Dont make new image unless resize

diff --git a/src/jalview/gui/IdCanvas.java b/src/jalview/gui/IdCanvas.java
index 5959493..d35a0f4 100755 (executable)
--- a/src/jalview/gui/IdCanvas.java
+++ b/src/jalview/gui/IdCanvas.java
@@ -173,6 +173,8 @@ public class IdCanvas extends JPanel
             return;\r
         }\r
 \r
+        int oldHeight = imgHeight;\r
+\r
         imgHeight = getHeight();\r
         imgHeight -= (imgHeight % av.charHeight);\r
 \r
@@ -181,15 +183,17 @@ public class IdCanvas extends JPanel
             return;\r
         }\r
 \r
-        image = new BufferedImage(getWidth(), imgHeight,\r
-                BufferedImage.TYPE_INT_RGB);\r
-        gg = (Graphics2D) image.getGraphics();\r
+        if(oldHeight!=imgHeight)\r
+        {\r
+          image = new BufferedImage(getWidth(), imgHeight,\r
+                                    BufferedImage.TYPE_INT_RGB);\r
+          gg = (Graphics2D) image.getGraphics();\r
+        }\r
 \r
         //Fill in the background\r
         gg.setColor(Color.white);\r
         gg.fillRect(0, 0, getWidth(), imgHeight);\r
 \r
-\r
         drawIds(av.getStartSeq(), av.endSeq);\r
 \r
         g.drawImage(image, 0, 0, this);\r