[Chromecast] Reactive WebContents presentation.

No more detatchWebContentsIfAny() and similar helpers.
This boils the presentation of WebContents into a simple state
machine compatible with Observables.

This refactor includes covering the business logic of
CastWebContentsSurfaceHelper in unittests. The implementation
details of CastWebContentsView are still not unit-tested, but
are now better isolated from other logic.

Bug: Internal b/36777136
Test: cast_shell_junit_tests
Change-Id: Ia555b4d3ea9ee07607bf54cc339b950fe068d220
Reviewed-on: https://chromium-review.googlesource.com/1003412Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Simeon Anfinrud <sanfin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551464}

chromecast/browser/android/BUILD.gn

@@ -112,6 +112,7 @@ android_library("cast_shell_java") {
     "$java_src_dir/org/chromium/chromecast/shell/CastWebContentsIntentUtils.java",
     "$java_src_dir/org/chromium/chromecast/shell/CastWebContentsService.java",
     "$java_src_dir/org/chromium/chromecast/shell/CastWebContentsSurfaceHelper.java",
+    "$java_src_dir/org/chromium/chromecast/shell/CastWebContentsView.java",
     "$java_src_dir/org/chromium/chromecast/shell/LogcatElision.java",
     "$java_src_dir/org/chromium/chromecast/shell/ElidedLogcatProvider.java",
   ]
@@ -160,6 +161,7 @@ junit_binary("cast_shell_junit_tests") {
     "junit/src/org/chromium/chromecast/shell/CastWebContentsActivityTest.java",
     "junit/src/org/chromium/chromecast/shell/CastWebContentsComponentTest.java",
     "junit/src/org/chromium/chromecast/shell/CastWebContentsIntentUtilsTest.java",
+    "junit/src/org/chromium/chromecast/shell/CastWebContentsSurfaceHelperTest.java",
     "junit/src/org/chromium/chromecast/shell/LocalBroadcastReceiverScopeTest.java",
     "junit/src/org/chromium/chromecast/shell/LogcatElisionUnitTest.java",
     "junit/src/org/chromium/chromecast/shell/ElidedLogcatProviderUnitTest.java",

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsActivity.java

@@ -7,7 +7,9 @@ package org.chromium.chromecast.shell;
 import android.app.Activity;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.graphics.Color;
 import android.media.AudioManager;
+import android.net.Uri;
 import android.os.Bundle;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
@@ -19,6 +21,7 @@ import android.widget.Toast;
 import org.chromium.base.Log;
 import org.chromium.base.annotations.RemovableInRelease;
 import org.chromium.chromecast.base.Both;
+import org.chromium.chromecast.base.CastSwitches;
 import org.chromium.chromecast.base.Controller;
 import org.chromium.chromecast.base.Observable;
 import org.chromium.chromecast.base.ScopeFactories;
@@ -86,8 +89,12 @@ public class CastWebContentsActivity extends Activity {
                     setContentView(R.layout.cast_web_contents_activity);
 
                     mSurfaceHelper = new CastWebContentsSurfaceHelper(this, /* hostActivity */
-                            (FrameLayout) findViewById(R.id.web_contents_container),
-                            false /* showInFragment */);
+                            CastWebContentsView.onLayout(getApplicationContext(),
+                                    (FrameLayout) findViewById(R.id.web_contents_container),
+                                    CastSwitches.getSwitchValueColor(
+                                            CastSwitches.CAST_APP_BACKGROUND_COLOR, Color.BLACK),
+                                    mResumedState),
+                            (Uri uri) -> mIsFinishingState.set("Delayed teardown for URI: " + uri));
                 }));
 
         // Initialize the audio manager in onCreate() if tests haven't already.
@@ -157,9 +164,6 @@ public class CastWebContentsActivity extends Activity {
         if (DEBUG) Log.d(TAG, "onPause");
         super.onPause();
         mResumedState.reset();
-        if (mSurfaceHelper != null) {
-            mSurfaceHelper.onPause();
-        }
     }
 
     @Override
@@ -167,9 +171,6 @@ public class CastWebContentsActivity extends Activity {
         if (DEBUG) Log.d(TAG, "onResume");
         super.onResume();
         mResumedState.set(Unit.unit());
-        if (mSurfaceHelper != null) {
-            mSurfaceHelper.onResume();
-        }
     }
 
     @Override

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsFragment.java

@@ -7,6 +7,8 @@ package org.chromium.chromecast.shell;
 import android.app.Fragment;
 import android.content.Context;
 import android.content.Intent;
+import android.graphics.Color;
+import android.net.Uri;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -16,6 +18,9 @@ import android.widget.Toast;
 
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
+import org.chromium.chromecast.base.CastSwitches;
+import org.chromium.chromecast.base.Controller;
+import org.chromium.chromecast.base.Unit;
 
 /**
  * Fragment for displaying a WebContents in CastShell.
@@ -31,14 +36,12 @@ import org.chromium.base.Log;
 public class CastWebContentsFragment extends Fragment {
     private static final String TAG = "cr_CastWebContentFrg";
 
-    private Context mPackageContext;
+    private final Controller<Unit> mResumedState = new Controller<>();
 
+    private Context mPackageContext;
     private CastWebContentsSurfaceHelper mSurfaceHelper;
-
     private View mFragmentRootView;
-
     private String mAppId;
-
     private int mInitialVisiblityPriority;
 
     @Override
@@ -61,12 +64,11 @@ public class CastWebContentsFragment extends Fragment {
         }
         if (mFragmentRootView == null) {
             mFragmentRootView = inflater.cloneInContext(getContext())
-                .inflate(R.layout.cast_web_contents_activity, null);
+                                        .inflate(R.layout.cast_web_contents_activity, null);
         }
         return mFragmentRootView;
     }
 
-
     @Override
     public Context getContext() {
         if (mPackageContext == null) {
@@ -88,8 +90,13 @@ public class CastWebContentsFragment extends Fragment {
         }
 
         mSurfaceHelper = new CastWebContentsSurfaceHelper(getActivity(), /* hostActivity */
-                    (FrameLayout) getView().findViewById(R.id.web_contents_container),
-                    true /* showInFragment */);
+                CastWebContentsView.onLayout(getContext(),
+                        (FrameLayout) getView().findViewById(R.id.web_contents_container),
+                        CastSwitches.getSwitchValueColor(
+                                CastSwitches.CAST_APP_BACKGROUND_COLOR, Color.BLACK),
+                        mResumedState),
+                (Uri uri) -> sendIntentSync(CastWebContentsIntentUtils.onWebContentStopped(uri)));
+
         Bundle bundle = getArguments();
         CastWebContentsSurfaceHelper.StartParams params =
                 CastWebContentsSurfaceHelper.StartParams.fromBundle(bundle);
@@ -106,18 +113,14 @@ public class CastWebContentsFragment extends Fragment {
     public void onPause() {
         Log.d(TAG, "onPause");
         super.onPause();
-        if (mSurfaceHelper != null) {
-            mSurfaceHelper.onPause();
-        }
+        mResumedState.reset();
     }
 
     @Override
     public void onResume() {
         Log.d(TAG, "onResume");
         super.onResume();
-        if (mSurfaceHelper != null) {
-            mSurfaceHelper.onResume();
-        }
+        mResumedState.set(Unit.unit());
     }
 
     @Override

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsService.java

@@ -13,13 +13,11 @@ import android.widget.Toast;
 
 import org.chromium.base.Log;
 import org.chromium.base.annotations.JNINamespace;
+import org.chromium.chromecast.base.Both;
 import org.chromium.chromecast.base.Controller;
+import org.chromium.chromecast.base.Observable;
 import org.chromium.chromecast.base.Unit;
-import org.chromium.components.content_view.ContentView;
-import org.chromium.content_public.browser.ContentViewCore;
 import org.chromium.content_public.browser.WebContents;
-import org.chromium.ui.base.ViewAndroidDelegate;
-import org.chromium.ui.base.WindowAndroid;
 
 /**
  * Service for "displaying" a WebContents in CastShell.
@@ -34,11 +32,31 @@ public class CastWebContentsService extends Service {
     private static final int CAST_NOTIFICATION_ID = 100;
 
     private final Controller<Unit> mLifetimeController = new Controller<>();
+    private final Controller<WebContents> mWebContentsState = new Controller<>();
     private String mInstanceId;
     private CastAudioManager mAudioManager;
-    private WindowAndroid mWindow;
-    private ContentViewCore mContentViewCore;
-    private ContentView mContentView;
+
+    {
+        // Construct an Observable that is deactivated when either mWebContentsState or
+        // mLifetimeController is reset, and has the activation data of mWebContentsState.
+        Observable<WebContents> hasWebContentsState =
+                mWebContentsState.and(mLifetimeController).map(Both::getFirst);
+        // React to web contents by presenting them in a headless view.
+        hasWebContentsState.watch(CastWebContentsView.withoutLayout(this));
+        hasWebContentsState.watch(() -> {
+            if (DEBUG) Log.d(TAG, "show web contents");
+            // TODO(thoren): Notification.Builder(Context) is deprecated in O. Use the
+            // (Context, String) constructor when CastWebContentsService starts supporting O.
+            Notification notification = new Notification.Builder(this).build();
+            startForeground(CAST_NOTIFICATION_ID, notification);
+            return () -> {
+                if (DEBUG) Log.d(TAG, "detach web contents");
+                stopForeground(true /*removeNotification*/);
+                // Inform CastContentWindowAndroid we're detaching.
+                CastWebContentsComponent.onComponentClosed(mInstanceId);
+            };
+        });
+    }
 
     protected void handleIntent(Intent intent) {
         intent.setExtrasClassLoader(WebContents.class.getClassLoader());
@@ -50,8 +68,7 @@ public class CastWebContentsService extends Service {
             return;
         }
 
-        detachWebContentsIfAny();
-        showWebContents(webContents);
+        mWebContentsState.set(webContents);
     }
 
     @Override
@@ -65,14 +82,11 @@ public class CastWebContentsService extends Service {
     @Override
     public void onCreate() {
         if (DEBUG) Log.d(TAG, "onCreate");
-
         if (!CastBrowserHelper.initializeBrowser(getApplicationContext())) {
             Toast.makeText(this, R.string.browser_process_initialization_failed, Toast.LENGTH_SHORT)
                     .show();
             stopSelf();
         }
-
-        mWindow = new WindowAndroid(this);
         CastAudioManager.getAudioManager(this).requestAudioFocusWhen(
                 mLifetimeController, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
         mLifetimeController.set(Unit.unit());
@@ -81,42 +95,7 @@ public class CastWebContentsService extends Service {
     @Override
     public IBinder onBind(Intent intent) {
         if (DEBUG) Log.d(TAG, "onBind");
-
         handleIntent(intent);
-
         return null;
     }
-
-    // Sets webContents to be the currently displayed webContents.
-    // TODO(thoren): Notification.Builder(Context) is deprecated in O. Use the (Context, String)
-    // constructor when CastWebContentsService starts supporting O.
-    @SuppressWarnings("deprecation")
-    private void showWebContents(WebContents webContents) {
-        if (DEBUG) Log.d(TAG, "showWebContents");
-
-        Notification notification = new Notification.Builder(this).build();
-        startForeground(CAST_NOTIFICATION_ID, notification);
-
-        mContentView = ContentView.createContentView(this, webContents);
-        // TODO(derekjchow): productVersion
-        mContentViewCore = ContentViewCore.create(this, "", webContents,
-                ViewAndroidDelegate.createBasicDelegate(mContentView), mContentView, mWindow);
-        // Enable display of current webContents.
-        webContents.onShow();
-    }
-
-    // Remove the currently displayed webContents. no-op if nothing is being displayed.
-    private void detachWebContentsIfAny() {
-        if (DEBUG) Log.d(TAG, "detachWebContentsIfAny");
-
-        stopForeground(true /*removeNotification*/);
-
-        if (mContentView != null) {
-            mContentView = null;
-            mContentViewCore = null;
-
-            // Inform CastContentWindowAndroid we're detaching.
-            CastWebContentsComponent.onComponentClosed(mInstanceId);
-        }
-    }
 }

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastWebContentsView.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.chromecast.shell;
+
+import android.content.Context;
+import android.widget.FrameLayout;
+
+import org.chromium.chromecast.base.Observable;
+import org.chromium.chromecast.base.ScopeFactory;
+import org.chromium.components.content_view.ContentView;
+import org.chromium.content.browser.ContentViewRenderView;
+import org.chromium.content_public.browser.ContentViewCore;
+import org.chromium.content_public.browser.WebContents;
+import org.chromium.ui.base.ViewAndroidDelegate;
+import org.chromium.ui.base.WindowAndroid;
+
+class CastWebContentsView {
+    public static ScopeFactory<WebContents> onLayout(
+            Context context, FrameLayout layout, int backgroundColor, Observable<?> resumedState) {
+        layout.setBackgroundColor(backgroundColor);
+        return (WebContents webContents) -> {
+            WindowAndroid window = new WindowAndroid(context);
+            ContentViewRenderView contentViewRenderView = new ContentViewRenderView(context) {
+                @Override
+                protected void onReadyToRender() {
+                    setOverlayVideoMode(true);
+                }
+            };
+            contentViewRenderView.onNativeLibraryLoaded(window);
+            contentViewRenderView.setSurfaceViewBackgroundColor(backgroundColor);
+            FrameLayout.LayoutParams matchParent = new FrameLayout.LayoutParams(
+                    FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT);
+            layout.addView(contentViewRenderView, matchParent);
+
+            ContentView contentView = ContentView.createContentView(context, webContents);
+            // TODO(derekjchow): productVersion
+            ContentViewCore contentViewCore = ContentViewCore.create(context, "", webContents,
+                    ViewAndroidDelegate.createBasicDelegate(contentView), contentView, window);
+
+            // Enable display of current webContents.
+            webContents.onShow();
+            layout.addView(contentView, matchParent);
+            contentView.setFocusable(true);
+            contentView.requestFocus();
+            contentViewRenderView.setCurrentWebContents(webContents);
+            resumedState.watch(() -> {
+                contentViewCore.onResume();
+                return contentViewCore::onPause;
+            });
+            return () -> {
+                layout.removeView(contentView);
+                layout.removeView(contentViewRenderView);
+                contentViewCore.destroy();
+                contentViewRenderView.destroy();
+                window.destroy();
+            };
+        };
+    }
+
+    public static ScopeFactory<WebContents> withoutLayout(Context context) {
+        return (WebContents webContents) -> {
+            WindowAndroid window = new WindowAndroid(context);
+            ContentView contentView = ContentView.createContentView(context, webContents);
+            // TODO(derekjchow): productVersion
+            ContentViewCore contentViewCore = ContentViewCore.create(context, "", webContents,
+                    ViewAndroidDelegate.createBasicDelegate(contentView), contentView, window);
+            // Enable display of current webContents.
+            webContents.onShow();
+            return webContents::onHide;
+        };
+    }
+}