feat: add Menu annotation (#19147)

Menu annotation has information like title, order and icon for automatically populated menu. Matches with ViewConfig menu API in Hilla.

Related-To: #19109

Author: tltv

flow-server/src/main/java/com/vaadin/flow/router/Menu.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2000-2024 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.flow.router;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Defines menu information for a route for automatically populated menu.
+ * <p>
+ * {@link Menu} is used together with {@link Route} to include it automatically
+ * in Hilla application's main menu, but only if server routes are being exposed
+ * for client-side via 'window.Vaadin.server.views' variable in the client-side.
+ * </p>
+ *
+ * @see Route
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+@Inherited
+@Documented
+public @interface Menu {
+
+    /**
+     * Title to use in the menu. Falls back the page title if not defined.
+     *
+     * @return the title of the item in the menu. Empty String by default.
+     */
+    String title() default "";
+
+    /**
+     * Used to determine the order in the menu. Ties are resolved based on the
+     * used title. Entries without explicitly defined ordering are put below
+     * entries with an order. {@link Long#MIN_VALUE} is the default value and
+     * considered as undefined.
+     *
+     * @return the order of the item in the menu. {@link Long#MIN_VALUE} by
+     *         default.
+     */
+    long order() default Long.MIN_VALUE;
+
+    /**
+     * Set to true to explicitly exclude a view from the automatically populated
+     * menu.
+     *
+     * @return true to exclude the view from the menu, false otherwise
+     */
+    boolean exclude() default false;
+
+    /**
+     * Icon to use in the menu. Value can go inside a {@code <vaadin-icon>}
+     * element's {@code icon} attribute which accepts icon group and name like
+     * 'vaadin:file'. Or it can go to a {@code <vaadin-icon>} element's
+     * {@code src} attribute which takes path to the icon. E.g.
+     * 'line-awesome/svg/lock-open-solid.svg'.
+     *
+     * @return A String for an icon. Empty String by default.
+     */
+    String icon() default "";
+}