Scan through Nearby when listing PW URLs

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

Index: chrome/android/java/src/org/chromium/chrome/browser/physicalweb/NearbyForegroundSubscription.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/NearbyForegroundSubscription.java b/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/NearbyForegroundSubscription.java
new file mode 100644
index 0000000000000000000000000000000000000000..5233ead501f461e43e2ec20d8ec5c386b101d5e0
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/physicalweb/NearbyForegroundSubscription.java
@@ -0,0 +1,72 @@
+// 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.chrome.browser.physicalweb;
+
+import android.content.Context;
+
+import com.google.android.gms.common.api.ResultCallback;
+import com.google.android.gms.common.api.Status;
+import com.google.android.gms.nearby.Nearby;
+import com.google.android.gms.nearby.messages.MessageListener;
+
+import org.chromium.base.Log;
+
+
+/**
+ * This class represents a connection to Google Play Services that does foreground
+ * subscription/unsubscription to Nearby Eddystone-URLs.
+ */
+class NearbyForegroundSubscription extends NearbySubscription {
+    private static final String TAG = "PhysicalWeb";
+    private final MessageListener mMessageListener;
+    private boolean mSubscribed;
+
+    NearbyForegroundSubscription(Context context) {
+        super(context);
+        mSubscribed = false;
+        mMessageListener = PhysicalWebBleClient.getInstance().createForegroundMessageListener();
+    }
+
+    @Override
+    public void onConnected() {
+        Nearby.Messages.subscribe(
+                getGoogleApiClient(), mMessageListener, createSubscribeOptions())
+                .setResultCallback(new ResultCallback<Status>() {
+                    @Override
+                    public void onResult(final Status status) {
+                        if (status.isSuccess()) {
+                            mSubscribed = true;
+                            Log.d(TAG, "Nearby foreground subscribe succeeded");
+                        } else {
+                            mSubscribed = false;
+                            Log.d(TAG, "Nearby foreground subscribe failed "
+                                    + status.getStatusMessage());
+                        }
+                    }
+                });
+    }
+
+    @Override
+    public void disconnect() {
+        if (!mSubscribed) {
+            super.disconnect();
+            return;
+        }
+
+        Nearby.Messages.unsubscribe(getGoogleApiClient(), mMessageListener)
+                .setResultCallback(new ResultCallback<Status>() {
+                    @Override
+                    public void onResult(final Status status) {
+                        if (status.isSuccess()) {
+                            Log.d(TAG, "Nearby foreground unsubscribe succeeded");
+                        } else {
+                            Log.d(TAG, "Nearby foreground unsubscribe failed "
+                                    + status.getStatusMessage());
+                        }
+                        NearbyForegroundSubscription.super.disconnect();
+                    }
+                });
+    }
+}