[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); }
+
+    private interface Delegate {
+        void start(Context context, WebContents webContents);
+        void stop(Context context);
+    }
+
+    private class ActivityDelegate implements Delegate {
+        private static final String TAG = "cr_CastWebComponent_AD";
+
+        @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);
+        }
+    }
+
+    private class ServiceDelegate implements Delegate {
+        private static final String TAG = "cr_CastWebComponent_SD";
+
+        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);
+        }
+    }
+
+    private class Receiver extends BroadcastReceiver {
+        @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);
+            }
+        }
+    }
+
+    static final String ACTION_DATA_SCHEME = "cast";
+    static final String ACTION_DATA_AUTHORITY = "webcontents";
+    static final String ACTION_EXTRA_WEB_CONTENTS =
+            "com.google.android.apps.castshell.intent.extra.WEB_CONTENTS";
+
+    private static final String TAG = "cr_CastWebComponent";
+    private static final boolean DEBUG = false;
+
+    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.DISPLAY_WEB_CONTENTS_IN_SERVICE) {
+            mDelegate = new ServiceDelegate();
+        } else {
+            mDelegate = new ActivityDelegate();
+        }
+    }
+
+    public void setOnComponentClosedHandler(OnComponentClosedHandler onComponentClosedHandler) {

[Simeon, 2017/05/17 00:31:56]

If we're only supporting one OnComponentClosedHandler and one OnKeyDownHandler,
I'd rather we inject these in the constructor than set them with method calls
later. Less mutating state to keep track of that way.

[thoren, 2017/05/17 18:20:37]

Done.

+        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) {

[Simeon, 2017/05/17 00:31:56]

I'd be interested in putting this logic in a different class, but this is fine
for now.

[thoren, 2017/05/17 18:20:36]

Acknowledged.

+        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;
+    }
+}