Add destroy method for Navigator (#10213).

Change-Id: Icb2676bd603bbe36a8d7d005128036234a5a0c62

2 files changed, 16 insertions, 1 deletions

diff --git a/server/src/com/vaadin/navigator/NavigationStateManager.java b/server/src/com/vaadin/navigator/NavigationStateManager.java
index d454d044cb..3e9c54c961 100644
--- a/server/src/com/vaadin/navigator/NavigationStateManager.java
+++ b/server/src/com/vaadin/navigator/NavigationStateManager.java
@@ -56,6 +56,8 @@ public interface NavigationStateManager extends Serializable {
      * Sets the Navigator used with this state manager. The state manager should
      * notify the provided navigator of user-triggered navigation state changes
      * by invoking <code>navigator.navigateTo(getState())</code>.
+     * {@code navigator} parameter value could be null if previously set
+     * navigator is destroyed.
      * <p>
      * This method should only be called by a Navigator.
      */
diff --git a/server/src/com/vaadin/navigator/Navigator.java b/server/src/com/vaadin/navigator/Navigator.java
index fa587a2eaa..82e8de920a 100644
--- a/server/src/com/vaadin/navigator/Navigator.java
+++ b/server/src/com/vaadin/navigator/Navigator.java
@@ -113,11 +113,15 @@ public class Navigator implements Serializable {
          */
         public UriFragmentManager(Page page) {
             this.page = page;
-            page.addUriFragmentChangedListener(this);
         }
 
         @Override
         public void setNavigator(Navigator navigator) {
+            if (this.navigator == null && navigator != null) {
+                page.addUriFragmentChangedListener(this);
+            } else if (this.navigator != null && navigator == null) {
+                page.removeUriFragmentChangedListener(this);
+            }
             this.navigator = navigator;
         }
 
@@ -980,4 +984,13 @@ public class Navigator implements Serializable {
     public void removeViewChangeListener(ViewChangeListener listener) {
         listeners.remove(listener);
     }
+
+    /**
+     * Destroys the navigator and cleans it up. The method detaches the
+     * navigator from UI and removes all view change listeners.
+     */
+    public void destroy() {
+        stateManager.setNavigator(null);
+        ui.setNavigator(null);
+    }
 }