JAL-2491 Tidies to Overview panel calls in light of new code

[jalview.git] / src / jalview / viewmodel / ViewportRanges.java

diff --git a/src/jalview/viewmodel/ViewportRanges.java b/src/jalview/viewmodel/ViewportRanges.java
index 267b50e..ac310cc 100644 (file)
--- a/src/jalview/viewmodel/ViewportRanges.java
+++ b/src/jalview/viewmodel/ViewportRanges.java
@@ -145,27 +145,38 @@ public class ViewportRanges extends ViewportProperties
    */
   public void setEndRes(int res)
   {
+    int startres = res;
     int width = getViewportWidth();
-    setStartEndRes(res - width + 1, res);
+    if (startres + width - 1 > al.getWidth() - 1)
+    {
+      startres = al.getWidth() - width;
+    }
+    setStartEndRes(startres - width + 1, startres);
   }
 
   /**
-   * Set the first sequence visible in the viewport. Fires a property change
-   * event.
+   * Set the first sequence visible in the viewport, maintaining the height. If
+   * the viewport would extend past the last sequence, sets the viewport so it
+   * sits at the bottom of the alignment. Fires a property change event.
    * 
    * @param seq
    *          sequence position
    */
   public void setStartSeq(int seq)
   {
+    int startseq = seq;
     int height = getViewportHeight();
-    setStartEndSeq(seq, seq + height - 1);
+    if (startseq + height - 1 > al.getHeight() - 1)
+    {
+      startseq = al.getHeight() - height;
+    }
+    setStartEndSeq(startseq, startseq + height - 1);
   }
 
   /**
-   * Set start and end sequences at the same time. This method only fires one
-   * event for the two changes, and should be used in preference to separate
-   * calls to setStartSeq and setEndSeq.
+   * Set start and end sequences at the same time. The viewport height may
+   * change. This method only fires one event for the two changes, and should be
+   * used in preference to separate calls to setStartSeq and setEndSeq.
    * 
    * @param start
    *          the start sequence