[gimp/metadata-improvements: 4/11] plug-ins: improve formatting of gps data in metadata-viewer.

[Jacob Boerema <jboerema src gnome org>]

commit 34407a6b7e1cef63a0d3cbe21df06b1509c0ea13
Author: Jacob Boerema <jgboerema gmail com>
Date:   Wed Nov 25 22:49:04 2020 -0500

    plug-ins: improve formatting of gps data in metadata-viewer.
    
    Adding metadata-tags to meson.build and Makefile.am for
    the metadata-viewer since until now it was only used in
    the metadata-editor.
    
    The Exif gps metadata tags for longitude, latitude and
    altitude get special handling to show them with more
    precision and let the string parts be translated.

 plug-ins/metadata/Makefile.am       |   4 +-
 plug-ins/metadata/meson.build       |   5 +-
 plug-ins/metadata/metadata-viewer.c | 138 ++++++++++++++++++++++++++++++++++--
 3 files changed, 136 insertions(+), 11 deletions(-)
---
diff --git a/plug-ins/metadata/Makefile.am b/plug-ins/metadata/Makefile.am
index d7be32fe91..23e00f2c8d 100644
--- a/plug-ins/metadata/Makefile.am
+++ b/plug-ins/metadata/Makefile.am
@@ -40,7 +40,9 @@ metadata_editor_SOURCES = \
        metadata-xml.h
 
 metadata_viewer_SOURCES = \
-       metadata-viewer.c
+       metadata-viewer.c       \
+       metadata-tags.c         \
+       metadata-tags.h
 
 AM_CPPFLAGS = \
        -I$(top_srcdir) \
diff --git a/plug-ins/metadata/meson.build b/plug-ins/metadata/meson.build
index 6ccdfc2e55..5f2353fcf0 100644
--- a/plug-ins/metadata/meson.build
+++ b/plug-ins/metadata/meson.build
@@ -43,6 +43,7 @@ plugin_name = 'metadata-viewer'
 
 plugin_sources = [
   'metadata-viewer.c',
+  'metadata-tags.c',
 ]
 
 if platform_windows
@@ -65,9 +66,7 @@ if platform_windows
 endif
 
 executable(plugin_name,
-  [
-    'metadata-viewer.c',
-  ],
+  plugin_sources,
   include_directories: [ rootInclude, ],
   dependencies: [
     gtk3, gegl, gexiv2,
diff --git a/plug-ins/metadata/metadata-viewer.c b/plug-ins/metadata/metadata-viewer.c
index 3d7aa93e47..01ddc03625 100644
--- a/plug-ins/metadata/metadata-viewer.c
+++ b/plug-ins/metadata/metadata-viewer.c
@@ -30,6 +30,7 @@
 
 #include "libgimp/stdplugins-intl.h"
 
+#include "metadata-tags.h"
 
 #define PLUG_IN_PROC   "plug-in-metadata-viewer"
 #define PLUG_IN_BINARY "metadata-viewer"
@@ -107,6 +108,18 @@ static void      metadata_dialog_append_tags      (GExiv2Metadata  *metadata,
                                                    gint             tag_column,
                                                    gint             value_column,
                                                    gboolean         load_iptc);
+static void metadata_dialog_add_tag               (GtkListStore    *store,
+                                                   GtkTreeIter      iter,
+                                                   gint             tag_column,
+                                                   gint             value_column,
+                                                   const gchar     *tag,
+                                                   const gchar     *value);
+static void metadata_dialog_add_translated_tag    (GExiv2Metadata  *metadata,
+                                                   GtkListStore    *store,
+                                                   GtkTreeIter      iter,
+                                                   gint             tag_column,
+                                                   gint             value_column,
+                                                   const gchar     *tag);
 static gchar   * metadata_dialog_format_tag_value (GExiv2Metadata  *metadata,
                                                    const gchar     *tag,
                                                    gboolean         truncate);
@@ -366,6 +379,40 @@ metadata_tag_is_string (const gchar *tag)
           g_strcmp0 (tag_type, NULL)        != 0);
 }
 
+static void
+metadata_dialog_add_tag (GtkListStore    *store,
+                         GtkTreeIter      iter,
+                         gint             tag_column,
+                         gint             value_column,
+                         const gchar     *tag,
+                         const gchar     *value)
+{
+  if (value)
+    {
+      gtk_list_store_append (store, &iter);
+      gtk_list_store_set (store, &iter,
+                          tag_column,   tag,
+                          value_column, value,
+                          -1);
+    }
+}
+
+static void
+metadata_dialog_add_translated_tag (GExiv2Metadata  *metadata,
+                                    GtkListStore    *store,
+                                    GtkTreeIter      iter,
+                                    gint             tag_column,
+                                    gint             value_column,
+                                    const gchar     *tag)
+{
+  gchar *value;
+
+  value = gexiv2_metadata_get_tag_interpreted_string (metadata, tag);
+  metadata_dialog_add_tag (store, iter, tag_column, value_column,
+                           tag, gettext (value));
+  g_free (value);
+}
+
 static void
 metadata_dialog_append_tags (GExiv2Metadata  *metadata,
                              gchar          **tags,
@@ -377,6 +424,7 @@ metadata_dialog_append_tags (GExiv2Metadata  *metadata,
   GtkTreeIter  iter;
   const gchar *tag;
   const gchar *last_tag = NULL;
+  gboolean     gps_done = FALSE;
 
   while ((tag = *tags++))
     {
@@ -421,19 +469,95 @@ metadata_dialog_append_tags (GExiv2Metadata  *metadata,
 
               g_strfreev (values);
             }
+        }
+      else if (! strcmp ("Exif.GPSInfo.GPSLongitude",    tag) ||
+               ! strcmp ("Exif.GPSInfo.GPSLongitudeRef", tag) ||
+               ! strcmp ("Exif.GPSInfo.GPSLatitude",     tag) ||
+               ! strcmp ("Exif.GPSInfo.GPSLatitudeRef",  tag) ||
+               ! strcmp ("Exif.GPSInfo.GPSAltitude",     tag) ||
+               ! strcmp ("Exif.GPSInfo.GPSAltitudeRef",  tag))
+        {
+          /* We need special handling for some of the GPS tags to
+           * be able to show better values than the default. */
+          if (! gps_done)
+            {
+              gdouble  lng, lat, alt;
+              gchar   *str;
+              gchar  *value;
 
+              if (gexiv2_metadata_get_gps_longitude (GEXIV2_METADATA (metadata),
+                                                     &lng))
+                {
+                  str = metadata_format_gps_longitude_latitude (lng);
+                  metadata_dialog_add_tag (store, iter,
+                                           tag_column, value_column,
+                                           "Exif.GPSInfo.GPSLongitude",
+                                           str);
+                  g_free (str);
+                }
+              metadata_dialog_add_translated_tag (metadata, store, iter,
+                                                  tag_column, value_column,
+                                                  "Exif.GPSInfo.GPSLongitudeRef");
+
+              if (gexiv2_metadata_get_gps_latitude (GEXIV2_METADATA (metadata),
+                                                    &lat))
+                {
+                  str = metadata_format_gps_longitude_latitude (lat);
+                  metadata_dialog_add_tag (store, iter,
+                                           tag_column, value_column,
+                                           "Exif.GPSInfo.GPSLatitude",
+                                           str);
+                  g_free (str);
+                }
+              metadata_dialog_add_translated_tag (metadata, store, iter,
+                                                  tag_column, value_column,
+                                                  "Exif.GPSInfo.GPSLatitudeRef");
+
+              if (gexiv2_metadata_get_gps_altitude (GEXIV2_METADATA (metadata),
+                                                    &alt))
+                {
+                  gchar *str2, *str3;
+
+                  str  = metadata_format_gps_altitude (alt, TRUE,  _(" meter"));
+                  str2 = metadata_format_gps_altitude (alt, FALSE, _(" feet"));
+                  str3 = g_strdup_printf ("%s (%s)", str, str2);
+                  metadata_dialog_add_tag (store, iter,
+                                           tag_column, value_column,
+                                           "Exif.GPSInfo.GPSAltitude",
+                                           str3);
+                  g_free (str);
+                  g_free (str2);
+                  g_free (str3);
+                  value = gexiv2_metadata_get_tag_string (metadata,
+                                                          "Exif.GPSInfo.GPSAltitudeRef");
+
+                  if (value)
+                    {
+                      gint index;
+
+                      if (value[0] == '0')
+                        index = 1;
+                      else if (value[0] == '1')
+                        index = 2;
+                      else
+                        index = 0;
+                      metadata_dialog_add_tag (store, iter,
+                                              tag_column, value_column,
+                                              "Exif.GPSInfo.GPSAltitudeRef",
+                                              gettext (gpsaltref[index]));
+                      g_free (value);
+                    }
+                }
+              gps_done = TRUE;
+            }
         }
       else
         {
           value = metadata_dialog_format_tag_value (metadata, tag,
                                                     /* truncate = */ TRUE);
-
-          gtk_list_store_append (store, &iter);
-          gtk_list_store_set (store, &iter,
-                              tag_column,   tag,
-                              value_column, value,
-                              -1);
-
+          metadata_dialog_add_tag (store, iter,
+                                   tag_column, value_column,
+                                   tag, value);
           g_free (value);
         }
     }