X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fgui%2FSeqCanvas.java;h=b3fcc542f3c0f6f7d2fc3899b172bf0fe3b551b3;hb=5e1f568e89eb53559f2c66bd2ac7292fb8c56349;hp=dc87eba55a5f8674acd0c07fd3ed3364fe8c7fe5;hpb=518c10ed28fbc64c637bbe1a0f336d8e3bf594a6;p=jalview.git

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index dc87eba..b3fcc54 100755
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -870,13 +870,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     int startx = startRes;
     int endx;
     int ypos = hgap; // vertical offset
-    int maxwidth = av.getAlignment().getWidth();
-
-    if (av.hasHiddenColumns())
-    {
-      maxwidth = av.getAlignment().getHiddenColumns()
-              .absoluteToVisibleColumn(maxwidth);
-    }
+    int maxwidth = av.getAlignment().getVisibleWidth();
 
     // chop the wrapped alignment extent up into panel-sized blocks and treat
     // each block as if it were a block from an unwrapped alignment
@@ -1661,7 +1655,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
       }
       ViewportRanges vpRanges = av.getRanges();
 
-      int range = vpRanges.getEndRes() - vpRanges.getStartRes();
+      int range = vpRanges.getEndRes() - vpRanges.getStartRes() + 1;
       if (scrollX > range)
       {
         scrollX = range;
@@ -1730,10 +1724,10 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
   {
     ViewportRanges ranges = av.getRanges();
 
-    if (Math.abs(scrollX) > ranges.getViewportWidth())
+    if (Math.abs(scrollX) >= ranges.getViewportWidth())
     {
       /*
-       * shift of more than one view width is 
+       * shift of one view width or more is 
        * overcomplicated to handle in this method
        */
       fastPaint = false;
@@ -1924,10 +1918,17 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
 
       while (y >= 0)
       {
+        /*
+         * shift 'widthToCopy' residues by 'positions' places to the right
+         */
         gg.copyArea(copyFromLeftStart, y, widthToCopy, heightToCopy,
                 positions * charWidth, 0);
         if (y > 0)
         {
+          /*
+           * copy 'positions' residue from the row above (right hand end)
+           * to this row's left hand end
+           */
           gg.copyArea(copyFromRightStart, y - wrappedRepeatHeightPx,
                   positions * charWidth, heightToCopy, -widthToCopy,
                   wrappedRepeatHeightPx);