X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fviewmodel%2FViewportProperties.java;h=a78a1c02d9ca5f42074de734de6860b6a86ec12b;hb=f3d0dc3395aff566e8005e6a6a9a13bf795c14a4;hp=246806e0a69de37ba96153e8fd9cdb482ffdbfb1;hpb=2baf7a0fe3faf4133a387359b8ce2ba475176eec;p=jalview.git

diff --git a/src/jalview/viewmodel/ViewportProperties.java b/src/jalview/viewmodel/ViewportProperties.java
index 246806e..a78a1c0 100644
--- a/src/jalview/viewmodel/ViewportProperties.java
+++ b/src/jalview/viewmodel/ViewportProperties.java
@@ -20,7 +20,21 @@
  */
 package jalview.viewmodel;
 
+import java.beans.PropertyChangeSupport;
+
 public abstract class ViewportProperties
 {
+  protected PropertyChangeSupport changeSupport = new PropertyChangeSupport(
+          this);
+
+  public void addPropertyChangeListener(ViewportListenerI listener)
+  {
+    changeSupport.addPropertyChangeListener(listener);
+  }
+
+  public void removePropertyChangeListener(ViewportListenerI listener)
+  {
+    changeSupport.removePropertyChangeListener(listener);
+  }
 
 }