO_VALUE);
  96         if (win != curwin) {
  97             xcb_change_window_attributes(dpy, curwin, XCB_CW_EVENT_MASK, values_reset);
  98             curwin = win;
  99         }
 100         xcb_generic_error_t *err = xcb_request_check(dpy, xcb_change_window_attributes_checked(dpy, win, XCB_CW_EVENT_MASK, values));
 101         if (err != NULL)
 102             running = false;
 103     } else {
 104         window_title = strdup(NO_VALUE);
 105     }
 106 }
 107
 108 void update_desktop_name(void)
 109 {
 110     uint32_t cd;
 111     xcb_ewmh_get_utf8_strings_reply_t names;
 112     unsigned int pos = 0, cnt = 0;
 113
 114     free(desktop_name);
 115
 116     if (xcb_ewmh_get_current_desktop_reply(&ewmh, xcb_ewmh_get_current_desktop(&ewmh, default_screen), &cd, NULL) == 1  && xcb_ewmh_get_desktop_names_reply(&ewmh, xcb_ewmh_get_desktop_names(&ewmh, default_screen), &names, NULL) == 1) {
 117         while (cnt < cd && pos < names.strings_len) {
 118             pos += strlen(names.strings + pos) + 1;
 119             cnt++;
 120         }
 121         desktop_name = strdup(names.strings + pos);
 122     } else {
 123         desktop_name = strdup(NO_VALUE);
 124     }
 125 }
 126
 127 void output_infos(void)
 128 {
 129     double left_width = text_width(desktop_name);
 130     double center_width = text_width(window_title);
 131     double right_width = text_width(external_infos);
 132     double available_center = screen_width - (left_width + right_width + 4 * horizontal_padding);
 133
 134     int left_pos = horizontal_padding;
 135     int center_pos = left_width + 2 * horizontal_padding + (available_center / 2) - (center_width / 2);
 136     int right_pos = screen_width - right_width - horizontal_padding;
 137
 138     printf("^pa(%i)%s^pa(%i)%s^pa(%i)%s\n", left_pos, desktop_name, center_pos, window_title, right_pos, external_infos);
 139     fflush(stdout);
 140 }
 141
 142 void handle_event(xcb_generic_event_t *evt)
 143 {
 144     xcb_property_notify_event_t *pne;
 145     switch (XCB_EVENT_RESPONSE_TYPE(evt)) {
 146         case XCB_PROPERTY_NOTIFY:
 147             pne = (xcb_property_notify_event_t *) evt;
 148             if (pne->atom == ewmh._NET_CURRENT_DESKTOP || pne->atom == ewmh._NET_DESKTOP_NAMES) {
 149                 update_desktop_name();
 150                 output_infos();
 151             } else if (pne->atom == ewmh._NET_ACTIVE_WINDOW) {
 152                 update_window_title();
 153                 output_infos();
 154             } else if (pne->window != screen->root && (pne->atom == ewmh._NET_WM_NAME || pne->atom == XCB_ATOM_WM_NAME)) {
 155                 update_window_title();
 156                 output_infos();
 157             }
 158         default:
 159             break;
 160     }
 161 }
 162
 163 void register_events(void)
 164 {
 165     xcb_generic_error_t *err;
 166     uint32_t values[] = {XCB_EVENT_MASK_PROPERTY_CHANGE};
 167     err = xcb_request_check(dpy, xcb_change_window_attributes_checked(dpy, screen->root, XCB_CW_EVENT_MASK, values));
 168     if (err != NULL)
 169         running = false;
 170 }
 171
 172 void setup(void)
 173 {
 174     dpy = xcb_connect(NULL, &default_screen);
 175     xcb_intern_atom_cookie_t *ewmh_cookies;
 176     ewmh_cookies = xcb_ewmh_init_atoms(dpy, &ewmh);
 177     xcb_ewmh_init_atoms_replies(&ewmh, ewmh_cookies, NULL);
 178     screen = ewmh.screens[default_screen];
 179     screen_width = screen->width_in_pixels;
 180     fifo_path = getenv(FIFO_PATH);
 181     mkfifo(fifo_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 182     /* http://www.outflux.net/blog/archives/2008/03/09/using-select-on-a-fifo/ */
 183     fifo_fd = open(fifo_path, O_RDWR | O_NONBLOCK);
 184     dpy_fd = xcb_get_file_descriptor(dpy);
 185     sel_fd = MAX(fifo_fd, dpy_fd) + 1;
 186     desktop_name = strdup(NO_VALUE);
 187     window_title = strdup(NO_VALUE);
 188     font_family = strdup(FONT_FAMILY);
 189     curwin = 0;
 190     running = true;
 191 }
 192
 193 int main(int argc, char *argv[])
 194 {
 195     fd_set descriptors;
 196     xcb_generic_event_t *evt;
 197     signal(SIGTERM, handle_signal);
 198     signal(SIGINT, handle_signal);
 199     signal(SIGHUP, handle_signal);
 200     setup();
 201     register_events();
 202     update_desktop_name();
 203     update_window_title();
 204
 205     if (argc > 1) {
 206         free(font_family);
 207         font_family = strdup(argv[1]);
 208         if (argc > 2) {
 209             font_size = atoi(argv[2]);
 210             if (argc > 3)
 211                 horizontal_padding = atoi(argv[3]);
 212         }
 213     }
 214
 215     output_infos();
 216     xcb_flush(dpy);
 217
 218     while (running) {
 219         FD_ZERO(&descriptors);
 220         FD_SET(fifo_fd, &descriptors);
 221         FD_SET(dpy_fd, &descriptors);
 222
 223         if (select(sel_fd, &descriptors, NULL, NULL, NULL)) {
 224             if (FD_ISSET(dpy_fd, &descriptors)) {
 225                 while ((evt = xcb_poll_for_event(dpy)) != NULL) {
 226                     handle_event(evt);
 227                     free(evt);
 228                 }
 229             }
 230
 231             if (FD_ISSET(fifo_fd, &descriptors)) {
 232                 int bytes = read(fifo_fd, external_infos, sizeof(external_infos));
 233                 if (bytes > 0) {
 234                     external_infos[bytes] = '\0';
 235                     output_infos();
 236                 }
 237             }
 238         }
 239     }
 240
 241     close(fifo_fd);
 242     xcb_disconnect(dpy);
 243     return 0;
 244 }