git.scottworley.com Git - batteryviewer/blob - batteryviewer.c

   1 // For vasprintf
   2 #define _GNU_SOURCE
   3
   4 #include "chart.h"
   5 #include <ctype.h>
   6 #include <errno.h>
   7 #include <glob.h>
   8 #include <gtk/gtk.h>
   9 #include <math.h>
  10 #include <stdarg.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14
  15 char *sasprintf(const char *fmt, ...) {
  16   char *result;
  17   va_list args;
  18   va_start(args, fmt);
  19   if (vasprintf(&result, fmt, args) == -1) {
  20     fprintf(stderr, "Can't allocate memory!?\n");
  21     abort();
  22   }
  23   va_end(args);
  24   return result;
  25 }
  26
  27 struct State {
  28   char *voltage_filename;
  29   char *current_filename;
  30   BVChart *voltage;
  31   BVChart *current;
  32 };
  33
  34 static float fatof(const char *filename) {
  35   FILE *f = fopen(filename, "r");
  36   if (f == NULL) {
  37     return NAN;
  38   }
  39
  40   const int bufsize = 1024;
  41   char buf[bufsize];
  42   const int read = fread(buf, sizeof(char), bufsize, f);
  43   if (read == 0 || read == bufsize || ferror(f)) {
  44     fclose(f);
  45     return NAN;
  46   }
  47   fclose(f);
  48
  49   char *end;
  50   errno = 0;
  51   float val = strtof(buf, &end);
  52   int parsed = end - buf;
  53   gboolean parsed_all = parsed == read;
  54   gboolean parsed_all_but_space = parsed == read - 1 && isspace(*end);
  55   gboolean parse_ok = parsed_all || parsed_all_but_space;
  56   if (errno != 0 || parsed == 0 || !parse_ok) {
  57     return NAN;
  58   }
  59   return val;
  60 }
  61
  62 static gboolean collect_data(struct State *state) {
  63   float now = g_get_monotonic_time() / 1e6;
  64   fprintf(stderr, "%f: Voltage: %f, current: %f\n", now,
  65           fatof(state->voltage_filename), fatof(state->current_filename));
  66   return TRUE;
  67 }
  68
  69 static void activate(GtkApplication *app, gpointer user_data) {
  70
  71   GtkWidget *window = gtk_application_window_new(app);
  72   gtk_window_set_title(GTK_WINDOW(window), "BatteryViewer");
  73   gtk_window_set_default_size(GTK_WINDOW(window), 200, 200);
  74
  75   GtkWidget *box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 1);
  76   gtk_container_add(GTK_CONTAINER(window), box);
  77
  78   struct State *state = (struct State *)user_data;
  79   state->voltage = BV_CHART(bv_chart_new());
  80   bv_chart_add_point(state->voltage, 0.0, 0.0);
  81   bv_chart_add_point(state->voltage, 1.0, 1.0);
  82   bv_chart_add_point(state->voltage, 3.0, 2.0);
  83   gboolean expand = TRUE;
  84   gboolean fill = TRUE;
  85   guint padding = 0;
  86   gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(state->voltage), expand, fill,
  87                      padding);
  88
  89   state->current = BV_CHART(bv_chart_new());
  90   bv_chart_add_point(state->current, 0.0, 1.0);
  91   bv_chart_add_point(state->current, 1.0, 0.0);
  92   gtk_box_pack_end(GTK_BOX(box), GTK_WIDGET(state->current), expand, fill,
  93                    padding);
  94
  95   gtk_widget_show_all(window);
  96
  97   g_timeout_add_seconds(1, (GSourceFunc)collect_data, user_data);
  98 }
  99
 100 char *find_battery_dir() {
 101   glob_t globbuf = {.gl_offs = 0};
 102   char pattern[] = "/sys/class/power_supply/*[Bb][Aa][Tt]*";
 103   if (glob(pattern, GLOB_ERR, NULL, &globbuf) != 0 || globbuf.gl_pathc == 0) {
 104     fprintf(stderr, "Could not find battery dir %s\n", pattern);
 105     exit(1);
 106   }
 107   if (globbuf.gl_pathc != 1) {
 108     // TODO: Filter for directories that have {voltage,current}_now files.
 109     // TODO: Support multiple batteries
 110     fprintf(stderr, "Multiple batteries found. Arbitrarily choosing %s\n",
 111             globbuf.gl_pathv[0]);
 112   }
 113   char *dir = strdup(globbuf.gl_pathv[0]);
 114   globfree(&globbuf);
 115   return dir;
 116 }
 117
 118 int main(int argc, char **argv) {
 119   char *battery_dir = find_battery_dir();
 120   struct State state = {
 121       .voltage_filename = sasprintf("%s/voltage_now", battery_dir),
 122       .current_filename = sasprintf("%s/current_now", battery_dir),
 123   };
 124
 125   GtkApplication *app = gtk_application_new("com.scottworley.batteryviewer",
 126                                             G_APPLICATION_DEFAULT_FLAGS);
 127   g_signal_connect(app, "activate", G_CALLBACK(activate), &state);
 128   int status = g_application_run(G_APPLICATION(app), argc, argv);
 129   g_object_unref(app);
 130
 131   return status;
 132 }