Drop NaNs

[batteryviewer] / batteryviewer.c

diff --git a/batteryviewer.c b/batteryviewer.c
index abc510691971f55cbc670229ea22af54e3aed714..798cddc7facf522253f042b8aacc6fc7140aa914 100644 (file)
--- a/batteryviewer.c
+++ b/batteryviewer.c
@@ -1,27 +1,133 @@
+// For vasprintf
+#define _GNU_SOURCE
+
 #include "chart.h"
+#include <ctype.h>
+#include <errno.h>
+#include <glob.h>
 #include <gtk/gtk.h>
+#include <math.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char *sasprintf(const char *fmt, ...) {
+  char *result;
+  va_list args;
+  va_start(args, fmt);
+  if (vasprintf(&result, fmt, args) == -1) {
+    fprintf(stderr, "Can't allocate memory!?\n");
+    abort();
+  }
+  va_end(args);
+  return result;
+}
+
+struct State {
+  char *voltage_filename;
+  char *current_filename;
+  BVChart *voltage;
+  BVChart *current;
+};
+
+static float fatof(const char *filename) {
+  FILE *f = fopen(filename, "r");
+  if (f == NULL) {
+    return NAN;
+  }
+
+  const int bufsize = 1024;
+  char buf[bufsize];
+  const int read = fread(buf, sizeof(char), bufsize, f);
+  if (read == 0 || read == bufsize || ferror(f)) {
+    fclose(f);
+    return NAN;
+  }
+  fclose(f);
+
+  char *end;
+  errno = 0;
+  float val = strtof(buf, &end);
+  int parsed = end - buf;
+  gboolean parsed_all = parsed == read;
+  gboolean parsed_all_but_space = parsed == read - 1 && isspace(*end);
+  gboolean parse_ok = parsed_all || parsed_all_but_space;
+  if (errno != 0 || parsed == 0 || !parse_ok) {
+    return NAN;
+  }
+  return val;
+}
+
+static gboolean collect_data(struct State *state) {
+  float now = g_get_monotonic_time() / 1e6;
+  float voltage = fatof(state->voltage_filename);
+  float current = fatof(state->current_filename);
+  if (!isnan(voltage)) {
+    bv_chart_add_point(state->voltage, now, voltage);
+    gtk_widget_queue_draw(GTK_WIDGET(state->voltage));
+  }
+  if (!isnan(current)) {
+    bv_chart_add_point(state->current, now, current);
+    gtk_widget_queue_draw(GTK_WIDGET(state->current));
+  }
+  return TRUE;
+}
 
-static void activate(GtkApplication *app,
-                     gpointer user_data __attribute__((unused))) {
+static void activate(GtkApplication *app, gpointer user_data) {
 
   GtkWidget *window = gtk_application_window_new(app);
-  gtk_window_set_title(GTK_WINDOW(window), "Window");
+  gtk_window_set_title(GTK_WINDOW(window), "BatteryViewer");
   gtk_window_set_default_size(GTK_WINDOW(window), 200, 200);
 
-  GtkWidget *chart_box = gtk_button_box_new(GTK_ORIENTATION_HORIZONTAL);
-  gtk_container_add(GTK_CONTAINER(window), chart_box);
+  GtkWidget *box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 1);
+  gtk_container_add(GTK_CONTAINER(window), box);
+
+  struct State *state = (struct State *)user_data;
+  state->voltage = BV_CHART(bv_chart_new());
+  gboolean expand = TRUE;
+  gboolean fill = TRUE;
+  guint padding = 0;
+  gtk_box_pack_start(GTK_BOX(box), GTK_WIDGET(state->voltage), expand, fill,
+                     padding);
 
-  GtkWidget *chart = bv_chart_new();
-  gtk_container_add(GTK_CONTAINER(chart_box), chart);
+  state->current = BV_CHART(bv_chart_new());
+  gtk_box_pack_end(GTK_BOX(box), GTK_WIDGET(state->current), expand, fill,
+                   padding);
 
   gtk_widget_show_all(window);
+
+  g_timeout_add_seconds(1, (GSourceFunc)collect_data, user_data);
+}
+
+char *find_battery_dir() {
+  glob_t globbuf = {.gl_offs = 0};
+  char pattern[] = "/sys/class/power_supply/*[Bb][Aa][Tt]*";
+  if (glob(pattern, GLOB_ERR, NULL, &globbuf) != 0 || globbuf.gl_pathc == 0) {
+    fprintf(stderr, "Could not find battery dir %s\n", pattern);
+    exit(1);
+  }
+  if (globbuf.gl_pathc != 1) {
+    // TODO: Filter for directories that have {voltage,current}_now files.
+    // TODO: Support multiple batteries
+    fprintf(stderr, "Multiple batteries found. Arbitrarily choosing %s\n",
+            globbuf.gl_pathv[0]);
+  }
+  char *dir = strdup(globbuf.gl_pathv[0]);
+  globfree(&globbuf);
+  return dir;
 }
 
 int main(int argc, char **argv) {
+  char *battery_dir = find_battery_dir();
+  struct State state = {
+      .voltage_filename = sasprintf("%s/voltage_now", battery_dir),
+      .current_filename = sasprintf("%s/current_now", battery_dir),
+  };
 
-  GtkApplication *app =
-      gtk_application_new("org.gtk.example", G_APPLICATION_DEFAULT_FLAGS);
-  g_signal_connect(app, "activate", G_CALLBACK(activate), NULL);
+  GtkApplication *app = gtk_application_new("com.scottworley.batteryviewer",
+                                            G_APPLICATION_DEFAULT_FLAGS);
+  g_signal_connect(app, "activate", G_CALLBACK(activate), &state);
   int status = g_application_run(G_APPLICATION(app), argc, argv);
   g_object_unref(app);