weblayer: shows toast when entering fullscreen

As the delegate is ultimately responsible for configuring fullscreen
the code adds a OnSystemUiVisibilityChangeListener. If the right
mode is entered in a short amount of time, the toast is shown.

I'm adding Skip-Translation-Screenshots-Check as I'm moving the
string, which has already been translated and didn't have a screenshot.

BUG=1127486
TEST=weblayer private tests verify this

Skip-Translation-Screenshots-Check: True
Change-Id: I788f9df3493b828e66afd57669f34d470865f60d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2419661Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809107}

chrome/browser/ui/android/strings/android_chrome_strings.grd

@@ -2117,11 +2117,6 @@ To change this setting, <ph name="BEGIN_LINK">&lt;resetlink&gt;</ph>reset sync<p
         Work profile
       </message>
 
-      <!-- Fullscreen -->
-      <message name="IDS_IMMERSIVE_FULLSCREEN_API_NOTIFICATION" desc="Notification message when a site has entered immersive fullscreen and the directions of how to exit.">
-        Drag from top and touch the back button to exit full screen.
-      </message>
-
       <!-- Download UI -->
       <message name="IDS_DOWNLOAD_NOTIFICATION_COMPLETED" desc="Download notification to be displayed when a download completes.">
         Download complete

components/browser_ui/strings/android/browser_ui_strings.grd

@@ -718,6 +718,11 @@
       <message name="IDS_ACCESSIBILITY_PLAYBACK_TIME" desc="The accessibility string for how much time has elapsed while viewing the video and how long the video is in total.">
         Elapsed time <ph name="ELAPSED_TIME">%1$s<ex>0:01</ex></ph> of <ph name="TOTAL_TIME">%2$s<ex>0:45</ex></ph>.
       </message>
+
+      <!-- Fullscreen -->
+      <message name="IDS_IMMERSIVE_FULLSCREEN_API_NOTIFICATION" desc="Notification message when a site has entered immersive fullscreen and the directions of how to exit.">
+        Drag from top and touch the back button to exit full screen.
+      </message>
     </messages>
   </release>
 </grit>

weblayer/browser/android/javatests/BUILD.gn

@@ -34,7 +34,6 @@ android_library("weblayer_java_tests") {
     "src/org/chromium/weblayer/test/TabCallbackTest.java",
     "src/org/chromium/weblayer/test/TabListCallbackTest.java",
     "src/org/chromium/weblayer/test/TabTest.java",
-    "src/org/chromium/weblayer/test/TestFullscreenCallback.java",
     "src/org/chromium/weblayer/test/TopControlsTest.java",
     "src/org/chromium/weblayer/test/WebLayerLoadingTest.java",
     "src/org/chromium/weblayer/test/WebLayerTest.java",
@@ -68,6 +67,7 @@ android_library("weblayer_private_java_tests") {
   testonly = true
   sources = [
     "src/org/chromium/weblayer/test/BrowserControlsTest.java",
+    "src/org/chromium/weblayer/test/FullscreenCallbackPrivateTest.java",
     "src/org/chromium/weblayer/test/GeolocationTest.java",
     "src/org/chromium/weblayer/test/InfoBarTest.java",
     "src/org/chromium/weblayer/test/MediaCaptureTest.java",
@@ -112,6 +112,7 @@ android_library("weblayer_java_test_support") {
     "src/org/chromium/weblayer/test/NavigationWaiter.java",
     "src/org/chromium/weblayer/test/NewTabCallbackImpl.java",
     "src/org/chromium/weblayer/test/ResourceUtil.java",
+    "src/org/chromium/weblayer/test/TestFullscreenCallback.java",
     "src/org/chromium/weblayer/test/WebLayerActivityTestRule.java",
     "src/org/chromium/weblayer/test/WebLayerJUnit4ClassRunner.java",
   ]

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/FullscreenCallbackPrivateTest.java

+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer.test;
+
+import android.os.RemoteException;
+import android.view.View;
+
+import androidx.test.filters.SmallTest;
+
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.content_public.browser.test.util.Criteria;
+import org.chromium.content_public.browser.test.util.CriteriaHelper;
+import org.chromium.content_public.browser.test.util.TestThreadUtils;
+import org.chromium.weblayer.FullscreenCallback;
+import org.chromium.weblayer.TestWebLayer;
+import org.chromium.weblayer.shell.InstrumentationActivity;
+
+/**
+ * Fullscreen test assertions that can only be done using private API.
+ */
+@RunWith(WebLayerJUnit4ClassRunner.class)
+public class FullscreenCallbackPrivateTest {
+    @Rule
+    public InstrumentationActivityTestRule mActivityTestRule =
+            new InstrumentationActivityTestRule();
+
+    private InstrumentationActivity mActivity;
+    private TestFullscreenCallback mDelegate;
+
+    @Before
+    public void setUp() {
+        String url = mActivityTestRule.getTestDataURL("fullscreen.html");
+        mActivity = mActivityTestRule.launchShellWithUrl(url);
+        Assert.assertNotNull(mActivity);
+        mDelegate = new TestFullscreenCallback();
+        TestThreadUtils.runOnUiThreadBlocking(
+                () -> { mActivity.getTab().setFullscreenCallback(mDelegate); });
+    }
+
+    private TestWebLayer getTestWebLayer() {
+        return TestWebLayer.getTestWebLayer(
+                mActivityTestRule.getActivity().getApplicationContext());
+    }
+
+    @Test
+    @SmallTest
+    public void testToastNotShownWhenFullscreenRequestIgnored() throws Throwable {
+        Assert.assertFalse(TestThreadUtils.runOnUiThreadBlocking(
+                () -> { return getTestWebLayer().didShowFullscreenToast(mActivity.getTab()); }));
+
+        // Touch to enter fullscreen
+        EventUtils.simulateTouchCenterOfView(mActivity.getWindow().getDecorView());
+        mDelegate.waitForFullscreen();
+        Assert.assertEquals(1, mDelegate.mEnterFullscreenCount);
+
+        Assert.assertFalse(TestThreadUtils.runOnUiThreadBlocking(
+                () -> { return getTestWebLayer().didShowFullscreenToast(mActivity.getTab()); }));
+    }
+
+    @Test
+    @SmallTest
+    public void testToastShown() throws Throwable {
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            mActivity.getTab().setFullscreenCallback(new FullscreenCallback() {
+                @Override
+                public void onEnterFullscreen(Runnable exitFullscreenRunner) {
+                    mActivity.getWindow().getDecorView().setSystemUiVisibility(
+                            View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
+                }
+
+                @Override
+                public void onExitFullscreen() {}
+            });
+        });
+
+        // Touch to enter fullscreen
+        EventUtils.simulateTouchCenterOfView(mActivity.getWindow().getDecorView());
+        CriteriaHelper.pollUiThread(() -> {
+            try {
+                Criteria.checkThat(getTestWebLayer().didShowFullscreenToast(mActivity.getTab()),
+                        Matchers.is(true));
+            } catch (RemoteException e) {
+                throw new RuntimeException(e);
+            }
+        });
+    }
+}

weblayer/browser/java/BUILD.gn

@@ -108,6 +108,7 @@ android_library("java") {
     "org/chromium/weblayer_private/FragmentAndroidPermissionDelegate.java",
     "org/chromium/weblayer_private/FragmentWindowAndroid.java",
     "org/chromium/weblayer_private/FullscreenCallbackProxy.java",
+    "org/chromium/weblayer_private/FullscreenToast.java",
     "org/chromium/weblayer_private/GoogleAccountsCallbackProxy.java",
     "org/chromium/weblayer_private/InfoBarContainer.java",
     "org/chromium/weblayer_private/InfoBarContainerView.java",

weblayer/browser/java/org/chromium/weblayer_private/BrowserImpl.java

@@ -21,6 +21,7 @@ import org.chromium.base.ObserverList;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 import org.chromium.base.annotations.NativeMethods;
+import org.chromium.components.embedder_support.view.ContentView;
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.base.WindowAndroid;
 import org.chromium.weblayer_private.interfaces.APICallException;
@@ -137,7 +138,7 @@ public class BrowserImpl extends IBrowser.Stub implements View.OnAttachStateChan
         return mWindowAndroid;
     }
 
-    public ViewGroup getViewAndroidDelegateContainerView() {
+    public ContentView getViewAndroidDelegateContainerView() {
         if (mViewController == null) return null;
         return mViewController.getContentView();
     }
@@ -410,7 +411,7 @@ public class BrowserImpl extends IBrowser.Stub implements View.OnAttachStateChan
         return true;
     }
 
-    public TabImpl getActiveTab() {
+    public @Nullable TabImpl getActiveTab() {
         return BrowserImplJni.get().getActiveTab(mNativeBrowser);
     }
 

weblayer/browser/java/org/chromium/weblayer_private/BrowserViewController.java

@@ -162,7 +162,7 @@ public final class BrowserViewController
         return mContentViewRenderView;
     }
 
-    public ViewGroup getContentView() {
+    public ContentView getContentView() {
         return mContentView;
     }
 

weblayer/browser/java/org/chromium/weblayer_private/FullscreenCallbackProxy.java

@@ -7,6 +7,8 @@ package org.chromium.weblayer_private;
 import android.os.RemoteException;
 import android.webkit.ValueCallback;
 
+import androidx.annotation.VisibleForTesting;
+
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ -23,12 +25,15 @@ import org.chromium.weblayer_private.interfaces.ObjectWrapper;
 public final class FullscreenCallbackProxy {
     private long mNativeFullscreenCallbackProxy;
     private IFullscreenCallbackClient mClient;
+    private TabImpl mTab;
+    private FullscreenToast mToast;
 
-    FullscreenCallbackProxy(long tab, IFullscreenCallbackClient client) {
+    FullscreenCallbackProxy(TabImpl tab, long nativeTab, IFullscreenCallbackClient client) {
         assert client != null;
         mClient = client;
+        mTab = tab;
         mNativeFullscreenCallbackProxy =
-                FullscreenCallbackProxyJni.get().createFullscreenCallbackProxy(this, tab);
+                FullscreenCallbackProxyJni.get().createFullscreenCallbackProxy(this, nativeTab);
     }
 
     public void setClient(IFullscreenCallbackClient client) {
@@ -40,6 +45,19 @@ public final class FullscreenCallbackProxy {
         FullscreenCallbackProxyJni.get().deleteFullscreenCallbackProxy(
                 mNativeFullscreenCallbackProxy);
         mNativeFullscreenCallbackProxy = 0;
+        destroyToast();
+        mTab = null;
+    }
+
+    public void destroyToast() {
+        if (mToast == null) return;
+        mToast.destroy();
+        mToast = null;
+    }
+
+    @VisibleForTesting
+    public boolean didShowFullscreenToast() {
+        return mToast != null && mToast.didShowFullscreenToast();
     }
 
     @CalledByNative
@@ -51,15 +69,19 @@ public final class FullscreenCallbackProxy {
                 if (mNativeFullscreenCallbackProxy == 0) {
                     throw new IllegalStateException("Called after destroy()");
                 }
+                destroyToast();
                 FullscreenCallbackProxyJni.get().doExitFullscreen(mNativeFullscreenCallbackProxy);
             }
         };
+        destroyToast();
+        mToast = new FullscreenToast(mTab);
         mClient.enterFullscreen(ObjectWrapper.wrap(exitFullscreenCallback));
     }
 
     @CalledByNative
     private void exitFullscreen() throws RemoteException {
         mClient.exitFullscreen();
+        destroyToast();
     }
 
     @NativeMethods

weblayer/browser/java/org/chromium/weblayer_private/FullscreenToast.java

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.weblayer_private;
+
+import android.view.Gravity;
+import android.view.View;
+
+import androidx.annotation.VisibleForTesting;
+
+import org.chromium.components.embedder_support.view.ContentView;
+import org.chromium.ui.widget.Toast;
+
+/**
+ * FullscreenToast is responsible for showing toast when fullscreen mode is entered. As the embedder
+ * is responsible for entering fullscreen mode, there is no guarantee when or if fullscreen mode
+ * will be entered. This waits for the system to enter fullscreen mode and then show the toast. If
+ * fullscreen isn't entered after a short delay this assumes the embedder won't enter fullscreen
+ * and the toast is never shown.
+ */
+public final class FullscreenToast {
+    // The tab the toast is showing from.
+    private TabImpl mTab;
+
+    // View used to register for system ui change notification.
+    private ContentView mView;
+
+    private View.OnSystemUiVisibilityChangeListener mSystemUiVisibilityChangeListener;
+
+    // Set to true once toast is shown.
+    private boolean mDidShowToast;
+
+    // The toast.
+    private Toast mToast;
+
+    FullscreenToast(TabImpl tab) {
+        mTab = tab;
+        // TODO(https://crbug.com/1130096): This should really be handled lower down in the stack.
+        if (tab.getBrowser().getActiveTab() != tab) return;
+        addSystemUiChangedObserver();
+    }
+
+    @VisibleForTesting
+    public boolean didShowFullscreenToast() {
+        return mDidShowToast;
+    }
+
+    public void destroy() {
+        // This may be called more than once.
+        if (mTab == null) return;
+
+        if (mSystemUiVisibilityChangeListener != null) {
+            // mSystemUiVisibilityChangeListener is only installed if mView is non-null.
+            assert mView != null;
+            mView.removeOnSystemUiVisibilityChangeListener(mSystemUiVisibilityChangeListener);
+            mSystemUiVisibilityChangeListener = null;
+        }
+        mTab = null;
+        mView = null;
+        if (mToast != null) {
+            mToast.cancel();
+            mToast = null;
+        }
+    }
+
+    private void addSystemUiChangedObserver() {
+        if (mTab.getBrowser().getViewAndroidDelegateContainerView() == null) {
+            return;
+        }
+        mView = mTab.getBrowser().getViewAndroidDelegateContainerView();
+        mSystemUiVisibilityChangeListener = new View.OnSystemUiVisibilityChangeListener() {
+            @Override
+            public void onSystemUiVisibilityChange(int visibility) {
+                // The listener should have been removed if destroy() was called.
+                assert mTab != null;
+                if ((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0) {
+                    // No longer in fullscreen. Destroy.
+                    destroy();
+                } else if ((visibility & View.SYSTEM_UI_FLAG_HIDE_NAVIGATION) != 0
+                        && !mDidShowToast) {
+                    // Only show the toast when navigation is hidden and toast wasn't already shown.
+                    showToast();
+                    mDidShowToast = true;
+                }
+            }
+        };
+        mView.addOnSystemUiVisibilityChangeListener(mSystemUiVisibilityChangeListener);
+        // See class description for details on why a timeout is used.
+        mView.postDelayed(() -> {
+            if (!mDidShowToast) destroy();
+        }, 1000);
+    }
+
+    private void showToast() {
+        assert mToast == null;
+        mDidShowToast = true;
+        int resId = R.string.immersive_fullscreen_api_notification;
+        mToast = Toast.makeText(mView.getContext(), resId, Toast.LENGTH_LONG);
+        mToast.setGravity(Gravity.TOP | Gravity.CENTER, 0, 0);
+        mToast.show();
+    }
+}

weblayer/browser/java/org/chromium/weblayer_private/TabImpl.java

@@ -419,6 +419,8 @@ public final class TabImpl extends ITab.Stub implements LoginPrompt.Observer {
             mAutofillProvider.hidePopup();
         }
 
+        if (mFullscreenCallbackProxy != null) mFullscreenCallbackProxy.destroyToast();
+
         hideFindInPageUiAndNotifyClient();
         updateWebContentsVisibility();
         updateDisplayCutoutController();
@@ -526,7 +528,7 @@ public final class TabImpl extends ITab.Stub implements LoginPrompt.Observer {
         StrictModeWorkaround.apply();
         if (client != null) {
             if (mFullscreenCallbackProxy == null) {
-                mFullscreenCallbackProxy = new FullscreenCallbackProxy(mNativeTab, client);
+                mFullscreenCallbackProxy = new FullscreenCallbackProxy(this, mNativeTab, client);
             } else {
                 mFullscreenCallbackProxy.setClient(client);
             }
@@ -984,6 +986,12 @@ public final class TabImpl extends ITab.Stub implements LoginPrompt.Observer {
         return mBrowserControlsVisibility.get() == BrowserControlsState.BOTH;
     }
 
+    @VisibleForTesting
+    public boolean didShowFullscreenToast() {
+        return mFullscreenCallbackProxy != null
+                && mFullscreenCallbackProxy.didShowFullscreenToast();
+    }
+
     private void onBrowserControlsConstraintUpdated(int constraint) {
         // If something has overridden the FIP's SHOWN constraint, cancel FIP. This causes FIP to
         // dismiss when entering fullscreen.

weblayer/browser/java/org/chromium/weblayer_private/test/TestWebLayerImpl.java

@@ -185,4 +185,10 @@ public final class TestWebLayerImpl extends ITestWebLayer.Stub {
         TabImpl tabImpl = (TabImpl) tab;
         return tabImpl.getTranslateInfoBarTargetLanguageForTesting();
     }
+
+    @Override
+    public boolean didShowFullscreenToast(ITab tab) {
+        TabImpl tabImpl = (TabImpl) tab;
+        return tabImpl.didShowFullscreenToast();
+    }
 }

weblayer/browser/java/org/chromium/weblayer_private/test_interfaces/ITestWebLayer.aidl

@@ -50,4 +50,7 @@ interface ITestWebLayer {
   // Returns the target language of the currently-showing translate infobar, or null if no translate
   // infobar is currently showing.
   String getTranslateInfoBarTargetLanguage(in ITab tab) = 16;
+
+  // Returns true if a fullscreen toast was shown for |tab|.
+  boolean didShowFullscreenToast(in ITab tab) = 17;
 }

weblayer/public/javatestutil/org/chromium/weblayer/TestWebLayer.java

@@ -125,4 +125,8 @@ public final class TestWebLayer {
     public static void disableWebViewCompatibilityMode() {
         WebLayer.disableWebViewCompatibilityMode();
     }
+
+    public boolean didShowFullscreenToast(Tab tab) throws RemoteException {
+        return mITestWebLayer.didShowFullscreenToast(tab.getITab());
+    }
 }