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