X-Git-Url: http://git.scottworley.com/batteryviewer/blobdiff_plain/6f50819eef408d0d7bc691bc1a239e26aae01cf5..HEAD:/batteryviewer.c?ds=sidebyside

diff --git a/batteryviewer.c b/batteryviewer.c
index 65d7009..a0fae4c 100644
--- a/batteryviewer.c
+++ b/batteryviewer.c
@@ -1,12 +1,92 @@
+/* batteryviewer: Display battery metrics
+ * Copyright (C) 2023 Scott Worley <scottworley@scottworley.com>
+
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+// 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 gboolean collect_data(struct State *state __attribute__((unused))) {
+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;
 }
 
@@ -21,9 +101,6 @@ static void activate(GtkApplication *app, gpointer user_data) {
 
   struct State *state = (struct State *)user_data;
   state->voltage = BV_CHART(bv_chart_new());
-  bv_chart_add_point(state->voltage, 0.0, 0.0);
-  bv_chart_add_point(state->voltage, 1.0, 1.0);
-  bv_chart_add_point(state->voltage, 3.0, 2.0);
   gboolean expand = TRUE;
   gboolean fill = TRUE;
   guint padding = 0;
@@ -31,8 +108,6 @@ static void activate(GtkApplication *app, gpointer user_data) {
                      padding);
 
   state->current = BV_CHART(bv_chart_new());
-  bv_chart_add_point(state->current, 0.0, 1.0);
-  bv_chart_add_point(state->current, 1.0, 0.0);
   gtk_box_pack_end(GTK_BOX(box), GTK_WIDGET(state->current), expand, fill,
                    padding);
 
@@ -41,11 +116,36 @@ static void activate(GtkApplication *app, gpointer user_data) {
   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) {
-  struct State state;
+  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("com.scottworley.batteryviewer",
-                                            G_APPLICATION_DEFAULT_FLAGS);
+  GtkApplication *app = gtk_application_new(
+      "com.scottworley.batteryviewer",
+      // G_APPLICATION_FLAGS_NONE is deprecated, but
+      // G_APPLICATION_DEFAULT_FLAGS isn't available on Stable Debian yet.
+      G_APPLICATION_FLAGS_NONE);
   g_signal_connect(app, "activate", G_CALLBACK(activate), &state);
   int status = g_application_run(G_APPLICATION(app), argc, argv);
   g_object_unref(app);