Change EXIF metadata handling into a registered function

This allows much greater flexibility from templates regarding
EXIF metadata handling, no more hardcoded symbols. It's possible
to display essentially any attribute known to Exiv2. Please see
http://exiv2.org/metadata.html

This brings two new functions that can be called from templates:
 * get_exif_value (exiv2_attribute)
 * get_exif_value_fixed (exiv2_attribute)

Both functions take a string argument of metadata attribute name
from Exiv2 namespace. The difference is that get_exif_value_fixed()
does some extra formatting for several basic attributes
(e.g. datetime format).

1 files changed, 43 insertions, 28 deletions

diff --git a/src/generators.c b/src/generators.c
index 48a377a..1d05eea 100644
--- a/src/generators.c
+++ b/src/generators.c
@@ -555,6 +555,27 @@ write_html_album (TGallerySetup *setup,
   return res;
 }
 
+static char *
+get_exif_value_cb (gchar **args, gpointer user_data)
+{
+  ExifData *exif = user_data;
+
+  g_return_val_if_fail (exif != NULL, NULL);
+  g_return_val_if_fail (g_strv_length (args) != 2, NULL);  /* incl. trailing NULL */
+
+  return get_exif_data (exif, *args);
+}
+
+static char *
+get_exif_value_fixed_cb (gchar **args, gpointer user_data)
+{
+  ExifData *exif = user_data;
+
+  g_return_val_if_fail (exif != NULL, NULL);
+  g_return_val_if_fail (g_strv_length (args) != 2, NULL);  /* incl. trailing NULL */
+
+  return get_exif_data_fixed (exif, *args);
+}
 
 /*
  *   write_html_image: process single image template file
@@ -581,7 +602,7 @@ write_html_image (TGallerySetup *setup,
   gchar *img_orig_src;
   gchar *img_orig_dst;
   gchar *img_orig_dst_page;
-  TExifData *exif;
+  ExifData *exif;
   unsigned long img_w, img_h;
   unsigned long img_orig_w, img_orig_h;
   unsigned int item_index, next_item_index, real_item_index, real_total_items;
@@ -676,13 +697,13 @@ write_html_image (TGallerySetup *setup,
   /*  Get EXIF data from the original image  */
   exif = NULL;
   if (img_orig_src) {
-    exif = get_exif (img_orig_src);
+    exif = read_exif (img_orig_src);
     if (exif == NULL)
       log_error ("write_html_image: error getting exif data from file \"%s\"\n", img_orig_src);
   }
   /*  Try destination image instead, though it might have the metadata stripped  */
   if (exif == NULL) {
-    exif = get_exif (img_dst);
+    exif = read_exif (img_dst);
     if (exif == NULL)
       log_error ("write_html_image: error getting exif data from file \"%s\"\n", img_dst);
   }
@@ -699,25 +720,30 @@ write_html_image (TGallerySetup *setup,
   title = g_strdup (item->title);
   title_desc = g_strdup (item->title_description);
   if (setup->use_iptc_exif && title == NULL && title_desc == NULL && exif != NULL) {
-    if (exif->iptc_caption)
-      title = g_strdup (exif->iptc_caption);
-    if (exif->jpeg_comment) {
+    title = get_exif_data_fixed (exif, IPTC_CAPTION);
+    s1 = get_exif_data_fixed (exif, JPEG_COMMENT);
+    if (s1) {
       if (! title)
-        title = g_strdup (exif->jpeg_comment);
+        title = g_strdup (s1);
       else
-        title_desc = g_strdup (exif->jpeg_comment);
+        title_desc = g_strdup (s1);
+      g_free (s1);
     }
-    if (exif->exif_imgdesc) {
+    s1 = get_exif_data_fixed (exif, EXIF_IMAGE_DESCRIPTION);
+    if (s1) {
       if (! title)
-        title = g_strdup (exif->exif_imgdesc);
+        title = g_strdup (s1);
 /*        if (! title_desc)   -- disabled
-        title_desc = g_strdup (exif->exif_imgdesc);  */
+        title_desc = g_strdup (s1);  */
+      g_free (s1);
     }
-    if (exif->exif_usercomment) {
+    s1 = get_exif_data_fixed (exif, EXIF_COMMENT);
+    if (s1) {
       if (! title)
-        title = g_strdup (exif->exif_usercomment);
+        title = g_strdup (s1);
       if (! title_desc)
-        title_desc = g_strdup (exif->exif_usercomment);
+        title_desc = g_strdup (s1);
+      g_free (s1);
     }
     /*  Convert line breaks to be visible in the HTML code  */
     if (title) {
@@ -794,19 +820,8 @@ write_html_image (TGallerySetup *setup,
   replace_table_add_key (replace_table, "TEMPLATES_PATH", setup->supplemental_files_use_common_root ? s1 : "");
   g_free (s1);
 
-  /*  EXIF values  */
-  if (exif) {
-    replace_table_add_key (replace_table, "EXIF_ISO", exif->iso ? exif->iso : "??");
-    replace_table_add_key (replace_table, "EXIF_TIME", exif->exposure ? exif->exposure : "??");
-    replace_table_add_key (replace_table, "EXIF_APERTURE", exif->aperture ? exif->aperture : "??");
-    replace_table_add_key (replace_table, "EXIF_FOCAL_LENGTH", exif->focal_length ? exif->focal_length : "??");
-    replace_table_add_key (replace_table, "EXIF_FLASH", exif->flash ? exif->flash : "??");
-    replace_table_add_key (replace_table, "EXIF_DATE", exif->datetime ? exif->datetime : "??");
-    replace_table_add_key (replace_table, "EXIF_CAMERA_MODEL", exif->camera_model ? exif->camera_model : "??");
-    s1 = g_strdup_printf ("(%s)", exif->focal_length_35mm);
-    replace_table_add_key (replace_table, "EXIF_FOCAL_35", exif->focal_length_35mm ? s1 : "");
-    g_free (s1);
-  }
+  replace_table_register_function (replace_table, "get_exif_value", get_exif_value_cb, exif);
+  replace_table_register_function (replace_table, "get_exif_value_fixed", get_exif_value_fixed_cb, exif);
 
   /*  Border style  */
   s1 = item->border_style;
@@ -912,7 +927,7 @@ write_html_image (TGallerySetup *setup,
   g_free (imgname);
   g_free (preload_imgname);
   g_hash_table_destroy (defines);
-  free_exif_data (exif);
+  exif_data_free (exif);
   replace_table_free (replace_table);
   block_parser_free (block_parser);
   return res;