JAL-4356 release date for 2.11.3.3 is 22nd May 2025

[jalview.git] / src / jalview / viewmodel / ViewportProperties.java

diff --git a/src/jalview/viewmodel/ViewportProperties.java b/src/jalview/viewmodel/ViewportProperties.java
index 246806e..a78a1c0 100644 (file)
--- 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);
+  }
 
 }