[gthumb] rename series: preview does not show example values

[Paolo Bacchilega <paobac src gnome org>]

commit 9dd28856e21b34bf9b90c31c904bc60c29801c6a
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Wed Aug 10 09:13:20 2022 +0200

    rename series: preview does not show example values

 extensions/rename_series/dlg-rename-series.c | 79 ++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
---
diff --git a/extensions/rename_series/dlg-rename-series.c b/extensions/rename_series/dlg-rename-series.c
index cc0612da..7a9df805 100644
--- a/extensions/rename_series/dlg-rename-series.c
+++ b/extensions/rename_series/dlg-rename-series.c
@@ -47,6 +47,7 @@ enum {
 #define DEFAULT_START_AT 1
 #define DEFAULT_CHANGE_CASE GTH_CHANGE_CASE_NONE
 #define UPDATE_DELAY 250
+#define PREVIEW_URI "file:///home/user/images/filename.jpeg"
 
 
 static GthTemplateCode Rename_Special_Codes[] = {
@@ -703,6 +704,81 @@ update_preview_cb (GtkWidget  *widget,
 }
 
 
+static gboolean
+template_dialog_preview_cb (TemplateFlags   flags,
+                           gunichar        parent_code,
+                           gunichar        code,
+                           char          **args,
+                           GString        *result,
+                           gpointer        user_data)
+{
+       char     *text;
+       GFile    *file;
+       char     *path;
+       GTimeVal  timeval;
+
+       if ((parent_code == 'D') || (parent_code == 'M')) {
+               /* strftime code, return the code itself. */
+               _g_string_append_template_code (result, code, args);
+               return FALSE;
+       }
+
+       if (code != 0)
+               g_string_append (result, "<span foreground=\"#4696f8\">");
+
+       switch (code) {
+       case '#':
+               text = _g_template_replace_enumerator (args[0], 1);
+               g_string_append (result, text);
+               g_free (text);
+               break;
+
+       case 'A':
+               g_string_append_printf (result, "{ %s }", args[0]);
+               break;
+
+       case 'E':
+               file = g_file_new_for_uri (PREVIEW_URI);
+               path = g_file_get_path (file);
+               g_string_append (result, _g_path_get_extension (path));
+               g_free (path);
+               g_object_unref (file);
+               break;
+
+       case 'F':
+               file = g_file_new_for_uri (PREVIEW_URI);
+               path = g_file_get_path (file);
+               g_string_append (result, _g_path_get_basename (path));
+               g_free (path);
+               g_object_unref (file);
+               break;
+
+       case 'N':
+               g_string_append (result, "123");
+               break;
+
+       case 'D':
+               g_get_current_time (&timeval);
+               text = _g_time_val_strftime (&timeval, (args[0] != NULL) ? args[0] : DEFAULT_STRFTIME_FORMAT);
+               g_string_append (result, text);
+               g_free (text);
+               break;
+
+       case 'M':
+               g_get_current_time (&timeval);
+               text = _g_time_val_strftime (&timeval, (args[0] != NULL) ? args[0] : DEFAULT_STRFTIME_FORMAT);
+               g_string_append (result, text);
+               g_free (text);
+               break;
+       }
+
+       if (code != 0)
+               g_string_append (result, "</span>");
+
+       return FALSE;
+}
+
+
 static void
 edit_template_button_clicked_cb (GtkWidget  *widget,
                                 DialogData *data)
@@ -714,6 +790,9 @@ edit_template_button_clicked_cb (GtkWidget  *widget,
                                                 0,
                                                 _("Edit Template"),
                                                 GTK_WINDOW (data->dialog));
+       gth_template_editor_dialog_set_preview_cb (GTH_TEMPLATE_EDITOR_DIALOG (dialog),
+                                                  template_dialog_preview_cb,
+                                                  data);
        gth_template_editor_dialog_set_template (GTH_TEMPLATE_EDITOR_DIALOG (dialog),
                                                 gtk_entry_get_text (GTK_ENTRY (GET_WIDGET 
("template_entry"))));
        g_signal_connect (dialog,