UI based on AbstractBasicComponentContainer (#2924)

Change-Id: I1614a3464b8e7a0e9ecdd8c3a76335cdb85bdf87

1 files changed, 63 insertions, 0 deletions

diff --git a/server/src/com/vaadin/ui/SingleComponentContainer.java b/server/src/com/vaadin/ui/SingleComponentContainer.java
new file mode 100644
index 0000000000..deb647e5eb
--- /dev/null
+++ b/server/src/com/vaadin/ui/SingleComponentContainer.java
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+/*
+ * 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.ui;
+
+import com.vaadin.ui.HasComponents.ComponentAttachDetachNotifier;
+
+/**
+ * Interface for component containers that have one child component and do not
+ * support adding or removing components.
+ * 
+ * For component containers that support multiple children, see
+ * {@link ComponentContainer} instead.
+ * 
+ * @since 7.0
+ */
+public interface SingleComponentContainer extends HasComponents,
+        ComponentAttachDetachNotifier {
+
+    /**
+     * Gets the number of children this {@link SingleComponentContainer} has.
+     * This must be symmetric with what {@link #iterator()} returns and thus
+     * typically return 1 if the content is set, 0 otherwise.
+     * 
+     * @return The number of child components this container has.
+     */
+    public int getComponentCount();
+
+    /**
+     * Gets the content of this container. The content is a component that
+     * serves as the outermost item of the visual contents.
+     * 
+     * @return a component to use as content
+     * 
+     * @see #setContent(Component)
+     */
+    public Component getContent();
+
+    /**
+     * Sets the content of this container. The content is a component that
+     * serves as the outermost item of the visual contents.
+     * 
+     * The content should always be set, either as a constructor parameter or by
+     * calling this method.
+     * 
+     * @return a component (typically a layout) to use as content
+     */
+    public void setContent(Component content);
+
+}