From f02e65ac3b489b25e5514d9972838af04298c148 Mon Sep 17 00:00:00 2001
From: kiramt <k.mourao@dundee.ac.uk>
Date: Mon, 13 Nov 2017 19:40:06 +0000
Subject: [PATCH] JAL-2811 Tidy

---
 src/jalview/gui/SeqCanvas.java |   98 +++++++++++++++++++++-------------------
 1 file changed, 51 insertions(+), 47 deletions(-)

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index 2d040a3..394a0b6 100755
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -1275,61 +1275,65 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     // define our cursor image
     BufferedImage cursorImage = null;
 
-    int yoffset = 0;
-    int xoffset = 0;
-    int startx = startRes;
-    int endx = endRes;
-    if (av.getWrapAlignment())
+    // don't do work unless we have to
+    if (av.cursorMode && cursorY >= startSeq && cursorY <= endSeq)
     {
-      // work out the correct offsets for the cursor
-      int charHeight = av.getCharHeight();
-      int charWidth = av.getCharWidth();
-      int canvasWidth = getWidth();
-      int canvasHeight = getHeight();
-
-      // height gap above each panel
-      int hgap = charHeight;
-      if (av.getScaleAboveWrapped())
+      int yoffset = 0;
+      int xoffset = 0;
+      int startx = startRes;
+      int endx = endRes;
+      if (av.getWrapAlignment())
       {
-        hgap += charHeight;
-      }
-
-      int cWidth = (canvasWidth - labelWidthEast - labelWidthWest)
-              / charWidth;
-      int cHeight = av.getAlignment().getHeight() * charHeight;
-
-      endx = startx + cWidth - 1;
-      int ypos = hgap; // vertical offset
+        // work out the correct offsets for the cursor
+        int charHeight = av.getCharHeight();
+        int charWidth = av.getCharWidth();
+        int canvasWidth = getWidth();
+        int canvasHeight = getHeight();
+
+        // height gap above each panel
+        int hgap = charHeight;
+        if (av.getScaleAboveWrapped())
+        {
+          hgap += charHeight;
+        }
 
-      // iterate down the wrapped panels
-      while ((ypos <= canvasHeight) && (endx < cursorX))
-      {
-        // update vertical offset
-        ypos += cHeight + getAnnotationHeight() + hgap;
+        int cWidth = (canvasWidth - labelWidthEast - labelWidthWest)
+                / charWidth;
+        int cHeight = av.getAlignment().getHeight() * charHeight;
 
-        // update horizontal offset
-        startx += cWidth;
         endx = startx + cWidth - 1;
-      }
-      yoffset = ypos;
-      xoffset = labelWidthWest;
-    }
+        int ypos = hgap; // vertical offset
 
-    if (av.cursorMode && cursorY >= startSeq && cursorY <= endSeq
-            && cursorX >= startx && cursorX <= endx)
-    {
-      // get a new image of the correct size
-      cursorImage = setupImage();
-      Graphics2D g = (Graphics2D) cursorImage.getGraphics();
+        // iterate down the wrapped panels
+        while ((ypos <= canvasHeight) && (endx < cursorX))
+        {
+          // update vertical offset
+          ypos += cHeight + getAnnotationHeight() + hgap;
 
-      // get the character the cursor is drawn at
-      SequenceI seq = av.getAlignment().getSequenceAt(cursorY);
-      char s = seq.getCharAt(cursorX);
+          // update horizontal offset
+          startx += cWidth;
+          endx = startx + cWidth - 1;
+        }
+        yoffset = ypos;
+        xoffset = labelWidthWest;
+      }
 
-      seqRdr.drawCursor(g, s,
-              xoffset + (cursorX - startx) * av.getCharWidth(),
-              yoffset + (cursorY - startSeq) * av.getCharHeight());
-      g.dispose();
+      // now check if cursor is within range for x values
+      if (cursorX >= startx && cursorX <= endx)
+      {
+        // get a new image of the correct size
+        cursorImage = setupImage();
+        Graphics2D g = (Graphics2D) cursorImage.getGraphics();
+
+        // get the character the cursor is drawn at
+        SequenceI seq = av.getAlignment().getSequenceAt(cursorY);
+        char s = seq.getCharAt(cursorX);
+
+        seqRdr.drawCursor(g, s,
+                xoffset + (cursorX - startx) * av.getCharWidth(),
+                yoffset + (cursorY - startSeq) * av.getCharHeight());
+        g.dispose();
+      }
     }
 
     return cursorImage;
-- 
1.7.10.2