JAL-2600 Tidies

[jalview.git] / src / jalview / appletgui / SeqCanvas.java

diff --git a/src/jalview/appletgui/SeqCanvas.java b/src/jalview/appletgui/SeqCanvas.java
index 469dec9..e996622 100755 (executable)
--- a/src/jalview/appletgui/SeqCanvas.java
+++ b/src/jalview/appletgui/SeqCanvas.java
@@ -884,13 +884,14 @@ public class SeqCanvas extends Panel implements ViewportListenerI
         // larger than the visible window
         ViewportRanges vpRanges = av.getRanges();
         scrollX = (int) evt.getNewValue() - (int) evt.getOldValue();
-        if (scrollX > vpRanges.getEndRes() - vpRanges.getStartRes())
+        int range = vpRanges.getEndRes() - vpRanges.getStartRes();
+        if (scrollX > range)
         {
-          scrollX = vpRanges.getEndRes() - vpRanges.getStartRes();
+          scrollX = range;
         }
-        else if (scrollX < vpRanges.getStartRes() - vpRanges.getEndRes())
+        else if (scrollX < -range)
         {
-          scrollX = vpRanges.getStartRes() - vpRanges.getEndRes();
+          scrollX = -range;
         }
       }