+ /** starting loading of the image is done by a urgency-based
+ * decision. Here we only call LoaderQueue::touch to request it.
+ */
+ void startLoading() const;
+
+ /** Monitor any changes to the file.
+ * There is no point monitoring the file before startLoading() is
+ * invoked.
+ */
+ void startMonitoring() const;
+ ///
+ bool monitoring() const;
+ /** Returns the check checksum of filename() so that, for example, you can
+ * ascertain whether to output a new PostScript version of the file
+ * for a LaTeX run.
+ */
+ unsigned long checksum() const;