Issue #1196 Added isDisposed to CaveJFACEDialog.

Change-Id: I6ad1c3e1ba9015d87d04603a30ac8d02bb36abe5

Former-commit-id: fa0913508c [formerly d1e52778db] [formerly bfd519cefe [formerly 0eee43ff9fc99f027a295abebf64a98bbfeabe26]]
Former-commit-id: bfd519cefe
Former-commit-id: 59b174d6bd

cave/com.raytheon.viz.ui/src/com/raytheon/viz/ui/dialogs/CaveJFACEDialog.java

@@ -216,6 +216,17 @@ public class CaveJFACEDialog extends Dialog implements
         return (getShell() != null && !getShell().isDisposed());
     }
 
+    /**
+     * Returns if the dialog is disposed, a null dialog will not mean it is
+     * disposed as it may not have been opened yet.
+     * 
+     * @return
+     */
+    public final boolean isDisposed() {
+        Shell shell = getShell();
+        return (shell != null && shell.isDisposed());
+    }
+
     /**
      * Add a callback to the dialog. This callback will be called when the
      * dialog is disposed.