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

   1 #include "chart.h"
   2 #include <ctype.h>
   3 #include <errno.h>
   4 #include <gtk/gtk.h>
   5 #include <math.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 const char voltage_filename[] = "/sys/class/power_supply/BAT0/voltage_now";
  10 const char current_filename[] = "/sys/class/power_supply/BAT0/current_now";
  11
  12 struct State {
  13   BVChart *voltage;
  14   BVChart *current;
  15 };
  16
  17 static float fatof(const char *filename) {
  18   FILE *f = fopen(filename, "r");
  19   if (f == NULL) {
  20     return NAN;
  21   }
  22
  23   const int bufsize = 1024;
  24   char buf[bufsize];
  25   const int read = fread(buf, sizeof(char), bufsize, f);
  26   if (read == 0 || read == bufsize || ferror(f)) {
  27     fclose(f);
  28     return NAN;
  29   }
  30   fclose(f);
  31
  32   char *end;
  33   errno = 0;
  34   float val = strtof(buf, &end);
  35   int parsed = end - buf;
  36   gboolean parsed_all = parsed == read;
  37   gboolean parsed_all_but_space = parsed == read - 1 && isspace(*end);
  38   gboolean parse_ok = parsed_all || parsed_all_but_space;
  39   if (errno != 0 || parsed == 0 || !parse_ok) {
  40     return NAN;
  41   }
  42   return val;
  43 }
  44
  45 static gboolean collect_data(struct State *state __attribute__((unused))) {
  46   fprintf(stderr, "Voltage: %f, current: %f\n", fatof(voltage_filename),
  47           fatof(current_filename));
  48   return TRUE;
  49 }
  50
  51 static void activate(GtkApplication *app, gpointer user_data) {
  52
  53   GtkWidget *window = gtk_application_window_new(app);
  54   gtk_window_set_title(GTK_WINDOW(window), "BatteryViewer");
  55   gtk_window_set_default_size(GTK_WINDOW(window), 200, 200);
  56
  57   GtkWidget *box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 1);
  58   gtk_container_add(GTK_CONTAINER(window), box);
  59
  60   struct State *state = (struct State *)user_data;
  61   state->voltage = BV_CHART(bv_chart_new());
  62   bv_chart_add_point(state->voltage, 0.0, 0.0);
  63   bv_chart_add_point(state->voltage, 1.0, 1.0);
  64   bv_chart_add_point(state->voltage, 3.0, 2.0);
  65   gboolean expand = TRUE;
  66   gboolean fill = TRUE;
  67   guint padding = 0;
  68   gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(state->voltage), expand, fill,
  69                      padding);
  70
  71   state->current = BV_CHART(bv_chart_new());
  72   bv_chart_add_point(state->current, 0.0, 1.0);
  73   bv_chart_add_point(state->current, 1.0, 0.0);
  74   gtk_box_pack_end(GTK_BOX(box), GTK_WIDGET(state->current), expand, fill,
  75                    padding);
  76
  77   gtk_widget_show_all(window);
  78
  79   g_timeout_add_seconds(1, (GSourceFunc)collect_data, user_data);
  80 }
  81
  82 int main(int argc, char **argv) {
  83   struct State state;
  84
  85   GtkApplication *app = gtk_application_new("com.scottworley.batteryviewer",
  86                                             G_APPLICATION_DEFAULT_FLAGS);
  87   g_signal_connect(app, "activate", G_CALLBACK(activate), &state);
  88   int status = g_application_run(G_APPLICATION(app), argc, argv);
  89   g_object_unref(app);
  90
  91   return status;
  92 }