Add RemotingAppLauncher and DefaultRemotingApp

The RemotingAppLauncher instantiates RemotingApps at runtime. It uses
the app manifest to find class names of RemotingApps, and loads them via
reflection.

The DefaultRemotingApp is a simple wrapper around the default media
receiver application.

Bug: 790766
Change-Id: I01f51ebe90de361b947d67fe904a2faddc35f5de
Reviewed-on: https://chromium-review.googlesource.com/c/1306778Reviewed-by: Zhiqiang Zhang <zqzhang@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605389}

chrome/android/java/AndroidManifest.xml

@@ -1165,6 +1165,8 @@ android:value="true" />
              controllers with its own list. -->
         <meta-data android:name="org.chromium.content.browser.REMOTE_MEDIA_PLAYERS"
             android:value="org.chromium.chrome.browser.media.remote.DefaultMediaRouteController"/>
+        <meta-data android:name="org.chromium.content.browser.REMOTE_PLAYBACK_APPS"
+            android:value="org.chromium.chrome.browser.media.router.cast.remoting.DefaultRemotingApp"/>
 
         {% endblock %}
     </application>

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java

@@ -175,11 +175,12 @@ public class CreateRouteRequest implements GoogleApiClient.ConnectionCallbacks,
         if (mState == State.API_CONNECTION_SUSPENDED) return;
 
         try {
-            launchApplication(mApiClient, mSource.getApplicationId(), true)
-                    .setResultCallback(this);
+            launchApplication(mApiClient, mSource.getApplicationId(), true).setResultCallback(this);
             mState = State.LAUNCHING_APPLICATION;
         } catch (Exception e) {
-            Log.e(TAG, "Launch application failed: %s", mSource.getApplicationId(), e);
+            // Do not log appId, as it can contain appIds overriden in downstream code that must not
+            // be leaked
+            Log.e(TAG, "Launch application failed", e);
             reportError();
         }
     }
@@ -209,8 +210,10 @@ public class CreateRouteRequest implements GoogleApiClient.ConnectionCallbacks,
 
         Status status = result.getStatus();
         if (!status.isSuccess()) {
-            Log.e(TAG, "Launch application failed with status: %s, %d, %s",
-                    mSource.getApplicationId(), status.getStatusCode(), status.getStatusMessage());
+            // Do not log appId, as it can contain appIds overriden in downstream code that must not
+            // be leaked
+            Log.e(TAG, "Launch application failed with status: %d, %s", status.getStatusCode(),
+                    status.getStatusMessage());
             reportError();
             return;
         }

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/remoting/DefaultRemotingApp.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.media.router.cast.remoting;
+
+import com.google.android.gms.cast.CastMediaControlIntent;
+import com.google.android.gms.common.api.GoogleApiClient;
+
+import org.chromium.base.annotations.UsedByReflection;
+import org.chromium.chrome.browser.UrlConstants;
+import org.chromium.chrome.browser.media.router.MediaSource;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+/**
+ * App corresponding to the default media receiver application.
+ */
+@UsedByReflection("RemotingAppLauncher.java")
+public class DefaultRemotingApp implements RemotingAppLauncher.RemotingApp {
+    private static final String TAG = "DefaultRmtApp";
+
+    public DefaultRemotingApp() {}
+
+    // RemotingApp implementation
+    @Override
+    public boolean canPlayMedia(RemotingMediaSource source) {
+        try {
+            String scheme = new URI(source.getMediaUrl()).getScheme();
+            if (scheme == null) return false;
+
+            return scheme.equals(UrlConstants.HTTP_SCHEME)
+                    || scheme.equals(UrlConstants.HTTPS_SCHEME);
+        } catch (URISyntaxException e) {
+            return false;
+        }
+    }
+
+    @Override
+    public String getApplicationId() {
+        // Can be overriden downstream.
+        return CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID;
+    }
+
+    @Override
+    public boolean hasCustomLoad() {
+        // Can be overriden downstream.
+        return false;
+    }
+
+    @Override
+    public void load(GoogleApiClient client, long startTime, MediaSource source) {
+        // Can be overriden downstream.
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/remoting/RemotingAppLauncher.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.media.router.cast.remoting;
+
+import android.app.Activity;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.os.Bundle;
+
+import com.google.android.gms.common.api.GoogleApiClient;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.Log;
+import org.chromium.chrome.browser.media.router.MediaSource;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Class that manages the instantiation of RemotingApps.
+ *
+ * A RemotingApp is essentially a wrapper around an application ID. We use them to protect certain
+ * application IDs in downstream code, and to override some app specific logic. The IDs correspond
+ * to Cast receiver apps.
+ *
+ * The types of RemotingApps are discovered by reflection. We find the class names via the
+ * REMOTE_PLAYBACK_APPS_KEY in AndroidManifest.xml. This allows us to specify different apps in the
+ * default chromium manifest, versus the official Chrome on Android manifest.
+ */
+public class RemotingAppLauncher {
+    private static final String TAG = "RemoteAppLnchr";
+
+    // This is a key for meta-data in the package manifest.
+    private static final String REMOTE_PLAYBACK_APPS_KEY =
+            "org.chromium.content.browser.REMOTE_PLAYBACK_APPS";
+
+    private static RemotingAppLauncher sInstance;
+
+    /**
+     * Interface that represents a Cast receiver app, that is compatible with remote playback.
+     */
+    public interface RemotingApp {
+        /**
+         * Returns true if the given app supports the source
+         */
+        public boolean canPlayMedia(RemotingMediaSource source);
+
+        /**
+         * Returns the application ID of the receiver app.
+         * NOTE: This string should not be added to logs, since this can be overriden
+         * by downstream and we would leak internal app IDs.
+         */
+        public String getApplicationId();
+
+        /**
+         * Returns true if RemoteMediaPlayer.load() should be avoided, and RemotingApp.load() should
+         * be called instead.
+         */
+        public boolean hasCustomLoad();
+
+        /**
+         * Loads the given source, at the given start time, for the already connected client.
+         */
+        public void load(GoogleApiClient client, long startTime, MediaSource source);
+    }
+
+    private List<RemotingApp> mRemotingApps = new ArrayList<RemotingApp>();
+
+    /**
+     * The private constructor to make sure the object is only created by the instance() method.
+     */
+    private RemotingAppLauncher() {}
+
+    private void createRemotingApps() {
+        // We only need to do this once
+        if (!mRemotingApps.isEmpty()) return;
+        try {
+            Activity currentActivity = ApplicationStatus.getLastTrackedFocusedActivity();
+            ApplicationInfo ai = currentActivity.getPackageManager().getApplicationInfo(
+                    currentActivity.getPackageName(), PackageManager.GET_META_DATA);
+            Bundle bundle = ai.metaData;
+            String classNameString = bundle.getString(REMOTE_PLAYBACK_APPS_KEY);
+
+            if (classNameString != null) {
+                String[] classNames = classNameString.split(",");
+                for (String className : classNames) {
+                    Log.d(TAG, "Adding remoting app %s", className.trim());
+                    Class<?> remotingAppClass = Class.forName(className.trim());
+                    Object remotingApp = remotingAppClass.newInstance();
+                    mRemotingApps.add((RemotingApp) remotingApp);
+                }
+            }
+        } catch (NameNotFoundException | ClassNotFoundException | SecurityException
+                | InstantiationException | IllegalAccessException | IllegalArgumentException e) {
+            // Should never happen, implies corrupt AndroidManifest
+            Log.e(TAG, "Couldn't instatiate RemotingApps", e);
+            assert false;
+        }
+    }
+
+    /**
+     * Returns the first RemotingApp that can support the given source, or null if none are found.
+     */
+    public RemotingApp getRemotingApp(MediaSource source) {
+        if (!(source instanceof RemotingMediaSource)) return null;
+
+        for (RemotingApp app : mRemotingApps) {
+            if (app.canPlayMedia((RemotingMediaSource) source)) {
+                return app;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * The singleton instance access method.
+     */
+    public static RemotingAppLauncher instance() {
+        if (sInstance == null) {
+            sInstance = new RemotingAppLauncher();
+            sInstance.createRemotingApps();
+        }
+
+        return sInstance;
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/remoting/RemotingMediaSource.java

@@ -33,7 +33,7 @@ public class RemotingMediaSource implements MediaSource {
     /**
      * The Cast application id.
      */
-    private final String mApplicationId;
+    private String mApplicationId = null;
 
     /**
      * The URL to fling to the Cast device.
@@ -61,9 +61,7 @@ public class RemotingMediaSource implements MediaSource {
             return null;
         }
 
-        // TODO(avayvod): check the content URL and override the app id if needed.
-        String applicationId = CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID;
-        return new RemotingMediaSource(sourceId, applicationId, mediaUrl);
+        return new RemotingMediaSource(sourceId, mediaUrl);
     }
 
     /**
@@ -75,7 +73,7 @@ public class RemotingMediaSource implements MediaSource {
     @Override
     public MediaRouteSelector buildRouteSelector() {
         return new MediaRouteSelector.Builder()
-                .addControlCategory(CastMediaControlIntent.categoryForCast(mApplicationId))
+                .addControlCategory(CastMediaControlIntent.categoryForCast(getApplicationId()))
                 .build();
     }
 
@@ -84,6 +82,12 @@ public class RemotingMediaSource implements MediaSource {
      */
     @Override
     public String getApplicationId() {
+        if (mApplicationId == null) {
+            RemotingAppLauncher.RemotingApp app =
+                    RemotingAppLauncher.instance().getRemotingApp(this);
+
+            mApplicationId = (app != null) ? app.getApplicationId() : "";
+        }
         return mApplicationId;
     }
 
@@ -102,9 +106,8 @@ public class RemotingMediaSource implements MediaSource {
         return mMediaUrl;
     }
 
-    private RemotingMediaSource(String sourceId, String applicationId, String mediaUrl) {
+    private RemotingMediaSource(String sourceId, String mediaUrl) {
         mSourceId = sourceId;
-        mApplicationId = applicationId;
         mMediaUrl = mediaUrl;
     }
 }

chrome/android/java_sources.gni

@@ -867,6 +867,8 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/media/router/cast/CastSessionInfo.java",
   "java/src/org/chromium/chrome/browser/media/router/cast/ChromeCastSessionManager.java",
   "java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java",
+  "java/src/org/chromium/chrome/browser/media/router/cast/remoting/DefaultRemotingApp.java",
+  "java/src/org/chromium/chrome/browser/media/router/cast/remoting/RemotingAppLauncher.java",
   "java/src/org/chromium/chrome/browser/media/router/cast/remoting/RemotingCastSession.java",
   "java/src/org/chromium/chrome/browser/media/router/cast/remoting/RemotingMediaRouteProvider.java",
   "java/src/org/chromium/chrome/browser/media/router/cast/remoting/RemotingMediaSource.java",