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Diffstat (limited to 'src/eom-exif-util.c')
-rw-r--r-- | src/eom-exif-util.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/src/eom-exif-util.c b/src/eom-exif-util.c new file mode 100644 index 0000000..93d54e0 --- /dev/null +++ b/src/eom-exif-util.c @@ -0,0 +1,214 @@ +/* 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; +} |