Support starting downloads and opening URLs from a menu item (#10478)

4 files changed, 159 insertions, 1 deletions

diff --git a/server/src/main/java/com/vaadin/server/BrowserWindowOpener.java b/server/src/main/java/com/vaadin/server/BrowserWindowOpener.java
index 838a78184a..1115acdddb 100644
--- a/server/src/main/java/com/vaadin/server/BrowserWindowOpener.java
+++ b/server/src/main/java/com/vaadin/server/BrowserWindowOpener.java
@@ -122,11 +122,30 @@ public class BrowserWindowOpener extends AbstractExtension {
         setResource(BrowserWindowOpenerState.locationResource, resource);
     }
 
+    /**
+     * Add this extension to the target component.
+     *
+     * @param target
+     *            the component to attach this extension to
+     */
     public void extend(AbstractComponent target) {
         super.extend(target);
     }
 
     /**
+     * Add this extension to the {@code EventTrigger}.
+     *
+     * @param eventTrigger
+     *            the trigger to attach this extension to
+     *
+     * @since
+     */
+    public void extend(EventTrigger eventTrigger) {
+        super.extend(eventTrigger.getConnector());
+        getState().partInformation = eventTrigger.getPartInformation();
+    }
+
+    /**
      * Sets the provided URL {@code url} for this instance. The {@code url} will
      * be opened in a new browser window/tab when the extended component is
      * clicked.
diff --git a/server/src/main/java/com/vaadin/server/EventTrigger.java b/server/src/main/java/com/vaadin/server/EventTrigger.java
new file mode 100644
index 0000000000..08b8dbca98
--- /dev/null
+++ b/server/src/main/java/com/vaadin/server/EventTrigger.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2000-2018 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.server;
+
+import java.io.Serializable;
+
+import com.vaadin.ui.Component;
+import com.vaadin.ui.MenuBar;
+
+/**
+ * Provides support for triggering an event from a given parts of a component or
+ * using various events.
+ * <p>
+ * Used by features such as {@link FileDownloader} and
+ * {@link BrowserWindowOpener} to listen to a given event on a given element on
+ * the client side. The component is the one responsible for deciding the
+ * element and the event to listen to and can communicate this to the client
+ * using {@link #getPartInformation()}.
+ * <p>
+ * This is the server side interface.
+ * <p>
+ * If a {@link Component} implements this interface, then the corresponding
+ * connector on the client side must implement
+ * {@code com.vaadin.client.extensions.EventTrigger}.
+ *
+ * @since
+ */
+public interface EventTrigger extends Serializable {
+
+    /**
+     * Gets the connector who will be used to offer the file download. Typically
+     * a component containing a certain DOM element, which in turn triggers the
+     * download.
+     *
+     * @return the connector for the file download
+     */
+    AbstractClientConnector getConnector();
+
+    /**
+     * Gets a free form string which identifies which part of the connector that
+     * should trigger the download. The string is passed to the connector
+     * (FileDownloaderHandler implementor) on the client side.
+     * <p>
+     * For example, {@link MenuBar} passes the id of a menu item through this
+     * method so that the client side can listen to events for that particular
+     * item only.
+     *
+     * @return a free form string which makes sense to the client side connector
+     */
+    String getPartInformation();
+
+}
diff --git a/server/src/main/java/com/vaadin/server/FileDownloader.java b/server/src/main/java/com/vaadin/server/FileDownloader.java
index a35278bd9d..df4240f368 100644
--- a/server/src/main/java/com/vaadin/server/FileDownloader.java
+++ b/server/src/main/java/com/vaadin/server/FileDownloader.java
@@ -66,11 +66,30 @@ public class FileDownloader extends AbstractExtension {
         setResource("dl", resource);
     }
 
+    /**
+     * Add this extension to the target component.
+     *
+     * @param target
+     *            the component to attach this extension to
+     */
     public void extend(AbstractComponent target) {
         super.extend(target);
     }
 
     /**
+     * Add this extension to the {@code EventTrigger}.
+     *
+     * @param eventTrigger
+     *            the trigger to attach this extension to
+     *
+     * @since
+     */
+    public void extend(EventTrigger eventTrigger) {
+        super.extend(eventTrigger.getConnector());
+        getState().partInformation = eventTrigger.getPartInformation();
+    }
+
+    /**
      * Gets the resource set for download.
      *
      * @return the resource that will be downloaded if clicking the extended
diff --git a/server/src/main/java/com/vaadin/ui/MenuBar.java b/server/src/main/java/com/vaadin/ui/MenuBar.java
index f6bafb5d15..4f7055bf6e 100644
--- a/server/src/main/java/com/vaadin/ui/MenuBar.java
+++ b/server/src/main/java/com/vaadin/ui/MenuBar.java
@@ -28,6 +28,8 @@ import org.jsoup.nodes.Element;
 import org.jsoup.nodes.Node;
 import org.jsoup.parser.Tag;
 
+import com.vaadin.server.AbstractClientConnector;
+import com.vaadin.server.EventTrigger;
 import com.vaadin.server.PaintException;
 import com.vaadin.server.PaintTarget;
 import com.vaadin.server.Resource;
@@ -218,6 +220,23 @@ implements LegacyComponent, Focusable {
     }
 
     /**
+     * Adds a new menu item to the menu bar
+     * <p>
+     * Clicking on this menu item has no effect. Use
+     * {@link #addItem(String, Command)} or {@link MenuItem#setCommand(Command)}
+     * to assign an action to the menu item.
+     *
+     * @param caption
+     *            the text for the menu item
+     * @throws IllegalArgumentException
+     *
+     * @since
+     */
+    public MenuBar.MenuItem addItem(String caption) {
+        return addItem(caption, null, null);
+    }
+
+    /**
      * Add a new item to the menu bar. Command can be null, but a caption must
      * be given.
      *
@@ -453,7 +472,7 @@ implements LegacyComponent, Focusable {
      * multiple MenuItems to a MenuItem and create a sub-menu.
      *
      */
-    public class MenuItem implements Serializable {
+    public class MenuItem implements Serializable, EventTrigger {
 
         /** Private members * */
         private final int itsId;
@@ -523,6 +542,22 @@ implements LegacyComponent, Focusable {
         }
 
         /**
+         * Add a new menu item inside this menu item, creating a sub-menu.
+         * <p>
+         * Clicking on the new item has no effect. Use
+         * {@link #addItem(String, Command)} or {@link #setCommand(Command)} to
+         * assign an action to the menu item.
+         *
+         * @param caption
+         *            the text for the menu item
+         *
+         * @since
+         */
+        public MenuBar.MenuItem addItem(String caption) {
+            return addItem(caption, null, null);
+        }
+
+        /**
          * Add a new item inside this item, thus creating a sub-menu. Command
          * can be null, but a caption must be given.
          *
@@ -992,6 +1027,26 @@ implements LegacyComponent, Focusable {
             this.checked = checked;
             markAsDirty();
         }
+
+        /**
+         * Gets the menu bar this item is part of.
+         *
+         * @return the menu bar this item is attached to
+         * @since
+         */
+        public MenuBar getMenuBar() {
+            return MenuBar.this;
+        }
+
+        @Override
+        public AbstractClientConnector getConnector() {
+            return getMenuBar();
+        }
+
+        @Override
+        public String getPartInformation() {
+            return String.valueOf(getId());
+        }
     }
 
     @Override