[Chromecast] Add service for "displaying" cast web contents.

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

+// Copyright 2016 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.BroadcastReceiver;
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.ServiceConnection;
+import android.net.Uri;
+import android.os.IBinder;
+import android.os.PatternMatcher;
+import android.support.v4.content.LocalBroadcastManager;
+
+import org.chromium.base.Log;
+import org.chromium.content_public.browser.WebContents;
+
+/**
+ * A layer of indirection between CastContentWindowAndroid and CastWebContents(Activity|Service).
+ * <p>
+ * On builds with CAST_ANDROID_USE_SERVICE set to false, it will use CastWebContentsActivity,
+ * otherwise, it will use CastWebContentsService.
+ */
+public class CastWebContentsComponent {
+    /**
+     * Callback interface for when the associated component is closed or the
+     * WebContents is detached.
+     */
+    public interface OnComponentClosedHandler { void onComponentClosed(); }
+
+    /**
+     * Callback interface for passing along keyDown events. This only applies
+     * to CastWebContentsActivity, really.
+     */
+    public interface OnKeyDownHandler { void onKeyDown(int keyCode); }
+
+    interface Delegate {
+        void start(Context context, WebContents webContents);
+        void stop(Context context);
+    }
+
+    class ActivityDelegate implements Delegate {

[Simeon, 2017/05/15 19:47:24]

Does this need to be package-private?

[thoren, 2017/05/15 22:25:24]

Nope. Went ahead and made it private.

+        private static final String TAG = CastWebContentsComponent.TAG + ".ActivityDelegate";

[Simeon, 2017/05/15 19:47:24]

We don't want dots in tag names because the log elider for crash reporting
interprets it as a web address, and filters it out for privacy reasons.

I'm also concerned about the total length of the tag for this and for
ServiceDelegate. I forget what the limit is, but can you confirm that the full
tag is printed in the logcat?

[thoren, 2017/05/15 22:25:24]

It was being printed, but I went ahead and changed it.

+
+        @Override
+        public void start(Context context, WebContents webContents) {
+            if (DEBUG) Log.d(TAG, "start");
+
+            Intent intent = new Intent(Intent.ACTION_VIEW, getInstanceUri(mInstanceId), context,
+                    CastWebContentsActivity.class);
+            intent.putExtra(ACTION_EXTRA_WEB_CONTENTS, webContents);
+            // FLAG_ACTIVITY_SINGLE_TOP will try to reuse existing activity.
+            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_MULTIPLE_TASK
+                    | Intent.FLAG_ACTIVITY_SINGLE_TOP);
+            context.startActivity(intent);
+        }
+
+        @Override
+        public void stop(Context context) {
+            if (DEBUG) Log.d(TAG, "stop");
+
+            Intent intent = new Intent(
+                    CastWebContentsActivity.ACTION_STOP_ACTIVITY, getInstanceUri(mInstanceId));
+            LocalBroadcastManager.getInstance(context).sendBroadcastSync(intent);
+        }
+    }
+
+    class ServiceDelegate implements Delegate {

[Simeon, 2017/05/15 19:47:24]

Does this need to be package-private?

[thoren, 2017/05/15 22:25:23]

Done.

+        private static final String TAG = CastWebContentsComponent.TAG + ".ServiceDelegate";
+
+        private ServiceConnection mConnection = new ServiceConnection() {
+            @Override
+            public void onServiceConnected(ComponentName name, IBinder service) {}
+
+            @Override
+            public void onServiceDisconnected(ComponentName name) {
+                if (DEBUG) Log.d(TAG, "onServiceDisconnected");
+
+                if (mComponentClosedHandler != null) mComponentClosedHandler.onComponentClosed();
+            }
+        };
+
+        @Override
+        public void start(Context context, WebContents webContents) {
+            if (DEBUG) Log.d(TAG, "start");
+
+            Intent intent = new Intent(Intent.ACTION_VIEW, getInstanceUri(mInstanceId), context,
+                    CastWebContentsService.class);
+            intent.putExtra(ACTION_EXTRA_WEB_CONTENTS, webContents);
+            context.bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
+        }
+
+        @Override
+        public void stop(Context context) {
+            if (DEBUG) Log.d(TAG, "stop");
+
+            context.unbindService(mConnection);
+        }
+    }
+
+    class Receiver extends BroadcastReceiver {

[Simeon, 2017/05/15 19:47:24]

Does this need to be package-private?

[thoren, 2017/05/15 22:25:23]

Done.

+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (intent.getAction().equals(ACTION_ACTIVITY_STOPPED)) {
+                if (DEBUG) Log.d(TAG, "onReceive ACTION_ACTIVITY_STOPPED");
+
+                if (mComponentClosedHandler != null) mComponentClosedHandler.onComponentClosed();
+            } else if (intent.getAction().equals(ACTION_KEY_EVENT)) {
+                if (DEBUG) Log.d(TAG, "onReceive ACTION_KEY_EVENT");
+
+                int keyCode = intent.getIntExtra(ACTION_EXTRA_KEY_CODE, 0);
+                if (mKeyDownHandler != null) mKeyDownHandler.onKeyDown(keyCode);
+            }
+        }
+    }
+
+    private static final String TAG = "cr_CastWebComponent";
+    private static final boolean DEBUG = true;

[Simeon, 2017/05/15 19:47:24]

We might want to make this false in the final patch set, unless we decide that
the activity lifecycle logging is useful enough to keep turned on.

[thoren, 2017/05/15 22:25:24]

Not that useful. Done.

+
+    private static final String ACTION_DATA_SCHEME = "cast";
+    private static final String ACTION_DATA_AUTHORITY = "webcontents";
+    private static final String ACTION_EXTRA_WEB_CONTENTS =
+            "com.google.android.apps.castshell.intent.extra.WEB_CONTENTS";

[Simeon, 2017/05/15 19:47:24]

These are redeclared in CastWebContentsService and CastWebContentsActivity. How
about making these package-private, or even moving them to a package-private
Constants class?

[thoren, 2017/05/15 22:25:24]

Done.

+    private static final String ACTION_EXTRA_KEY_CODE =
+            "com.google.android.apps.castshell.intent.extra.KEY_CODE";
+    private static final String ACTION_KEY_EVENT =
+            "com.google.android.apps.castshell.intent.action.KEY_EVENT";
+    private static final String ACTION_ACTIVITY_STOPPED =
+            "com.google.android.apps.castshell.intent.action.ACTIVITY_STOPPED";
+
+    private Delegate mDelegate;
+    private OnComponentClosedHandler mComponentClosedHandler;
+    private OnKeyDownHandler mKeyDownHandler;
+    private Receiver mReceiver;
+    private String mInstanceId;
+
+    public CastWebContentsComponent(String instanceId) {
+        mInstanceId = instanceId;
+        if (BuildConfig.CAST_ANDROID_USE_SERVICE) {
+            mDelegate = new ServiceDelegate();
+        } else {
+            mDelegate = new ActivityDelegate();
+        }
+    }
+
+    public void setOnComponentClosedHandler(OnComponentClosedHandler onComponentClosedHandler) {
+        mComponentClosedHandler = onComponentClosedHandler;
+    }
+
+    public void setOnKeyDownHandler(OnKeyDownHandler onKeyDownHandler) {
+        mKeyDownHandler = onKeyDownHandler;
+    }
+
+    public void start(Context context, WebContents webContents) {
+        if (DEBUG) Log.d(TAG, "start");
+
+        Uri instanceUri = getInstanceUri(mInstanceId);
+        mReceiver = new Receiver();
+        IntentFilter filter = new IntentFilter();
+        filter.addDataScheme(instanceUri.getScheme());
+        filter.addDataAuthority(instanceUri.getAuthority(), null);
+        filter.addDataPath(instanceUri.getPath(), PatternMatcher.PATTERN_LITERAL);
+        filter.addAction(ACTION_ACTIVITY_STOPPED);
+        filter.addAction(ACTION_KEY_EVENT);
+        LocalBroadcastManager.getInstance(context).registerReceiver(mReceiver, filter);
+
+        mDelegate.start(context, webContents);
+    }
+
+    public void stop(Context context) {
+        if (DEBUG) Log.d(TAG, "stop");
+
+        LocalBroadcastManager.getInstance(context).unregisterReceiver(mReceiver);
+        mDelegate.stop(context);
+    }
+
+    public static void onComponentClosed(Context context, String instanceId) {
+        if (DEBUG) Log.d(TAG, "onComponentClosed");
+
+        Intent intent = new Intent(ACTION_ACTIVITY_STOPPED, getInstanceUri(instanceId));
+        LocalBroadcastManager.getInstance(context).sendBroadcastSync(intent);
+    }
+
+    public static void onKeyDown(Context context, String instanceId, int keyCode) {
+        if (DEBUG) Log.d(TAG, "onKeyDown");
+
+        Intent intent = new Intent(ACTION_KEY_EVENT, getInstanceUri(instanceId));
+        intent.putExtra(ACTION_EXTRA_KEY_CODE, keyCode);
+        LocalBroadcastManager.getInstance(context).sendBroadcastSync(intent);
+    }
+
+    private static Uri getInstanceUri(String instanceId) {
+        Uri instanceUri = new Uri.Builder()
+                                  .scheme(ACTION_DATA_SCHEME)
+                                  .authority(ACTION_DATA_AUTHORITY)
+                                  .path(instanceId)
+                                  .build();
+        return instanceUri;
+    }
+}