Display Cutout: Add controller and factory to Android

Add a DisplayCutoutController that will decide when
to adjust the layout based on the cutout. This depends
on Android P APIs which are called by reflection.

BUG=838400

Change-Id: Iaf808709ded2f3c1b3d7a060942ea8c65396ad9f
Reviewed-on: https://chromium-review.googlesource.com/1043248
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565494}

chrome/android/java/src/org/chromium/chrome/browser/display_cutout/DisplayCutoutController.java

+// Copyright 2018 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.chrome.browser.display_cutout;
+
+import android.support.annotation.VisibleForTesting;
+import android.view.Window;
+import android.view.WindowManager.LayoutParams;
+
+import org.chromium.blink.mojom.ViewportFit;
+import org.chromium.chrome.browser.tab.EmptyTabObserver;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tab.TabObserver;
+import org.chromium.content_public.browser.WebContentsObserver;
+
+/**
+ * Controls the display cutout state for the tab.
+ */
+public class DisplayCutoutController {
+    /** These are the property names of the different cutout mode states. */
+    private static final String VIEWPORT_FIT_AUTO = "LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT";
+    private static final String VIEWPORT_FIT_CONTAIN = "LAYOUT_IN_DISPLAY_CUTOUT_MODE_NEVER";
+    private static final String VIEWPORT_FIT_COVER = "LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES";
+
+    /** The tab that this controller belongs to. */
+    private Tab mTab;
+
+    /** The current viewport fit value. */
+    private @WebContentsObserver.ViewportFitType int mViewportFit = ViewportFit.AUTO;
+
+    /** Listens to various Tab events. */
+    private final TabObserver mTabObserver = new EmptyTabObserver() {
+        @Override
+        public void onShown(Tab tab) {
+            assert tab == mTab;
+
+            // Force a layout update if we are now being shown.
+            maybeUpdateLayout();
+        }
+
+        @Override
+        public void onInteractabilityChanged(boolean interactable) {
+            // Force a layout update if the tab is now in the foreground.
+            maybeUpdateLayout();
+        }
+    };
+
+    /**
+     * Constructs a new DisplayCutoutController for a specific tab.
+     * @param tab The tab that this controller belongs to.
+     */
+    public DisplayCutoutController(Tab tab) {
+        mTab = tab;
+        tab.addObserver(mTabObserver);
+    }
+
+    /**
+     * Set the viewport fit value for the tab.
+     * @param value The new viewport fit value.
+     */
+    public void setViewportFit(@WebContentsObserver.ViewportFitType int value) {
+        if (value == mViewportFit) return;
+
+        mViewportFit = value;
+        maybeUpdateLayout();
+    }
+
+    /**
+     * Converts a {@link ViewportFit} value into the Android P+ equivalent.
+     * @returns String containing the {@link LayoutParams} field name of the
+     *     equivalent value.
+     */
+    @VisibleForTesting
+    protected String getDisplayCutoutMode() {
+        // If we are not interactable then force the default mode.
+        if (!mTab.isUserInteractable()) return VIEWPORT_FIT_AUTO;
+
+        switch (mViewportFit) {
+            case ViewportFit.CONTAIN:
+                return VIEWPORT_FIT_CONTAIN;
+            case ViewportFit.COVER:
+                return VIEWPORT_FIT_COVER;
+            case ViewportFit.AUTO:
+            default:
+                return VIEWPORT_FIT_AUTO;
+        }
+    }
+
+    /** Updates the layout based on internal state. */
+    @VisibleForTesting
+    protected void maybeUpdateLayout() {
+        try {
+            Window window = mTab.getActivity().getWindow();
+            LayoutParams attributes = window.getAttributes();
+
+            LayoutParams.class.getDeclaredField("layoutInDisplayCutoutMode")
+                    .setInt(attributes,
+                            LayoutParams.class.getDeclaredField(getDisplayCutoutMode())
+                                    .getInt(null));
+            window.setAttributes(attributes);
+        } catch (Exception ex) {
+            // API is not available.
+            return;
+        }
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/display_cutout/OWNERS

+beccahughes@chromium.org
+mlamouri@chromium.org
+
+# COMPONENT: Blink>Layout

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

@@ -62,6 +62,7 @@ import org.chromium.chrome.browser.contextmenu.ContextMenuPopulator;
 import org.chromium.chrome.browser.contextualsearch.ContextualSearchTabHelper;
 import org.chromium.chrome.browser.crypto.CipherFactory;
 import org.chromium.chrome.browser.customtabs.CustomTabActivity;
+import org.chromium.chrome.browser.display_cutout.DisplayCutoutController;
 import org.chromium.chrome.browser.document.ChromeLauncherActivity;
 import org.chromium.chrome.browser.download.ChromeDownloadDelegate;
 import org.chromium.chrome.browser.feature_engagement.TrackerFactory;
@@ -559,6 +560,9 @@ public class Tab
     /** Whether or not the tab's active view is attached to the window. */
     private boolean mIsViewAttachedToWindow;
 
+    /** Controls display cutout states on the tab. */
+    private DisplayCutoutController mDisplayCutoutController;
+
     /**
      * Creates an instance of a {@link Tab}.
      *
@@ -645,6 +649,8 @@ public class Tab
                 updateInteractableState();
             }
         };
+
+        mDisplayCutoutController = new DisplayCutoutController(this);
     }
 
     private int calculateDefaultThemeColor() {
@@ -907,6 +913,13 @@ public class Tab
         return mInfoBarContainer;
     }
 
+    /**
+     * @return The display cutout controller for the tab.
+     */
+    public final DisplayCutoutController getDisplayCutoutController() {
+        return mDisplayCutoutController;
+    }
+
     /** @return An opaque "state" object that can be persisted to storage. */
     public TabState getState() {
         if (!isInitialized()) return null;

chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java

@@ -280,6 +280,11 @@ public class TabWebContentsObserver extends WebContentsObserver {
         mTab.notifyNavigationEntriesDeleted();
     }
 
+    @Override
+    public void viewportFitChanged(@WebContentsObserver.ViewportFitType int value) {
+        mTab.getDisplayCutoutController().setViewportFit(value);
+    }
+
     @Override
     public void destroy() {
         MediaCaptureNotificationService.updateMediaNotificationForTab(

chrome/android/java_sources.gni

@@ -380,6 +380,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/datausage/DataUseTabUIManager.java",
   "java/src/org/chromium/chrome/browser/datausage/ExternalDataUseObserver.java",
   "java/src/org/chromium/chrome/browser/device/DeviceClassManager.java",
+  "java/src/org/chromium/chrome/browser/display_cutout/DisplayCutoutController.java",
   "java/src/org/chromium/chrome/browser/document/ChromeLauncherActivity.java",
   "java/src/org/chromium/chrome/browser/document/DocumentActivity.java",
   "java/src/org/chromium/chrome/browser/document/DocumentUtils.java",
@@ -2048,6 +2049,7 @@ chrome_junit_test_java_sources = [
   "junit/src/org/chromium/chrome/browser/cookies/CanonicalCookieTest.java",
   "junit/src/org/chromium/chrome/browser/crash/LogcatExtractionRunnableUnitTest.java",
   "junit/src/org/chromium/chrome/browser/customtabs/NavigationInfoCaptureTriggerTest.java",
+  "junit/src/org/chromium/chrome/browser/display_cutout/DisplayCutoutControllerTest.java",
   "junit/src/org/chromium/chrome/browser/download/DownloadSharedPreferenceEntryTest.java",
   "junit/src/org/chromium/chrome/browser/download/home/filter/DeleteUndoOfflineItemFilterTest.java",
   "junit/src/org/chromium/chrome/browser/download/home/filter/FiltersTest.java",

chrome/android/junit/src/org/chromium/chrome/browser/display_cutout/DisplayCutoutControllerTest.java

+// Copyright 2018 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.chrome.browser.display_cutout;
+
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.support.test.filters.SmallTest;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.annotation.Config;
+
+import org.chromium.blink.mojom.ViewportFit;
+import org.chromium.chrome.browser.tab.Tab;
+import org.chromium.chrome.browser.tab.TabObserver;
+import org.chromium.testing.local.LocalRobolectricTestRunner;
+
+/**
+ * Tests for {@link DisplayCutoutController} class.
+ */
+@RunWith(LocalRobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class DisplayCutoutControllerTest {
+    @Mock
+    private Tab mTab;
+
+    @Captor
+    private ArgumentCaptor<TabObserver> mTabObserverCaptor;
+
+    private DisplayCutoutController mDisplayCutoutController;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+
+        mDisplayCutoutController = spy(new DisplayCutoutController(mTab));
+    }
+
+    @Test
+    @SmallTest
+    public void testViewportFitUpdate() throws Throwable {
+        verify(mDisplayCutoutController, never()).maybeUpdateLayout();
+
+        mDisplayCutoutController.setViewportFit(ViewportFit.COVER);
+        verify(mDisplayCutoutController).maybeUpdateLayout();
+    }
+
+    @Test
+    @SmallTest
+    public void testViewportFitUpdateNotChanged() throws Throwable {
+        verify(mDisplayCutoutController, never()).maybeUpdateLayout();
+
+        mDisplayCutoutController.setViewportFit(ViewportFit.AUTO);
+        verify(mDisplayCutoutController, never()).maybeUpdateLayout();
+    }
+
+    @Test
+    @SmallTest
+    public void testCutoutModeWhenAutoAndInteractable() throws Throwable {
+        when(mTab.isUserInteractable()).thenReturn(true);
+
+        mDisplayCutoutController.setViewportFit(ViewportFit.AUTO);
+        Assert.assertEquals("LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT",
+                mDisplayCutoutController.getDisplayCutoutMode());
+    }
+
+    @Test
+    @SmallTest
+    public void testCutoutModeWhenCoverAndInteractable() throws Throwable {
+        when(mTab.isUserInteractable()).thenReturn(true);
+
+        mDisplayCutoutController.setViewportFit(ViewportFit.COVER);
+        Assert.assertEquals("LAYOUT_IN_DISPLAY_CUTOUT_MODE_SHORT_EDGES",
+                mDisplayCutoutController.getDisplayCutoutMode());
+    }
+
+    @Test
+    @SmallTest
+    public void testCutoutModeWhenContainAndInteractable() throws Throwable {
+        when(mTab.isUserInteractable()).thenReturn(true);
+
+        mDisplayCutoutController.setViewportFit(ViewportFit.CONTAIN);
+        Assert.assertEquals("LAYOUT_IN_DISPLAY_CUTOUT_MODE_NEVER",
+                mDisplayCutoutController.getDisplayCutoutMode());
+    }
+
+    @Test
+    @SmallTest
+    public void testCutoutModeWhenAutoAndNotInteractable() throws Throwable {
+        mDisplayCutoutController.setViewportFit(ViewportFit.AUTO);
+        Assert.assertEquals("LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT",
+                mDisplayCutoutController.getDisplayCutoutMode());
+    }
+
+    @Test
+    @SmallTest
+    public void testCutoutModeWhenCoverAndNotInteractable() throws Throwable {
+        mDisplayCutoutController.setViewportFit(ViewportFit.COVER);
+        Assert.assertEquals("LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT",
+                mDisplayCutoutController.getDisplayCutoutMode());
+    }
+
+    @Test
+    @SmallTest
+    public void testCutoutModeWhenContainAndNotInteractable() throws Throwable {
+        mDisplayCutoutController.setViewportFit(ViewportFit.CONTAIN);
+        Assert.assertEquals("LAYOUT_IN_DISPLAY_CUTOUT_MODE_DEFAULT",
+                mDisplayCutoutController.getDisplayCutoutMode());
+    }
+
+    @Test
+    @SmallTest
+    public void testLayoutOnInteractability_True() throws Throwable {
+        // In this test we are checking for a side effect of maybeUpdateLayout.
+        // This is because the tab observer holds a reference to the original
+        // mDisplayCutoutController and not the spied one.
+        verify(mTab, never()).getActivity();
+
+        verify(mTab).addObserver(mTabObserverCaptor.capture());
+        mTabObserverCaptor.getValue().onInteractabilityChanged(true);
+
+        verify(mTab).getActivity();
+    }
+
+    @Test
+    @SmallTest
+    public void testLayoutOnInteractability_False() throws Throwable {
+        // In this test we are checking for a side effect of maybeUpdateLayout.
+        // This is because the tab observer holds a reference to the original
+        // mDisplayCutoutController and not the spied one.
+        verify(mTab, never()).getActivity();
+
+        verify(mTab).addObserver(mTabObserverCaptor.capture());
+        mTabObserverCaptor.getValue().onInteractabilityChanged(false);
+
+        verify(mTab).getActivity();
+    }
+
+    @Test
+    @SmallTest
+    public void testLayoutOnShown() throws Throwable {
+        // In this test we are checking for a side effect of maybeUpdateLayout.
+        // This is because the tab observer holds a reference to the original
+        // mDisplayCutoutController and not the spied one.
+        verify(mTab, never()).getActivity();
+
+        verify(mTab).addObserver(mTabObserverCaptor.capture());
+        mTabObserverCaptor.getValue().onShown(mTab);
+
+        verify(mTab).getActivity();
+    }
+}

chrome/android/junit/src/org/chromium/chrome/browser/display_cutout/OWNERS

+beccahughes@chromium.org
+mlamouri@chromium.org
+
+# COMPONENT: Blink>Layout

content/browser/android/web_contents_observer_proxy.cc

@@ -270,4 +270,11 @@ void WebContentsObserverProxy::SetToBaseURLForDataURLIfNeeded(
   }
 }
 
+void WebContentsObserverProxy::ViewportFitChanged(
+    blink::mojom::ViewportFit value) {
+  JNIEnv* env = AttachCurrentThread();
+  Java_WebContentsObserverProxy_viewportFitChanged(
+      env, java_observer_, as_jint(static_cast<int>(value)));
+}
+
 }  // namespace content

content/browser/android/web_contents_observer_proxy.h

@@ -58,6 +58,7 @@ class WebContentsObserverProxy : public WebContentsObserver {
   void DidChangeThemeColor(SkColor color) override;
   void MediaEffectivelyFullscreenChanged(bool is_fullscreen) override;
   void SetToBaseURLForDataURLIfNeeded(std::string* url);
+  void ViewportFitChanged(blink::mojom::ViewportFit value) override;
 
   base::android::ScopedJavaGlobalRef<jobject> java_observer_;
   GURL base_url_of_last_started_data_url_;

content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsObserverProxy.java

@@ -226,6 +226,14 @@ class WebContentsObserverProxy extends WebContentsObserver {
         }
     }
 
+    @Override
+    @CalledByNative
+    public void viewportFitChanged(@WebContentsObserver.ViewportFitType int value) {
+        for (mObserversIterator.rewind(); mObserversIterator.hasNext();) {
+            mObserversIterator.next().viewportFitChanged(value);
+        }
+    }
+
     @Override
     @CalledByNative
     public void destroy() {

content/public/android/java/src/org/chromium/content_public/browser/WebContentsObserver.java

@@ -4,8 +4,13 @@
 
 package org.chromium.content_public.browser;
 
+import android.support.annotation.IntDef;
 import android.support.annotation.Nullable;
 
+import org.chromium.blink.mojom.ViewportFit;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.lang.ref.WeakReference;
 
 /**
@@ -161,6 +166,20 @@ public abstract class WebContentsObserver {
      */
     public void hasEffectivelyFullscreenVideoChange(boolean isFullscreen) {}
 
+    /**
+     * The Viewport Fit Type passed to viewportFitChanged. This is mirrored
+     * in an enum in display_cutout.mojom.
+     */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef({ViewportFit.AUTO, ViewportFit.CONTAIN, ViewportFit.COVER})
+    public @interface ViewportFitType {}
+
+    /**
+     * Called when the viewport fit of the Web Contents changes.
+     * @param value the new viewport fit value.
+     */
+    public void viewportFitChanged(@ViewportFitType int value) {}
+
     /**
      * Stop observing the web contents and clean up associated references.
      */