JAL-2609 adjustments for test findings

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index adc36f9..6c6e87a 100755 (executable)
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -697,7 +697,6 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
      * ensuring a part height includes at least one sequence
      */
     ViewportRanges ranges = av.getRanges();
-    int xMax = ranges.getVisibleAlignmentWidth();
     wrappedVisibleWidths = canvasHeight / wrappedRepeatHeightPx;
     int remainder = canvasHeight % wrappedRepeatHeightPx;
     if (remainder >= (wrappedSpaceAboveAlignment + charHeight))
@@ -713,8 +712,10 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     /*
      *  limit visibleWidths to not exceed width of alignment
      */
-    int maxWidths = (xMax - ranges.getStartRes()) / wrappedWidthInResidues;
-    if (xMax % wrappedWidthInResidues > 0)
+    int xMax = ranges.getVisibleAlignmentWidth();
+    int startToEnd = xMax - ranges.getStartRes();
+    int maxWidths = startToEnd / wrappedWidthInResidues;
+    if (startToEnd % wrappedWidthInResidues > 0)
     {
       maxWidths++;
     }
@@ -863,6 +864,9 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
   }
 
   /**
+   * Draws markers (triangles) above hidden column positions between startColumn
+   * and endColumn.
+   * 
    * @param g
    * @param ypos
    * @param startColumn
@@ -881,7 +885,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     {
       int res = pos - startColumn;
 
-      if (res < 0 || res > endColumn - startColumn)
+      if (res < 0 || res > endColumn - startColumn + 1)
       {
         continue;
       }
@@ -1662,7 +1666,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
         // larger than the visible window
         ViewportRanges vpRanges = av.getRanges();
         scrollX = (int) evt.getNewValue() - (int) evt.getOldValue();
-        int range = vpRanges.getEndRes() - vpRanges.getStartRes();
+        int range = vpRanges.getEndRes() - vpRanges.getStartRes() + 1;
         if (scrollX > range)
         {
           scrollX = range;