+ return String::compose ("%1 %2 %3", path_summary(), digest(), position().seconds());
+}
+
+DCPTime
+Content::length_after_trim () const
+{
+ return max (DCPTime (), full_length() - DCPTime (trim_start() + trim_end(), film()->active_frame_rate_change (position ())));
+}
+
+/** @return string which changes when something about this content changes which affects
+ * the appearance of its video.
+ */
+string
+Content::identifier () const
+{
+ SafeStringStream s;
+
+ s << Content::digest()
+ << "_" << position().get()
+ << "_" << trim_start().get()
+ << "_" << trim_end().get();
+
+ return s.str ();
+}
+
+bool
+Content::paths_valid () const
+{
+ for (vector<boost::filesystem::path>::const_iterator i = _paths.begin(); i != _paths.end(); ++i) {
+ if (!boost::filesystem::exists (*i)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+void
+Content::set_path (boost::filesystem::path path)
+{
+ _paths.clear ();
+ _paths.push_back (path);
+ signal_changed (ContentProperty::PATH);
+}
+
+string
+Content::path_summary () const
+{
+ /* XXX: should handle multiple paths more gracefully */
+
+ DCPOMATIC_ASSERT (number_of_paths ());
+
+ string s = path(0).filename().string ();
+ if (number_of_paths() > 1) {
+ s += " ...";
+ }
+
+ return s;
+}
+
+/** @return a list of properties that might be interesting to the user; first string is the property name,
+ * second is the value.
+ */
+list<pair<string, string> >
+Content::properties () const
+{
+ list<pair<string, string> > p;
+ add_properties (p);
+ return p;
+}
+
+shared_ptr<const Film>
+Content::film () const
+{
+ shared_ptr<const Film> film = _film.lock ();
+ DCPOMATIC_ASSERT (film);
+ return film;