--- /dev/null
+package jalview.api;
+
+import jalview.datamodel.SequenceI;
+
+public interface AlignmentRowsCollectionI extends Iterable<Integer>
+{
+ /**
+ * Answers if the sequence at the given position is hidden.
+ *
+ * @param r
+ * the row index to check
+ * @return true if the sequence at r is hidden
+ */
+ public boolean isHidden(int r);
+
+ /**
+ * Answers the sequence at the given position in the alignment
+ *
+ * @param r
+ * the row index to locate
+ * @return the sequence
+ */
+ public SequenceI getSequence(int r);
+}