log: add initial logging capabilities

src/Makefile.am

@@ -56,6 +56,8 @@ gnome_calendar_SOURCES =                                  \
     gcal-event.h                                          \
     gcal-event-widget.c                                   \
     gcal-event-widget.h                                   \
+    gcal-log.c                                            \
+    gcal-log.h                                            \
     gcal-manager.c                                        \
     gcal-manager.h                                        \
     gcal-multi-choice.c                                   \

src/gcal-log.c

@@ -0,0 +1,96 @@
+/* gcal-log.c
+ *
+ * Copyright (C) 2017 Georges Basile Stavracas Neto <georges.stavracas@gmail.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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "gcal-log.h"
+
+#include <unistd.h>
+#include <glib.h>
+
+G_LOCK_DEFINE_STATIC (channel_lock);
+
+GIOChannel *standard_channel = NULL;
+
+static const gchar *
+log_level_str (GLogLevelFlags log_level)
+{
+  switch (((gulong)log_level & G_LOG_LEVEL_MASK))
+    {
+    case G_LOG_LEVEL_ERROR:    return "   \033[1;31mERROR\033[0m";
+    case G_LOG_LEVEL_CRITICAL: return "\033[1;35mCRITICAL\033[0m";
+    case G_LOG_LEVEL_WARNING:  return " \033[1;33mWARNING\033[0m";
+    case G_LOG_LEVEL_MESSAGE:  return " \033[1;34mMESSAGE\033[0m";
+    case G_LOG_LEVEL_INFO:     return "    \033[1;32mINFO\033[0m";
+    case G_LOG_LEVEL_DEBUG:    return "   \033[1;32mDEBUG\033[0m";
+
+    default:
+      return " UNKNOWN";
+    }
+}
+
+static void
+gcal_log_handler (const gchar    *domain,
+                  GLogLevelFlags  log_level,
+                  const gchar    *message,
+                  gpointer        user_data)
+{
+  GTimeVal tv;
+  struct tm tt;
+  time_t t;
+  const gchar *level;
+  gchar ftime[32];
+  gchar *buffer;
+
+  level = log_level_str (log_level);
+  g_get_current_time (&tv);
+  t = (time_t) tv.tv_sec;
+  tt = *localtime (&t);
+  strftime (ftime, sizeof (ftime), "%H:%M:%S", &tt);
+  buffer = g_strdup_printf ("%s.%04ld  %24s: %s: %s\n",
+                            ftime,
+                            tv.tv_usec / 1000,
+                            domain,
+                            level,
+                            message);
+
+  /* Safely write to the channel */
+  G_LOCK (channel_lock);
+
+  g_io_channel_write_chars (standard_channel, buffer, -1, NULL, NULL);
+  g_io_channel_flush (standard_channel, NULL);
+
+  G_UNLOCK (channel_lock);
+
+  g_free (buffer);
+}
+
+void
+gcal_log_init (void)
+{
+  static gsize initialized = FALSE;
+
+  if (g_once_init_enter (&initialized))
+    {
+      standard_channel = g_io_channel_unix_new (STDOUT_FILENO);
+
+      g_log_set_default_handler (gcal_log_handler, NULL);
+
+      g_once_init_leave (&initialized, TRUE);
+    }
+}
+

src/gcal-log.h

@@ -0,0 +1,30 @@
+/* gcal-log.h
+ *
+ * Copyright (C) 2017 Georges Basile Stavracas Neto <georges.stavracas@gmail.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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GCAL_LOG_H
+#define GCAL_LOG_H
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+void                 gcal_log_init                               (void);
+
+G_END_DECLS
+
+#endif /* GCAL_LOG_H */

src/main.c

@@ -20,7 +20,7 @@
 #include <config.h>
 #include <gtk/gtk.h>
 #include "gcal-application.h"
-
+#include "gcal-log.h"
 
 #include <glib/gi18n.h>
 
@@ -32,6 +32,7 @@ main (int   argc,
   GcalApplication *app;
   int status;
 
+  gcal_log_init ();
 
 #ifdef ENABLE_NLS
   bindtextdomain (GETTEXT_PACKAGE, PACKAGE_LOCALE_DIR);
@@ -44,4 +45,4 @@ main (int   argc,
   g_object_unref (app);
 
   return status;
-}
+}