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+/* Eye Of Mate - EXIF Utilities
+ *
+ * Copyright (C) 2006-2007 The Free Software Foundation
+ *
+ * Author: Lucas Rocha <[email protected]>
+ * Author: Claudio Saavedra <[email protected]>
+ * Author: Felix Riemann <[email protected]>
+ *
+ * Based on code by:
+ * - Jens Finke <[email protected]>
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_STRPTIME
+#define _XOPEN_SOURCE
+#endif
+#include <time.h>
+
+#include "eom-exif-util.h"
+
+#include <string.h>
+#include <glib/gi18n.h>
+
+#define DATE_BUF_SIZE 200
+
+/* gboolean <-> gpointer conversion macros taken from gedit */
+#ifndef GBOOLEAN_TO_POINTER
+#define GBOOLEAN_TO_POINTER(i) (GINT_TO_POINTER ((i) ? 2 : 1))
+#endif
+#ifndef GPOINTER_TO_BOOLEAN
+#define GPOINTER_TO_BOOLEAN(i) ((gboolean) ((GPOINTER_TO_INT (i) == 2) ? TRUE : FALSE))
+#endif
+
+static gpointer
+_check_strptime_updates_wday (gpointer data)
+{
+ struct tm tm;
+
+ memset (&tm, '\0', sizeof (tm));
+ strptime ("2008:12:24 20:30:45", "%Y:%m:%d %T", &tm);
+ /* Check if tm.tm_wday is set to Wednesday (3) now */
+ return GBOOLEAN_TO_POINTER (tm.tm_wday == 3);
+}
+
+/**
+ * _calculate_wday_yday:
+ * @tm: A struct tm that should be updated.
+ *
+ * Ensure tm_wday and tm_yday are set correctly in a struct tm.
+ * The other date (dmy) values must have been set already.
+ **/
+static void
+_calculate_wday_yday (struct tm *tm)
+{
+ GDate *exif_date;
+ struct tm tmp_tm;
+
+ exif_date = g_date_new_dmy (tm->tm_mday,
+ tm->tm_mon+1,
+ tm->tm_year+1900);
+
+ g_return_if_fail (exif_date != NULL && g_date_valid (exif_date));
+
+ // Use this to get GLib <-> libc corrected values
+ g_date_to_struct_tm (exif_date, &tmp_tm);
+ g_date_free (exif_date);
+
+ tm->tm_wday = tmp_tm.tm_wday;
+ tm->tm_yday = tmp_tm.tm_yday;
+}
+
+#ifdef HAVE_STRPTIME
+static gchar *
+eom_exif_util_format_date_with_strptime (const gchar *date)
+{
+ static GOnce strptime_updates_wday = G_ONCE_INIT;
+ gchar *new_date = NULL;
+ gchar tmp_date[DATE_BUF_SIZE];
+ gchar *p;
+ gsize dlen;
+ struct tm tm;
+
+ memset (&tm, '\0', sizeof (tm));
+ p = strptime (date, "%Y:%m:%d %T", &tm);
+
+ if (p == date + strlen (date)) {
+ g_once (&strptime_updates_wday,
+ _check_strptime_updates_wday,
+ NULL);
+
+ // Ensure tm.tm_wday and tm.tm_yday are set
+ if (!GPOINTER_TO_BOOLEAN (strptime_updates_wday.retval))
+ _calculate_wday_yday (&tm);
+
+ /* A strftime-formatted string, to display the date the image was taken. */
+ dlen = strftime (tmp_date, DATE_BUF_SIZE * sizeof(gchar), _("%a, %d %B %Y %X"), &tm);
+ new_date = g_strndup (tmp_date, dlen);
+ }
+
+ return new_date;
+}
+#else
+static gchar *
+eom_exif_util_format_date_by_hand (const gchar *date)
+{
+ int year, month, day, hour, minutes, seconds;
+ int result;
+ gchar *new_date = NULL;
+
+ result = sscanf (date, "%d:%d:%d %d:%d:%d",
+ &year, &month, &day, &hour, &minutes, &seconds);
+
+ if (result < 3 || !g_date_valid_dmy (day, month, year)) {
+ return NULL;
+ } else {
+ gchar tmp_date[DATE_BUF_SIZE];
+ gsize dlen;
+ time_t secs;
+ struct tm tm;
+
+ memset (&tm, '\0', sizeof (tm));
+ tm.tm_mday = day;
+ tm.tm_mon = month-1;
+ tm.tm_year = year-1900;
+ // Calculate tm.tm_wday
+ _calculate_wday_yday (&tm);
+
+ if (result < 5) {
+ /* A strftime-formatted string, to display the date the image was taken, for the case we don't have the time. */
+ dlen = strftime (tmp_date, DATE_BUF_SIZE * sizeof(gchar), _("%a, %d %B %Y"), &tm);
+ } else {
+ tm.tm_sec = result < 6 ? 0 : seconds;
+ tm.tm_min = minutes;
+ tm.tm_hour = hour;
+ /* A strftime-formatted string, to display the date the image was taken. */
+ dlen = strftime (tmp_date, DATE_BUF_SIZE * sizeof(gchar), _("%a, %d %B %Y %X"), &tm);
+ }
+
+ if (dlen == 0)
+ return NULL;
+ else
+ new_date = g_strndup (tmp_date, dlen);
+ }
+ return new_date;
+}
+#endif /* HAVE_STRPTIME */
+
+/**
+ * eom_exif_util_format_date:
+ * @date: a date string following Exif specifications
+ *
+ * Takes a date string formatted after Exif specifications and generates a
+ * more readable, possibly localized, string out of it.
+ *
+ * Returns: a newly allocated date string formatted according to the
+ * current locale.
+ */
+gchar *
+eom_exif_util_format_date (const gchar *date)
+{
+ gchar *new_date;
+#ifdef HAVE_STRPTIME
+ new_date = eom_exif_util_format_date_with_strptime (date);
+#else
+ new_date = eom_exif_util_format_date_by_hand (date);
+#endif /* HAVE_STRPTIME */
+ return new_date;
+}
+
+/**
+ * eom_exif_util_get_value:
+ * @exif_data: pointer to an <structname>ExifData</structname> struct
+ * @tag_id: the requested tag's id. See <filename>exif-tag.h</filename>
+ * from the libexif package for possible values (e.g. %EXIF_TAG_EXPOSURE_MODE).
+ * @buffer: a pre-allocated output buffer
+ * @buf_size: size of @buffer
+ *
+ * Convenience function to extract a string representation of an Exif tag
+ * directly from an <structname>ExifData</structname> struct. The string is
+ * written into @buffer as far as @buf_size permits.
+ *
+ * Returns: a pointer to @buffer.
+ */
+const gchar *
+eom_exif_util_get_value (ExifData *exif_data, gint tag_id, gchar *buffer, guint buf_size)
+{
+ ExifEntry *exif_entry;
+ const gchar *exif_value;
+
+ exif_entry = exif_data_get_entry (exif_data, tag_id);
+
+ buffer[0] = 0;
+
+ exif_value = exif_entry_get_value (exif_entry, buffer, buf_size);
+
+ return exif_value;
+}