Delegate UI.replaceComponent() to content instead of throwing UOE (#9967)

* Added a test, also renamed tests/server/component/root to tests/server/component/ui

Change-Id: I80d30dd5acb3643cfb3cfc0b972f52ffa4512691

3 files changed, 71 insertions, 2 deletions

diff --git a/server/src/com/vaadin/ui/UI.java b/server/src/com/vaadin/ui/UI.java
index 31a7446e96..2878d10fa1 100644
--- a/server/src/com/vaadin/ui/UI.java
+++ b/server/src/com/vaadin/ui/UI.java
@@ -556,9 +556,13 @@ public abstract class UI extends AbstractComponentContainer implements
         return this;
     }
 
+    /**
+     * This implementation replaces a component in the content container (
+     * {@link #getContent()}) instead of in the actual UI.
+     */
     @Override
     public void replaceComponent(Component oldComponent, Component newComponent) {
-        throw new UnsupportedOperationException();
+        getContent().replaceComponent(oldComponent, newComponent);
     }
 
     /**
diff --git a/server/tests/src/com/vaadin/tests/server/component/root/CustomUIClassLoader.java b/server/tests/src/com/vaadin/tests/server/component/ui/CustomUIClassLoader.java
index 405d3d1931..82b9944371 100644
--- a/server/tests/src/com/vaadin/tests/server/component/root/CustomUIClassLoader.java
+++ b/server/tests/src/com/vaadin/tests/server/component/ui/CustomUIClassLoader.java
@@ -1,4 +1,4 @@
-package com.vaadin.tests.server.component.root;
+package com.vaadin.tests.server.component.ui;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/server/tests/src/com/vaadin/tests/server/component/ui/UIAddRemoveComponents.java b/server/tests/src/com/vaadin/tests/server/component/ui/UIAddRemoveComponents.java
new file mode 100644
index 0000000000..1b07321605
--- /dev/null
+++ b/server/tests/src/com/vaadin/tests/server/component/ui/UIAddRemoveComponents.java
@@ -0,0 +1,65 @@
+package com.vaadin.tests.server.component.ui;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertSame;
+
+import org.junit.Test;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.UI;
+
+public class UIAddRemoveComponents {
+
+    private static class TestUI extends UI {
+        @Override
+        protected void init(VaadinRequest request) {
+        }
+    }
+
+    @Test
+    public void addComponent() {
+        UI ui = new TestUI();
+        Component c = new Label("abc");
+
+        ui.addComponent(c);
+
+        assertSame(c, ui.iterator().next());
+        assertSame(c, ui.getContent().iterator().next());
+        assertEquals(1, ui.getComponentCount());
+        assertEquals(1, ui.getContent().getComponentCount());
+    }
+
+    @Test
+    public void removeComponent() {
+        UI ui = new TestUI();
+        Component c = new Label("abc");
+
+        ui.addComponent(c);
+
+        ui.removeComponent(c);
+
+        assertFalse(ui.iterator().hasNext());
+        assertFalse(ui.getContent().iterator().hasNext());
+        assertEquals(0, ui.getComponentCount());
+        assertEquals(0, ui.getContent().getComponentCount());
+    }
+
+    @Test
+    public void replaceComponent() {
+        UI ui = new TestUI();
+        Component c = new Label("abc");
+        Component d = new Label("def");
+
+        ui.addComponent(c);
+
+        ui.replaceComponent(c, d);
+
+        assertSame(d, ui.iterator().next());
+        assertSame(d, ui.getContent().iterator().next());
+        assertEquals(1, ui.getComponentCount());
+        assertEquals(1, ui.getContent().getComponentCount());
+    }
+}