+
+ /**
+ * Get width of viewport in residues
+ *
+ * @return width of viewport
+ */
+ public int getViewportWidth()
+ {
+ return (endRes - startRes + 1); // TODO get for wrapped alignments too
+ }
+
+ /**
+ * Get height of viewport in residues
+ *
+ * @return height of viewport
+ */
+ public int getViewportHeight()
+ {
+ return (endSeq - startSeq + 1);
+ }
+
+ // return value is true if the scroll is valid
+ public boolean scrollUp(boolean up)
+ {
+ if (up)
+ {
+ if (startSeq < 1)
+ {
+ return false;
+ }
+
+ setStartSeq(startSeq - 1);
+ }
+ else
+ {
+ if (endSeq >= al.getHeight() - 1)
+ {
+ return false;
+ }
+
+ setStartSeq(startSeq + 1);
+ }
+ return true;
+ }
+
+ /**
+ * DOCUMENT ME!
+ *
+ * @param right
+ * DOCUMENT ME!
+ *
+ * @return DOCUMENT ME!
+ */
+ public boolean scrollRight(boolean right)
+ {
+ if (!right)
+ {
+ if (startRes < 1)
+ {
+ return false;
+ }
+
+ setStartRes(startRes - 1);
+ }
+ else
+ {
+ if (endRes > al.getWidth() - 1)
+ {
+ return false;
+ }
+
+ setStartRes(startRes + 1);
+ }
+
+ return true;
+ }
+
+ public void scrollToWrappedVisible(int res)
+ {
+ if (res < startRes || res > endRes)
+ {
+ setEndSeq(res / getViewportWidth());
+ }
+
+ }
+