Use lambda with Handlers (#10229)

Also improve naming by replacing one-letter variable names.

30 files changed, 183 insertions, 388 deletions

diff --git a/uitest/src/main/java/com/vaadin/tests/application/NavigateWithOngoingXHR.java b/uitest/src/main/java/com/vaadin/tests/application/NavigateWithOngoingXHR.java
index 6193b4d5ee..4941994e73 100644
--- a/uitest/src/main/java/com/vaadin/tests/application/NavigateWithOngoingXHR.java
+++ b/uitest/src/main/java/com/vaadin/tests/application/NavigateWithOngoingXHR.java
@@ -16,50 +16,43 @@
 
 package com.vaadin.tests.application;
 
-import java.io.IOException;
 import java.io.PrintWriter;
 
 import com.vaadin.server.ExternalResource;
 import com.vaadin.server.RequestHandler;
 import com.vaadin.server.VaadinRequest;
-import com.vaadin.server.VaadinResponse;
-import com.vaadin.server.VaadinSession;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
 import com.vaadin.ui.Link;
 import com.vaadin.v7.shared.ui.progressindicator.ProgressIndicatorServerRpc;
 import com.vaadin.v7.ui.ProgressIndicator;
 
 public class NavigateWithOngoingXHR extends AbstractReindeerTestUI {
-    private final RequestHandler slowRequestHandler = new RequestHandler() {
-        @Override
-        public boolean handleRequest(VaadinSession session,
-                VaadinRequest request, VaadinResponse response)
-                throws IOException {
-            if ("/slowRequestHandler".equals(request.getPathInfo())) {
-                // Make the navigation request last longer to keep the
-                // communication error visible
-                // System.out.println("Got slow content request");
-                try {
-                    Thread.sleep(5000);
-                } catch (InterruptedException e) {
-                    e.printStackTrace();
-                }
+    private final RequestHandler slowRequestHandler = (session, request,
+            response) -> {
+        if ("/slowRequestHandler".equals(request.getPathInfo())) {
+            // Make the navigation request last longer to keep the
+            // communication error visible
+            // System.out.println("Got slow content request");
+            try {
+                Thread.sleep(5000);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
 
-                if (request.getParameter("download") != null) {
-                    response.setHeader("Content-Disposition", "attachment");
-                }
+            if (request.getParameter("download") != null) {
+                response.setHeader("Content-Disposition", "attachment");
+            }
 
-                response.setContentType("text/plain");
-                PrintWriter writer = response.getWriter();
-                writer.println("Loaded slowly");
-                writer.close();
+            response.setContentType("text/plain");
+            PrintWriter writer = response.getWriter();
+            writer.println("Loaded slowly");
+            writer.close();
 
-                // System.out.println("Finished slow content request");
+            // System.out.println("Finished slow content request");
 
-                return true;
-            }
-            return false;
+            return true;
         }
+        return false;
     };
 
     @Override
diff --git a/uitest/src/main/java/com/vaadin/tests/applicationservlet/TestingServiceInitListener.java b/uitest/src/main/java/com/vaadin/tests/applicationservlet/TestingServiceInitListener.java
index d100108c3c..5b9db4ea9c 100644
--- a/uitest/src/main/java/com/vaadin/tests/applicationservlet/TestingServiceInitListener.java
+++ b/uitest/src/main/java/com/vaadin/tests/applicationservlet/TestingServiceInitListener.java
@@ -15,17 +15,12 @@
  */
 package com.vaadin.tests.applicationservlet;
 
-import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import com.vaadin.server.ConnectorIdGenerationEvent;
 import com.vaadin.server.ConnectorIdGenerator;
-import com.vaadin.server.RequestHandler;
 import com.vaadin.server.ServiceInitEvent;
-import com.vaadin.server.VaadinRequest;
-import com.vaadin.server.VaadinResponse;
 import com.vaadin.server.VaadinServiceInitListener;
-import com.vaadin.server.VaadinSession;
 
 public class TestingServiceInitListener implements VaadinServiceInitListener {
 
@@ -37,14 +32,9 @@ public class TestingServiceInitListener implements VaadinServiceInitListener {
     public void serviceInit(ServiceInitEvent event) {
         initCount.incrementAndGet();
 
-        event.addRequestHandler(new RequestHandler() {
-            @Override
-            public boolean handleRequest(VaadinSession session,
-                    VaadinRequest request, VaadinResponse response)
-                    throws IOException {
-                requestCount.incrementAndGet();
-                return false;
-            }
+        event.addRequestHandler((session, request, response) -> {
+            requestCount.incrementAndGet();
+            return false;
         });
 
         event.addConnectorIdGenerator(new ConnectorIdGenerator() {
diff --git a/uitest/src/main/java/com/vaadin/tests/components/abstractcomponent/ResponseWritingErrorHandling.java b/uitest/src/main/java/com/vaadin/tests/components/abstractcomponent/ResponseWritingErrorHandling.java
index 679ad6f18d..2f8cdae641 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/abstractcomponent/ResponseWritingErrorHandling.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/abstractcomponent/ResponseWritingErrorHandling.java
@@ -24,12 +24,9 @@ public class ResponseWritingErrorHandling extends AbstractTestUIWithLog {
 
     @Override
     protected void setup(VaadinRequest request) {
-        ErrorHandler errorHandler = new ErrorHandler() {
-            @Override
-            public void error(com.vaadin.server.ErrorEvent event) {
-                String message = event.getThrowable().getMessage();
-                log(message);
-            }
+        ErrorHandler errorHandler = event -> {
+            String message = event.getThrowable().getMessage();
+            log(message);
         };
 
         Button button = new Button("Throw in beforeClientResponse") {
diff --git a/uitest/src/main/java/com/vaadin/tests/components/abstractfield/TextFieldConversions.java b/uitest/src/main/java/com/vaadin/tests/components/abstractfield/TextFieldConversions.java
index 49745d96ca..94fd1b98e5 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/abstractfield/TextFieldConversions.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/abstractfield/TextFieldConversions.java
@@ -2,8 +2,6 @@ package com.vaadin.tests.components.abstractfield;
 
 import java.util.Date;
 
-import com.vaadin.server.ErrorEvent;
-import com.vaadin.server.ErrorHandler;
 import com.vaadin.server.UserError;
 import com.vaadin.v7.data.util.ObjectProperty;
 import com.vaadin.v7.ui.ComboBox;
@@ -34,12 +32,7 @@ public class TextFieldConversions extends AbstractComponentDataBindingTest {
 
         tf = new TextField("TextField");
         addComponent(tf);
-        tf.setErrorHandler(new ErrorHandler() {
-
-            @Override
-            public void error(ErrorEvent event) {
-                tf.setComponentError(new UserError("Invalid value"));
-            }
-        });
+        tf.setErrorHandler(
+                event -> tf.setComponentError(new UserError("Invalid value")));
     }
 }
diff --git a/uitest/src/main/java/com/vaadin/tests/components/combobox/NewItemsESCPress.java b/uitest/src/main/java/com/vaadin/tests/components/combobox/NewItemsESCPress.java
index 95af0ad435..99ee908173 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/combobox/NewItemsESCPress.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/combobox/NewItemsESCPress.java
@@ -1,7 +1,6 @@
 package com.vaadin.tests.components.combobox;
 
 import com.vaadin.tests.components.TestBase;
-import com.vaadin.v7.ui.AbstractSelect.NewItemHandler;
 import com.vaadin.v7.ui.ComboBox;
 import com.vaadin.v7.ui.TextArea;
 
@@ -16,13 +15,10 @@ public class NewItemsESCPress extends TestBase {
 
         final ComboBox box = new ComboBox("New items are allowed");
         box.setNewItemsAllowed(true);
-        box.setNewItemHandler(new NewItemHandler() {
-            @Override
-            public void addNewItem(String newItemCaption) {
-                String value = addedItems.getValue();
-                addedItems.setValue(value + newItemCaption + "\n");
-                box.addItem(newItemCaption);
-            }
+        box.setNewItemHandler(newItemCaption -> {
+            String value = addedItems.getValue();
+            addedItems.setValue(value + newItemCaption + "\n");
+            box.addItem(newItemCaption);
         });
         box.setImmediate(true);
         addComponent(box);
diff --git a/uitest/src/main/java/com/vaadin/tests/components/table/TableWithBrokenGeneratorAndContainer.java b/uitest/src/main/java/com/vaadin/tests/components/table/TableWithBrokenGeneratorAndContainer.java
index 4c779c33f0..0d947c1dc7 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/table/TableWithBrokenGeneratorAndContainer.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/table/TableWithBrokenGeneratorAndContainer.java
@@ -18,8 +18,6 @@ package com.vaadin.tests.components.table;
 import java.lang.reflect.InvocationTargetException;
 
 import com.vaadin.event.ListenerMethod.MethodException;
-import com.vaadin.server.ErrorEvent;
-import com.vaadin.server.ErrorHandler;
 import com.vaadin.server.ServerRpcManager.RpcInvocationException;
 import com.vaadin.server.VaadinSession;
 import com.vaadin.tests.components.TestBase;
@@ -118,25 +116,21 @@ public class TableWithBrokenGeneratorAndContainer extends TestBase {
 
     protected void setErrorHandler(boolean enabled) {
         if (enabled) {
-            VaadinSession.getCurrent().setErrorHandler(new ErrorHandler() {
-
-                @Override
-                public void error(ErrorEvent event) {
-                    Throwable t = event.getThrowable();
-                    if (t instanceof RpcInvocationException) {
+            VaadinSession.getCurrent().setErrorHandler(event -> {
+                Throwable t = event.getThrowable();
+                if (t instanceof RpcInvocationException) {
+                    t = t.getCause();
+                    if (t instanceof InvocationTargetException) {
                         t = t.getCause();
-                        if (t instanceof InvocationTargetException) {
+                        if (t instanceof MethodException) {
                             t = t.getCause();
-                            if (t instanceof MethodException) {
-                                t = t.getCause();
-                                if (t instanceof CacheUpdateException) {
-                                    Table table = ((CacheUpdateException) t)
-                                            .getTable();
-                                    table.removeAllItems();
-                                    Notification.show(
-                                            "Problem updating table. Please try again later",
-                                            Notification.Type.ERROR_MESSAGE);
-                                }
+                            if (t instanceof CacheUpdateException) {
+                                Table table = ((CacheUpdateException) t)
+                                        .getTable();
+                                table.removeAllItems();
+                                Notification.show(
+                                        "Problem updating table. Please try again later",
+                                        Notification.Type.ERROR_MESSAGE);
                             }
                         }
                     }
diff --git a/uitest/src/main/java/com/vaadin/tests/components/tabsheet/TabSheetTest.java b/uitest/src/main/java/com/vaadin/tests/components/tabsheet/TabSheetTest.java
index 6fa8511b0a..7c4a31bf05 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/tabsheet/TabSheetTest.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/tabsheet/TabSheetTest.java
@@ -4,9 +4,7 @@ import java.util.LinkedHashMap;
 
 import com.vaadin.server.Resource;
 import com.vaadin.tests.components.AbstractComponentContainerTest;
-import com.vaadin.ui.Component;
 import com.vaadin.ui.TabSheet;
-import com.vaadin.ui.TabSheet.CloseHandler;
 import com.vaadin.ui.TabSheet.SelectedTabChangeEvent;
 import com.vaadin.ui.TabSheet.SelectedTabChangeListener;
 import com.vaadin.ui.TabSheet.Tab;
@@ -42,23 +40,14 @@ public class TabSheetTest<T extends TabSheet> extends
         @Override
         public void execute(T c, Boolean value, Object data) {
             if (value) {
-                c.setCloseHandler(new CloseHandler() {
-                    @Override
-                    public void onTabClose(TabSheet tabsheet, Component c) {
-                        tabClosed(tabsheet, tabsheet.getTab(c));
-                        tabsheet.removeComponent(c);
-                    }
-
+                c.setCloseHandler((tabsheet, comp) -> {
+                    tabClosed(tabsheet, tabsheet.getTab(comp));
+                    tabsheet.removeComponent(comp);
                 });
             } else {
-                c.setCloseHandler(new CloseHandler() {
-                    @Override
-                    public void onTabClose(TabSheet tabsheet, Component c) {
-                        tabsheet.removeComponent(c);
-                    }
-                });
+                c.setCloseHandler(
+                        (tabsheet, comp) -> tabsheet.removeComponent(comp));
             }
-
         }
     };
     private Command<T, Boolean> setSelectedTabListener = new Command<T, Boolean>() {
diff --git a/uitest/src/main/java/com/vaadin/tests/components/ui/UIInitException.java b/uitest/src/main/java/com/vaadin/tests/components/ui/UIInitException.java
index 76573d1f81..c57578824a 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/ui/UIInitException.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/ui/UIInitException.java
@@ -1,6 +1,5 @@
 package com.vaadin.tests.components.ui;
 
-import com.vaadin.server.ErrorHandler;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
 import com.vaadin.ui.Label;
@@ -9,14 +8,9 @@ public class UIInitException extends AbstractReindeerTestUI {
 
     @Override
     protected void setup(VaadinRequest request) {
-        setErrorHandler(new ErrorHandler() {
-            @Override
-            public void error(com.vaadin.server.ErrorEvent event) {
-                addComponent(new Label("An exception occurred: "
-                        + event.getThrowable().getMessage()));
-
-            }
-        });
+        setErrorHandler(
+                event -> addComponent(new Label("An exception occurred: "
+                        + event.getThrowable().getMessage())));
         throw new RuntimeException("Catch me if you can");
     }
 
diff --git a/uitest/src/main/java/com/vaadin/tests/dd/DDTest1.java b/uitest/src/main/java/com/vaadin/tests/dd/DDTest1.java
index 06027bf820..4ffb0c2466 100644
--- a/uitest/src/main/java/com/vaadin/tests/dd/DDTest1.java
+++ b/uitest/src/main/java/com/vaadin/tests/dd/DDTest1.java
@@ -182,7 +182,6 @@ public class DDTest1 extends TestBase {
                         copyChildren(source, target, childId);
                     }
                 }
-
             }
 
             @Override
diff --git a/uitest/src/main/java/com/vaadin/tests/errorhandler/ErrorHandlers.java b/uitest/src/main/java/com/vaadin/tests/errorhandler/ErrorHandlers.java
index 15c5196abd..38b8ba8859 100644
--- a/uitest/src/main/java/com/vaadin/tests/errorhandler/ErrorHandlers.java
+++ b/uitest/src/main/java/com/vaadin/tests/errorhandler/ErrorHandlers.java
@@ -38,15 +38,8 @@ public class ErrorHandlers extends AbstractReindeerTestUI {
 
         final VerticalLayout layoutWithErrorHandler = new VerticalLayout(
                 runtimeExceptionOnClick(new Button("Error handler on parent")));
-        ErrorHandler e = new ErrorHandler() {
-
-            @Override
-            public void error(com.vaadin.server.ErrorEvent event) {
-                layoutWithErrorHandler.addComponent(
-                        new Label("Layout error: " + getErrorMessage(event)));
-            }
-
-        };
+        ErrorHandler e = event -> layoutWithErrorHandler.addComponent(
+                new Label("Layout error: " + getErrorMessage(event)));
         layoutWithErrorHandler.setErrorHandler(e);
         layoutWithErrorHandler.addComponent(notificationErrorHandler(
                 npeOnClick(new Button("Error handler on button and parent"))));
diff --git a/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a1/DynamicImageUI.java b/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a1/DynamicImageUI.java
index a24278de3f..e9e0b99ecf 100644
--- a/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a1/DynamicImageUI.java
+++ b/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a1/DynamicImageUI.java
@@ -1,7 +1,6 @@
 package com.vaadin.tests.minitutorials.v7a1;
 
 import java.awt.image.BufferedImage;
-import java.io.IOException;
 
 import javax.imageio.ImageIO;
 
@@ -9,36 +8,30 @@ import com.vaadin.server.ExternalResource;
 import com.vaadin.server.RequestHandler;
 import com.vaadin.server.Resource;
 import com.vaadin.server.VaadinRequest;
-import com.vaadin.server.VaadinResponse;
-import com.vaadin.server.VaadinSession;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
 import com.vaadin.ui.Image;
 
 public class DynamicImageUI extends AbstractReindeerTestUI {
     public static final String IMAGE_URL = "myimage.png";
 
-    private final RequestHandler requestHandler = new RequestHandler() {
-        @Override
-        public boolean handleRequest(VaadinSession session,
-                VaadinRequest request, VaadinResponse response)
-                throws IOException {
-            if (("/" + IMAGE_URL).equals(request.getPathInfo())) {
-                // Create an image, draw the "text" parameter to it and output
-                // it to the browser.
-                String text = request.getParameter("text");
-                BufferedImage bi = new BufferedImage(100, 30,
-                        BufferedImage.TYPE_3BYTE_BGR);
-                bi.getGraphics().drawChars(text.toCharArray(), 0, text.length(),
-                        10, 20);
-                response.setContentType("image/png");
-                ImageIO.write(bi, "png", response.getOutputStream());
+    private final RequestHandler requestHandler = (session, request,
+            response) -> {
+        if (("/" + IMAGE_URL).equals(request.getPathInfo())) {
+            // Create an image, draw the "text" parameter to it and output
+            // it to the browser.
+            String text = request.getParameter("text");
+            BufferedImage bi = new BufferedImage(100, 30,
+                    BufferedImage.TYPE_3BYTE_BGR);
+            bi.getGraphics().drawChars(text.toCharArray(), 0, text.length(), 10,
+                    20);
+            response.setContentType("image/png");
+            ImageIO.write(bi, "png", response.getOutputStream());
 
-                return true;
-            }
-            // If the URL did not match our image URL, let the other request
-            // handlers handle it
-            return false;
+            return true;
         }
+        // If the URL did not match our image URL, let the other request
+        // handlers handle it
+        return false;
     };
 
     @Override
diff --git a/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a2/MyPickerWidget.java b/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a2/MyPickerWidget.java
index 49ec4da0b2..985ede4aa7 100644
--- a/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a2/MyPickerWidget.java
+++ b/uitest/src/main/java/com/vaadin/tests/minitutorials/v7a2/MyPickerWidget.java
@@ -2,8 +2,6 @@ package com.vaadin.tests.minitutorials.v7a2;
 
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Style.Unit;
-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.ComplexPanel;
 import com.google.gwt.user.client.ui.PushButton;
@@ -26,12 +24,8 @@ public class MyPickerWidget extends ComplexPanel {
         add(textBox, getElement());
         add(button, getElement());
 
-        button.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                Window.alert("Calendar picker not yet supported!");
-            }
-        });
+        button.addClickHandler(
+                event -> Window.alert("Calendar picker not yet supported!"));
     }
 
     public void setButtonText(String buttonText, boolean adjustSpace) {
diff --git a/uitest/src/main/java/com/vaadin/tests/push/PushErrorHandling.java b/uitest/src/main/java/com/vaadin/tests/push/PushErrorHandling.java
index 92f073aad4..82b922db37 100644
--- a/uitest/src/main/java/com/vaadin/tests/push/PushErrorHandling.java
+++ b/uitest/src/main/java/com/vaadin/tests/push/PushErrorHandling.java
@@ -4,13 +4,11 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
-import com.vaadin.server.ErrorHandler;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.server.VaadinSession;
 import com.vaadin.shared.communication.PushMode;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
 import com.vaadin.ui.Button;
-import com.vaadin.ui.Button.ClickEvent;
 import com.vaadin.ui.Label;
 import com.vaadin.v7.data.util.AbstractInMemoryContainer;
 import com.vaadin.v7.data.util.BeanContainer;
@@ -24,23 +22,16 @@ public class PushErrorHandling extends AbstractReindeerTestUI {
     protected void setup(VaadinRequest request) {
         getPushConfiguration().setPushMode(PushMode.AUTOMATIC);
 
-        VaadinSession.getCurrent().setErrorHandler(new ErrorHandler() {
-
-            @Override
-            public void error(com.vaadin.server.ErrorEvent event) {
-                addComponent(new Label(
-                        "An error! " + event.getThrowable().getMessage()));
-                System.err.println(
-                        "An error! " + event.getThrowable().getMessage());
-            }
+        VaadinSession.getCurrent().setErrorHandler(event -> {
+            addComponent(
+                    new Label(
+                            "An error! " + event.getThrowable().getMessage()));
+            System.err
+                    .println("An error! " + event.getThrowable().getMessage());
         });
 
-        final Button button = new Button("Click for NPE!",
-                new Button.ClickListener() {
-                    @Override
-                    public void buttonClick(ClickEvent event) {
-                        ((String) null).length(); // Null-pointer exception
-                    }
+        final Button button = new Button("Click for NPE!", event -> {
+                    ((String) null).length(); // Null-pointer exception
                 });
         button.setId("npeButton");
         addComponent(button);
diff --git a/uitest/src/main/java/com/vaadin/tests/themes/valo/CalendarTest.java b/uitest/src/main/java/com/vaadin/tests/themes/valo/CalendarTest.java
index ad5a13e744..9d735ad2e2 100644
--- a/uitest/src/main/java/com/vaadin/tests/themes/valo/CalendarTest.java
+++ b/uitest/src/main/java/com/vaadin/tests/themes/valo/CalendarTest.java
@@ -39,7 +39,6 @@ import com.vaadin.v7.ui.DateField;
 import com.vaadin.v7.ui.TextArea;
 import com.vaadin.v7.ui.TextField;
 import com.vaadin.v7.ui.components.calendar.CalendarComponentEvents.DateClickEvent;
-import com.vaadin.v7.ui.components.calendar.CalendarComponentEvents.EventClick;
 import com.vaadin.v7.ui.components.calendar.CalendarComponentEvents.EventClickHandler;
 import com.vaadin.v7.ui.components.calendar.CalendarComponentEvents.RangeSelectEvent;
 import com.vaadin.v7.ui.components.calendar.CalendarComponentEvents.RangeSelectHandler;
@@ -625,13 +624,9 @@ public class CalendarTest extends GridLayout implements View {
             }
         });
 
-        calendarComponent.setHandler(new EventClickHandler() {
-
-            @Override
-            public void eventClick(EventClick event) {
-                showEventPopup(event.getCalendarEvent(), false);
-            }
-        });
+        calendarComponent
+                .setHandler((EventClickHandler)
+        event -> showEventPopup(event.getCalendarEvent(), false));
 
         calendarComponent.setHandler(new BasicDateClickHandler() {
 
@@ -644,13 +639,9 @@ public class CalendarTest extends GridLayout implements View {
             }
         });
 
-        calendarComponent.setHandler(new RangeSelectHandler() {
-
-            @Override
-            public void rangeSelect(RangeSelectEvent event) {
-                handleRangeSelect(event);
-            }
-        });
+        calendarComponent
+                .setHandler(
+                        (RangeSelectHandler) event -> handleRangeSelect(event));
     }
 
     private ComboBox createTimeZoneSelect() {
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/ResizeTerrorizerControlConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/ResizeTerrorizerControlConnector.java
index ab300a9e81..4a4bb58488 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/ResizeTerrorizerControlConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/ResizeTerrorizerControlConnector.java
@@ -19,11 +19,8 @@ import java.util.Arrays;
 
 import com.google.gwt.animation.client.AnimationScheduler;
 import com.google.gwt.animation.client.AnimationScheduler.AnimationCallback;
-import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.KeyCodes;
-import com.google.gwt.event.dom.client.KeyUpEvent;
-import com.google.gwt.event.dom.client.KeyUpHandler;
 import com.google.gwt.event.logical.shared.ValueChangeEvent;
 import com.google.gwt.event.logical.shared.ValueChangeHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
@@ -63,14 +60,10 @@ public class ResizeTerrorizerControlConnector extends AbstractComponentConnector
         private IntegerBox endHeight = new IntegerBox();
 
         private final Button terrorizeButton = new Button("Terrorize",
-                new ClickHandler() {
-                    @Override
-                    public void onClick(ClickEvent event) {
-                        terrorize(startWidth.getValue(), endWidth.getValue(),
-                                startHeight.getValue(), endHeight.getValue(),
-                                1000);
-                    }
-                });
+                (ClickHandler) event -> terrorize(startWidth.getValue(),
+                        endWidth.getValue(), startHeight.getValue(),
+                        endHeight.getValue(),
+                        1000));
 
         private HandlerRegistration historyHandlerRegistration;
 
@@ -98,12 +91,9 @@ public class ResizeTerrorizerControlConnector extends AbstractComponentConnector
             // Emulate button click from enter on any of the text boxes
             for (IntegerBox box : Arrays.asList(startWidth, endWidth,
                     startHeight, endHeight)) {
-                box.addKeyUpHandler(new KeyUpHandler() {
-                    @Override
-                    public void onKeyUp(KeyUpEvent event) {
-                        if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
-                            terrorizeButton.click();
-                        }
+                box.addKeyUpHandler(event -> {
+                    if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
+                        terrorizeButton.click();
                     }
                 });
             }
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/RunOverflowFixConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/RunOverflowFixConnector.java
index a212dcedfe..203e813a80 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/RunOverflowFixConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/RunOverflowFixConnector.java
@@ -2,7 +2,6 @@ package com.vaadin.tests.widgetset.client;
 
 import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.Unit;
-import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.Element;
@@ -41,47 +40,35 @@ public class RunOverflowFixConnector
         overflowY.addStyleName("third-scrollbar");
 
         Button runFix = new Button("Click to runWebkitOverflowAutoFix",
-                new ClickHandler() {
-                    @Override
-                    public void onClick(ClickEvent event) {
-                        overflow.getElement().getStyle()
-                                .setOverflow(Style.Overflow.SCROLL);
-                        WidgetUtil.runWebkitOverflowAutoFix(
-                                overflow.getElement());
-
-                        overflowX.getElement().getStyle()
-                                .setOverflowX(Style.Overflow.HIDDEN);
-                        WidgetUtil.runWebkitOverflowAutoFix(
-                                overflowX.getElement());
-
-                        overflowY.getElement().getStyle()
-                                .setOverflowY(Style.Overflow.HIDDEN);
-                        WidgetUtil.runWebkitOverflowAutoFix(
-                                overflowY.getElement());
-                    }
+                (ClickHandler) event -> {
+                    overflow.getElement().getStyle()
+                            .setOverflow(Style.Overflow.SCROLL);
+                    WidgetUtil.runWebkitOverflowAutoFix(overflow.getElement());
+
+                    overflowX.getElement().getStyle()
+                            .setOverflowX(Style.Overflow.HIDDEN);
+                    WidgetUtil.runWebkitOverflowAutoFix(overflowX.getElement());
+
+                    overflowY.getElement().getStyle()
+                            .setOverflowY(Style.Overflow.HIDDEN);
+                    WidgetUtil.runWebkitOverflowAutoFix(overflowY.getElement());
                 });
         runFix.addStyleName("run-button-one");
         getWidget().add(runFix);
 
         Button runFix2 = new Button("Click to runWebkitOverflowAutoFix 2",
-                new ClickHandler() {
-                    @Override
-                    public void onClick(ClickEvent event) {
-                        overflow.getElement().getStyle()
-                                .setOverflow(Style.Overflow.VISIBLE);
-                        WidgetUtil.runWebkitOverflowAutoFix(
-                                overflow.getElement());
-
-                        overflowX.getElement().getStyle()
-                                .setOverflowX(Style.Overflow.SCROLL);
-                        WidgetUtil.runWebkitOverflowAutoFix(
-                                overflowX.getElement());
-
-                        overflowY.getElement().getStyle()
-                                .setOverflowY(Style.Overflow.AUTO);
-                        WidgetUtil.runWebkitOverflowAutoFix(
-                                overflowY.getElement());
-                    }
+                (ClickHandler) event -> {
+                    overflow.getElement().getStyle()
+                            .setOverflow(Style.Overflow.VISIBLE);
+                    WidgetUtil.runWebkitOverflowAutoFix(overflow.getElement());
+
+                    overflowX.getElement().getStyle()
+                            .setOverflowX(Style.Overflow.SCROLL);
+                    WidgetUtil.runWebkitOverflowAutoFix(overflowX.getElement());
+
+                    overflowY.getElement().getStyle()
+                            .setOverflowY(Style.Overflow.AUTO);
+                    WidgetUtil.runWebkitOverflowAutoFix(overflowY.getElement());
                 });
         runFix2.addStyleName("run-button-two");
         getWidget().add(runFix2);
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/WidgetUtilTestWidget.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/WidgetUtilTestWidget.java
index 17d27feed2..07eba9accc 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/WidgetUtilTestWidget.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/WidgetUtilTestWidget.java
@@ -22,7 +22,6 @@ import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.BorderStyle;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.WidgetUtil;
 
@@ -43,12 +42,7 @@ public class WidgetUtilTestWidget extends Widget {
         root.addClassName("v-widget-util-test");
         setElement(root);
 
-        addDomHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                showSizes();
-            }
-        }, ClickEvent.getType());
+        addDomHandler(event -> showSizes(), ClickEvent.getType());
     }
 
     public void construct(boolean inline) {
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/csrf/CsrfButtonConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/csrf/CsrfButtonConnector.java
index bb3b09aedf..1c626ba73d 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/csrf/CsrfButtonConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/csrf/CsrfButtonConnector.java
@@ -19,8 +19,6 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.google.gwt.core.shared.GWT;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.vaadin.client.ui.AbstractComponentConnector;
 import com.vaadin.client.ui.VButton;
 import com.vaadin.shared.ui.Connect;
@@ -60,13 +58,8 @@ public class CsrfButtonConnector extends AbstractComponentConnector {
 
         getWidget().getElement().setId(ID);
         getWidget().setText(csrfTokenInfo());
-        getWidget().addClickHandler(new ClickHandler() {
-
-            @Override
-            public void onClick(ClickEvent event) {
-                getWidget().setText(csrfTokenInfo());
-            }
-        });
+        getWidget()
+                .addClickHandler(event -> getWidget().setText(csrfTokenInfo()));
     }
 
     private String csrfTokenInfo() {
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/extension/BrowserContextMenuExtensionConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/extension/BrowserContextMenuExtensionConnector.java
index 030fbe8110..336d48ccdf 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/extension/BrowserContextMenuExtensionConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/extension/BrowserContextMenuExtensionConnector.java
@@ -16,7 +16,6 @@
 package com.vaadin.tests.widgetset.client.extension;
 
 import com.google.gwt.event.dom.client.ContextMenuEvent;
-import com.google.gwt.event.dom.client.ContextMenuHandler;
 import com.vaadin.client.ServerConnector;
 import com.vaadin.client.extensions.AbstractExtensionConnector;
 import com.vaadin.client.ui.AbstractComponentConnector;
@@ -32,13 +31,9 @@ public class BrowserContextMenuExtensionConnector
 
     @Override
     protected void extend(ServerConnector target) {
-        getParent().getWidget().addDomHandler(new ContextMenuHandler() {
-
-            @Override
-            public void onContextMenu(ContextMenuEvent event) {
-                // Stop context click events from propagating.
-                event.stopPropagation();
-            }
+        getParent().getWidget().addDomHandler(event -> {
+            // Stop context click events from propagating.
+            event.stopPropagation();
         }, ContextMenuEvent.getType());
     }
 
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/grid/GridCellFocusOnResetSizeWidget.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/grid/GridCellFocusOnResetSizeWidget.java
index b5e1e824eb..f7f385e154 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/grid/GridCellFocusOnResetSizeWidget.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/grid/GridCellFocusOnResetSizeWidget.java
@@ -18,8 +18,6 @@ package com.vaadin.tests.widgetset.client.grid;
 import java.util.ArrayList;
 import java.util.List;
 
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.ui.Button;
 import com.vaadin.client.data.DataChangeHandler;
 import com.vaadin.client.data.DataSource;
@@ -110,13 +108,7 @@ public class GridCellFocusOnResetSizeWidget
         final MyDataSource dataSource = new MyDataSource();
         grid.setDataSource(dataSource);
         Button widget = new Button("Change Container Size");
-        widget.addClickHandler(new ClickHandler() {
-
-            @Override
-            public void onClick(ClickEvent event) {
-                dataSource.changeSize();
-            }
-        });
+        widget.addClickHandler(event -> dataSource.changeSize());
         addNorth(grid, 400);
         addNorth(widget, 50);
     }
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/gwtrpc/GwtRpcButtonConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/gwtrpc/GwtRpcButtonConnector.java
index 478ac51fde..4a06cb9914 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/gwtrpc/GwtRpcButtonConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/gwtrpc/GwtRpcButtonConnector.java
@@ -19,8 +19,6 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.google.gwt.core.shared.GWT;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.rpc.AsyncCallback;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.DialogBox;
@@ -66,14 +64,7 @@ public class GwtRpcButtonConnector extends AbstractComponentConnector {
         log("GwtRpcButtonTestConnector init");
 
         getWidget().setText("Click me");
-        getWidget().addClickHandler(new ClickHandler() {
-
-            @Override
-            public void onClick(ClickEvent event) {
-                doRPC();
-            }
-
-        });
+        getWidget().addClickHandler(event -> doRPC());
     }
 
     /**
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a2/MyComponentConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a2/MyComponentConnector.java
index aee16c334d..4a099fa3ff 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a2/MyComponentConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a2/MyComponentConnector.java
@@ -1,7 +1,5 @@
 package com.vaadin.tests.widgetset.client.minitutorials.v7a2;
 
-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.vaadin.client.MouseEventDetailsBuilder;
 import com.vaadin.client.annotations.OnStateChange;
@@ -18,16 +16,12 @@ public class MyComponentConnector extends AbstractComponentConnector {
             this);
 
     public MyComponentConnector() {
-        getWidget().addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-
-                final MouseEventDetails mouseDetails = MouseEventDetailsBuilder
-                        .buildMouseEventDetails(event.getNativeEvent(),
-                                getWidget().getElement());
+        getWidget().addClickHandler(event -> {
+            final MouseEventDetails mouseDetails = MouseEventDetailsBuilder
+                    .buildMouseEventDetails(event.getNativeEvent(),
+                            getWidget().getElement());
 
-                rpc.clicked(mouseDetails);
-            }
+            rpc.clicked(mouseDetails);
         });
         registerRpc(MyComponentClientRpc.class, new MyComponentClientRpc() {
             @Override
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/CapsLockWarningConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/CapsLockWarningConnector.java
index 3ac0db54fa..b093917cf9 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/CapsLockWarningConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/CapsLockWarningConnector.java
@@ -1,7 +1,6 @@
 package com.vaadin.tests.widgetset.client.minitutorials.v7a3;
 
 import com.google.gwt.event.dom.client.KeyPressEvent;
-import com.google.gwt.event.dom.client.KeyPressHandler;
 import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.ComponentConnector;
@@ -22,14 +21,11 @@ public class CapsLockWarningConnector extends AbstractExtensionConnector {
         warning.setOwner(passwordWidget);
         warning.add(new HTML("Caps Lock is enabled!"));
 
-        passwordWidget.addDomHandler(new KeyPressHandler() {
-            @Override
-            public void onKeyPress(KeyPressEvent event) {
-                if (isEnabled() && isCapsLockOn(event)) {
-                    warning.showRelativeTo(passwordWidget);
-                } else {
-                    warning.hide();
-                }
+        passwordWidget.addDomHandler(event -> {
+            if (isEnabled() && isCapsLockOn(event)) {
+                warning.showRelativeTo(passwordWidget);
+            } else {
+                warning.hide();
             }
         }, KeyPressEvent.getType());
     }
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/ClientSideModule.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/ClientSideModule.java
index cbe12b57a2..15e703e9b2 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/ClientSideModule.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7a3/ClientSideModule.java
@@ -17,8 +17,6 @@
 package com.vaadin.tests.widgetset.client.minitutorials.v7a3;
 
 import com.google.gwt.core.client.EntryPoint;
-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.Button;
 import com.google.gwt.user.client.ui.RootPanel;
@@ -38,14 +36,11 @@ public class ClientSideModule implements EntryPoint {
         vp.add(button);
         RootPanel.get().add(vp);
 
-        button.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                if ("GWT User".equals(nameField.getText())) {
-                    Window.alert("User OK");
-                } else {
-                    Window.alert("Unauthorized user");
-                }
+        button.addClickHandler(event -> {
+            if ("GWT User".equals(nameField.getText())) {
+                Window.alert("User OK");
+            } else {
+                Window.alert("Unauthorized user");
             }
         });
     }
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7b1/CapsLockWarningWithRpcConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7b1/CapsLockWarningWithRpcConnector.java
index d8d1f43c32..a2091f1d0c 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7b1/CapsLockWarningWithRpcConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/minitutorials/v7b1/CapsLockWarningWithRpcConnector.java
@@ -1,7 +1,6 @@
 package com.vaadin.tests.widgetset.client.minitutorials.v7b1;
 
 import com.google.gwt.event.dom.client.KeyPressEvent;
-import com.google.gwt.event.dom.client.KeyPressHandler;
 import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.ComponentConnector;
@@ -25,18 +24,15 @@ public class CapsLockWarningWithRpcConnector
         warning.setOwner(passwordWidget);
         warning.add(new HTML("Caps Lock is enabled!"));
 
-        passwordWidget.addDomHandler(new KeyPressHandler() {
-            @Override
-            public void onKeyPress(KeyPressEvent event) {
-                if (isEnabled() && isCapsLockOn(event)) {
-                    warning.showRelativeTo(passwordWidget);
-                    rpc.isCapsLockEnabled(true); // Added to send message to the
-                                                 // server
-                } else {
-                    warning.hide();
-                    rpc.isCapsLockEnabled(false); // Added to send message to
-                                                  // the server
-                }
+        passwordWidget.addDomHandler(event -> {
+            if (isEnabled() && isCapsLockOn(event)) {
+                warning.showRelativeTo(passwordWidget);
+                // Added to send message to the server
+                rpc.isCapsLockEnabled(true);
+            } else {
+                warning.hide();
+                // Added to send message to the server
+                rpc.isCapsLockEnabled(false);
             }
         }, KeyPressEvent.getType());
     }
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridBasicClientFeaturesWidget.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridBasicClientFeaturesWidget.java
index d41df99886..0fb967610c 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridBasicClientFeaturesWidget.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridBasicClientFeaturesWidget.java
@@ -27,7 +27,6 @@ import java.util.logging.Logger;
 import com.google.gwt.core.client.Scheduler;
 import com.google.gwt.core.client.Scheduler.ScheduledCommand;
 import com.google.gwt.dom.client.Style.Unit;
-import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.ContextMenuEvent;
 import com.google.gwt.event.dom.client.ContextMenuHandler;
@@ -79,8 +78,6 @@ import com.vaadin.v7.client.widget.grid.events.GridKeyUpEvent;
 import com.vaadin.v7.client.widget.grid.events.HeaderKeyDownHandler;
 import com.vaadin.v7.client.widget.grid.events.HeaderKeyPressHandler;
 import com.vaadin.v7.client.widget.grid.events.HeaderKeyUpHandler;
-import com.vaadin.v7.client.widget.grid.events.ScrollEvent;
-import com.vaadin.v7.client.widget.grid.events.ScrollHandler;
 import com.vaadin.v7.client.widget.grid.selection.SelectionModel;
 import com.vaadin.v7.client.widget.grid.selection.SelectionModel.None;
 import com.vaadin.v7.client.widgets.Grid;
@@ -450,14 +447,10 @@ public class GridBasicClientFeaturesWidget
                 if (scrollHandler != null) {
                     return;
                 }
-                scrollHandler = grid.addScrollHandler(new ScrollHandler() {
-                    @Override
-                    public void onScroll(ScrollEvent event) {
-                        @SuppressWarnings("hiding")
-                        final Grid<?> grid = (Grid<?>) event.getSource();
-                        label.setText("scrollTop: " + grid.getScrollTop()
-                                + ", scrollLeft: " + grid.getScrollLeft());
-                    }
+                scrollHandler = grid.addScrollHandler(event -> {
+                    final Grid<?> grid = (Grid<?>) event.getSource();
+                    label.setText("scrollTop: " + grid.getScrollTop()
+                            + ", scrollLeft: " + grid.getScrollLeft());
                 });
             }
         }, listenersPath);
@@ -526,26 +519,22 @@ public class GridBasicClientFeaturesWidget
         addMenuCommand("Add context menu listener", new ScheduledCommand() {
 
             HandlerRegistration handler = null;
-            ContextMenuHandler contextMenuHandler = new ContextMenuHandler() {
-
-                @Override
-                public void onContextMenu(ContextMenuEvent event) {
-                    event.preventDefault();
-                    final String location;
-                    EventCellReference<?> cellRef = grid.getEventCell();
-                    if (cellRef.isHeader()) {
-                        location = "header";
-                    } else if (cellRef.isBody()) {
-                        location = "body";
-                    } else if (cellRef.isFooter()) {
-                        location = "footer";
-                    } else {
-                        location = "somewhere";
-                    }
-
-                    getLogger().info("Prevented opening a context menu in grid "
-                            + location);
+            ContextMenuHandler contextMenuHandler = event -> {
+                event.preventDefault();
+                final String location;
+                EventCellReference<?> cellRef = grid.getEventCell();
+                if (cellRef.isHeader()) {
+                    location = "header";
+                } else if (cellRef.isBody()) {
+                    location = "body";
+                } else if (cellRef.isFooter()) {
+                    location = "footer";
+                } else {
+                    location = "somewhere";
                 }
+
+                getLogger().info(
+                        "Prevented opening a context menu in grid " + location);
             };
 
             @Override
@@ -913,13 +902,7 @@ public class GridBasicClientFeaturesWidget
                 @Override
                 public void execute() {
                     final Button button = new Button("Button Header");
-                    button.addClickHandler(new ClickHandler() {
-
-                        @Override
-                        public void onClick(ClickEvent event) {
-                            button.setText("Clicked");
-                        }
-                    });
+                    button.addClickHandler(event -> button.setText("Clicked"));
                     grid.getHeaderRow(0).getCell(column).setWidget(button);
                 }
             }, "Component", "Columns", "Column " + i, "Header Type");
@@ -942,13 +925,7 @@ public class GridBasicClientFeaturesWidget
                 @Override
                 public void execute() {
                     final Button button = new Button("Button Footer");
-                    button.addClickHandler(new ClickHandler() {
-
-                        @Override
-                        public void onClick(ClickEvent event) {
-                            button.setText("Clicked");
-                        }
-                    });
+                    button.addClickHandler(event -> button.setText("Clicked"));
                     grid.getFooterRow(0).getCell(column).setWidget(button);
                 }
             }, "Component", "Columns", "Column " + i, "Footer Type");
@@ -1459,12 +1436,8 @@ public class GridBasicClientFeaturesWidget
 
                         final Label label = new Label("Row: " + rowIndex + ".");
                         Button button = new Button("Button",
-                                new ClickHandler() {
-                                    @Override
-                                    public void onClick(ClickEvent event) {
-                                        label.setText("clicked");
-                                    }
-                                });
+                                (ClickHandler) event -> label
+                                        .setText("clicked"));
 
                         panel.add(label);
                         panel.add(button);
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridClientColumnRendererConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridClientColumnRendererConnector.java
index a651da1a44..d243573d7c 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridClientColumnRendererConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/v7/grid/GridClientColumnRendererConnector.java
@@ -22,8 +22,6 @@ import java.util.List;
 
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.Timer;
 import com.google.gwt.user.client.Window.Location;
 import com.google.gwt.user.client.ui.Button;
@@ -280,13 +278,7 @@ public class GridClientColumnRendererConnector
                 @Override
                 public Button createWidget() {
                     final Button button = new Button("");
-                    button.addClickHandler(new ClickHandler() {
-
-                        @Override
-                        public void onClick(ClickEvent event) {
-                            button.setText("Clicked");
-                        }
-                    });
+                    button.addClickHandler(event -> button.setText("Clicked"));
                     return button;
                 }
 
diff --git a/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java b/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java
index 07e8b9389f..294026f06e 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java
@@ -256,7 +256,7 @@ public class CheckBoxGroupTest extends MultiBrowserTest {
     @Test
     public void testDisabled() {
         List<String> optionsCssClasses = getSelect().getOptionElements()
-                .stream().map(event -> event.getAttribute("class"))
+                .stream().map(element -> element.getAttribute("class"))
                 .collect(Collectors.toList());
         for (int i = 0; i < optionsCssClasses.size(); i++) {
             String cssClassList = optionsCssClasses.get(i);
diff --git a/uitest/src/test/java/com/vaadin/tests/components/listselect/ListSelectTest.java b/uitest/src/test/java/com/vaadin/tests/components/listselect/ListSelectTest.java
index 365d1cd7ad..af6abf5a24 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/listselect/ListSelectTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/listselect/ListSelectTest.java
@@ -236,7 +236,7 @@ public class ListSelectTest extends SingleBrowserTestPhantomJS2 {
         Select select = new Select(
                 getListSelect().findElement(By.tagName("select")));
         return select.getAllSelectedOptions().stream()
-                .map(event -> event.getText())
+                .map(element -> element.getText())
                 .collect(Collectors.toList());
     }
 
diff --git a/uitest/src/test/java/com/vaadin/tests/components/tree/TreeBasicFeaturesTest.java b/uitest/src/test/java/com/vaadin/tests/components/tree/TreeBasicFeaturesTest.java
index 7695564970..e2c60b9506 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/tree/TreeBasicFeaturesTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/tree/TreeBasicFeaturesTest.java
@@ -22,16 +22,16 @@ import com.vaadin.tests.tb3.MultiBrowserTest;
 public class TreeBasicFeaturesTest extends MultiBrowserTest {
 
     private static final Predicate<TestBenchElement> THEME_RESOURCE =
-            e -> e.isElementPresent(By.tagName("img"))
-                    && e.findElement(By.tagName("img")).getAttribute("src")
+            element -> element.isElementPresent(By.tagName("img"))
+            && element.findElement(By.tagName("img")).getAttribute("src")
                     .contains("bullet.png");
     private static final Predicate<TestBenchElement> VAADIN_ICON =
-            e -> e.isElementPresent(By.className("v-icon")) && e
-                    .findElement(By.className("v-icon")).getAttribute("class")
+            element -> element.isElementPresent(By.className("v-icon"))
+            && element.findElement(By.className("v-icon")).getAttribute("class")
                     .contains("Vaadin-Icons");
     private static final Predicate<TestBenchElement> CLASS_RESOURCE =
-            e -> e.isElementPresent(By.tagName("img"))
-                    && e.findElement(By.tagName("img")).getAttribute("src")
+            element -> element.isElementPresent(By.tagName("img"))
+            && element.findElement(By.tagName("img")).getAttribute("src")
                     .contains("m.gif");
 
     @Before