Add destroy method for Navigator (#10213).

Change-Id: Icb2676bd603bbe36a8d7d005128036234a5a0c62

4 files changed, 175 insertions, 6 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);
+    }
 }
diff --git a/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java b/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java
index 2c045d53fa..0de804fa0b 100644
--- a/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java
+++ b/server/tests/src/com/vaadin/tests/server/navigator/NavigatorTest.java
@@ -23,14 +23,19 @@ import junit.framework.TestCase;
 import org.easymock.EasyMock;
 import org.easymock.IArgumentMatcher;
 import org.easymock.IMocksControl;
+import org.junit.Assert;
 
 import com.vaadin.navigator.NavigationStateManager;
 import com.vaadin.navigator.Navigator;
+import com.vaadin.navigator.Navigator.UriFragmentManager;
 import com.vaadin.navigator.View;
 import com.vaadin.navigator.ViewChangeListener;
 import com.vaadin.navigator.ViewChangeListener.ViewChangeEvent;
 import com.vaadin.navigator.ViewDisplay;
 import com.vaadin.navigator.ViewProvider;
+import com.vaadin.server.Page;
+import com.vaadin.server.Page.UriFragmentChangedEvent;
+import com.vaadin.server.VaadinRequest;
 import com.vaadin.tests.server.navigator.ClassBasedViewProviderTest.TestView;
 import com.vaadin.tests.server.navigator.ClassBasedViewProviderTest.TestView2;
 import com.vaadin.ui.Component;
@@ -84,6 +89,10 @@ public class NavigatorTest extends TestCase {
             super(createMockUI(), new NullFragmentManager(), new TestDisplay());
         }
 
+        public TestNavigator(UI ui) {
+            super(ui, EasyMock.createMock(ViewDisplay.class));
+        }
+
         public View getView(String viewAndParameters) {
             try {
                 navigateTo(viewAndParameters);
@@ -92,6 +101,11 @@ public class NavigatorTest extends TestCase {
             }
             return ((TestDisplay) getDisplay()).getCurrentView();
         }
+
+        @Override
+        protected NavigationStateManager getStateManager() {
+            return super.getStateManager();
+        }
     }
 
     public static class ViewChangeTestListener implements ViewChangeListener {
@@ -181,6 +195,55 @@ public class NavigatorTest extends TestCase {
         }
     }
 
+    private static class TestUI extends UI {
+
+        TestUI(Page page) {
+            this.page = page;
+        }
+
+        @Override
+        protected void init(VaadinRequest request) {
+        }
+
+        @Override
+        public Page getPage() {
+            return page;
+        }
+
+        private Page page;
+    }
+
+    private static class TestPage extends Page {
+
+        public TestPage() {
+            super(null, null);
+        }
+
+        @Override
+        public void addUriFragmentChangedListener(
+                UriFragmentChangedListener listener) {
+            addUriFragmentCalled = true;
+        }
+
+        @Override
+        public void removeUriFragmentChangedListener(
+                UriFragmentChangedListener listener) {
+            removeUriFragmentCalled = true;
+        }
+
+        boolean addUriFragmentCalled() {
+            return addUriFragmentCalled;
+        }
+
+        boolean removeUriFragmentCalled() {
+            return removeUriFragmentCalled;
+        }
+
+        private boolean addUriFragmentCalled;
+
+        private boolean removeUriFragmentCalled;
+    }
+
     public static ViewChangeEvent eventParametersEqual(final String expected) {
         EasyMock.reportMatcher(new IArgumentMatcher() {
             @Override
@@ -210,6 +273,35 @@ public class NavigatorTest extends TestCase {
         return new Navigator(createMockUI(), manager, display);
     }
 
+    public void testDestroy_unsetNavigatorInUIAndUriFragmentManager() {
+        TestPage page = new TestPage();
+        UI ui = new TestUI(page);
+
+        TestNavigator navigator = new TestNavigator(ui);
+        Assert.assertTrue("Add URI fragment Page method has not been called",
+                page.addUriFragmentCalled());
+        Assert.assertFalse("Unexpected remove URI fragment Page method call",
+                page.removeUriFragmentCalled());
+        Assert.assertNotNull("Navigator is null in UI", ui.getNavigator());
+
+        navigator.destroy();
+        Assert.assertTrue(
+                "Remove URI fragment Page method has not been called after destroy",
+                page.removeUriFragmentCalled());
+        Assert.assertNull("Navigator is not null in UI after destroy",
+                ui.getNavigator());
+        UriFragmentManager manager = (UriFragmentManager) navigator
+                .getStateManager();
+        try {
+            manager.uriFragmentChanged(EasyMock
+                    .createMock(UriFragmentChangedEvent.class));
+            Assert.assertTrue(
+                    "Expected null pointer exception after call uriFragmentChanged "
+                            + "for destroyed navigator", false);
+        } catch (NullPointerException e) {
+        }
+    }
+
     public void testBasicNavigation() {
         IMocksControl control = EasyMock.createControl();
         NavigationStateManager manager = control
diff --git a/server/tests/src/com/vaadin/tests/server/navigator/UriFragmentManagerTest.java b/server/tests/src/com/vaadin/tests/server/navigator/UriFragmentManagerTest.java
index 85de106e23..327baae21f 100644
--- a/server/tests/src/com/vaadin/tests/server/navigator/UriFragmentManagerTest.java
+++ b/server/tests/src/com/vaadin/tests/server/navigator/UriFragmentManagerTest.java
@@ -16,18 +16,19 @@
 
 package com.vaadin.tests.server.navigator;
 
-import junit.framework.TestCase;
-
 import org.easymock.EasyMock;
 import org.easymock.IMocksControl;
+import org.junit.Assert;
+import org.junit.Test;
 
 import com.vaadin.navigator.Navigator;
 import com.vaadin.navigator.Navigator.UriFragmentManager;
 import com.vaadin.server.Page;
 import com.vaadin.server.Page.UriFragmentChangedEvent;
 
-public class UriFragmentManagerTest extends TestCase {
+public class UriFragmentManagerTest {
 
+    @Test
     public void testGetSetUriFragment() {
         Page page = EasyMock.createMock(Page.class);
         UriFragmentManager manager = new UriFragmentManager(page);
@@ -39,11 +40,13 @@ public class UriFragmentManagerTest extends TestCase {
         EasyMock.replay(page);
 
         // test manager using the mock
-        assertEquals("Incorrect fragment value", "", manager.getState());
+        Assert.assertEquals("Incorrect fragment value", "", manager.getState());
         manager.setState("test");
-        assertEquals("Incorrect fragment value", "test", manager.getState());
+        Assert.assertEquals("Incorrect fragment value", "test",
+                manager.getState());
     }
 
+    @Test
     public void testListener() {
         // create mocks
         IMocksControl control = EasyMock.createControl();
@@ -61,4 +64,63 @@ public class UriFragmentManagerTest extends TestCase {
                 "oldtest");
         manager.uriFragmentChanged(event);
     }
+
+    @Test
+    public void setNavigator_someNavigatorInstance_uriFragmentChangedListenerIsRemoved() {
+        TestPage page = new TestPage();
+
+        UriFragmentManager manager = new UriFragmentManager(page);
+        manager.setNavigator(EasyMock.createMock(Navigator.class));
+
+        Assert.assertTrue(
+                "addUriFragmentChangedListener() method is not called for the Page",
+                page.addUriFragmentCalled());
+        Assert.assertFalse(
+                "removeUriFragmentChangedListener() method is called for the Page",
+                page.removeUriFragmentCalled());
+    }
+
+    @Test
+    public void setNavigator_nullNavigatorInstance_uriFragmentChangedListenerIsRemoved() {
+        TestPage page = new TestPage();
+
+        UriFragmentManager manager = new UriFragmentManager(page);
+        manager.setNavigator(EasyMock.createMock(Navigator.class));
+
+        manager.setNavigator(null);
+        Assert.assertTrue(
+                "removeUriFragmentChangedListener() method is not called for the Page",
+                page.removeUriFragmentCalled());
+    }
+
+    private static class TestPage extends Page {
+
+        public TestPage() {
+            super(null, null);
+        }
+
+        @Override
+        public void addUriFragmentChangedListener(
+                UriFragmentChangedListener listener) {
+            addUriFragmentCalled = true;
+        }
+
+        @Override
+        public void removeUriFragmentChangedListener(
+                UriFragmentChangedListener listener) {
+            removeUriFragmentCalled = true;
+        }
+
+        boolean addUriFragmentCalled() {
+            return addUriFragmentCalled;
+        }
+
+        boolean removeUriFragmentCalled() {
+            return removeUriFragmentCalled;
+        }
+
+        private boolean addUriFragmentCalled;
+
+        private boolean removeUriFragmentCalled;
+    }
 }