Fail if a Window is attached to something else than a UI (#10374)

Change-Id: Ibe0fcbda1222e2aa781ae14f479fbedd99715ff9

server/src/com/vaadin/ui/UI.java

@@ -969,4 +969,20 @@ public abstract class UI extends AbstractSingleComponentContainer implements
     public void detach() {
         super.detach();
     }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * com.vaadin.ui.AbstractSingleComponentContainer#setContent(com.vaadin.
+     * ui.Component)
+     */
+    @Override
+    public void setContent(Component content) {
+        if (content instanceof Window) {
+            throw new IllegalArgumentException(
+                    "A Window cannot be added using setContent. Use addWindow(Window window) instead");
+        }
+        super.setContent(content);
+    }
 }

server/src/com/vaadin/ui/Window.java

@@ -31,6 +31,7 @@ import com.vaadin.event.ShortcutAction;
 import com.vaadin.event.ShortcutAction.KeyCode;
 import com.vaadin.event.ShortcutAction.ModifierKey;
 import com.vaadin.event.ShortcutListener;
+import com.vaadin.server.ClientConnector;
 import com.vaadin.server.PaintException;
 import com.vaadin.server.PaintTarget;
 import com.vaadin.shared.MouseEventDetails;
@@ -123,6 +124,23 @@ public class Window extends Panel implements FocusNotifier, BlurNotifier,
         super.paintContent(target);
     }
 
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * com.vaadin.ui.AbstractComponent#setParent(com.vaadin.server.ClientConnector
+     * )
+     */
+    @Override
+    public void setParent(ClientConnector parent) {
+        if (parent == null || parent instanceof UI) {
+            super.setParent(parent);
+        } else {
+            throw new IllegalArgumentException(
+                    "A Window can only be added to a UI using UI.addWindow(Window window)");
+        }
+    }
+
     /*
      * (non-Javadoc)
      * 

server/tests/src/com/vaadin/tests/server/component/window/WindowAttach.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2012 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.tests.server.component.window;
+
+import org.junit.Test;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.VerticalLayout;
+import com.vaadin.ui.Window;
+
+public class WindowAttach {
+
+    private static class MyUI extends UI {
+        @Override
+        protected void init(VaadinRequest request) {
+        }
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testAttachUsingSetContent() {
+        UI ui = new MyUI();
+        ui.setContent(new Window("foo"));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testAddToLayout() {
+        VerticalLayout vl = new VerticalLayout();
+        vl.addComponent(new Window("foo"));
+    }
+}