feat: add MenuConfiguration

New public API for building application menu: adds `MenuConfiguration`, `MenuOptions` and `MenuOption` where `MenuConfiguration` is the main entry point to access menu data to build main menu.

Fixes: #20063

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

@@ -19,12 +19,14 @@
 import java.io.Serializable;
 import java.util.Objects;
 
+import com.vaadin.flow.component.Component;
+
 /**
  * Data class for menu item information.
  * <p>
  * Only for read as data is immutable.
  */
-public record MenuData(String title, Double order, boolean exclude, String icon) implements Serializable {
+public record MenuData(String title, Double order, boolean exclude, String icon, Class<? extends Component> menuClass) implements Serializable {
 
     /**
      * Gets the title of the menu item.
@@ -65,20 +67,7 @@ public String getIcon() {
     @Override
     public String toString() {
         return "MenuData{" + "title='" + title + '\'' + ", order=" + order
-                + ", exclude=" + exclude + ", icon='" + icon + '\'' + '}';
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        return obj instanceof MenuData other
-                && Objects.equals(title, other.title)
-                && Objects.equals(order, other.order)
-                && Objects.equals(exclude, other.exclude)
-                && Objects.equals(icon, other.icon);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(title, order, exclude, icon);
+                + ", exclude=" + exclude + ", icon='" + icon + "', menuClass='"
+                + menuClass + "'" + '}';
     }
 }

flow-server/src/main/java/com/vaadin/flow/router/internal/AbstractRouteRegistry.java

@@ -324,7 +324,7 @@ private void populateRegisteredRoutes(ConfiguredRoutes configuration,
                         (Objects.equals(menu.order(), Double.MIN_VALUE)) ? null
                                 : menu.order(),
                         excludeFromMenu,
-                        (menu.icon().isBlank() ? null : menu.icon())))
+                        (menu.icon().isBlank() ? null : menu.icon()), target))
                 .orElse(null);
 
         RouteData route = new RouteData(parentLayouts, template, parameters,

flow-server/src/main/java/com/vaadin/flow/server/menu/MenuConfiguration.java

@@ -0,0 +1,36 @@
+/*
+ * 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.server.menu;
+
+import java.io.Serializable;
+
+/**
+ * Menu configuration helper class to retrieve available menu options for
+ * application main menu.
+ */
+public class MenuConfiguration implements Serializable {
+
+    /**
+     * Get the {@link MenuOptions} instance containing all menu options for the
+     * application.
+     *
+     * @return the {@link MenuOptions} instance
+     */
+    public static MenuOptions getMenuOptions() {
+        return MenuOptions.getInstance();
+    }
+}

flow-server/src/main/java/com/vaadin/flow/server/menu/MenuOption.java

@@ -0,0 +1,46 @@
+/*
+ * 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.server.menu;
+
+import java.io.Serializable;
+
+import com.vaadin.flow.component.Component;
+
+/**
+ * Menu option for the main menu.
+ *
+ * @param path
+ *            the path to navigate to
+ * @param title
+ *            the title to display
+ * @param order
+ *            the order in the menu or null for default order
+ * @param exclude
+ *            whether to exclude the menu option
+ * @param icon
+ *            Icon to use in the menu or null for no icon. 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'.
+ * @param menuClass
+ *            the source class with {@link com.vaadin.flow.router.Menu}
+ *            annotation or null if not available
+ */
+public record MenuOption(String path, String title, Double order,
+        boolean exclude, String icon, Class<? extends Component> menuClass) implements Serializable  {
+}

flow-server/src/main/java/com/vaadin/flow/server/menu/MenuOptions.java

@@ -0,0 +1,73 @@
+/*
+ * 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.server.menu;
+
+import java.io.Serializable;
+import java.util.List;
+import java.util.stream.Stream;
+
+/**
+ * {@link MenuOptions} holds a list of menu options.
+ */
+public class MenuOptions implements Serializable {
+
+    private final List<MenuOption> menuOptions;
+
+    private MenuOptions(List<MenuOption> menuOptions) {
+        this.menuOptions = menuOptions;
+    }
+
+    /**
+     * Construct a new instance containing all available menu options.
+     */
+    public static MenuOptions getInstance() {
+        return new MenuOptions(
+                MenuRegistry.collectMenuItemsList().stream().map(viewInfo -> {
+                    if (viewInfo.menu() == null) {
+                        return new MenuOption(viewInfo.route(),
+                                viewInfo.title(), null, false, null, null);
+                    }
+                    return new MenuOption(viewInfo.route(),
+                            (viewInfo.menu().title() != null
+                                    && !viewInfo.menu().title().isBlank()
+                                            ? viewInfo.menu().title()
+                                            : viewInfo.title()),
+                            viewInfo.menu().order(), viewInfo.menu().exclude(),
+                            viewInfo.menu().icon(),
+                            viewInfo.menu().menuClass());
+                }).toList());
+    }
+
+    /**
+     * Get a stream of the menu options.
+     *
+     * @return the menu options stream
+     */
+    public Stream<MenuOption> stream() {
+        return menuOptions.stream();
+    }
+
+    /**
+     * Get the list of the menu options. Returned list is mutable and any
+     * changes to it will also change {@link MenuOptions} state.
+     *
+     * @return the menu options list
+     */
+    public List<MenuOption> get() {
+        return menuOptions;
+    }
+}