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 <gtk/gtk.h>
   8 #include <math.h>
   9 #include <stdarg.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12
  13 char *sasprintf(const char *fmt, ...) {
  14   char *result;
  15   va_list args;
  16   va_start(args, fmt);
  17   if (vasprintf(&result, fmt, args) == -1) {
  18     fprintf(stderr, "Can't allocate memory!?\n");
  19     abort();
  20   }
  21   va_end(args);
  22   return result;
  23 }
  24
  25 struct State {
  26   char *voltage_filename;
  27   char *current_filename;
  28   BVChart *voltage;
  29   BVChart *current;
  30 };
  31
  32 static float fatof(const char *filename) {
  33   FILE *f = fopen(filename, "r");
  34   if (f == NULL) {
  35     return NAN;
  36   }
  37
  38   const int bufsize = 1024;
  39   char buf[bufsize];
  40   const int read = fread(buf, sizeof(char), bufsize, f);
  41   if (read == 0 || read == bufsize || ferror(f)) {
  42     fclose(f);
  43     return NAN;
  44   }
  45   fclose(f);
  46
  47   char *end;
  48   errno = 0;
  49   float val = strtof(buf, &end);
  50   int parsed = end - buf;
  51   gboolean parsed_all = parsed == read;
  52   gboolean parsed_all_but_space = parsed == read - 1 && isspace(*end);
  53   gboolean parse_ok = parsed_all || parsed_all_but_space;
  54   if (errno != 0 || parsed == 0 || !parse_ok) {
  55     return NAN;
  56   }
  57   return val;
  58 }
  59
  60 static gboolean collect_data(struct State *state) {
  61   fprintf(stderr, "Voltage: %f, current: %f\n", fatof(state->voltage_filename),
  62           fatof(state->current_filename));
  63   return TRUE;
  64 }
  65
  66 static void activate(GtkApplication *app, gpointer user_data) {
  67
  68   GtkWidget *window = gtk_application_window_new(app);
  69   gtk_window_set_title(GTK_WINDOW(window), "BatteryViewer");
  70   gtk_window_set_default_size(GTK_WINDOW(window), 200, 200);
  71
  72   GtkWidget *box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 1);
  73   gtk_container_add(GTK_CONTAINER(window), box);
  74
  75   struct State *state = (struct State *)user_data;
  76   state->voltage = BV_CHART(bv_chart_new());
  77   bv_chart_add_point(state->voltage, 0.0, 0.0);
  78   bv_chart_add_point(state->voltage, 1.0, 1.0);
  79   bv_chart_add_point(state->voltage, 3.0, 2.0);
  80   gboolean expand = TRUE;
  81   gboolean fill = TRUE;
  82   guint padding = 0;
  83   gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(state->voltage), expand, fill,
  84                      padding);
  85
  86   state->current = BV_CHART(bv_chart_new());
  87   bv_chart_add_point(state->current, 0.0, 1.0);
  88   bv_chart_add_point(state->current, 1.0, 0.0);
  89   gtk_box_pack_end(GTK_BOX(box), GTK_WIDGET(state->current), expand, fill,
  90                    padding);
  91
  92   gtk_widget_show_all(window);
  93
  94   g_timeout_add_seconds(1, (GSourceFunc)collect_data, user_data);
  95 }
  96
  97 int main(int argc, char **argv) {
  98   char *battery_dir = "/sys/class/power_supply/BAT0";
  99   struct State state = {
 100       .voltage_filename = sasprintf("%s/voltage_now", battery_dir),
 101       .current_filename = sasprintf("%s/current_now", battery_dir),
 102   };
 103
 104   GtkApplication *app = gtk_application_new("com.scottworley.batteryviewer",
 105                                             G_APPLICATION_DEFAULT_FLAGS);
 106   g_signal_connect(app, "activate", G_CALLBACK(activate), &state);
 107   int status = g_application_run(G_APPLICATION(app), argc, argv);
 108   g_object_unref(app);
 109
 110   return status;
 111 }