+
+
+string
+StringTextFileContent::identifier () const
+{
+ auto s = Content::identifier ();
+ s += "_" + only_text()->identifier();
+ return s;
+}
+
+
+/** In 5a820bb8fae34591be5ac6d19a73461b9dab532a there were some changes to subtitle font management.
+ *
+ * With StringTextFileContent we used to write a <Font> tag to the metadata with the id "font". Users
+ * could then set a font file that content should use, and (with some luck) it would end up in the DCP
+ * that way.
+ *
+ * After the changes we write a <Font> tag for every different font "id" (i.e. name) found in the source
+ * file (including a <Font> with id "" in the .srt case where there are no font names).
+ *
+ * However, this meant that making DCPs from old projects would fail, as the new code would see a font name
+ * in the source, then lookup a Font object for it from the Content, and fail in doing so (since the content
+ * only contains a font called "font").
+ *
+ * To put it another way: after the changes, the code expects that any font ID (i.e. name) used in some content
+ * will have a <Font> in the metadata and so a Font object in the TextContent. Without that, making DCPs fails.
+ *
+ * To work around this problem, this check_font_ids() is called for all subtitle content written by DoM versions
+ * before 2.16.14. We find all the font IDs in the content and map them all to the "legacy" font name (if there
+ * is one). This is more-or-less a re-examine()-ation, except that we try to preserve any settings that
+ * the user had previously set up.
+ *
+ * See #2271.
+ */
+void
+StringTextFileContent::check_font_ids()
+{
+ StringTextFile file (shared_from_this());
+ auto names = font_names(file);
+
+ auto content = only_text();
+ optional<boost::filesystem::path> legacy_font_file;
+ if (auto legacy_font = content->get_font("font")) {
+ legacy_font_file = legacy_font->file();
+ }
+
+ for (auto name: names) {
+ if (!content->get_font(name)) {
+ if (legacy_font_file) {
+ content->add_font(make_shared<Font>(name, *legacy_font_file));
+ } else {
+ content->add_font(make_shared<Font>(name));
+ }
+ }
+ }
+}
+