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

6 files changed, 207 insertions, 37 deletions

diff --git a/client/src/main/java/com/vaadin/client/extensions/AbstractEventTriggerExtensionConnector.java b/client/src/main/java/com/vaadin/client/extensions/AbstractEventTriggerExtensionConnector.java
new file mode 100644
index 0000000000..29a7da9208
--- /dev/null
+++ b/client/src/main/java/com/vaadin/client/extensions/AbstractEventTriggerExtensionConnector.java
@@ -0,0 +1,73 @@
+/*
+ * 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.client.extensions;
+
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.user.client.ui.Widget;
+import com.google.web.bindery.event.shared.HandlerRegistration;
+import com.vaadin.client.ComponentConnector;
+import com.vaadin.client.ServerConnector;
+import com.vaadin.shared.extension.PartInformationState;
+
+/**
+ * An abstract extension connector with trigger support. Implementor's
+ * {@link #trigger} method call may be initiated by another {@code Component}
+ * without server round-trip. The class is used to overcome browser security
+ * limitations. For instance, window may not be open with the round-trip.
+ *
+ * @author Vaadin Ltd.
+ * @since
+ */
+public abstract class AbstractEventTriggerExtensionConnector
+        extends AbstractExtensionConnector {
+
+    private HandlerRegistration eventHandlerRegistration;
+
+    /**
+     * Called whenever a click occurs on the widget (if widget does not
+     * implement {@link EventTrigger}) or when the {@link EventTrigger} fires.
+     *
+     */
+    protected abstract void trigger();
+
+    @Override
+    public PartInformationState getState() {
+        return (PartInformationState) super.getState();
+    }
+
+    @Override
+    protected void extend(ServerConnector target) {
+        Widget targetWidget = ((ComponentConnector) target).getWidget();
+        if (targetWidget instanceof EventTrigger) {
+            String partInformation = getState().partInformation;
+            eventHandlerRegistration = ((EventTrigger) targetWidget)
+                    .addTrigger(this::trigger, partInformation);
+        } else {
+            eventHandlerRegistration = targetWidget
+                    .addDomHandler(e -> trigger(), ClickEvent.getType());
+        }
+    }
+
+    @Override
+    public void onUnregister() {
+        super.onUnregister();
+
+        if (eventHandlerRegistration != null) {
+            eventHandlerRegistration.removeHandler();
+            eventHandlerRegistration = null;
+        }
+    }
+}
diff --git a/client/src/main/java/com/vaadin/client/extensions/BrowserWindowOpenerConnector.java b/client/src/main/java/com/vaadin/client/extensions/BrowserWindowOpenerConnector.java
index 77844d9084..009af93f1a 100644
--- a/client/src/main/java/com/vaadin/client/extensions/BrowserWindowOpenerConnector.java
+++ b/client/src/main/java/com/vaadin/client/extensions/BrowserWindowOpenerConnector.java
@@ -18,13 +18,8 @@ package com.vaadin.client.extensions;
 
 import java.util.Map.Entry;
 
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.http.client.URL;
 import com.google.gwt.user.client.Window;
-import com.google.gwt.user.client.ui.Widget;
-import com.vaadin.client.ComponentConnector;
-import com.vaadin.client.ServerConnector;
 import com.vaadin.server.BrowserWindowOpener;
 import com.vaadin.shared.ui.BrowserWindowOpenerState;
 import com.vaadin.shared.ui.Connect;
@@ -37,15 +32,8 @@ import com.vaadin.shared.util.SharedUtil;
  * @since 7.0.0
  */
 @Connect(BrowserWindowOpener.class)
-public class BrowserWindowOpenerConnector extends AbstractExtensionConnector
-        implements ClickHandler {
-
-    @Override
-    protected void extend(ServerConnector target) {
-        final Widget targetWidget = ((ComponentConnector) target).getWidget();
-
-        targetWidget.addDomHandler(this, ClickEvent.getType());
-    }
+public class BrowserWindowOpenerConnector
+        extends AbstractEventTriggerExtensionConnector {
 
     @Override
     public BrowserWindowOpenerState getState() {
@@ -53,7 +41,7 @@ public class BrowserWindowOpenerConnector extends AbstractExtensionConnector
     }
 
     @Override
-    public void onClick(ClickEvent event) {
+    protected void trigger() {
         String url = getResourceUrl(BrowserWindowOpenerState.locationResource);
         url = addParametersAndFragment(url);
         if (url != null) {
diff --git a/client/src/main/java/com/vaadin/client/extensions/EventTrigger.java b/client/src/main/java/com/vaadin/client/extensions/EventTrigger.java
new file mode 100644
index 0000000000..eecba64515
--- /dev/null
+++ b/client/src/main/java/com/vaadin/client/extensions/EventTrigger.java
@@ -0,0 +1,55 @@
+/*
+ * 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.client.extensions;
+
+import com.google.gwt.user.client.Command;
+import com.google.gwt.user.client.ui.Widget;
+import com.google.web.bindery.event.shared.HandlerRegistration;
+
+/**
+ * Provides support for triggering an event from a given parts of a component or
+ * using various events.
+ * <p>
+ * Used by features such as {@link FileDownloaderConnector} and
+ * {@link BrowserWindowOpenerConnector} to listen to a given event on a given
+ * element. The component is the one responsible for deciding the element and
+ * the event to listen to.
+ * <p>
+ * This is the client side interface.
+ * <p>
+ * If the component on the server side implements
+ * {@code com.vaadin.server.EventTrigger} then this interface should be
+ * implemented by the {@link Widget} used by the client side connector.
+ *
+ * @since
+ */
+public interface EventTrigger {
+
+    /**
+     * Adds an appropriate event handler on the correct element inside the
+     * widget and invokes the given file downloader when the event occurs.
+     *
+     * @param command
+     *            The command to execute when the event occurs
+     * @param partInformation
+     *            Information passed from the server, typically telling which
+     *            element to attach the DOM handler to
+     * @return a registration handler which can be used to remove the handler
+     */
+    public HandlerRegistration addTrigger(Command command,
+            String partInformation);
+
+}
diff --git a/client/src/main/java/com/vaadin/client/extensions/FileDownloaderConnector.java b/client/src/main/java/com/vaadin/client/extensions/FileDownloaderConnector.java
index d4023c299c..3edd79bde4 100644
--- a/client/src/main/java/com/vaadin/client/extensions/FileDownloaderConnector.java
+++ b/client/src/main/java/com/vaadin/client/extensions/FileDownloaderConnector.java
@@ -21,33 +21,27 @@ import com.google.gwt.dom.client.IFrameElement;
 import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.dom.client.Style.Visibility;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.Window;
 import com.google.gwt.user.client.ui.RootPanel;
-import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.BrowserInfo;
-import com.vaadin.client.ComponentConnector;
 import com.vaadin.client.ServerConnector;
 import com.vaadin.server.FileDownloader;
 import com.vaadin.shared.extension.filedownloader.FileDownloaderState;
 import com.vaadin.shared.ui.Connect;
 
 @Connect(FileDownloader.class)
-public class FileDownloaderConnector extends AbstractExtensionConnector
-        implements ClickHandler {
+public class FileDownloaderConnector
+        extends AbstractEventTriggerExtensionConnector {
 
     private IFrameElement iframe;
 
+    /**
+     * Called when the download should start.
+     *
+     * @since
+     */
     @Override
-    protected void extend(ServerConnector target) {
-        final Widget downloadWidget = ((ComponentConnector) target).getWidget();
-
-        downloadWidget.addDomHandler(this, ClickEvent.getType());
-    }
-
-    @Override
-    public void onClick(ClickEvent event) {
+    protected void trigger() {
         final String url = getResourceUrl("dl");
         if (url != null && !url.isEmpty()) {
             BrowserInfo browser = BrowserInfo.get();
diff --git a/client/src/main/java/com/vaadin/client/ui/VMenuBar.java b/client/src/main/java/com/vaadin/client/ui/VMenuBar.java
index d95954b26d..9dedb78205 100644
--- a/client/src/main/java/com/vaadin/client/ui/VMenuBar.java
+++ b/client/src/main/java/com/vaadin/client/ui/VMenuBar.java
@@ -16,8 +16,10 @@
 package com.vaadin.client.ui;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 import java.util.Queue;
 
 import com.google.gwt.core.client.GWT;
@@ -46,6 +48,7 @@ import com.google.gwt.user.client.ui.HasHTML;
 import com.google.gwt.user.client.ui.PopupPanel;
 import com.google.gwt.user.client.ui.RootPanel;
 import com.google.gwt.user.client.ui.Widget;
+import com.google.web.bindery.event.shared.HandlerRegistration;
 import com.vaadin.client.ApplicationConnection;
 import com.vaadin.client.BrowserInfo;
 import com.vaadin.client.LayoutManager;
@@ -53,12 +56,13 @@ import com.vaadin.client.TooltipInfo;
 import com.vaadin.client.UIDL;
 import com.vaadin.client.Util;
 import com.vaadin.client.WidgetUtil;
+import com.vaadin.client.extensions.EventTrigger;
 import com.vaadin.shared.ui.ContentMode;
 import com.vaadin.shared.ui.menubar.MenuBarConstants;
 
 public class VMenuBar extends FocusableFlowPanel
-implements CloseHandler<PopupPanel>, KeyPressHandler, KeyDownHandler,
-FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
+        implements CloseHandler<PopupPanel>, KeyPressHandler, KeyDownHandler,
+        FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler, EventTrigger {
 
     // The hierarchy of VMenuBar is a bit weird as VMenuBar is the Paintable,
     // used for the root menu but also used for the sub menus.
@@ -117,6 +121,8 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
     /** For internal use only. May be removed or replaced in the future. */
     public boolean htmlContentAllowed;
 
+    private Map<String, List<Command>> triggers = new HashMap<>();
+
     public VMenuBar() {
         // Create an empty horizontal menubar
         this(false, null);
@@ -414,9 +420,12 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
      * @param item
      */
     public void itemClick(CustomMenuItem item) {
-        if (item.getCommand() != null) {
+        boolean triggered = triggerEventIfNeeded(item);
+        if (item.getCommand() != null || triggered) {
             try {
-                item.getCommand().execute();
+                if (item.getCommand() != null) {
+                    item.getCommand().execute();
+                }
             } finally {
                 setSelected(null);
                 if (visibleChildMenu != null) {
@@ -808,6 +817,7 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
         protected ContentMode descriptionContentMode = null;
 
         private String styleName;
+        private String id;
 
         /**
          * Default menu item {@link Widget} constructor for GWT.create().
@@ -1166,6 +1176,14 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
             return null;
         }
 
+        public String getId() {
+            return id;
+        }
+
+        public void setId(String id) {
+            this.id = id;
+        }
+
     }
 
     /**
@@ -1642,6 +1660,7 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
                 openMenuAndFocusFirstIfPossible(getSelected());
             } else {
                 try {
+                    triggerEventIfNeeded(getSelected());
                     final Command command = getSelected().getCommand();
                     if (command != null) {
                         command.execute();
@@ -1654,10 +1673,7 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
                     // not leave menu to visible ("hover open") mode
                     menuVisible = false;
 
-                    VMenuBar root = this;
-                    while (root.getParentMenu() != null) {
-                        root = root.getParentMenu();
-                    }
+                    VMenuBar root = getRoot();
                     root.ignoreFocus = true;
                     root.getElement().focus();
                     root.ignoreFocus = false;
@@ -1669,6 +1685,17 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
         return false;
     }
 
+    private boolean triggerEventIfNeeded(CustomMenuItem item) {
+        List<Command> commands = getTriggers().get(item.getId());
+        if (commands != null) {
+            for (Command command : commands) {
+                command.execute();
+            }
+            return true;
+        }
+        return false;
+    }
+
     private void selectFirstItem() {
         for (int i = 0; i < items.size(); i++) {
             CustomMenuItem item = items.get(i);
@@ -1877,4 +1904,36 @@ FocusHandler, SubPartAware, MouseOutHandler, MouseOverHandler {
     public void onMouseOut(MouseOutEvent event) {
         LazyCloser.schedule();
     }
+
+    private VMenuBar getRoot() {
+        VMenuBar root = this;
+
+        while (root.getParentMenu() != null) {
+            root = root.getParentMenu();
+        }
+
+        return root;
+    }
+
+    @Override
+    public HandlerRegistration addTrigger(Command command,
+            String partInformation) {
+        if (partInformation == null || partInformation.isEmpty()) {
+            throw new IllegalArgumentException(
+                    "The 'partInformation' parameter must contain the menu item id");
+        }
+
+        getTriggers().computeIfAbsent(partInformation, s-> new ArrayList<>()).add(command);
+        return () -> {
+            List<Command> commands = getTriggers().get(partInformation);
+            if (commands != null) {
+                commands.remove(command);
+            }
+        };
+    }
+
+    private Map<String, List<Command>> getTriggers() {
+        return getRoot().triggers;
+    }
+
 }
diff --git a/client/src/main/java/com/vaadin/client/ui/menubar/MenuBarConnector.java b/client/src/main/java/com/vaadin/client/ui/menubar/MenuBarConnector.java
index 6e6869edb2..8697f07d49 100644
--- a/client/src/main/java/com/vaadin/client/ui/menubar/MenuBarConnector.java
+++ b/client/src/main/java/com/vaadin/client/ui/menubar/MenuBarConnector.java
@@ -129,6 +129,7 @@ public class MenuBarConnector extends AbstractComponentConnector
             }
 
             currentItem = currentMenu.addItem(itemHTML, cmd);
+            currentItem.setId("" + itemId);
             currentItem.updateFromUIDL(item, client);
 
             if (item.getChildCount() > 0) {