X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fappletgui%2FOverviewPanel.java;fp=src%2Fjalview%2Fappletgui%2FOverviewPanel.java;h=456a38ca6d7ee26c391a66ba7f36f46936eddb45;hb=4a9a2fc8a1b1a66b21e66429083f27a6fc8541b9;hp=76c4e862e4332f871df12b646c6d3e699d0eb8c2;hpb=30f552046feaba47955d5ffdcec6d0fc67a7e13b;p=jalview.git

diff --git a/src/jalview/appletgui/OverviewPanel.java b/src/jalview/appletgui/OverviewPanel.java
index 76c4e86..456a38c 100755
--- a/src/jalview/appletgui/OverviewPanel.java
+++ b/src/jalview/appletgui/OverviewPanel.java
@@ -209,6 +209,14 @@ public class OverviewPanel extends Panel implements Runnable,
    */
   public void updateOverviewImage()
   {
+    if (oviewCanvas == null)
+    {
+      /*
+       * panel has been disposed
+       */
+      return;
+    }
+
     if ((getSize().width > 0) && (getSize().height > 0))
     {
       od.setWidth(getSize().width);
@@ -306,4 +314,21 @@ public class OverviewPanel extends Panel implements Runnable,
     oviewCanvas.resetOviewDims(od);
     updateOverviewImage();
   }
+
+  /**
+   * Removes this object as a property change listener, and nulls references
+   */
+  protected void dispose()
+  {
+    try
+    {
+      av.getRanges().removePropertyChangeListener(this);
+    } finally
+    {
+      av = null;
+      oviewCanvas = null;
+      ap = null;
+      od = null;
+    }
+  }
 }