Add PhysicalWebBroadcastService

chrome/android/java/src/org/chromium/chrome/browser/physicalweb/PhysicalWebBroadcastService.java

+// Copyright 2017 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.physicalweb;
+
+import android.annotation.TargetApi;
+import android.app.Service;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.os.Build;
+import android.os.IBinder;
+
+import org.chromium.base.ContextUtils;
+
+/**
+ * Broadcasts Physical Web URLs via Bluetooth Low Energy (BLE).
+ *
+ * This background service will start when the user activates the Physical Web Sharing item in the
+ * sharing chooser intent. If the URL received from the triggering Tab is validated
+ * by the Physical Web Service then it will encode the URL into an Eddystone URL and
+ * broadcast the URL through BLE.
+ *
+ * To notify and provide the user with the ability to terminate broadcasting
+ * a persistent notification with a cancel button will be created. This cancel button will stop the
+ * service and will be the only way for the user to stop the service.
+ *
+ * If the user terminates Chrome or the OS shuts down this service mid-broadcasting, when the
+ * service get's restarted it will restart broadcasting as well by gathering the URL from
+ * shared preferences. This will create a seemless experience to the user by behaving as
+ * though broadcasting is not connected to the Chrome application.
+ *
+ * bluetooth.le.AdvertiseCallback and bluetooth.BluetoothAdapter require API level 21.
+ * This will only be run on M and above.
+ **/
+
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+public class PhysicalWebBroadcastService extends Service {
+    public static final String DISPLAY_URL_KEY = "display_url";
+
+    public static final String PREVIOUS_BROADCAST_URL_KEY = "previousUrl";
+
+    private boolean mStartedByRestart;
+
+    @Override
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        String displayUrl = fetchDisplayUrl(intent);
+
+        // This should never happen.
+        if (displayUrl == null) {
+            stopSelf();
+            return START_STICKY;
+        }
+
+        // TODO(iankc): implement parsing, broadcasting, and notifications.
+        stopSelf();
+        return START_STICKY;
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    private String fetchDisplayUrl(Intent intent) {
+        mStartedByRestart = intent == null;
+        if (mStartedByRestart) {
+            SharedPreferences sharedPrefs = ContextUtils.getAppSharedPreferences();
+            return sharedPrefs.getString(PREVIOUS_BROADCAST_URL_KEY, null);
+        }
+
+        String displayUrl = intent.getStringExtra(DISPLAY_URL_KEY);
+        ContextUtils.getAppSharedPreferences()
+                .edit()
+                .putString(PREVIOUS_BROADCAST_URL_KEY, displayUrl)
+                .commit();
+        return displayUrl;
+    }
+}