JAL-2849 JAL-2863 file format preferences TODO

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

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index cf1375e..1e1105f 100755 (executable)
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -780,8 +780,8 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
      * white fill the region to be drawn (so incremental fast paint doesn't
      * scribble over an existing image)
      */
-    gg.setColor(Color.white);
-    gg.fillRect(0, ypos, (endx - startColumn + 1) * charWidth,
+    g.setColor(Color.white);
+    g.fillRect(0, ypos, (endx - startColumn + 1) * charWidth,
             wrappedRepeatHeightPx);
 
     drawPanel(g, startColumn, endx, 0, av.getAlignment().getHeight() - 1,
@@ -1659,7 +1659,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
    */
   protected boolean drawMappedPositions(SearchResultsI results)
   {
-    if (results == null)
+    if ((results == null) || (gg == null)) // JAL-2784 check gg is not null
     {
       return false;
     }
@@ -1783,31 +1783,15 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
       {
         scrollX = -range;
       }
-
-      // Both scrolling and resizing change viewport ranges: scrolling changes
-      // both start and end points, but resize only changes end values.
-      // Here we only want to fastpaint on a scroll, with resize using a normal
-      // paint, so scroll events are identified as changes to the horizontal or
-      // vertical start value.
-      if (eventName.equals(ViewportRanges.STARTRES))
-      {
-         if (av.getWrapAlignment())
-          {
-            fastPaintWrapped(scrollX);
-          }
-          else
-          {
-            fastPaint(scrollX, 0);
-          }
-      }
-      else if (eventName.equals(ViewportRanges.STARTSEQ))
-      {
-        // scroll
-        fastPaint(0, (int) evt.getNewValue() - (int) evt.getOldValue());
-      }
-      else if (eventName.equals(ViewportRanges.STARTRESANDSEQ))
-      {
-        if (av.getWrapAlignment())
+    }
+    // Both scrolling and resizing change viewport ranges: scrolling changes
+    // both start and end points, but resize only changes end values.
+    // Here we only want to fastpaint on a scroll, with resize using a normal
+    // paint, so scroll events are identified as changes to the horizontal or
+    // vertical start value.
+    if (eventName.equals(ViewportRanges.STARTRES))
+    {
+      if (av.getWrapAlignment())
         {
           fastPaintWrapped(scrollX);
         }
@@ -1815,11 +1799,26 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
         {
           fastPaint(scrollX, 0);
         }
-        // bizarrely, we only need to scroll on the x value here as fastpaint
-        // copies the full height of the image anyway. Passing in the y value
-        // causes nasty repaint artefacts, which only disappear on a full
-        // repaint.
+    }
+    else if (eventName.equals(ViewportRanges.STARTSEQ))
+    {
+      // scroll
+      fastPaint(0, (int) evt.getNewValue() - (int) evt.getOldValue());
+    }
+    else if (eventName.equals(ViewportRanges.STARTRESANDSEQ))
+    {
+      if (av.getWrapAlignment())
+      {
+        fastPaintWrapped(scrollX);
+      }
+      else
+      {
+        fastPaint(scrollX, 0);
       }
+      // bizarrely, we only need to scroll on the x value here as fastpaint
+      // copies the full height of the image anyway. Passing in the y value
+      // causes nasty repaint artefacts, which only disappear on a full
+      // repaint.
     }
   }
 
@@ -2088,7 +2087,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
    */
   protected boolean drawMappedPositionsWrapped(SearchResultsI results)
   {
-    if (results == null)
+    if ((results == null) || (gg == null)) // JAL-2784 check gg is not null
     {
       return false;
     }