Use lambda with Handlers (#10229)

Also improve naming by replacing one-letter variable names.

client/src/main/java/com/vaadin/client/ApplicationConfiguration.java

@@ -26,7 +26,6 @@ import java.util.logging.Logger;
 
 import com.google.gwt.core.client.EntryPoint;
 import com.google.gwt.core.client.GWT;
-import com.google.gwt.core.client.GWT.UncaughtExceptionHandler;
 import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.core.client.JsArrayString;
 import com.google.gwt.core.client.RunAsyncCallback;
@@ -708,18 +707,16 @@ public class ApplicationConfiguration implements EntryPoint {
         PointerEventSupport.init();
 
         if (LogConfiguration.loggingIsEnabled()) {
-            GWT.setUncaughtExceptionHandler(new UncaughtExceptionHandler() {
-
-                @Override
-                public void onUncaughtException(Throwable e) {
-                    /*
-                     * If the debug window is not enabled (?debug), this will
-                     * not show anything to normal users. "a1 is not an object"
-                     * style errors helps nobody, especially end user. It does
-                     * not work tells just as much.
-                     */
-                    getLogger().log(Level.SEVERE, e.getMessage(), e);
-                }
+            GWT.setUncaughtExceptionHandler(throwable -> {
+
+                /*
+                 * If the debug window is not enabled (?debug), this will not
+                 * show anything to normal users. "a1 is not an object" style
+                 * errors helps nobody, especially end user. It does not work
+                 * tells just as much.
+                 */
+                getLogger().log(Level.SEVERE, throwable.getMessage(),
+                        throwable);
             });
 
             if (isProductionMode()) {

client/src/main/java/com/vaadin/client/JavaScriptConnectorHelper.java

@@ -30,8 +30,6 @@ import com.google.gwt.core.client.JsArray;
 import com.google.gwt.dom.client.Element;
 import com.vaadin.client.communication.JavaScriptMethodInvocation;
 import com.vaadin.client.communication.ServerRpcQueue;
-import com.vaadin.client.communication.StateChangeEvent;
-import com.vaadin.client.communication.StateChangeEvent.StateChangeHandler;
 import com.vaadin.client.ui.layout.ElementResizeListener;
 import com.vaadin.shared.JavaScriptConnectorState;
 import com.vaadin.shared.communication.MethodInvocation;
@@ -70,12 +68,7 @@ public class JavaScriptConnectorHelper {
     private int processedResponseId = -1;
 
     public void init() {
-        connector.addStateChangeHandler(new StateChangeHandler() {
-            @Override
-            public void onStateChanged(StateChangeEvent stateChangeEvent) {
-                processStateChanges();
-            }
-        });
+        connector.addStateChangeHandler(event -> processStateChanges());
     }
 
     /**

client/src/main/java/com/vaadin/client/SimpleTree.java

@@ -25,7 +25,6 @@ import com.google.gwt.dom.client.Style.Display;
 import com.google.gwt.dom.client.Style.TextAlign;
 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.DoubleClickEvent;
 import com.google.gwt.event.dom.client.DoubleClickHandler;
 import com.google.gwt.event.dom.client.HasDoubleClickHandlers;
@@ -77,27 +76,22 @@ public class SimpleTree extends ComplexPanel implements HasDoubleClickHandlers {
         style.setDisplay(Display.NONE);
 
         getElement().appendChild(children);
-        addDomHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                if (event.getNativeEvent().getEventTarget().cast() == handle) {
-                    if (children.getStyle().getDisplay()
-                            .intern() == Display.NONE.getCssName()) {
-                        open(event.getNativeEvent().getAltKey());
-                    } else {
-                        close();
-                    }
-
-                } else if (event.getNativeEvent().getEventTarget()
-                        .cast() == text) {
-                    select(event);
+        addDomHandler(event -> {
+            if (event.getNativeEvent().getEventTarget().cast() == handle) {
+                if (children.getStyle().getDisplay().intern() == Display.NONE
+                        .getCssName()) {
+                    open(event.getNativeEvent().getAltKey());
+                } else {
+                    close();
                 }
+
+            } else if (event.getNativeEvent().getEventTarget().cast() == text) {
+                select(event);
             }
         }, ClickEvent.getType());
     }
 
     protected void select(ClickEvent event) {
-
     }
 
     public void close() {
@@ -178,13 +172,9 @@ public class SimpleTree extends ComplexPanel implements HasDoubleClickHandlers {
             DoubleClickHandler handler) {
         if (textDoubleClickHandlerManager == null) {
             textDoubleClickHandlerManager = new HandlerManager(this);
-            addDomHandler(new DoubleClickHandler() {
-                @Override
-                public void onDoubleClick(DoubleClickEvent event) {
-                    if (event.getNativeEvent().getEventTarget()
-                            .cast() == text) {
-                        textDoubleClickHandlerManager.fireEvent(event);
-                    }
+            addDomHandler(event -> {
+                if (event.getNativeEvent().getEventTarget().cast() == text) {
+                    textDoubleClickHandlerManager.fireEvent(event);
                 }
             }, DoubleClickEvent.getType());
         }

client/src/main/java/com/vaadin/client/VUIDLBrowser.java

@@ -27,7 +27,6 @@ import com.google.gwt.dom.client.Style.Position;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.MouseOutEvent;
-import com.google.gwt.event.dom.client.MouseOutHandler;
 import com.google.gwt.user.client.ui.RootPanel;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.ui.UnknownComponentConnector;
@@ -103,12 +102,7 @@ public class VUIDLBrowser extends SimpleTree {
 
         protected StateChangeItem() {
             setTitle(HELP);
-            addDomHandler(new MouseOutHandler() {
-                @Override
-                public void onMouseOut(MouseOutEvent event) {
-                    deHiglight();
-                }
-            }, MouseOutEvent.getType());
+            addDomHandler(event -> deHiglight(), MouseOutEvent.getType());
         }
 
         @Override

client/src/main/java/com/vaadin/client/communication/AtmospherePushConnection.java

@@ -25,7 +25,6 @@ import com.google.gwt.user.client.Window.Location;
 import com.vaadin.client.ApplicationConfiguration;
 import com.vaadin.client.ApplicationConnection;
 import com.vaadin.client.ApplicationConnection.ApplicationStoppedEvent;
-import com.vaadin.client.ApplicationConnection.ApplicationStoppedHandler;
 import com.vaadin.client.ResourceLoader;
 import com.vaadin.client.ResourceLoader.ResourceLoadEvent;
 import com.vaadin.client.ResourceLoader.ResourceLoadListener;
@@ -151,23 +150,17 @@ public class AtmospherePushConnection implements PushConnection {
         this.connection = connection;
 
         connection.addHandler(ApplicationStoppedEvent.TYPE,
-                new ApplicationStoppedHandler() {
+                event -> {
+                    if (state == State.DISCONNECT_PENDING
+                            || state == State.DISCONNECTED) {
+                        return;
+                    }
 
-                    @Override
-                    public void onApplicationStopped(
-                            ApplicationStoppedEvent event) {
-                        if (state == State.DISCONNECT_PENDING
-                                || state == State.DISCONNECTED) {
-                            return;
+                    disconnect(new Command() {
+                        @Override
+                        public void execute() {
                         }
-
-                        disconnect(new Command() {
-                            @Override
-                            public void execute() {
-                            }
-                        });
-
-                    }
+                    });
                 });
         config = createConfig();
         String debugParameter = Location.getParameter("debug");

client/src/main/java/com/vaadin/client/communication/DefaultConnectionStateHandler.java

@@ -26,7 +26,6 @@ import com.google.gwt.regexp.shared.RegExp;
 import com.google.gwt.user.client.Timer;
 import com.vaadin.client.ApplicationConnection;
 import com.vaadin.client.ApplicationConnection.ApplicationStoppedEvent;
-import com.vaadin.client.ApplicationConnection.ApplicationStoppedHandler;
 import com.vaadin.client.WidgetUtil;
 import com.vaadin.client.communication.AtmospherePushConnection.AtmosphereResponse;
 import com.vaadin.shared.ui.ui.UIState.ReconnectDialogConfigurationState;
@@ -94,19 +93,14 @@ public class DefaultConnectionStateHandler implements ConnectionStateHandler {
         this.connection = connection;
 
         connection.addHandler(ApplicationStoppedEvent.TYPE,
-                new ApplicationStoppedHandler() {
-                    @Override
-                    public void onApplicationStopped(
-                            ApplicationStoppedEvent event) {
-                        if (isReconnecting()) {
-                            giveUp();
-                        }
-                        if (scheduledReconnect != null
-                                && scheduledReconnect.isRunning()) {
-                            scheduledReconnect.cancel();
-                        }
+                event -> {
+                    if (isReconnecting()) {
+                        giveUp();
+                    }
+                    if (scheduledReconnect != null
+                            && scheduledReconnect.isRunning()) {
+                        scheduledReconnect.cancel();
                     }
-
                 });
 
         // Allow dialog to cache needed resources to make them available when we

client/src/main/java/com/vaadin/client/communication/DefaultReconnectDialog.java

@@ -21,7 +21,6 @@ import com.google.gwt.dom.client.BodyElement;
 import com.google.gwt.dom.client.Document;
 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.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.HTML;
@@ -80,12 +79,9 @@ public class DefaultReconnectDialog extends VOverlay
 
         // Click to refresh after giving up
         if (!reconnecting) {
-            clickHandler = addDomHandler(new ClickHandler() {
-                @Override
-                public void onClick(ClickEvent event) {
-                    // refresh
-                    WidgetUtil.redirect(null);
-                }
+            clickHandler = addDomHandler(event -> {
+                // refresh
+                WidgetUtil.redirect(null);
             }, ClickEvent.getType());
         } else {
             if (clickHandler != null) {

client/src/main/java/com/vaadin/client/communication/Heartbeat.java

@@ -24,7 +24,6 @@ import com.google.gwt.http.client.RequestException;
 import com.google.gwt.http.client.Response;
 import com.google.gwt.user.client.Timer;
 import com.vaadin.client.ApplicationConnection;
-import com.vaadin.client.ApplicationConnection.ApplicationStoppedEvent;
 import com.vaadin.shared.ApplicationConstants;
 import com.vaadin.shared.ui.ui.UIConstants;
 import com.vaadin.shared.util.SharedUtil;
@@ -72,14 +71,7 @@ public class Heartbeat {
 
         connection.addHandler(
                 ApplicationConnection.ApplicationStoppedEvent.TYPE,
-                new ApplicationConnection.ApplicationStoppedHandler() {
-
-                    @Override
-                    public void onApplicationStopped(
-                            ApplicationStoppedEvent event) {
-                        setInterval(-1);
-                    }
-                });
+                event -> setInterval(-1));
     }
 
     /**

client/src/main/java/com/vaadin/client/debug/internal/AnalyzeLayoutsPanel.java

@@ -23,11 +23,8 @@ import java.util.Set;
 import com.google.gwt.core.client.JsArray;
 import com.google.gwt.dom.client.Style.TextDecoration;
 import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.MouseOutEvent;
-import com.google.gwt.event.dom.client.MouseOutHandler;
 import com.google.gwt.event.dom.client.MouseOverEvent;
-import com.google.gwt.event.dom.client.MouseOverHandler;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.Label;
@@ -124,31 +121,20 @@ public class AnalyzeLayoutsPanel extends FlowPanel {
                     Highlight.show(parentConnector, "yellow");
                 }
 
-                errorDetails.addMouseOverHandler(new MouseOverHandler() {
-                    @Override
-                    public void onMouseOver(MouseOverEvent event) {
-                        Highlight.hideAll();
-                        Highlight.show(parentConnector, "yellow");
-                        Highlight.show(connector);
-                        errorDetails.getElement().getStyle()
-                                .setTextDecoration(TextDecoration.UNDERLINE);
-                    }
-                });
-                errorDetails.addMouseOutHandler(new MouseOutHandler() {
-                    @Override
-                    public void onMouseOut(MouseOutEvent event) {
-                        Highlight.hideAll();
-                        errorDetails.getElement().getStyle()
-                                .setTextDecoration(TextDecoration.NONE);
-                    }
+                errorDetails.addMouseOverHandler(event -> {
+                    Highlight.hideAll();
+                    Highlight.show(parentConnector, "yellow");
+                    Highlight.show(connector);
+                    errorDetails.getElement().getStyle()
+                            .setTextDecoration(TextDecoration.UNDERLINE);
                 });
-                errorDetails.addClickHandler(new ClickHandler() {
-                    @Override
-                    public void onClick(ClickEvent event) {
-                        fireSelectEvent(connector);
-                    }
+                errorDetails.addMouseOutHandler(event -> {
+                    Highlight.hideAll();
+                    errorDetails.getElement().getStyle()
+                            .setTextDecoration(TextDecoration.NONE);
                 });
-
+                errorDetails
+                        .addClickHandler(event -> fireSelectEvent(connector));
             }
 
             Highlight.show(connector);
@@ -174,30 +160,21 @@ public class AnalyzeLayoutsPanel extends FlowPanel {
 
         final SimpleTree errorNode = new SimpleTree(
                 connector.getClass().getSimpleName() + " id: " + pid);
-        errorNode.addDomHandler(new MouseOverHandler() {
-            @Override
-            public void onMouseOver(MouseOverEvent event) {
-                Highlight.showOnly(connector);
-                ((Widget) event.getSource()).getElement().getStyle()
-                        .setTextDecoration(TextDecoration.UNDERLINE);
-            }
+        errorNode.addDomHandler(event -> {
+            Highlight.showOnly(connector);
+            ((Widget) event.getSource()).getElement().getStyle()
+                    .setTextDecoration(TextDecoration.UNDERLINE);
         }, MouseOverEvent.getType());
-        errorNode.addDomHandler(new MouseOutHandler() {
-            @Override
-            public void onMouseOut(MouseOutEvent event) {
-                Highlight.hideAll();
-                ((Widget) event.getSource()).getElement().getStyle()
-                        .setTextDecoration(TextDecoration.NONE);
-            }
+        errorNode.addDomHandler(event -> {
+            Highlight.hideAll();
+            ((Widget) event.getSource()).getElement().getStyle()
+                    .setTextDecoration(TextDecoration.NONE);
         }, MouseOutEvent.getType());
 
-        errorNode.addDomHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                if (event.getNativeEvent().getEventTarget().cast() == errorNode
-                        .getElement().getChild(1).cast()) {
-                    fireSelectEvent(connector);
-                }
+        errorNode.addDomHandler(event -> {
+            if (event.getNativeEvent().getEventTarget().cast() == errorNode
+                    .getElement().getChild(1).cast()) {
+                fireSelectEvent(connector);
             }
         }, ClickEvent.getType());
 

client/src/main/java/com/vaadin/client/debug/internal/HierarchyPanel.java

@@ -19,9 +19,6 @@ 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.event.dom.client.DoubleClickEvent;
-import com.google.gwt.event.dom.client.DoubleClickHandler;
 import com.google.gwt.event.dom.client.HasDoubleClickHandlers;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.HasWidgets;
@@ -104,12 +101,9 @@ public class HierarchyPanel extends FlowPanel {
         if (children == null || children.isEmpty()) {
             // Leaf node, just add a label
             Label label = new Label(connectorString);
-            label.addClickHandler(new ClickHandler() {
-                @Override
-                public void onClick(ClickEvent event) {
-                    Highlight.showOnly(connector);
-                    showServerDebugInfo(connector);
-                }
+            label.addClickHandler(event -> {
+                Highlight.showOnly(connector);
+                showServerDebugInfo(connector);
             });
             widget = label;
         } else {
@@ -132,12 +126,7 @@ public class HierarchyPanel extends FlowPanel {
 
         if (widget instanceof HasDoubleClickHandlers) {
             HasDoubleClickHandlers has = (HasDoubleClickHandlers) widget;
-            has.addDoubleClickHandler(new DoubleClickHandler() {
-                @Override
-                public void onDoubleClick(DoubleClickEvent event) {
-                    fireSelectEvent(connector);
-                }
-            });
+            has.addDoubleClickHandler(event -> fireSelectEvent(connector));
         }
 
         return widget;

client/src/main/java/com/vaadin/client/debug/internal/HierarchySection.java

@@ -16,12 +16,9 @@
 package com.vaadin.client.debug.internal;
 
 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.event.dom.client.KeyCodes;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.Event;
-import com.google.gwt.user.client.Event.NativePreviewEvent;
 import com.google.gwt.user.client.Event.NativePreviewHandler;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.FlowPanel;
@@ -132,50 +129,29 @@ public class HierarchySection implements Section {
     public HierarchySection() {
         controls.add(showHierarchy);
         showHierarchy.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        showHierarchy.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                showHierarchy();
-            }
-        });
+        showHierarchy.addClickHandler(event -> showHierarchy());
 
         controls.add(find);
         find.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        find.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                toggleFind(inspectComponent);
-            }
-        });
+        find.addClickHandler(event -> toggleFind(inspectComponent));
 
         controls.add(analyze);
         analyze.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        analyze.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                stopFind();
-                analyzeLayouts();
-            }
+        analyze.addClickHandler(event -> {
+            stopFind();
+            analyzeLayouts();
         });
 
         controls.add(generateWS);
         generateWS.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        generateWS.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                generateWidgetset();
-            }
-        });
+        generateWS.addClickHandler(event -> generateWidgetset());
 
         controls.add(generateDesign);
         generateDesign.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        generateDesign.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                content.setWidget(new HTML(
-                        "Select a layout or component to generate the declarative design"));
-                toggleFind(showComponentDesign);
-            }
+        generateDesign.addClickHandler(event -> {
+            content.setWidget(new HTML(
+                    "Select a layout or component to generate the declarative design"));
+            toggleFind(showComponentDesign);
         });
 
         hierarchyPanel.addListener(
@@ -321,76 +297,70 @@ public class HierarchySection implements Section {
         content.setWidget(infoPanel);
     }
 
-    private final NativePreviewHandler highlightModeHandler = new NativePreviewHandler() {
-
-        @Override
-        public void onPreviewNativeEvent(NativePreviewEvent event) {
-
-            if (event.getTypeInt() == Event.ONKEYDOWN && event.getNativeEvent()
-                    .getKeyCode() == KeyCodes.KEY_ESCAPE) {
-                stopFind();
-                Highlight.hideAll();
+    private final NativePreviewHandler highlightModeHandler = event -> {
+        if (event.getTypeInt() == Event.ONKEYDOWN
+                && event.getNativeEvent().getKeyCode() == KeyCodes.KEY_ESCAPE) {
+            stopFind();
+            Highlight.hideAll();
+            return;
+        }
+        if (event.getTypeInt() == Event.ONMOUSEMOVE) {
+            Highlight.hideAll();
+            Element eventTarget = WidgetUtil.getElementFromPoint(
+                    event.getNativeEvent().getClientX(),
+                    event.getNativeEvent().getClientY());
+
+            if (VDebugWindow.get().getElement().isOrHasChild(eventTarget)) {
+                // Do not prevent using debug window controls
+                infoPanel.clear();
                 return;
             }
-            if (event.getTypeInt() == Event.ONMOUSEMOVE) {
-                Highlight.hideAll();
-                Element eventTarget = WidgetUtil.getElementFromPoint(
-                        event.getNativeEvent().getClientX(),
-                        event.getNativeEvent().getClientY());
-
-                if (VDebugWindow.get().getElement().isOrHasChild(eventTarget)) {
-                    // Do not prevent using debug window controls
-                    infoPanel.clear();
-                    return;
-                }
 
-                for (ApplicationConnection a : ApplicationConfiguration
-                        .getRunningApplications()) {
-                    ComponentConnector connector = Util.getConnectorForElement(
-                            a, a.getUIConnector().getWidget(), eventTarget);
-                    if (connector == null) {
-                        connector = Util.getConnectorForElement(a,
-                                RootPanel.get(), eventTarget);
-                    }
-                    if (connector != null) {
-                        activeFindHandler.onHover(connector);
-                        event.cancel();
-                        event.consume();
-                        event.getNativeEvent().stopPropagation();
-                        return;
-                    }
+            for (ApplicationConnection a : ApplicationConfiguration
+                    .getRunningApplications()) {
+                ComponentConnector connector = Util.getConnectorForElement(a,
+                        a.getUIConnector().getWidget(), eventTarget);
+                if (connector == null) {
+                    connector = Util.getConnectorForElement(a, RootPanel.get(),
+                            eventTarget);
                 }
-                // Not over any connector
-                activeFindHandler.onHover(null);
-            }
-            if (event.getTypeInt() == Event.ONCLICK) {
-                Highlight.hideAll();
-                event.cancel();
-                event.consume();
-                event.getNativeEvent().stopPropagation();
-                Element eventTarget = WidgetUtil.getElementFromPoint(
-                        event.getNativeEvent().getClientX(),
-                        event.getNativeEvent().getClientY());
-                for (ApplicationConnection a : ApplicationConfiguration
-                        .getRunningApplications()) {
-                    ComponentConnector connector = Util.getConnectorForElement(
-                            a, a.getUIConnector().getWidget(), eventTarget);
-                    if (connector == null) {
-                        connector = Util.getConnectorForElement(a,
-                                RootPanel.get(), eventTarget);
-                    }
-
-                    if (connector != null) {
-                        activeFindHandler.onSelected(connector);
-                        return;
-                    }
+                if (connector != null) {
+                    activeFindHandler.onHover(connector);
+                    event.cancel();
+                    event.consume();
+                    event.getNativeEvent().stopPropagation();
+                    return;
                 }
-                // Click on something else -> stop find operation
-                stopFind();
             }
-            event.cancel();
+            // Not over any connector
+            activeFindHandler.onHover(null);
         }
+        if (event.getTypeInt() == Event.ONCLICK) {
+            Highlight.hideAll();
+            event.cancel();
+            event.consume();
+            event.getNativeEvent().stopPropagation();
+            Element eventTarget = WidgetUtil.getElementFromPoint(
+                    event.getNativeEvent().getClientX(),
+                    event.getNativeEvent().getClientY());
+            for (ApplicationConnection a : ApplicationConfiguration
+                    .getRunningApplications()) {
+                ComponentConnector connector = Util.getConnectorForElement(a,
+                        a.getUIConnector().getWidget(), eventTarget);
+                if (connector == null) {
+                    connector = Util.getConnectorForElement(a, RootPanel.get(),
+                            eventTarget);
+                }
 
+                if (connector != null) {
+                    activeFindHandler.onSelected(connector);
+                    return;
+                }
+            }
+            // Click on something else -> stop find operation
+            stopFind();
+        }
+        event.cancel();
     };
 
 }

client/src/main/java/com/vaadin/client/debug/internal/LogSection.java

@@ -22,8 +22,6 @@ import java.util.logging.LogRecord;
 import java.util.logging.Logger;
 
 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.logging.client.HtmlLogFormatter;
 import com.google.gwt.storage.client.Storage;
 import com.google.gwt.user.client.DOM;
@@ -125,49 +123,30 @@ public class LogSection implements Section {
         // clear log button
         controls.add(clear);
         clear.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        clear.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                clear();
-            }
-        });
+        clear.addClickHandler(event -> clear());
 
         // reset timer button
         controls.add(reset);
         reset.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        reset.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                resetTimer();
-            }
-        });
+        reset.addClickHandler(event -> resetTimer());
 
         // scroll lock toggle
         controls.add(scroll);
         scroll.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        scroll.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                toggleScrollLock();
-            }
-        });
+        scroll.addClickHandler(event -> toggleScrollLock());
 
         // select message if row is clicked
-        content.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                Element el = Element
-                        .as(event.getNativeEvent().getEventTarget());
-                while (!el.getClassName()
-                        .contains(VDebugWindow.STYLENAME + "-message")) {
-                    if (el == contentElement) {
-                        // clicked something else
-                        return;
-                    }
-                    el = el.getParentElement();
+        content.addClickHandler(event -> {
+            Element el = Element.as(event.getNativeEvent().getEventTarget());
+            while (!el.getClassName()
+                    .contains(VDebugWindow.STYLENAME + "-message")) {
+                if (el == contentElement) {
+                    // clicked something else
+                    return;
                 }
-                selectText(el);
+                el = el.getParentElement();
             }
+            selectText(el);
         });
 
         // Add handler to the root logger

client/src/main/java/com/vaadin/client/debug/internal/TestBenchSection.java

@@ -19,8 +19,6 @@ import java.util.HashMap;
 import java.util.Map;
 
 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.event.dom.client.KeyCodes;
 import com.google.gwt.event.dom.client.MouseOutEvent;
 import com.google.gwt.event.dom.client.MouseOutHandler;
@@ -110,21 +108,11 @@ public class TestBenchSection implements Section {
 
         controls.add(find);
         find.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        find.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                toggleFind();
-            }
-        });
+        find.addClickHandler(event -> toggleFind());
 
         controls.add(clear);
         clear.setStylePrimaryName(VDebugWindow.STYLENAME_BUTTON);
-        clear.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                clearResults();
-            }
-        });
+        clear.addClickHandler(event -> clearResults());
 
         content.setStylePrimaryName(VDebugWindow.STYLENAME + "-testbench");
         content.add(selectorPanel);

client/src/main/java/com/vaadin/client/debug/internal/VDebugWindow.java

@@ -197,28 +197,15 @@ public final class VDebugWindow extends VOverlay {
 
         // add controls TODO move these
         controls.add(menu);
-        menu.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                menuPopup.showRelativeTo(menu);
-            }
-        });
+        menu.addClickHandler(event -> menuPopup.showRelativeTo(menu));
 
         controls.add(minimize);
-        minimize.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                toggleMinimized();
-                writeStoredState();
-            }
+        minimize.addClickHandler(event -> {
+            toggleMinimized();
+            writeStoredState();
         });
         controls.add(close);
-        close.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                close();
-            }
-        });
+        close.addClickHandler(event -> close());
 
         Style s = content.getElement().getStyle();
         s.setOverflow(Overflow.AUTO);

client/src/main/java/com/vaadin/client/metadata/ConnectorBundleLoader.java

@@ -29,10 +29,6 @@ import com.google.gwt.dom.client.Style.TextAlign;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.dom.client.Style.Visibility;
 import com.google.gwt.dom.client.Style.WhiteSpace;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
-import com.google.gwt.event.dom.client.TouchStartEvent;
-import com.google.gwt.event.dom.client.TouchStartHandler;
 import com.google.gwt.user.client.ui.HTML;
 import com.google.gwt.user.client.ui.RootPanel;
 import com.vaadin.client.FastStringMap;
@@ -167,18 +163,8 @@ public abstract class ConnectorBundleLoader {
     private void notice(String productName) {
         if (notice == null) {
             notice = new HTML();
-            notice.addClickHandler(new ClickHandler() {
-                @Override
-                public void onClick(ClickEvent event) {
-                    notice.removeFromParent();
-                }
-            });
-            notice.addTouchStartHandler(new TouchStartHandler() {
-                @Override
-                public void onTouchStart(TouchStartEvent event) {
-                    notice.removeFromParent();
-                }
-            });
+            notice.addClickHandler(event -> notice.removeFromParent());
+            notice.addTouchStartHandler(event -> notice.removeFromParent());
         }
         String msg = notice.getText().trim();
         msg += msg.isEmpty() ? "Using Evaluation License of: " : ", ";

client/src/main/java/com/vaadin/client/ui/AbstractClickEventHandler.java

@@ -29,7 +29,6 @@ import com.google.gwt.event.dom.client.MouseUpHandler;
 import com.google.gwt.event.shared.EventHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.Event;
-import com.google.gwt.user.client.Event.NativePreviewEvent;
 import com.google.gwt.user.client.Event.NativePreviewHandler;
 import com.vaadin.client.ComponentConnector;
 import com.vaadin.client.VConsole;
@@ -63,24 +62,20 @@ public abstract class AbstractClickEventHandler implements MouseDownHandler,
      * Previews events after a mousedown to detect where the following mouseup
      * hits.
      */
-    private final NativePreviewHandler mouseUpPreviewHandler = new NativePreviewHandler() {
-
-        @Override
-        public void onPreviewNativeEvent(NativePreviewEvent event) {
-            if (event.getTypeInt() == Event.ONMOUSEUP) {
-                mouseUpEventPreviewRegistration.removeHandler();
-
-                // Event's reported target not always correct if event
-                // capture is in use
-                Element elementUnderMouse = WidgetUtil
-                        .getElementUnderMouse(event.getNativeEvent());
-                if (lastMouseDownTarget != null
-                        && elementUnderMouse == lastMouseDownTarget) {
-                    mouseUpPreviewMatched = true;
-                } else {
-                    VConsole.log("Ignoring mouseup from " + elementUnderMouse
-                            + " when mousedown was on " + lastMouseDownTarget);
-                }
+    private final NativePreviewHandler mouseUpPreviewHandler = event -> {
+        if (event.getTypeInt() == Event.ONMOUSEUP) {
+            mouseUpEventPreviewRegistration.removeHandler();
+
+            // Event's reported target not always correct if event
+            // capture is in use
+            Element elementUnderMouse = WidgetUtil
+                    .getElementUnderMouse(event.getNativeEvent());
+            if (lastMouseDownTarget != null
+                    && elementUnderMouse == lastMouseDownTarget) {
+                mouseUpPreviewMatched = true;
+            } else {
+                VConsole.log("Ignoring mouseup from " + elementUnderMouse
+                        + " when mousedown was on " + lastMouseDownTarget);
             }
         }
     };

client/src/main/java/com/vaadin/client/ui/AbstractComponentConnector.java

@@ -21,13 +21,10 @@ import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.EventTarget;
 import com.google.gwt.dom.client.Touch;
 import com.google.gwt.event.dom.client.ContextMenuEvent;
-import com.google.gwt.event.dom.client.ContextMenuHandler;
 import com.google.gwt.event.dom.client.TouchEndEvent;
-import com.google.gwt.event.dom.client.TouchEndHandler;
 import com.google.gwt.event.dom.client.TouchMoveEvent;
 import com.google.gwt.event.dom.client.TouchMoveHandler;
 import com.google.gwt.event.dom.client.TouchStartEvent;
-import com.google.gwt.event.dom.client.TouchStartHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.Timer;
 import com.google.gwt.user.client.ui.Focusable;
@@ -109,19 +106,15 @@ public abstract class AbstractComponentConnector extends AbstractConnector
     void handleContextClickListenerChange() {
         if (contextHandler == null && hasEventListener(EventId.CONTEXT_CLICK)) {
             contextHandler = getWidget()
-                    .addDomHandler(new ContextMenuHandler() {
-                        @Override
-                        public void onContextMenu(ContextMenuEvent event) {
-                            final MouseEventDetails mouseEventDetails = MouseEventDetailsBuilder
-                                    .buildMouseEventDetails(
-                                            event.getNativeEvent(),
-                                            getWidget().getElement());
-
-                            event.preventDefault();
-                            event.stopPropagation();
-                            sendContextClickEvent(mouseEventDetails,
-                                    event.getNativeEvent().getEventTarget());
-                        }
+                    .addDomHandler(event -> {
+                        final MouseEventDetails mouseEventDetails = MouseEventDetailsBuilder
+                                .buildMouseEventDetails(event.getNativeEvent(),
+                                        getWidget().getElement());
+
+                        event.preventDefault();
+                        event.stopPropagation();
+                        sendContextClickEvent(mouseEventDetails,
+                                event.getNativeEvent().getEventTarget());
                     }, ContextMenuEvent.getType());
 
             // if the widget has a contextclick listener, add touch support as
@@ -178,60 +171,55 @@ public abstract class AbstractComponentConnector extends AbstractConnector
      * @since 7.6
      */
     protected void registerTouchHandlers() {
-        touchStartHandler = getWidget().addDomHandler(new TouchStartHandler() {
-
-            @Override
-            public void onTouchStart(final TouchStartEvent event) {
-                if (longTouchTimer != null && longTouchTimer.isRunning()) {
-                    return;
-                }
-
-                // Prevent selection for the element while pending long tap.
-                WidgetUtil.setTextSelectionEnabled(getWidget().getElement(),
-                        false);
+        touchStartHandler = getWidget().addDomHandler(event -> {
+            if (longTouchTimer != null && longTouchTimer.isRunning()) {
+                return;
+            }
 
-                if (BrowserInfo.get().isAndroid()) {
-                    // Android fires ContextMenu events automatically.
-                    return;
-                }
+            // Prevent selection for the element while pending long tap.
+            WidgetUtil.setTextSelectionEnabled(getWidget().getElement(),
+                    false);
 
-                /*
-                 * we need to build mouseEventDetails eagerly - the event won't
-                 * be guaranteed to be around when the timer executes. At least
-                 * this was the case with iOS devices.
-                 */
+            if (BrowserInfo.get().isAndroid()) {
+                // Android fires ContextMenu events automatically.
+                return;
+            }
 
-                final MouseEventDetails mouseEventDetails = MouseEventDetailsBuilder
-                        .buildMouseEventDetails(event.getNativeEvent(),
-                                getWidget().getElement());
+            /*
+             * we need to build mouseEventDetails eagerly - the event won't
+             * be guaranteed to be around when the timer executes. At least
+             * this was the case with iOS devices.
+             */
 
-                final EventTarget eventTarget = event.getNativeEvent()
-                        .getEventTarget();
+            final MouseEventDetails mouseEventDetails = MouseEventDetailsBuilder
+                    .buildMouseEventDetails(event.getNativeEvent(),
+                            getWidget().getElement());
 
-                longTouchTimer = new Timer() {
+            final EventTarget eventTarget = event.getNativeEvent()
+                    .getEventTarget();
 
-                    @Override
-                    public void run() {
-                        // we're handling this event, our parent components
-                        // don't need to bother with it anymore.
-                        cancelParentTouchTimers();
-                        // The default context click
-                        // implementation only provides the
-                        // mouse coordinates relative to root
-                        // element of widget.
+            longTouchTimer = new Timer() {
 
-                        sendContextClickEvent(mouseEventDetails, eventTarget);
-                        preventNextTouchEnd = true;
-                    }
-                };
+                @Override
+                public void run() {
+                    // we're handling this event, our parent components
+                    // don't need to bother with it anymore.
+                    cancelParentTouchTimers();
+                    // The default context click
+                    // implementation only provides the
+                    // mouse coordinates relative to root
+                    // element of widget.
 
-                Touch touch = event.getChangedTouches().get(0);
-                touchStartX = touch.getClientX();
-                touchStartY = touch.getClientY();
+                    sendContextClickEvent(mouseEventDetails, eventTarget);
+                    preventNextTouchEnd = true;
+                }
+            };
 
-                longTouchTimer.schedule(TOUCH_CONTEXT_MENU_TIMEOUT);
+            Touch touch = event.getChangedTouches().get(0);
+            touchStartX = touch.getClientX();
+            touchStartY = touch.getClientY();
 
-            }
+            longTouchTimer.schedule(TOUCH_CONTEXT_MENU_TIMEOUT);
         }, TouchStartEvent.getType());
 
         touchMoveHandler = getWidget().addDomHandler(new TouchMoveHandler() {
@@ -272,17 +260,13 @@ public abstract class AbstractComponentConnector extends AbstractConnector
             }
         }, TouchMoveEvent.getType());
 
-        touchEndHandler = getWidget().addDomHandler(new TouchEndHandler() {
-
-            @Override
-            public void onTouchEnd(TouchEndEvent event) {
-                // cancel the timer so the event doesn't fire
-                cancelTouchTimer();
+        touchEndHandler = getWidget().addDomHandler(event -> {
+            // cancel the timer so the event doesn't fire
+            cancelTouchTimer();
 
-                if (preventNextTouchEnd) {
-                    event.preventDefault();
-                    preventNextTouchEnd = false;
-                }
+            if (preventNextTouchEnd) {
+                event.preventDefault();
+                preventNextTouchEnd = false;
             }
         }, TouchEndEvent.getType());
     }

client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java

@@ -28,7 +28,6 @@ import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.event.dom.client.BlurEvent;
 import com.google.gwt.event.dom.client.BlurHandler;
-import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.event.dom.client.DomEvent;
 import com.google.gwt.event.dom.client.FocusEvent;
@@ -125,43 +124,6 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
 
     private static final String CN_OUTSIDE_RANGE = "outside-range";
 
-    /**
-     * Represents a click handler for when a user selects a value by using the
-     * mouse
-     */
-    private ClickHandler dayClickHandler = new ClickHandler() {
-        /*
-         * (non-Javadoc)
-         *
-         * @see
-         * com.google.gwt.event.dom.client.ClickHandler#onClick(com.google.gwt
-         * .event.dom.client.ClickEvent)
-         */
-        @Override
-        public void onClick(ClickEvent event) {
-            if (!isEnabled() || isReadonly()) {
-                return;
-            }
-
-            Date newDate = ((Day) event.getSource()).getDate();
-            if (!isDateInsideRange(newDate,
-                    getResolution(VAbstractCalendarPanel.this::isDay))) {
-                return;
-            }
-            if (newDate.getMonth() != displayedMonth.getMonth()
-                    || newDate.getYear() != displayedMonth.getYear()) {
-                // If an off-month date was clicked, we must change the
-                // displayed month and re-render the calendar (#8931)
-                displayedMonth.setMonth(newDate.getMonth());
-                displayedMonth.setYear(newDate.getYear());
-                renderCalendar();
-            }
-            focusDay(newDate);
-            selectFocused();
-            onSubmit();
-        }
-    };
-
     private VEventButton prevYear;
 
     private VEventButton nextYear;
@@ -202,6 +164,33 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
 
     private boolean initialRenderDone = false;
 
+    /**
+     * Represents a click handler for when a user selects a value by using the
+     * mouse
+     */
+    private ClickHandler dayClickHandler = event -> {
+        if (!isEnabled() || isReadonly()) {
+            return;
+        }
+
+        Date newDate = ((Day) event.getSource()).getDate();
+        if (!isDateInsideRange(newDate,
+                getResolution(VAbstractCalendarPanel.this::isDay))) {
+            return;
+        }
+        if (newDate.getMonth() != displayedMonth.getMonth()
+                || newDate.getYear() != displayedMonth.getYear()) {
+            // If an off-month date was clicked, we must change the
+            // displayed month and re-render the calendar (#8931)
+            displayedMonth.setMonth(newDate.getMonth());
+            displayedMonth.setYear(newDate.getYear());
+            renderCalendar();
+        }
+        focusDay(newDate);
+        selectFocused();
+        onSubmit();
+    };
+
     public VAbstractCalendarPanel() {
         getElement().setId(DOM.createUniqueId());
         setStyleName(VDateField.CLASSNAME + "-calendarpanel");

client/src/main/java/com/vaadin/client/ui/VAbstractPopupCalendar.java

@@ -26,9 +26,7 @@ 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.MouseOutEvent;
-import com.google.gwt.event.dom.client.MouseOutHandler;
 import com.google.gwt.event.dom.client.MouseOverEvent;
-import com.google.gwt.event.dom.client.MouseOverHandler;
 import com.google.gwt.event.logical.shared.CloseEvent;
 import com.google.gwt.event.logical.shared.CloseHandler;
 import com.google.gwt.i18n.client.DateTimeFormat;
@@ -104,19 +102,13 @@ public abstract class VAbstractPopupCalendar<PANEL extends VAbstractCalendarPane
         calendarToggle.setText("");
         calendarToggle.addClickHandler(this);
 
-        calendarToggle.addDomHandler(new MouseOverHandler() {
-            @Override
-            public void onMouseOver(MouseOverEvent event) {
-                cursorOverCalendarToggleButton = true;
-            }
-        }, MouseOverEvent.getType());
+        calendarToggle.addDomHandler(
+                event -> cursorOverCalendarToggleButton = true,
+                MouseOverEvent.getType());
 
-        calendarToggle.addDomHandler(new MouseOutHandler() {
-            @Override
-            public void onMouseOut(MouseOutEvent event) {
-                cursorOverCalendarToggleButton = false;
-            }
-        }, MouseOutEvent.getType());
+        calendarToggle.addDomHandler(
+                event -> cursorOverCalendarToggleButton = false,
+                MouseOutEvent.getType());
 
         // -2 instead of -1 to avoid FocusWidget.onAttach to reset it
         calendarToggle.getElement().setTabIndex(-2);

client/src/main/java/com/vaadin/client/ui/VAbstractSplitPanel.java

@@ -25,13 +25,9 @@ import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.Position;
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.event.dom.client.TouchCancelEvent;
-import com.google.gwt.event.dom.client.TouchCancelHandler;
 import com.google.gwt.event.dom.client.TouchEndEvent;
-import com.google.gwt.event.dom.client.TouchEndHandler;
 import com.google.gwt.event.dom.client.TouchMoveEvent;
-import com.google.gwt.event.dom.client.TouchMoveHandler;
 import com.google.gwt.event.dom.client.TouchStartEvent;
-import com.google.gwt.event.dom.client.TouchStartHandler;
 import com.google.gwt.event.shared.EventHandler;
 import com.google.gwt.event.shared.GwtEvent;
 import com.google.gwt.user.client.DOM;
@@ -140,36 +136,24 @@ public abstract class VAbstractSplitPanel extends ComplexPanel {
 
         makeScrollable();
 
-        addDomHandler(new TouchCancelHandler() {
-            @Override
-            public void onTouchCancel(TouchCancelEvent event) {
-                // TODO When does this actually happen??
-                VConsole.log("TOUCH CANCEL");
-            }
+        addDomHandler(event -> {
+            // TODO When does this actually happen??
+            VConsole.log("TOUCH CANCEL");
         }, TouchCancelEvent.getType());
-        addDomHandler(new TouchStartHandler() {
-            @Override
-            public void onTouchStart(TouchStartEvent event) {
-                Node target = event.getTouches().get(0).getTarget().cast();
-                if (splitter.isOrHasChild(target)) {
-                    onMouseDown(Event.as(event.getNativeEvent()));
-                }
+        addDomHandler(event -> {
+            Node target = event.getTouches().get(0).getTarget().cast();
+            if (splitter.isOrHasChild(target)) {
+                onMouseDown(Event.as(event.getNativeEvent()));
             }
         }, TouchStartEvent.getType());
-        addDomHandler(new TouchMoveHandler() {
-            @Override
-            public void onTouchMove(TouchMoveEvent event) {
-                if (resizing) {
-                    onMouseMove(Event.as(event.getNativeEvent()));
-                }
+        addDomHandler(event -> {
+            if (resizing) {
+                onMouseMove(Event.as(event.getNativeEvent()));
             }
         }, TouchMoveEvent.getType());
-        addDomHandler(new TouchEndHandler() {
-            @Override
-            public void onTouchEnd(TouchEndEvent event) {
-                if (resizing) {
-                    onMouseUp(Event.as(event.getNativeEvent()));
-                }
+        addDomHandler(event -> {
+            if (resizing) {
+                onMouseUp(Event.as(event.getNativeEvent()));
             }
         }, TouchEndEvent.getType());
 

client/src/main/java/com/vaadin/client/ui/VCheckBox.java

@@ -17,8 +17,6 @@
 package com.vaadin.client.ui;
 
 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.DOM;
 import com.google.gwt.user.client.Event;
 import com.vaadin.client.ApplicationConnection;
@@ -60,12 +58,7 @@ public class VCheckBox extends com.google.gwt.user.client.ui.CheckBox
         if (BrowserInfo.get().isWebkit() || BrowserInfo.get().isFirefox()) {
             // Webkit and Firefox do not focus non-text input elements on click
             // (#3944)
-            addClickHandler(new ClickHandler() {
-                @Override
-                public void onClick(ClickEvent event) {
-                    setFocus(true);
-                }
-            });
+            addClickHandler(event -> setFocus(true));
         }
     }
 

client/src/main/java/com/vaadin/client/ui/VCheckBoxGroup.java

@@ -106,8 +106,9 @@ public class VCheckBoxGroup extends FocusableFlowPanelComposite
      */
     public JsonObject getItem(Element element) {
         return optionsToItems.entrySet().stream()
-                .filter(e -> e.getKey().getElement().isOrHasChild(element))
-                .map(e -> e.getValue()).findFirst().orElse(null);
+                .filter(entry -> entry.getKey().getElement()
+                        .isOrHasChild(element))
+                .map(entry -> entry.getValue()).findFirst().orElse(null);
     }
 
     private void remove(Widget widget) {

client/src/main/java/com/vaadin/client/ui/VComboBox.java

@@ -2048,12 +2048,9 @@ public class VComboBox extends Composite implements Field, KeyDownHandler,
                     ClickEvent.getType());
             selectedItemIcon.addDomHandler(VComboBox.this,
                     MouseDownEvent.getType());
-            selectedItemIcon.addDomHandler(new LoadHandler() {
-                @Override
-                public void onLoad(LoadEvent event) {
-                    afterSelectedItemIconChange();
-                }
-            }, LoadEvent.getType());
+            selectedItemIcon.addDomHandler(
+                    event -> afterSelectedItemIconChange(),
+                    LoadEvent.getType());
             panel.insert(selectedItemIcon, 0);
             afterSelectedItemIconChange();
         }

client/src/main/java/com/vaadin/client/ui/VDateField.java

@@ -270,8 +270,8 @@ public abstract class VDateField<R extends Enum<R>> extends FlowPanel
     public void sendBufferedValues() {
         rpc.update(bufferedDateString,
                 bufferedResolutions.entrySet().stream().collect(Collectors
-                        .toMap(e -> e.getKey().name(),
-                                e -> e.getValue())));
+                        .toMap(entry -> entry.getKey().name(),
+                                entry -> entry.getValue())));
         bufferedDateString = null;
         bufferedResolutions.clear();
     }

client/src/main/java/com/vaadin/client/ui/VDateTimeCalendarPanel.java

@@ -20,8 +20,6 @@ import java.util.Date;
 import com.google.gwt.event.dom.client.ChangeEvent;
 import com.google.gwt.event.dom.client.ChangeHandler;
 import com.google.gwt.event.dom.client.KeyCodes;
-import com.google.gwt.event.dom.client.KeyDownEvent;
-import com.google.gwt.event.dom.client.KeyDownHandler;
 import com.google.gwt.user.client.Element;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.ListBox;
@@ -179,17 +177,12 @@ public class VDateTimeCalendarPanel
             updateTimes();
 
             ListBox lastDropDown = getLastDropDown();
-            lastDropDown.addKeyDownHandler(new KeyDownHandler() {
-                @Override
-                public void onKeyDown(KeyDownEvent event) {
-                    boolean shiftKey = event.getNativeEvent().getShiftKey();
-                    if (shiftKey) {
-                        return;
-                    } else {
-                        int nativeKeyCode = event.getNativeKeyCode();
-                        if (nativeKeyCode == KeyCodes.KEY_TAB) {
-                            onTabOut(event);
-                        }
+            lastDropDown.addKeyDownHandler(event -> {
+                boolean shiftKey = event.getNativeEvent().getShiftKey();
+                if (!shiftKey) {
+                    int nativeKeyCode = event.getNativeKeyCode();
+                    if (nativeKeyCode == KeyCodes.KEY_TAB) {
+                        onTabOut(event);
                     }
                 }
             });

client/src/main/java/com/vaadin/client/ui/VDragAndDropWrapper.java

@@ -26,11 +26,8 @@ import com.google.gwt.core.client.Scheduler;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.event.dom.client.MouseDownEvent;
-import com.google.gwt.event.dom.client.MouseDownHandler;
 import com.google.gwt.event.dom.client.MouseUpEvent;
-import com.google.gwt.event.dom.client.MouseUpHandler;
 import com.google.gwt.event.dom.client.TouchStartEvent;
-import com.google.gwt.event.dom.client.TouchStartHandler;
 import com.google.gwt.user.client.Command;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.Event;
@@ -86,47 +83,33 @@ public class VDragAndDropWrapper extends VCustomComponent
         hookHtml5Events(getElement());
         setStyleName(CLASSNAME);
 
-        addDomHandler(new MouseDownHandler() {
-
-            @Override
-            public void onMouseDown(final MouseDownEvent event) {
-                if (getConnector().isEnabled()
-                        && event.getNativeEvent()
-                                .getButton() == Event.BUTTON_LEFT
-                        && startDrag(event.getNativeEvent())) {
-                    event.preventDefault(); // prevent text selection
-                    startX = event.getClientX();
-                    startY = event.getClientY();
-                }
+        addDomHandler(event -> {
+            if (getConnector().isEnabled()
+                    && event.getNativeEvent().getButton() == Event.BUTTON_LEFT
+                    && startDrag(event.getNativeEvent())) {
+                event.preventDefault(); // prevent text selection
+                startX = event.getClientX();
+                startY = event.getClientY();
             }
         }, MouseDownEvent.getType());
 
-        addDomHandler(new MouseUpHandler() {
-
-            @Override
-            public void onMouseUp(final MouseUpEvent event) {
-                final int deltaX = Math.abs(event.getClientX() - startX);
-                final int deltaY = Math.abs(event.getClientY() - startY);
-                if ((deltaX + deltaY) < MIN_PX_DELTA) {
-                    Element clickedElement = WidgetUtil.getElementFromPoint(
-                            event.getClientX(), event.getClientY());
-                    clickedElement.focus();
-                }
+        addDomHandler(event -> {
+            final int deltaX = Math.abs(event.getClientX() - startX);
+            final int deltaY = Math.abs(event.getClientY() - startY);
+            if ((deltaX + deltaY) < MIN_PX_DELTA) {
+                Element clickedElement = WidgetUtil.getElementFromPoint(
+                        event.getClientX(), event.getClientY());
+                clickedElement.focus();
             }
-
         }, MouseUpEvent.getType());
 
-        addDomHandler(new TouchStartHandler() {
-
-            @Override
-            public void onTouchStart(TouchStartEvent event) {
-                if (getConnector().isEnabled()
-                        && startDrag(event.getNativeEvent())) {
-                    /*
-                     * Don't let e.g. panel start scrolling.
-                     */
-                    event.stopPropagation();
-                }
+        addDomHandler(event -> {
+            if (getConnector().isEnabled()
+                    && startDrag(event.getNativeEvent())) {
+                /*
+                 * Don't let e.g. panel start scrolling.
+                 */
+                event.stopPropagation();
             }
         }, TouchStartEvent.getType());
 
@@ -226,18 +209,14 @@ public class VDragAndDropWrapper extends VCustomComponent
 
     private boolean uploading;
 
-    private final ReadyStateChangeHandler readyStateChangeHandler = new ReadyStateChangeHandler() {
-
-        @Override
-        public void onReadyStateChange(XMLHttpRequest xhr) {
-            if (xhr.getReadyState() == XMLHttpRequest.DONE) {
-                // #19616 Notify the upload handler that the request is complete
-                // and let it poll the server for changes.
-                uploadHandler.uploadDone();
-                uploading = false;
-                startNextUpload();
-                xhr.clearOnReadyStateChange();
-            }
+    private final ReadyStateChangeHandler readyStateChangeHandler = xhr -> {
+        if (xhr.getReadyState() == XMLHttpRequest.DONE) {
+            // #19616 Notify the upload handler that the request is complete
+            // and let it poll the server for changes.
+            uploadHandler.uploadDone();
+            uploading = false;
+            startNextUpload();
+            xhr.clearOnReadyStateChange();
         }
     };
     private Timer dragleavetimer;

client/src/main/java/com/vaadin/client/ui/VPopupView.java

@@ -22,11 +22,8 @@ import java.util.Set;
 
 import com.google.gwt.core.client.Scheduler;
 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.event.dom.client.KeyCodes;
 import com.google.gwt.event.dom.client.KeyDownEvent;
-import com.google.gwt.event.dom.client.KeyDownHandler;
 import com.google.gwt.event.logical.shared.CloseEvent;
 import com.google.gwt.event.logical.shared.CloseHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
@@ -93,15 +90,12 @@ public class VPopupView extends HTML
         popup.setWidget(loading);
 
         // When we click to open the popup...
-        addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                if (isEnabled()) {
-                    preparePopup(popup);
-                    showPopup(popup);
-                    center();
-                    fireEvent(new VisibilityChangeEvent(true));
-                }
+        addClickHandler(event -> {
+            if (isEnabled()) {
+                preparePopup(popup);
+                showPopup(popup);
+                center();
+                fireEvent(new VisibilityChangeEvent(true));
             }
         });
 
@@ -249,13 +243,11 @@ public class VPopupView extends HTML
             // Delegate popup keyboard events to the relevant handler. The
             // events do not propagate automatically because the popup is
             // directly attached to the RootPanel.
-            addDomHandler(new KeyDownHandler() {
-                @Override
-                public void onKeyDown(KeyDownEvent event) {
-                    if (shortcutActionHandler != null) {
-                        shortcutActionHandler.handleKeyboardEvent(
-                                Event.as(event.getNativeEvent()));
-                    }
+            addDomHandler(event -> {
+                if (shortcutActionHandler != null) {
+                    shortcutActionHandler
+                            .handleKeyboardEvent(
+                                    Event.as(event.getNativeEvent()));
                 }
             }, KeyDownEvent.getType());
         }

client/src/main/java/com/vaadin/client/ui/VRadioButtonGroup.java

@@ -121,8 +121,8 @@ public class VRadioButtonGroup extends FocusableFlowPanelComposite
 
     private Optional<JsonObject> tryGetItem(Element element) {
         return optionsToItems.entrySet().stream()
-                .filter(e -> e.getKey().getElement().equals(element))
-                .map(e -> e.getValue()).findFirst();
+                .filter(entry -> entry.getKey().getElement().equals(element))
+                .map(entry -> entry.getValue()).findFirst();
     }
 
     private void remove(Widget widget) {

client/src/main/java/com/vaadin/client/ui/VTwinColSelect.java

@@ -362,14 +362,16 @@ public class VTwinColSelect extends Composite implements MultiSelectWidget,
         Set<String> movedItems = moveSelectedItems(optionsListBox,
                 selectionsListBox);
         selectionChangeListeners
-                .forEach(e -> e.accept(movedItems, Collections.emptySet()));
+                .forEach(listener -> listener.accept(movedItems,
+                        Collections.emptySet()));
     }
 
     private void moveSelectedItemsRightToLeft() {
         Set<String> movedItems = moveSelectedItems(selectionsListBox,
                 optionsListBox);
         selectionChangeListeners
-                .forEach(e -> e.accept(Collections.emptySet(), movedItems));
+                .forEach(listener -> listener.accept(Collections.emptySet(),
+                        movedItems));
     }
 
     private static Set<String> moveSelectedItems(ListBox source,

client/src/main/java/com/vaadin/client/ui/VUpload.java

@@ -23,8 +23,6 @@ import com.google.gwt.dom.client.DivElement;
 import com.google.gwt.dom.client.Document;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.FormElement;
-import com.google.gwt.event.dom.client.ClickEvent;
-import com.google.gwt.event.dom.client.ClickHandler;
 import com.google.gwt.user.client.Command;
 import com.google.gwt.user.client.Event;
 import com.google.gwt.user.client.Timer;
@@ -143,15 +141,12 @@ public class VUpload extends SimplePanel {
         panel.add(maxfilesize);
         panel.add(fu);
         submitButton = new VButton();
-        submitButton.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                if (isImmediateMode()) {
-                    // fire click on upload (e.g. focused button and hit space)
-                    fireNativeClick(fu.getElement());
-                } else {
-                    submit();
-                }
+        submitButton.addClickHandler(event -> {
+            if (isImmediateMode()) {
+                // fire click on upload (e.g. focused button and hit space)
+                fireNativeClick(fu.getElement());
+            } else {
+                submit();
             }
         });
         panel.add(submitButton);

client/src/main/java/com/vaadin/client/ui/VWindow.java

@@ -48,7 +48,6 @@ import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.Command;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.Event;
-import com.google.gwt.user.client.Event.NativePreviewEvent;
 import com.google.gwt.user.client.Event.NativePreviewHandler;
 import com.google.gwt.user.client.Window;
 import com.google.gwt.user.client.ui.Widget;
@@ -434,35 +433,29 @@ public class VWindow extends VOverlay implements ShortcutActionHandlerOwner,
 
         // Handlers to Prevent tab to leave the window
         // and backspace to cause browser navigation
-        topEventBlocker = new NativePreviewHandler() {
-            @Override
-            public void onPreviewNativeEvent(NativePreviewEvent event) {
-                NativeEvent nativeEvent = event.getNativeEvent();
-                if (nativeEvent.getEventTarget().cast() == topTabStop
-                        && nativeEvent.getKeyCode() == KeyCodes.KEY_TAB
-                        && nativeEvent.getShiftKey()) {
-                    nativeEvent.preventDefault();
-                }
-                if (nativeEvent.getEventTarget().cast() == topTabStop
-                        && nativeEvent.getKeyCode() == KeyCodes.KEY_BACKSPACE) {
-                    nativeEvent.preventDefault();
-                }
+        topEventBlocker = event -> {
+            NativeEvent nativeEvent = event.getNativeEvent();
+            if (nativeEvent.getEventTarget().cast() == topTabStop
+                    && nativeEvent.getKeyCode() == KeyCodes.KEY_TAB
+                    && nativeEvent.getShiftKey()) {
+                nativeEvent.preventDefault();
+            }
+            if (nativeEvent.getEventTarget().cast() == topTabStop
+                    && nativeEvent.getKeyCode() == KeyCodes.KEY_BACKSPACE) {
+                nativeEvent.preventDefault();
             }
         };
 
-        bottomEventBlocker = new NativePreviewHandler() {
-            @Override
-            public void onPreviewNativeEvent(NativePreviewEvent event) {
-                NativeEvent nativeEvent = event.getNativeEvent();
-                if (nativeEvent.getEventTarget().cast() == bottomTabStop
-                        && nativeEvent.getKeyCode() == KeyCodes.KEY_TAB
-                        && !nativeEvent.getShiftKey()) {
-                    nativeEvent.preventDefault();
-                }
-                if (nativeEvent.getEventTarget().cast() == bottomTabStop
-                        && nativeEvent.getKeyCode() == KeyCodes.KEY_BACKSPACE) {
-                    nativeEvent.preventDefault();
-                }
+        bottomEventBlocker = event -> {
+            NativeEvent nativeEvent = event.getNativeEvent();
+            if (nativeEvent.getEventTarget().cast() == bottomTabStop
+                    && nativeEvent.getKeyCode() == KeyCodes.KEY_TAB
+                    && !nativeEvent.getShiftKey()) {
+                nativeEvent.preventDefault();
+            }
+            if (nativeEvent.getEventTarget().cast() == bottomTabStop
+                    && nativeEvent.getKeyCode() == KeyCodes.KEY_BACKSPACE) {
+                nativeEvent.preventDefault();
             }
         };
     }

client/src/main/java/com/vaadin/client/ui/absolutelayout/AbsoluteLayoutConnector.java

@@ -58,24 +58,20 @@ public class AbsoluteLayoutConnector extends AbstractComponentContainerConnector
         }
     };
 
-    private StateChangeHandler childStateChangeHandler = new StateChangeHandler() {
-        @Override
-        public void onStateChanged(StateChangeEvent stateChangeEvent) {
-            ComponentConnector child = (ComponentConnector) stateChangeEvent
-                    .getConnector();
-            List<String> childStyles = child.getState().styles;
-            if (childStyles == null) {
-                getWidget().setWidgetWrapperStyleNames(child.getWidget(),
-                        (String[]) null);
-            } else {
-                getWidget().setWidgetWrapperStyleNames(child.getWidget(),
-                        childStyles.toArray(new String[childStyles.size()]));
-            }
+    private StateChangeHandler childStateChangeHandler = event -> {
+        ComponentConnector child = (ComponentConnector) event.getConnector();
+        List<String> childStyles = child.getState().styles;
+        if (childStyles == null) {
+            getWidget().setWidgetWrapperStyleNames(child.getWidget(),
+                    (String[]) null);
+        } else {
+            getWidget().setWidgetWrapperStyleNames(child.getWidget(),
+                    childStyles.toArray(new String[childStyles.size()]));
+        }
 
-            if (stateChangeEvent.hasPropertyChanged("height")
-                    || stateChangeEvent.hasPropertyChanged("width")) {
-                setChildWidgetPosition(child);
-            }
+        if (event.hasPropertyChanged("height")
+                || event.hasPropertyChanged("width")) {
+            setChildWidgetPosition(child);
         }
     };
 

client/src/main/java/com/vaadin/client/ui/dd/DragAndDropHandler.java

@@ -104,49 +104,44 @@ public class DragAndDropHandler {
         }
     };
 
-    private final NativePreviewHandler dragPreviewHandler = new NativePreviewHandler() {
-
-        @Override
-        public void onPreviewNativeEvent(NativePreviewEvent event) {
-            if (dragging) {
-                final int typeInt = event.getTypeInt();
-                switch (typeInt) {
-                case Event.ONMOUSEMOVE:
-                case Event.ONTOUCHMOVE:
-                    callback.onDragUpdate(Event.as(event.getNativeEvent()));
-                    break;
-                case Event.ONKEYDOWN:
-                    // End drag if ESC is pressed
-                    int keyCode = event.getNativeEvent().getKeyCode();
-                    if (keyCode == KeyCodes.KEY_ESCAPE) {
-                        cancelDrag(event);
-                    }
-                    break;
-                case Event.ONTOUCHCANCEL:
+    private final NativePreviewHandler dragPreviewHandler = event -> {
+        if (dragging) {
+            final int typeInt = event.getTypeInt();
+            switch (typeInt) {
+            case Event.ONMOUSEMOVE:
+            case Event.ONTOUCHMOVE:
+                callback.onDragUpdate(Event.as(event.getNativeEvent()));
+                break;
+            case Event.ONKEYDOWN:
+                // End drag if ESC is pressed
+                int keyCode = event.getNativeEvent().getKeyCode();
+                if (keyCode == KeyCodes.KEY_ESCAPE) {
                     cancelDrag(event);
-                    break;
-                case Event.ONTOUCHEND:
-                case Event.ONMOUSEUP:
-                    callback.onDragUpdate(Event.as(event.getNativeEvent()));
-                    callback.onDrop();
-                    stopDrag();
-                    break;
-                case Event.ONCLICK:
-                    break;
-                default:
-                    break;
                 }
-            } else {
+                break;
+            case Event.ONTOUCHCANCEL:
+                cancelDrag(event);
+                break;
+            case Event.ONTOUCHEND:
+            case Event.ONMOUSEUP:
+                callback.onDragUpdate(Event.as(event.getNativeEvent()));
+                callback.onDrop();
                 stopDrag();
+                break;
+            case Event.ONCLICK:
+                break;
+            default:
+                break;
             }
-
-            // Kill events - as long as this thing is active, we don't want to
-            // let any event through.
-            event.getNativeEvent().stopPropagation();
-            event.getNativeEvent().preventDefault();
-            event.cancel();
+        } else {
+            stopDrag();
         }
 
+        // Kill events - as long as this thing is active, we don't want to
+        // let any event through.
+        event.getNativeEvent().stopPropagation();
+        event.getNativeEvent().preventDefault();
+        event.cancel();
     };
 
     /**

client/src/main/java/com/vaadin/client/ui/image/ImageConnector.java

@@ -17,7 +17,6 @@ package com.vaadin.client.ui.image;
 
 import com.google.gwt.dom.client.NativeEvent;
 import com.google.gwt.event.dom.client.LoadEvent;
-import com.google.gwt.event.dom.client.LoadHandler;
 import com.vaadin.client.communication.StateChangeEvent;
 import com.vaadin.client.ui.AbstractComponentConnector;
 import com.vaadin.client.ui.ClickEventHandler;
@@ -34,14 +33,10 @@ public class ImageConnector extends AbstractComponentConnector {
     @Override
     protected void init() {
         super.init();
-        getWidget().addHandler(new LoadHandler() {
-
-            @Override
-            public void onLoad(LoadEvent event) {
-                getLayoutManager().setNeedsMeasure(ImageConnector.this);
-            }
-
-        }, LoadEvent.getType());
+        getWidget().addHandler(
+                event -> getLayoutManager()
+                        .setNeedsMeasure(ImageConnector.this),
+                LoadEvent.getType());
     }
 
     @Override

client/src/main/java/com/vaadin/client/ui/loginform/LoginFormConnector.java

@@ -18,14 +18,11 @@ package com.vaadin.client.ui.loginform;
 
 import com.google.gwt.core.client.Scheduler;
 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.event.dom.client.KeyCodes;
 import com.google.gwt.event.dom.client.KeyDownEvent;
 import com.google.gwt.event.dom.client.KeyDownHandler;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.ui.FocusWidget;
-import com.google.gwt.user.client.ui.FormPanel;
 import com.vaadin.client.ComponentConnector;
 import com.vaadin.client.ConnectorHierarchyChangeEvent;
 import com.vaadin.client.communication.StateChangeEvent;
@@ -61,15 +58,10 @@ public class LoginFormConnector
         super.init();
 
         loginFormRpc = getRpcProxy(LoginFormRpc.class);
-        getWidget().addSubmitCompleteHandler(
-                new FormPanel.SubmitCompleteHandler() {
-                    @Override
-                    public void onSubmitComplete(
-                            FormPanel.SubmitCompleteEvent event) {
-                        valuesChanged();
-                        loginFormRpc.submitCompleted();
-                    }
-                });
+        getWidget().addSubmitCompleteHandler(event -> {
+            valuesChanged();
+            loginFormRpc.submitCompleted();
+        });
     }
 
     @Override
@@ -153,12 +145,7 @@ public class LoginFormConnector
     }
 
     private void addSubmitButtonClickHandler(FocusWidget button) {
-        button.addClickHandler(new ClickHandler() {
-            @Override
-            public void onClick(ClickEvent event) {
-                login();
-            }
-        });
+        button.addClickHandler(event -> login());
     }
 
     private void valuesChanged() {

client/src/main/java/com/vaadin/client/ui/orderedlayout/AbstractOrderedLayoutConnector.java

@@ -73,25 +73,22 @@ public abstract class AbstractOrderedLayoutConnector
         }
     };
 
-    private StateChangeHandler childStateChangeHandler = new StateChangeHandler() {
-        @Override
-        public void onStateChanged(StateChangeEvent stateChangeEvent) {
-            // Child state has changed, update stuff it hasn't already been done
-            updateInternalState();
+    private StateChangeHandler childStateChangeHandler = event -> {
+        // Child state has changed, update stuff it hasn't already been done
+        updateInternalState();
 
-            /*
-             * Some changes must always be done after each child's own state
-             * change handler has been run because it might have changed some
-             * styles that are overridden here.
-             */
-            ServerConnector child = stateChangeEvent.getConnector();
-            if (child instanceof ComponentConnector) {
-                ComponentConnector component = (ComponentConnector) child;
-                Slot slot = getWidget().getSlot(component.getWidget());
+        /*
+         * Some changes must always be done after each child's own state change
+         * handler has been run because it might have changed some styles that
+         * are overridden here.
+         */
+        ServerConnector child = event.getConnector();
+        if (child instanceof ComponentConnector) {
+            ComponentConnector component = (ComponentConnector) child;
+            Slot slot = getWidget().getSlot(component.getWidget());
 
-                slot.setRelativeWidth(component.isRelativeWidth());
-                slot.setRelativeHeight(component.isRelativeHeight());
-            }
+            slot.setRelativeWidth(component.isRelativeWidth());
+            slot.setRelativeHeight(component.isRelativeHeight());
         }
     };
 

client/src/main/java/com/vaadin/client/ui/richtextarea/RichTextAreaConnector.java

@@ -15,8 +15,6 @@
  */
 package com.vaadin.client.ui.richtextarea;
 
-import com.google.gwt.event.dom.client.BlurEvent;
-import com.google.gwt.event.dom.client.BlurHandler;
 import com.vaadin.client.annotations.OnStateChange;
 import com.vaadin.client.ui.AbstractFieldConnector;
 import com.vaadin.client.ui.ConnectorFocusAndBlurHandler;
@@ -48,12 +46,7 @@ public class RichTextAreaConnector extends AbstractFieldConnector
 
     @Override
     protected void init() {
-        getWidget().addBlurHandler(new BlurHandler() {
-            @Override
-            public void onBlur(BlurEvent event) {
-                flush();
-            }
-        });
+        getWidget().addBlurHandler(event -> flush());
         getWidget().addInputHandler(
                 () -> valueChangeHandler.scheduleValueChange());
 

client/src/main/java/com/vaadin/client/ui/splitpanel/AbstractSplitPanelConnector.java

@@ -35,7 +35,6 @@ import com.vaadin.client.ui.AbstractComponentContainerConnector;
 import com.vaadin.client.ui.ClickEventHandler;
 import com.vaadin.client.ui.SimpleManagedLayout;
 import com.vaadin.client.ui.VAbstractSplitPanel;
-import com.vaadin.client.ui.VAbstractSplitPanel.SplitterMoveHandler;
 import com.vaadin.client.ui.VAbstractSplitPanel.SplitterMoveHandler.SplitterMoveEvent;
 import com.vaadin.shared.MouseEventDetails;
 import com.vaadin.shared.ui.ComponentStateUtil;
@@ -52,27 +51,21 @@ public abstract class AbstractSplitPanelConnector extends
         // TODO Remove
         getWidget().client = getConnection();
 
-        getWidget().addHandler(new SplitterMoveHandler() {
-
-            @Override
-            public void splitterMoved(SplitterMoveEvent event) {
-                String position = getWidget().getSplitterPosition();
-                float pos = 0;
-                if (position.indexOf("%") > 0) {
-                    // Send % values as a fraction to avoid that the splitter
-                    // "jumps" when server responds with the integer pct value
-                    // (e.g. dragged 16.6% -> should not jump to 17%)
-                    pos = Float.valueOf(
-                            position.substring(0, position.length() - 1));
-                } else {
-                    pos = Integer.parseInt(
-                            position.substring(0, position.length() - 2));
-                }
-
-                getRpcProxy(AbstractSplitPanelRpc.class)
-                        .setSplitterPosition(pos);
+        getWidget().addHandler(event -> {
+            String position = getWidget().getSplitterPosition();
+            float pos = 0;
+            if (position.indexOf("%") > 0) {
+                // Send % values as a fraction to avoid that the splitter
+                // "jumps" when server responds with the integer pct value
+                // (e.g. dragged 16.6% -> should not jump to 17%)
+                pos = Float
+                        .valueOf(position.substring(0, position.length() - 1));
+            } else {
+                pos = Integer
+                        .parseInt(position.substring(0, position.length() - 2));
             }
 
+            getRpcProxy(AbstractSplitPanelRpc.class).setSplitterPosition(pos);
         }, SplitterMoveEvent.TYPE);
     }
 

client/src/main/java/com/vaadin/client/ui/ui/UIConnector.java

@@ -36,11 +36,8 @@ import com.google.gwt.dom.client.Style;
 import com.google.gwt.dom.client.Style.Position;
 import com.google.gwt.dom.client.StyleInjector;
 import com.google.gwt.event.dom.client.KeyDownEvent;
-import com.google.gwt.event.dom.client.KeyDownHandler;
 import com.google.gwt.event.dom.client.ScrollEvent;
 import com.google.gwt.event.dom.client.ScrollHandler;
-import com.google.gwt.event.logical.shared.ResizeEvent;
-import com.google.gwt.event.logical.shared.ResizeHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.user.client.Command;
 import com.google.gwt.user.client.DOM;
@@ -122,35 +119,28 @@ public class UIConnector extends AbstractSingleComponentContainerConnector
      */
     private String currentLocation;
 
-    private final StateChangeHandler childStateChangeHandler = new StateChangeHandler() {
-        @Override
-        public void onStateChanged(StateChangeEvent stateChangeEvent) {
-            // TODO Should use a more specific handler that only reacts to
-            // size changes
-            onChildSizeChange();
-        }
+    private final StateChangeHandler childStateChangeHandler = event -> {
+        // TODO Should use a more specific handler that only reacts to
+        // size changes
+        onChildSizeChange();
     };
 
-    private WindowOrderHandler windowOrderHandler = new WindowOrderHandler() {
-
-        @Override
-        public void onWindowOrderChange(WindowOrderEvent event) {
-            VWindow[] windows = event.getWindows();
-            Map<Integer, Connector> orders = new HashMap<>();
-            boolean hasEventListener = hasEventListener(EventId.WINDOW_ORDER);
-            for (VWindow window : windows) {
-                Connector connector = Util.findConnectorFor(window);
-                orders.put(window.getWindowOrder(), connector);
-                if (connector instanceof AbstractConnector
-                        && ((AbstractConnector) connector)
-                                .hasEventListener(EventId.WINDOW_ORDER)) {
-                    hasEventListener = true;
-                }
-            }
-            if (hasEventListener) {
-                getRpcProxy(WindowOrderRpc.class).windowOrderChanged(orders);
+    private WindowOrderHandler windowOrderHandler = event -> {
+        VWindow[] windows = event.getWindows();
+        Map<Integer, Connector> orders = new HashMap<>();
+        boolean hasEventListener = hasEventListener(EventId.WINDOW_ORDER);
+        for (VWindow window : windows) {
+            Connector connector = Util.findConnectorFor(window);
+            orders.put(window.getWindowOrder(), connector);
+            if (connector instanceof AbstractConnector
+                    && ((AbstractConnector) connector)
+                            .hasEventListener(EventId.WINDOW_ORDER)) {
+                hasEventListener = true;
             }
         }
+        if (hasEventListener) {
+            getRpcProxy(WindowOrderRpc.class).windowOrderChanged(orders);
+        }
     };
 
     @Override
@@ -214,14 +204,11 @@ public class UIConnector extends AbstractSingleComponentContainerConnector
             }-*/;
         });
 
-        getWidget().addResizeHandler(new ResizeHandler() {
-            @Override
-            public void onResize(ResizeEvent event) {
-                getRpcProxy(UIServerRpc.class).resize(event.getWidth(),
-                        event.getHeight(), Window.getClientWidth(),
-                        Window.getClientHeight());
-                getConnection().getServerRpcQueue().flush();
-            }
+        getWidget().addResizeHandler(event -> {
+            getRpcProxy(UIServerRpc.class).resize(event.getWidth(),
+                    event.getHeight(), Window.getClientWidth(),
+                    Window.getClientHeight());
+            getConnection().getServerRpcQueue().flush();
         });
         getWidget().addScrollHandler(new ScrollHandler() {
             private int lastSentScrollTop = Integer.MAX_VALUE;
@@ -524,22 +511,18 @@ public class UIConnector extends AbstractSingleComponentContainerConnector
             shortcutContextWidget = RootPanel.get(); // document body
         }
 
-        shortcutContextWidget.addDomHandler(new KeyDownHandler() {
-            @Override
-            public void onKeyDown(KeyDownEvent event) {
-                if (VWindow.isModalWindowOpen()) {
-                    return;
-                }
-                if (getWidget().actionHandler != null) {
-                    Element target = Element
-                            .as(event.getNativeEvent().getEventTarget());
-                    if (target == Document.get().getBody()
-                            || getWidget().getElement().isOrHasChild(target)) {
-                        // Only react to body and elements inside the UI
-                        getWidget().actionHandler.handleKeyboardEvent(
-                                (Event) event.getNativeEvent().cast());
-                    }
-
+        shortcutContextWidget.addDomHandler(event -> {
+            if (VWindow.isModalWindowOpen()) {
+                return;
+            }
+            if (getWidget().actionHandler != null) {
+                Element target = Element
+                        .as(event.getNativeEvent().getEventTarget());
+                if (target == Document.get().getBody()
+                        || getWidget().getElement().isOrHasChild(target)) {
+                    // Only react to body and elements inside the UI
+                    getWidget().actionHandler.handleKeyboardEvent(
+                            (Event) event.getNativeEvent().cast());
                 }
             }
         }, KeyDownEvent.getType());

client/src/main/java/com/vaadin/client/ui/upload/UploadConnector.java

@@ -16,8 +16,6 @@
 
 package com.vaadin.client.ui.upload;
 
-import com.google.gwt.event.dom.client.ChangeEvent;
-import com.google.gwt.event.dom.client.ChangeHandler;
 import com.vaadin.client.ApplicationConnection;
 import com.vaadin.client.Paintable;
 import com.vaadin.client.UIDL;
@@ -48,13 +46,10 @@ public class UploadConnector extends AbstractComponentConnector
     protected void init() {
         super.init();
 
-        getWidget().fu.addChangeHandler(new ChangeHandler() {
-            @Override
-            public void onChange(ChangeEvent event) {
-                if (hasEventListener(EventId.CHANGE)) {
-                    getRpcProxy(UploadServerRpc.class)
-                            .change(getWidget().fu.getFilename());
-                }
+        getWidget().fu.addChangeHandler(event -> {
+            if (hasEventListener(EventId.CHANGE)) {
+                getRpcProxy(UploadServerRpc.class)
+                        .change(getWidget().fu.getFilename());
             }
         });
     }

client/src/main/java/com/vaadin/client/widget/escalator/ScrollbarBundle.java

@@ -435,12 +435,7 @@ public abstract class ScrollbarBundle implements DeferredWorker {
             }
             // must be a field because Java insists.
             offsetSizeTemporaryScrollHandler = addScrollHandler(
-                    new ScrollHandler() {
-                        @Override
-                        public void onScroll(ScrollEvent event) {
-                            setOffsetSizeNow(px);
-                        }
-                    });
+                    event -> setOffsetSizeNow(px));
             setScrollPos(0);
         } else {
             setOffsetSizeNow(px);
@@ -523,12 +518,9 @@ public abstract class ScrollbarBundle implements DeferredWorker {
         if (!WidgetUtil.pixelValuesEqual(oldScrollPos, scrollPos)) {
             if (scrollInProgress == null) {
                 // Only used for tracking that there is "workPending"
-                scrollInProgress = addScrollHandler(new ScrollHandler() {
-                    @Override
-                    public void onScroll(ScrollEvent event) {
-                        scrollInProgress.removeHandler();
-                        scrollInProgress = null;
-                    }
+                scrollInProgress = addScrollHandler(event -> {
+                    scrollInProgress.removeHandler();
+                    scrollInProgress = null;
                 });
             }
             if (isInvisibleScrollbar) {
@@ -662,12 +654,7 @@ public abstract class ScrollbarBundle implements DeferredWorker {
                     scrollSizeTemporaryScrollHandler.removeHandler();
                 }
                 scrollSizeTemporaryScrollHandler = addScrollHandler(
-                        new ScrollHandler() {
-                            @Override
-                            public void onScroll(ScrollEvent event) {
-                                setScrollSizeNow(px);
-                            }
-                        });
+                        event -> setScrollSizeNow(px));
             }
             setScrollPos(0);
             if (!delayedSizeSet) {

client/src/main/java/com/vaadin/client/widget/grid/selection/MultiSelectionRenderer.java

@@ -487,30 +487,27 @@ public class MultiSelectionRenderer<T>
         /** The registration info for {@link #scrollPreviewHandler} */
         private HandlerRegistration handlerRegistration;
 
-        private final NativePreviewHandler scrollPreviewHandler = new NativePreviewHandler() {
-            @Override
-            public void onPreviewNativeEvent(final NativePreviewEvent event) {
-                if (autoScroller == null) {
-                    stop();
-                    return;
-                }
+        private final NativePreviewHandler scrollPreviewHandler = event -> {
+            if (autoScroller == null) {
+                stop();
+                return;
+            }
 
-                final NativeEvent nativeEvent = event.getNativeEvent();
-                int pageY = 0;
-                int pageX = 0;
-                switch (event.getTypeInt()) {
-                case Event.ONMOUSEMOVE:
-                case Event.ONTOUCHMOVE:
-                    pageY = WidgetUtil.getTouchOrMouseClientY(nativeEvent);
-                    pageX = WidgetUtil.getTouchOrMouseClientX(nativeEvent);
-                    autoScroller.updatePointerCoords(pageX, pageY);
-                    break;
-                case Event.ONMOUSEUP:
-                case Event.ONTOUCHEND:
-                case Event.ONTOUCHCANCEL:
-                    stop();
-                    break;
-                }
+            final NativeEvent nativeEvent = event.getNativeEvent();
+            int pageY = 0;
+            int pageX = 0;
+            switch (event.getTypeInt()) {
+            case Event.ONMOUSEMOVE:
+            case Event.ONTOUCHMOVE:
+                pageY = WidgetUtil.getTouchOrMouseClientY(nativeEvent);
+                pageX = WidgetUtil.getTouchOrMouseClientX(nativeEvent);
+                autoScroller.updatePointerCoords(pageX, pageY);
+                break;
+            case Event.ONMOUSEUP:
+            case Event.ONTOUCHEND:
+            case Event.ONTOUCHCANCEL:
+                stop();
+                break;
             }
         };
 

client/src/main/java/com/vaadin/client/widgets/Grid.java

@@ -49,7 +49,6 @@ import com.google.gwt.dom.client.TableCellElement;
 import com.google.gwt.dom.client.TableRowElement;
 import com.google.gwt.dom.client.TableSectionElement;
 import com.google.gwt.dom.client.Touch;
-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.KeyDownEvent;
@@ -62,8 +61,6 @@ import com.google.gwt.event.shared.HandlerRegistration;
 import com.google.gwt.touch.client.Point;
 import com.google.gwt.user.client.DOM;
 import com.google.gwt.user.client.Event;
-import com.google.gwt.user.client.Event.NativePreviewEvent;
-import com.google.gwt.user.client.Event.NativePreviewHandler;
 import com.google.gwt.user.client.Timer;
 import com.google.gwt.user.client.ui.Button;
 import com.google.gwt.user.client.ui.CheckBox;
@@ -98,7 +95,6 @@ import com.vaadin.client.widget.escalator.EscalatorUpdater;
 import com.vaadin.client.widget.escalator.FlyweightCell;
 import com.vaadin.client.widget.escalator.Row;
 import com.vaadin.client.widget.escalator.RowContainer;
-import com.vaadin.client.widget.escalator.RowVisibilityChangeEvent;
 import com.vaadin.client.widget.escalator.RowVisibilityChangeHandler;
 import com.vaadin.client.widget.escalator.ScrollbarBundle.Direction;
 import com.vaadin.client.widget.escalator.Spacer;
@@ -1458,22 +1454,16 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
         public Editor() {
             saveButton = new Button();
             saveButton.setText(GridConstants.DEFAULT_SAVE_CAPTION);
-            saveButton.addClickHandler(new ClickHandler() {
-                @Override
-                public void onClick(ClickEvent event) {
-                    save();
-                    FocusUtil.setFocus(grid, true);
-                }
+            saveButton.addClickHandler(event -> {
+                save();
+                FocusUtil.setFocus(grid, true);
             });
 
             cancelButton = new Button();
             cancelButton.setText(GridConstants.DEFAULT_CANCEL_CAPTION);
-            cancelButton.addClickHandler(new ClickHandler() {
-                @Override
-                public void onClick(ClickEvent event) {
-                    cancel();
-                    FocusUtil.setFocus(grid, true);
-                }
+            cancelButton.addClickHandler(event -> {
+                cancel();
+                FocusUtil.setFocus(grid, true);
             });
         }
 
@@ -1613,13 +1603,10 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
             if (escalator.getVisibleRowRange().contains(rowIndex)) {
                 show(rowIndex, columnIndexDOM);
             } else {
-                vScrollHandler = grid.addScrollHandler(new ScrollHandler() {
-                    @Override
-                    public void onScroll(ScrollEvent event) {
-                        if (escalator.getVisibleRowRange().contains(rowIndex)) {
-                            show(rowIndex, columnIndexDOM);
-                            vScrollHandler.removeHandler();
-                        }
+                vScrollHandler = grid.addScrollHandler(event -> {
+                    if (escalator.getVisibleRowRange().contains(rowIndex)) {
+                        show(rowIndex, columnIndexDOM);
+                        vScrollHandler.removeHandler();
                     }
                 });
                 grid.scrollToRow(rowIndex,
@@ -1829,12 +1816,9 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
             TableRowElement tr = grid.getEscalator().getBody()
                     .getRowElement(rowIndex);
 
-            hScrollHandler = grid.addScrollHandler(new ScrollHandler() {
-                @Override
-                public void onScroll(ScrollEvent event) {
-                    updateHorizontalScrollPosition();
-                    updateVerticalScrollPosition();
-                }
+            hScrollHandler = grid.addScrollHandler(event -> {
+                updateHorizontalScrollPosition();
+                updateVerticalScrollPosition();
             });
 
             gridElement.appendChild(editorOverlay);
@@ -3781,15 +3765,11 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
      */
     private static class Sidebar extends Composite implements HasEnabled {
 
-        private final ClickHandler openCloseButtonHandler = new ClickHandler() {
-
-            @Override
-            public void onClick(ClickEvent event) {
-                if (!isOpen()) {
-                    open();
-                } else {
-                    close();
-                }
+        private final ClickHandler openCloseButtonHandler = event -> {
+            if (!isOpen()) {
+                open();
+            } else {
+                close();
             }
         };
 
@@ -3872,13 +3852,9 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
                     }
                 }
             };
-            KeyDownHandler keyDownHandler = new KeyDownHandler() {
-
-                @Override
-                public void onKeyDown(KeyDownEvent event) {
-                    if (event.getNativeKeyCode() == KeyCodes.KEY_ESCAPE) {
-                        close();
-                    }
+            KeyDownHandler keyDownHandler = event -> {
+                if (event.getNativeKeyCode() == KeyCodes.KEY_ESCAPE) {
+                    close();
                 }
             };
             openCloseButton.addDomHandler(keyDownHandler,
@@ -4542,18 +4518,12 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
             // mouse was released on top of the dragged cell
             if (columnSortPreventRegistration == null) {
                 columnSortPreventRegistration = Event
-                        .addNativePreviewHandler(new NativePreviewHandler() {
-
-                            @Override
-                            public void onPreviewNativeEvent(
-                                    NativePreviewEvent event) {
-                                if (event.getTypeInt() == Event.ONCLICK) {
-                                    event.cancel();
-                                    event.getNativeEvent().preventDefault();
-                                    columnSortPreventRegistration
-                                            .removeHandler();
-                                    columnSortPreventRegistration = null;
-                                }
+                        .addNativePreviewHandler(event -> {
+                            if (event.getTypeInt() == Event.ONCLICK) {
+                                event.cancel();
+                                event.getNativeEvent().preventDefault();
+                                columnSortPreventRegistration.removeHandler();
+                                columnSortPreventRegistration = null;
                             }
                         });
             }
@@ -6156,23 +6126,14 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
 
         escalator.getBody().setSpacerUpdater(gridSpacerUpdater);
 
-        escalator.addScrollHandler(new ScrollHandler() {
-            @Override
-            public void onScroll(ScrollEvent event) {
-                fireEvent(new ScrollEvent());
-            }
-        });
+        escalator.addScrollHandler(event -> fireEvent(new ScrollEvent()));
 
         escalator.addRowVisibilityChangeHandler(
-                new RowVisibilityChangeHandler() {
-                    @Override
-                    public void onRowVisibilityChange(
-                            RowVisibilityChangeEvent event) {
-                        if (dataSource != null && dataSource.size() != 0) {
-                            dataSource.ensureAvailability(
-                                    event.getFirstVisibleRow(),
-                                    event.getVisibleRowCount());
-                        }
+                event -> {
+                    if (dataSource != null && dataSource.size() != 0) {
+                        dataSource.ensureAvailability(
+                                event.getFirstVisibleRow(),
+                                event.getVisibleRowCount());
                     }
                 });
 
@@ -6193,18 +6154,15 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
                 BrowserEvents.MOUSEDOWN, BrowserEvents.CLICK));
 
         // Make ENTER and SHIFT+ENTER in the header perform sorting
-        addHeaderKeyUpHandler(new HeaderKeyUpHandler() {
-            @Override
-            public void onKeyUp(GridKeyUpEvent event) {
-                if (event.getNativeKeyCode() != KeyCodes.KEY_ENTER) {
-                    return;
-                }
-                if (getHeader().getRow(event.getFocusedCell().getRowIndex())
-                        .isDefault()) {
-                    // Only sort for enter on the default header
-                    sorter.sort(event.getFocusedCell().getColumn(),
-                            event.isShiftKeyDown());
-                }
+        addHeaderKeyUpHandler(event -> {
+            if (event.getNativeKeyCode() != KeyCodes.KEY_ENTER) {
+                return;
+            }
+            if (getHeader().getRow(event.getFocusedCell().getRowIndex())
+                    .isDefault()) {
+                // Only sort for enter on the default header
+                sorter.sort(event.getFocusedCell().getColumn(),
+                        event.isShiftKeyDown());
             }
         });
 

server/src/test/java/com/vaadin/tests/design/DeclarativeTestBaseBase.java

@@ -176,7 +176,6 @@ public abstract class DeclarativeTestBaseBase<T extends Component> {
 
             @Override
             public void close() throws SecurityException {
-
             }
         };
 

testbench-api/src/main/java/com/vaadin/testbench/elements/GridElement.java

@@ -462,10 +462,9 @@ public class GridElement extends AbstractComponentElement {
         Optional<WebElement> toggleButton = getDriver()
                 .findElement(By.className("v-grid-sidebar-content"))
                 .findElements(By.className("column-hiding-toggle")).stream()
-                .filter(e -> e.getText().equals(toggleCaption))
-                .findAny();
+                .filter(element -> element.getText().equals(toggleCaption)).findAny();
         if (toggleButton.isPresent()) {
-            toggleButton.ifPresent(e -> e.click());
+            toggleButton.ifPresent(element -> element.click());
         } else {
             throw new IllegalArgumentException(
                     "No column hiding toggle with caption '" + toggleCaption

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

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() {

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") {

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")));
     }
 }

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);

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);
                             }
                         }
                     }

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>() {

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");
     }
 

uitest/src/main/java/com/vaadin/tests/dd/DDTest1.java

@@ -182,7 +182,6 @@ public class DDTest1 extends TestBase {
                         copyChildren(source, target, childId);
                     }
                 }
-
             }
 
             @Override

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"))));

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

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) {

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);

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() {

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();
                     }
                 });
             }

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);

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) {

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() {

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());
     }
 

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);
     }

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());
     }
 
     /**

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

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());
     }

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");
             }
         });
     }

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());
     }

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);

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;
                 }
 

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);

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());
     }
 

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