enable focus listeners in disabled state, add tests

vaadin-button-flow-parent/vaadin-button-flow-integration-tests/src/main/java/com/vaadin/flow/component/button/tests/AccessibleDisabledButtonPage.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2000-2025 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.button.tests;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+import com.vaadin.experimental.FeatureFlags;
+import com.vaadin.flow.component.Key;
+import com.vaadin.flow.component.KeyModifier;
+import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.router.Route;
+import com.vaadin.flow.server.VaadinService;
+
+import elemental.json.Json;
+import elemental.json.JsonObject;
+
+@Route("vaadin-button/accessible-disabled-button")
+public class AccessibleDisabledButtonPage extends Div {
+    private AtomicInteger blurListenerCounter = new AtomicInteger(0);
+    private AtomicInteger focusListenerCounter = new AtomicInteger(0);
+    private AtomicInteger clickListenerCounter = new AtomicInteger(0);
+    private AtomicInteger doubleClickListenerCounter = new AtomicInteger(0);
+
+    private Div listenerCounters;
+
+    public AccessibleDisabledButtonPage() {
+        FeatureFlags.get(VaadinService.getCurrent().getContext())
+                .setEnabled("exampleFeatureFlag", true);
+
+        Button button = new Button("Disabled button");
+        button.setEnabled(false);
+
+        button.addFocusShortcut(Key.KEY_A, KeyModifier.ALT);
+        button.addBlurListener(
+                event -> incrementListenerCounter(blurListenerCounter));
+        button.addFocusListener(
+                event -> incrementListenerCounter(focusListenerCounter));
+        button.addClickListener(
+                event -> incrementListenerCounter(clickListenerCounter));
+        button.addDoubleClickListener(
+                event -> incrementListenerCounter(doubleClickListenerCounter));
+
+        listenerCounters = new Div();
+        listenerCounters.setId("listener-counters");
+
+        add(button, listenerCounters);
+    }
+
+    private void incrementListenerCounter(AtomicInteger listenerCounter) {
+        listenerCounter.incrementAndGet();
+        updateListenerCounters();
+    }
+
+    private void updateListenerCounters() {
+        JsonObject json = Json.createObject();
+        json.put("blur", blurListenerCounter.get());
+        json.put("focus", focusListenerCounter.get());
+        json.put("click", clickListenerCounter.get());
+        json.put("doubleClick", doubleClickListenerCounter.get());
+        listenerCounters.setText(json.toJson());
+    }
+}

vaadin-button-flow-parent/vaadin-button-flow-integration-tests/src/main/resources/vaadin-featureflags.properties

@@ -0,0 +1,2 @@
+# Example feature. Will be removed once the first real feature flag is added
+com.vaadin.experimental.exampleFeatureFlag=true

vaadin-button-flow-parent/vaadin-button-flow-integration-tests/src/test/java/com/vaadin/flow/component/button/tests/AccessibleDisabledButtonIT.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2000-2025 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.button.tests;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.openqa.selenium.Keys;
+import org.openqa.selenium.interactions.Actions;
+
+import com.vaadin.flow.component.button.testbench.ButtonElement;
+import com.vaadin.flow.testutil.TestPath;
+import com.vaadin.testbench.TestBenchElement;
+import com.vaadin.tests.AbstractComponentIT;
+
+import elemental.json.Json;
+import elemental.json.JsonObject;
+
+@TestPath("vaadin-button/accessible-disabled-button")
+public class AccessibleDisabledButtonIT extends AbstractComponentIT {
+    private ButtonElement button;
+    private TestBenchElement listenerCounters;
+
+    @Before
+    public void init() {
+        open();
+        button = $(ButtonElement.class).first();
+        listenerCounters = $("div").id("listener-counters");
+    }
+
+    @Test
+    public void click_noClickEvent() {
+        button.click();
+        assertListenerCounter("click", 0);
+    }
+
+    @Test
+    public void doubleClick_noDoubleClickEvent() {
+        button.doubleClick();
+        assertListenerCounter("doubleClick", 0);
+    }
+
+    @Test
+    public void focus_focusEventIsFired() {
+        button.focus();
+        assertListenerCounter("focus", 1);
+    }
+
+    @Test
+    public void focusWithShortcut_focusEventIsFired() {
+        new Actions(getDriver()).keyDown(Keys.ALT).sendKeys("A").keyUp(Keys.ALT)
+                .build().perform();
+        assertListenerCounter("focus", 1);
+    }
+
+    @Test
+    public void blur_blurEventIsFired() {
+        button.sendKeys(Keys.TAB);
+        assertListenerCounter("blur", 1);
+    }
+
+    private void assertListenerCounter(String name, int expectedCount) {
+        JsonObject json = Json.parse(listenerCounters.getText());
+        Assert.assertEquals("Unexpected " + name + " value", expectedCount,
+                (int) json.getNumber(name));
+    }
+}

vaadin-button-flow-parent/vaadin-button-flow/src/main/java/com/vaadin/flow/component/button/Button.java

@@ -20,6 +20,8 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import com.vaadin.experimental.Feature;
+import com.vaadin.experimental.FeatureFlags;
 import com.vaadin.flow.component.ClickEvent;
 import com.vaadin.flow.component.ClickNotifier;
 import com.vaadin.flow.component.Component;
@@ -30,7 +32,11 @@
 import com.vaadin.flow.component.HasSize;
 import com.vaadin.flow.component.HasStyle;
 import com.vaadin.flow.component.HasText;
+import com.vaadin.flow.component.Key;
+import com.vaadin.flow.component.KeyModifier;
+import com.vaadin.flow.component.ShortcutRegistration;
 import com.vaadin.flow.component.Tag;
+import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.dependency.JsModule;
 import com.vaadin.flow.component.dependency.NpmPackage;
 import com.vaadin.flow.component.html.Image;
@@ -39,7 +45,9 @@
 import com.vaadin.flow.component.shared.HasThemeVariant;
 import com.vaadin.flow.component.shared.HasTooltip;
 import com.vaadin.flow.component.shared.internal.DisableOnClickController;
+import com.vaadin.flow.dom.DisabledUpdateMode;
 import com.vaadin.flow.dom.Element;
+import com.vaadin.flow.shared.Registration;
 
 /**
  * The Button component allows users to perform actions. It comes in several
@@ -160,6 +168,43 @@ public Button(String text, Component icon,
         addClickListener(clickListener);
     }
 
+    @Override
+    public ShortcutRegistration addFocusShortcut(Key key,
+            KeyModifier... keyModifiers) {
+        ShortcutRegistration registration = Focusable.super.addFocusShortcut(
+                key, keyModifiers);
+        if (isFeatureFlagEnabled(FeatureFlags.EXAMPLE)) {
+            registration.setDisabledUpdateMode(DisabledUpdateMode.ALWAYS);
+        }
+        return registration;
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    @Override
+    public Registration addFocusListener(
+            ComponentEventListener<FocusEvent<Button>> listener) {
+        return getEventBus().addListener(FocusEvent.class,
+                (ComponentEventListener) listener, registration -> {
+                    if (isFeatureFlagEnabled(FeatureFlags.EXAMPLE)) {
+                        registration.setDisabledUpdateMode(
+                                DisabledUpdateMode.ALWAYS);
+                    }
+                });
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    @Override
+    public Registration addBlurListener(
+            ComponentEventListener<BlurEvent<Button>> listener) {
+        return getEventBus().addListener(BlurEvent.class,
+                (ComponentEventListener) listener, registration -> {
+                    if (isFeatureFlagEnabled(FeatureFlags.EXAMPLE)) {
+                        registration.setDisabledUpdateMode(
+                                DisabledUpdateMode.ALWAYS);
+                    }
+                });
+    }
+
     /**
      * Sets the given string as the text content of this component.
      * <p>
@@ -427,4 +472,22 @@ private void updateThemeAttribute() {
             getThemeNames().remove("icon");
         }
     }
+
+    /**
+     * Checks whether the give feature flag is active.
+     *
+     * @param feature
+     *            the feature flag to check
+     * @return {@code true} if the feature flag is active, {@code false}
+     *         otherwise
+     */
+    private boolean isFeatureFlagEnabled(Feature feature) {
+        UI ui = UI.getCurrent();
+        if (ui == null) {
+            return false;
+        }
+
+        return FeatureFlags.get(ui.getSession().getService().getContext())
+                .isEnabled(feature);
+    }
 }