Merge "Expose additional WifiScanner @SystemApis"
diff --git a/api/system-current.txt b/api/system-current.txt
index 39c786e..5a695a5 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -5580,6 +5580,7 @@
     method @NonNull @RequiresPermission(android.Manifest.permission.LOCATION_HARDWARE) public java.util.List<java.lang.Integer> getAvailableChannels(int);
     method @RequiresPermission(android.Manifest.permission.LOCATION_HARDWARE) public boolean getScanResults();
     method @NonNull @RequiresPermission(android.Manifest.permission.LOCATION_HARDWARE) public java.util.List<android.net.wifi.ScanResult> getSingleScanResults();
+    method @RequiresPermission(android.Manifest.permission.NETWORK_STACK) public void registerScanListener(@NonNull java.util.concurrent.Executor, @NonNull android.net.wifi.WifiScanner.ScanListener);
     method @RequiresPermission(android.Manifest.permission.NETWORK_STACK) public void setScanningEnabled(boolean);
     method @RequiresPermission(android.Manifest.permission.LOCATION_HARDWARE) public void startBackgroundScan(android.net.wifi.WifiScanner.ScanSettings, android.net.wifi.WifiScanner.ScanListener);
     method @RequiresPermission(android.Manifest.permission.LOCATION_HARDWARE) public void startBackgroundScan(android.net.wifi.WifiScanner.ScanSettings, android.net.wifi.WifiScanner.ScanListener, android.os.WorkSource);
@@ -5591,6 +5592,7 @@
     method @RequiresPermission(android.Manifest.permission.LOCATION_HARDWARE) public void stopScan(android.net.wifi.WifiScanner.ScanListener);
     method @Deprecated public void stopTrackingBssids(android.net.wifi.WifiScanner.BssidListener);
     method @Deprecated public void stopTrackingWifiChange(android.net.wifi.WifiScanner.WifiChangeListener);
+    method public void unregisterScanListener(@NonNull android.net.wifi.WifiScanner.ScanListener);
     field public static final int MAX_SCAN_PERIOD_MS = 1024000; // 0xfa000
     field public static final int MIN_SCAN_PERIOD_MS = 1000; // 0x3e8
     field public static final int REASON_DUPLICATE_REQEUST = -5; // 0xfffffffb
@@ -5603,6 +5605,9 @@
     field public static final int REPORT_EVENT_AFTER_EACH_SCAN = 1; // 0x1
     field public static final int REPORT_EVENT_FULL_SCAN_RESULT = 2; // 0x2
     field public static final int REPORT_EVENT_NO_BATCH = 4; // 0x4
+    field public static final int SCAN_TYPE_HIGH_ACCURACY = 2; // 0x2
+    field public static final int SCAN_TYPE_LOW_LATENCY = 0; // 0x0
+    field public static final int SCAN_TYPE_LOW_POWER = 1; // 0x1
     field public static final int WIFI_BAND_24_GHZ = 1; // 0x1
     field public static final int WIFI_BAND_5_GHZ = 2; // 0x2
     field public static final int WIFI_BAND_5_GHZ_DFS_ONLY = 4; // 0x4
@@ -5671,6 +5676,7 @@
     ctor public WifiScanner.ScanSettings();
     field public int band;
     field public android.net.wifi.WifiScanner.ChannelSpec[] channels;
+    field @NonNull @RequiresPermission(android.Manifest.permission.NETWORK_STACK) public final java.util.List<android.net.wifi.WifiScanner.ScanSettings.HiddenNetwork> hiddenNetworks;
     field public boolean hideFromAppOps;
     field public boolean ignoreLocationSettings;
     field public int maxPeriodInMs;
@@ -5679,6 +5685,12 @@
     field public int periodInMs;
     field public int reportEvents;
     field public int stepCount;
+    field @RequiresPermission(android.Manifest.permission.NETWORK_STACK) public int type;
+  }
+
+  public static class WifiScanner.ScanSettings.HiddenNetwork {
+    ctor public WifiScanner.ScanSettings.HiddenNetwork(@NonNull String);
+    field @NonNull public final String ssid;
   }
 
   @Deprecated public static interface WifiScanner.WifiChangeListener extends android.net.wifi.WifiScanner.ActionListener {
diff --git a/api/system-lint-baseline.txt b/api/system-lint-baseline.txt
index ab0f0f9..fcf5178 100644
--- a/api/system-lint-baseline.txt
+++ b/api/system-lint-baseline.txt
@@ -65,7 +65,7 @@
 MissingNullability: android.media.tv.TvRecordingClient.RecordingCallback#onEvent(String, String, android.os.Bundle) parameter #1:
     
 MissingNullability: android.media.tv.TvRecordingClient.RecordingCallback#onEvent(String, String, android.os.Bundle) parameter #2:
-    
+
 MissingNullability: android.net.wifi.rtt.RangingRequest.Builder#addResponder(android.net.wifi.rtt.ResponderConfig):
     
 MissingNullability: android.printservice.recommendation.RecommendationService#attachBaseContext(android.content.Context) parameter #0:
@@ -181,6 +181,8 @@
     Bare field saePasswordId must be marked final, or moved behind accessors if mutable
 MutableBareField: android.net.wifi.WifiConfiguration#shared:
     Bare field shared must be marked final, or moved behind accessors if mutable
+MutableBareField: android.net.wifi.WifiScanner.ScanSettings#type:
+    Bare field type must be marked final, or moved behind accessors if mutable
 
 
 NoClone: android.service.contentcapture.ContentCaptureService#dump(java.io.FileDescriptor, java.io.PrintWriter, String[]) parameter #0:
diff --git a/wifi/java/android/net/wifi/SynchronousExecutor.java b/wifi/java/android/net/wifi/SynchronousExecutor.java
new file mode 100644
index 0000000..9926b1b
--- /dev/null
+++ b/wifi/java/android/net/wifi/SynchronousExecutor.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.net.wifi;
+
+import java.util.concurrent.Executor;
+
+/**
+ * An executor implementation that runs synchronously on the current thread.
+ * @hide
+ */
+public class SynchronousExecutor implements Executor {
+    @Override
+    public void execute(Runnable r) {
+        r.run();
+    }
+}
diff --git a/wifi/java/android/net/wifi/WifiScanner.java b/wifi/java/android/net/wifi/WifiScanner.java
index 0de5066..77f7b9e 100644
--- a/wifi/java/android/net/wifi/WifiScanner.java
+++ b/wifi/java/android/net/wifi/WifiScanner.java
@@ -17,13 +17,16 @@
 package android.net.wifi;
 
 import android.Manifest;
+import android.annotation.CallbackExecutor;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
 import android.annotation.SuppressLint;
 import android.annotation.SystemApi;
 import android.annotation.SystemService;
 import android.content.Context;
+import android.os.Binder;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
@@ -45,6 +48,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.concurrent.Executor;
 
 /**
  * This class provides a way to scan the Wifi universe around the device
@@ -196,24 +200,29 @@
      */
     public static final int REPORT_EVENT_NO_BATCH = (1 << 2);
 
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = {"SCAN_TYPE_"}, value = {
+            SCAN_TYPE_LOW_LATENCY,
+            SCAN_TYPE_LOW_POWER,
+            SCAN_TYPE_HIGH_ACCURACY})
+    public @interface ScanType {}
+
     /**
-     * This is used to indicate the purpose of the scan to the wifi chip in
-     * {@link ScanSettings#type}.
-     * On devices with multiple hardware radio chains (and hence different modes of scan),
-     * this type serves as an indication to the hardware on what mode of scan to perform.
-     * Only apps holding android.Manifest.permission.NETWORK_STACK permission can set this value.
-     *
-     * Note: This serves as an intent and not as a stipulation, the wifi chip
-     * might honor or ignore the indication based on the current radio conditions. Always
-     * use the {@link ScanResult#radioChainInfos} to figure out the radio chain configuration used
-     * to receive the corresponding scan result.
+     * Optimize the scan for lower latency.
+     * @see ScanSettings#type
      */
-    /** {@hide} */
-    public static final int TYPE_LOW_LATENCY = 0;
-    /** {@hide} */
-    public static final int TYPE_LOW_POWER = 1;
-    /** {@hide} */
-    public static final int TYPE_HIGH_ACCURACY = 2;
+    public static final int SCAN_TYPE_LOW_LATENCY = 0;
+    /**
+     * Optimize the scan for lower power usage.
+     * @see ScanSettings#type
+     */
+    public static final int SCAN_TYPE_LOW_POWER = 1;
+    /**
+     * Optimize the scan for higher accuracy.
+     * @see ScanSettings#type
+     */
+    public static final int SCAN_TYPE_HIGH_ACCURACY = 2;
 
     /** {@hide} */
     public static final String SCAN_PARAMS_SCAN_SETTINGS_KEY = "ScanSettings";
@@ -228,18 +237,14 @@
      * scan configuration parameters to be sent to {@link #startBackgroundScan}
      */
     public static class ScanSettings implements Parcelable {
-        /**
-         * Hidden network to be scanned for.
-         * {@hide}
-         */
+        /** Hidden network to be scanned for. */
         public static class HiddenNetwork {
             /** SSID of the network */
-            public String ssid;
+            @NonNull
+            public final String ssid;
 
-            /**
-             * Default constructor for HiddenNetwork.
-             */
-            public HiddenNetwork(String ssid) {
+            /** Default constructor for HiddenNetwork. */
+            public HiddenNetwork(@NonNull String ssid) {
                 this.ssid = ssid;
             }
         }
@@ -249,12 +254,12 @@
         /** list of channels; used when band is set to WIFI_BAND_UNSPECIFIED */
         public ChannelSpec[] channels;
         /**
-         * list of hidden networks to scan for. Explicit probe requests are sent out for such
+         * List of hidden networks to scan for. Explicit probe requests are sent out for such
          * networks during scan. Only valid for single scan requests.
-         * {@hide}
          */
+        @NonNull
         @RequiresPermission(android.Manifest.permission.NETWORK_STACK)
-        public HiddenNetwork[] hiddenNetworks;
+        public final List<HiddenNetwork> hiddenNetworks = new ArrayList<>();
         /** period of background scan; in millisecond, 0 => single shot scan */
         public int periodInMs;
         /** must have a valid REPORT_EVENT value */
@@ -285,11 +290,24 @@
         public boolean isPnoScan;
         /**
          * Indicate the type of scan to be performed by the wifi chip.
-         * Default value: {@link #TYPE_LOW_LATENCY}.
-         * {@hide}
+         *
+         * On devices with multiple hardware radio chains (and hence different modes of scan),
+         * this type serves as an indication to the hardware on what mode of scan to perform.
+         * Only apps holding {@link android.Manifest.permission.NETWORK_STACK} permission can set
+         * this value.
+         *
+         * Note: This serves as an intent and not as a stipulation, the wifi chip
+         * might honor or ignore the indication based on the current radio conditions. Always
+         * use the {@link ScanResult#radioChainInfos} to figure out the radio chain configuration
+         * used to receive the corresponding scan result.
+         *
+         * One of {@link #SCAN_TYPE_LOW_LATENCY}, {@link #SCAN_TYPE_LOW_POWER},
+         * {@link #SCAN_TYPE_HIGH_ACCURACY}.
+         * Default value: {@link #SCAN_TYPE_LOW_LATENCY}.
          */
+        @ScanType
         @RequiresPermission(android.Manifest.permission.NETWORK_STACK)
-        public int type = TYPE_LOW_LATENCY;
+        public int type = SCAN_TYPE_LOW_LATENCY;
         /**
          * This scan request may ignore location settings while receiving scans. This should only
          * be used in emergency situations.
@@ -336,13 +354,9 @@
             } else {
                 dest.writeInt(0);
             }
-            if (hiddenNetworks != null) {
-                dest.writeInt(hiddenNetworks.length);
-                for (int i = 0; i < hiddenNetworks.length; i++) {
-                    dest.writeString(hiddenNetworks[i].ssid);
-                }
-            } else {
-                dest.writeInt(0);
+            dest.writeInt(hiddenNetworks.size());
+            for (HiddenNetwork hiddenNetwork : hiddenNetworks) {
+                dest.writeString(hiddenNetwork.ssid);
             }
         }
 
@@ -372,10 +386,10 @@
                             settings.channels[i] = spec;
                         }
                         int numNetworks = in.readInt();
-                        settings.hiddenNetworks = new HiddenNetwork[numNetworks];
+                        settings.hiddenNetworks.clear();
                         for (int i = 0; i < numNetworks; i++) {
                             String ssid = in.readString();
-                            settings.hiddenNetworks[i] = new HiddenNetwork(ssid);;
+                            settings.hiddenNetworks.add(new HiddenNetwork(ssid));
                         }
                         return settings;
                     }
@@ -801,33 +815,44 @@
     }
 
     /**
-     * Register a listener that will receive results from all single scans
-     * Either the onSuccess/onFailure will be called once when the listener is registered. After
-     * (assuming onSuccess was called) all subsequent single scan results will be delivered to the
-     * listener. It is possible that onFullResult will not be called for all results of the first
-     * scan if the listener was registered during the scan.
+     * Register a listener that will receive results from all single scans.
+     * Either the {@link ScanListener#onSuccess()} or  {@link ScanListener#onFailure(int, String)}
+     * method will be called once when the listener is registered.
+     * Afterwards (assuming onSuccess was called), all subsequent single scan results will be
+     * delivered to the listener. It is possible that onFullResult will not be called for all
+     * results of the first scan if the listener was registered during the scan.
      *
      * @param listener specifies the object to report events to. This object is also treated as a
      *                 key for this request, and must also be specified to cancel the request.
      *                 Multiple requests should also not share this object.
-     * {@hide}
      */
     @RequiresPermission(Manifest.permission.NETWORK_STACK)
-    public void registerScanListener(ScanListener listener) {
+    public void registerScanListener(@NonNull @CallbackExecutor Executor executor,
+            @NonNull ScanListener listener) {
+        Preconditions.checkNotNull(executor, "executor cannot be null");
         Preconditions.checkNotNull(listener, "listener cannot be null");
-        int key = addListener(listener);
+        int key = addListener(listener, executor);
         if (key == INVALID_KEY) return;
         validateChannel();
         mAsyncChannel.sendMessage(CMD_REGISTER_SCAN_LISTENER, 0, key);
     }
 
     /**
+     * Overload of {@link #registerScanListener(Executor, ScanListener)} that executes the callback
+     * synchronously.
+     * @hide
+     */
+    @RequiresPermission(Manifest.permission.NETWORK_STACK)
+    public void registerScanListener(@NonNull ScanListener listener) {
+        registerScanListener(new SynchronousExecutor(), listener);
+    }
+
+    /**
      * Deregister a listener for ongoing single scans
      * @param listener specifies which scan to cancel; must be same object as passed in {@link
      *  #registerScanListener}
-     * {@hide}
      */
-    public void deregisterScanListener(ScanListener listener) {
+    public void unregisterScanListener(@NonNull ScanListener listener) {
         Preconditions.checkNotNull(listener, "listener cannot be null");
         int key = removeListener(listener);
         if (key == INVALID_KEY) return;
@@ -1280,6 +1305,7 @@
     private int mListenerKey = 1;
 
     private final SparseArray mListenerMap = new SparseArray();
+    private final SparseArray<Executor> mExecutorMap = new SparseArray<>();
     private final Object mListenerMapLock = new Object();
 
     private AsyncChannel mAsyncChannel;
@@ -1327,10 +1353,14 @@
                 "No permission to access and change wifi or a bad initialization");
     }
 
+    private int addListener(ActionListener listener) {
+        return addListener(listener, null);
+    }
+
     // Add a listener into listener map. If the listener already exists, return INVALID_KEY and
     // send an error message to internal handler; Otherwise add the listener to the listener map and
     // return the key of the listener.
-    private int addListener(ActionListener listener) {
+    private int addListener(ActionListener listener, Executor executor) {
         synchronized (mListenerMapLock) {
             boolean keyExists = (getListenerKey(listener) != INVALID_KEY);
             // Note we need to put the listener into listener map even if it's a duplicate as the
@@ -1346,6 +1376,7 @@
                 message.sendToTarget();
                 return INVALID_KEY;
             } else {
+                mExecutorMap.put(key, executor);
                 return key;
             }
         }
@@ -1363,11 +1394,22 @@
         return key;
     }
 
-    private Object getListener(int key) {
-        if (key == INVALID_KEY) return null;
+    private static class ListenerWithExecutor {
+        @Nullable final Object mListener;
+        @Nullable final Executor mExecutor;
+
+        ListenerWithExecutor(@Nullable Object listener, @Nullable Executor executor) {
+            mListener = listener;
+            mExecutor = executor;
+        }
+    }
+
+    private ListenerWithExecutor getListenerWithExecutor(int key) {
+        if (key == INVALID_KEY) return new ListenerWithExecutor(null, null);
         synchronized (mListenerMapLock) {
             Object listener = mListenerMap.get(key);
-            return listener;
+            Executor executor = mExecutorMap.get(key);
+            return new ListenerWithExecutor(listener, executor);
         }
     }
 
@@ -1388,6 +1430,7 @@
         synchronized (mListenerMapLock) {
             Object listener = mListenerMap.get(key);
             mListenerMap.remove(key);
+            mExecutorMap.remove(key);
             return listener;
         }
     }
@@ -1400,6 +1443,7 @@
         }
         synchronized (mListenerMapLock) {
             mListenerMap.remove(key);
+            mExecutorMap.remove(key);
             return key;
         }
     }
@@ -1458,7 +1502,8 @@
                     return;
             }
 
-            Object listener = getListener(msg.arg2);
+            ListenerWithExecutor listenerWithExecutor = getListenerWithExecutor(msg.arg2);
+            Object listener = listenerWithExecutor.mListener;
 
             if (listener == null) {
                 if (DBG) Log.d(TAG, "invalid listener key = " + msg.arg2);
@@ -1467,36 +1512,52 @@
                 if (DBG) Log.d(TAG, "listener key = " + msg.arg2);
             }
 
+            Executor executor = listenerWithExecutor.mExecutor;
+            if (executor == null) {
+                executor = new SynchronousExecutor();
+            }
+
             switch (msg.what) {
-                    /* ActionListeners grouped together */
-                case CMD_OP_SUCCEEDED :
-                    ((ActionListener) listener).onSuccess();
-                    break;
-                case CMD_OP_FAILED : {
-                        OperationResult result = (OperationResult)msg.obj;
-                        ((ActionListener) listener).onFailure(result.reason, result.description);
-                        removeListener(msg.arg2);
-                    }
-                    break;
-                case CMD_SCAN_RESULT :
-                    ((ScanListener) listener).onResults(
-                            ((ParcelableScanData) msg.obj).getResults());
-                    return;
-                case CMD_FULL_SCAN_RESULT :
+                /* ActionListeners grouped together */
+                case CMD_OP_SUCCEEDED: {
+                    ActionListener actionListener = (ActionListener) listener;
+                    Binder.clearCallingIdentity();
+                    executor.execute(actionListener::onSuccess);
+                } break;
+                case CMD_OP_FAILED: {
+                    OperationResult result = (OperationResult) msg.obj;
+                    ActionListener actionListener = (ActionListener) listener;
+                    removeListener(msg.arg2);
+                    Binder.clearCallingIdentity();
+                    executor.execute(() ->
+                            actionListener.onFailure(result.reason, result.description));
+                } break;
+                case CMD_SCAN_RESULT: {
+                    ScanListener scanListener = (ScanListener) listener;
+                    ParcelableScanData parcelableScanData = (ParcelableScanData) msg.obj;
+                    Binder.clearCallingIdentity();
+                    executor.execute(() -> scanListener.onResults(parcelableScanData.getResults()));
+                } break;
+                case CMD_FULL_SCAN_RESULT: {
                     ScanResult result = (ScanResult) msg.obj;
-                    ((ScanListener) listener).onFullResult(result);
-                    return;
-                case CMD_SINGLE_SCAN_COMPLETED:
+                    ScanListener scanListener = ((ScanListener) listener);
+                    Binder.clearCallingIdentity();
+                    executor.execute(() -> scanListener.onFullResult(result));
+                } break;
+                case CMD_SINGLE_SCAN_COMPLETED: {
                     if (DBG) Log.d(TAG, "removing listener for single scan");
                     removeListener(msg.arg2);
-                    break;
-                case CMD_PNO_NETWORK_FOUND:
-                    ((PnoScanListener) listener).onPnoNetworkFound(
-                            ((ParcelableScanResults) msg.obj).getResults());
-                    return;
-                default:
+                } break;
+                case CMD_PNO_NETWORK_FOUND: {
+                    PnoScanListener pnoScanListener = (PnoScanListener) listener;
+                    ParcelableScanResults parcelableScanResults = (ParcelableScanResults) msg.obj;
+                    Binder.clearCallingIdentity();
+                    executor.execute(() ->
+                            pnoScanListener.onPnoNetworkFound(parcelableScanResults.getResults()));
+                } break;
+                default: {
                     if (DBG) Log.d(TAG, "Ignoring message " + msg.what);
-                    return;
+                } break;
             }
         }
     }
diff --git a/wifi/tests/src/android/net/wifi/WifiManagerTest.java b/wifi/tests/src/android/net/wifi/WifiManagerTest.java
index 8cdcba6..d326201 100644
--- a/wifi/tests/src/android/net/wifi/WifiManagerTest.java
+++ b/wifi/tests/src/android/net/wifi/WifiManagerTest.java
@@ -1437,15 +1437,6 @@
     }
 
     /**
-     * Defined for testing purpose.
-     */
-    class SynchronousExecutor implements Executor {
-        public void execute(Runnable r) {
-            r.run();
-        }
-    }
-
-    /**
      * Test behavior of isEnhancedOpenSupported
      */
     @Test
diff --git a/wifi/tests/src/android/net/wifi/WifiScannerTest.java b/wifi/tests/src/android/net/wifi/WifiScannerTest.java
index f4fa38b..b1436c90 100644
--- a/wifi/tests/src/android/net/wifi/WifiScannerTest.java
+++ b/wifi/tests/src/android/net/wifi/WifiScannerTest.java
@@ -22,7 +22,9 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.validateMockitoUsage;
@@ -33,6 +35,7 @@
 import android.net.wifi.WifiScanner.PnoSettings;
 import android.net.wifi.WifiScanner.PnoSettings.PnoNetwork;
 import android.net.wifi.WifiScanner.ScanData;
+import android.net.wifi.WifiScanner.ScanListener;
 import android.net.wifi.WifiScanner.ScanSettings;
 import android.os.Bundle;
 import android.os.Handler;
@@ -51,8 +54,10 @@
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.mockito.Spy;
 
 import java.util.Arrays;
+import java.util.concurrent.Executor;
 
 /**
  * Unit tests for {@link android.net.wifi.WifiScanner}.
@@ -63,6 +68,13 @@
     private Context mContext;
     @Mock
     private IWifiScanner mService;
+    @Spy
+    private Executor mExecutor = new SynchronousExecutor();
+    @Mock
+    private ScanListener mScanListener;
+    @Mock
+    private WifiScanner.ParcelableScanData mParcelableScanData;
+    private ScanData[] mScanData = {};
 
     private static final boolean TEST_PNOSETTINGS_IS_CONNECTED = false;
     private static final int TEST_PNOSETTINGS_MIN_5GHZ_RSSI = -60;
@@ -76,6 +88,7 @@
     private static final String TEST_SSID_2 = "TEST2";
     private static final int[] TEST_FREQUENCIES_1 = {};
     private static final int[] TEST_FREQUENCIES_2 = {2500, 5124};
+    private static final String DESCRIPTION_NOT_AUTHORIZED = "Not authorized";
 
     private WifiScanner mWifiScanner;
     private TestLooper mLooper;
@@ -95,6 +108,7 @@
         when(mService.getMessenger()).thenReturn(mBidirectionalAsyncChannelServer.getMessenger());
         mWifiScanner = new WifiScanner(mContext, mService, mLooper.getLooper());
         mLooper.dispatchAll();
+        when(mParcelableScanData.getResults()).thenReturn(mScanData);
     }
 
     /**
@@ -111,7 +125,7 @@
     @Test
     public void verifyScanSettingsParcelWithBand() throws Exception {
         ScanSettings writeSettings = new ScanSettings();
-        writeSettings.type = WifiScanner.TYPE_LOW_POWER;
+        writeSettings.type = WifiScanner.SCAN_TYPE_LOW_POWER;
         writeSettings.band = WifiScanner.WIFI_BAND_BOTH_WITH_DFS;
 
         ScanSettings readSettings = parcelWriteRead(writeSettings);
@@ -126,7 +140,7 @@
     @Test
     public void verifyScanSettingsParcelWithChannels() throws Exception {
         ScanSettings writeSettings = new ScanSettings();
-        writeSettings.type = WifiScanner.TYPE_HIGH_ACCURACY;
+        writeSettings.type = WifiScanner.SCAN_TYPE_HIGH_ACCURACY;
         writeSettings.band = WifiScanner.WIFI_BAND_UNSPECIFIED;
         writeSettings.channels = new WifiScanner.ChannelSpec[] {
                 new WifiScanner.ChannelSpec(5),
@@ -243,13 +257,13 @@
 
 
     /**
-     * Test behavior of {@link WifiScanner#startScan(ScanSettings, WifiScanner.ScanListener)}
+     * Test behavior of {@link WifiScanner#startScan(ScanSettings, ScanListener)}
      * @throws Exception
      */
     @Test
     public void testStartScan() throws Exception {
         ScanSettings scanSettings = new ScanSettings();
-        WifiScanner.ScanListener scanListener = mock(WifiScanner.ScanListener.class);
+        ScanListener scanListener = mock(ScanListener.class);
 
         mWifiScanner.startScan(scanSettings, scanListener);
         mLooper.dispatchAll();
@@ -273,13 +287,13 @@
     }
 
     /**
-     * Test behavior of {@link WifiScanner#stopScan(WifiScanner.ScanListener)}
+     * Test behavior of {@link WifiScanner#stopScan(ScanListener)}
      * @throws Exception
      */
     @Test
     public void testStopScan() throws Exception {
         ScanSettings scanSettings = new ScanSettings();
-        WifiScanner.ScanListener scanListener = mock(WifiScanner.ScanListener.class);
+        ScanListener scanListener = mock(ScanListener.class);
 
         mWifiScanner.startScan(scanSettings, scanListener);
         mLooper.dispatchAll();
@@ -302,13 +316,13 @@
     }
 
     /**
-     * Test behavior of {@link WifiScanner#startScan(ScanSettings, WifiScanner.ScanListener)}
+     * Test behavior of {@link WifiScanner#startScan(ScanSettings, ScanListener)}
      * @throws Exception
      */
     @Test
     public void testStartScanListenerOnSuccess() throws Exception {
         ScanSettings scanSettings = new ScanSettings();
-        WifiScanner.ScanListener scanListener = mock(WifiScanner.ScanListener.class);
+        ScanListener scanListener = mock(ScanListener.class);
 
         mWifiScanner.startScan(scanSettings, scanListener);
         mLooper.dispatchAll();
@@ -332,13 +346,13 @@
     }
 
     /**
-     * Test behavior of {@link WifiScanner#startScan(ScanSettings, WifiScanner.ScanListener)}
+     * Test behavior of {@link WifiScanner#startScan(ScanSettings, ScanListener)}
      * @throws Exception
      */
     @Test
     public void testStartScanListenerOnResults() throws Exception {
         ScanSettings scanSettings = new ScanSettings();
-        WifiScanner.ScanListener scanListener = mock(WifiScanner.ScanListener.class);
+        ScanListener scanListener = mock(ScanListener.class);
 
         mWifiScanner.startScan(scanSettings, scanListener);
         mLooper.dispatchAll();
@@ -425,7 +439,7 @@
     }
 
     /**
-     * Test behavior of {@link WifiScanner#stopPnoScan(WifiScanner.ScanListener)}
+     * Test behavior of {@link WifiScanner#stopPnoScan(ScanListener)}
      * WifiScanner.PnoScanListener)}
      * @throws Exception
      */
@@ -480,4 +494,134 @@
         assertEquals(scanData.getResults().length, readScanData.getResults().length);
         assertEquals(scanData.getResults()[0].SSID, readScanData.getResults()[0].SSID);
     }
+
+    /** Tests that upon registration success, {@link ScanListener#onSuccess()} is called. */
+    @Test
+    public void testRegisterScanListenerSuccess() throws Exception {
+        mWifiScanner.registerScanListener(mExecutor, mScanListener);
+        mLooper.dispatchAll();
+
+        ArgumentCaptor<Message> messageArgumentCaptor = ArgumentCaptor.forClass(Message.class);
+        verify(mHandler).handleMessage(messageArgumentCaptor.capture());
+        Message sentMessage = messageArgumentCaptor.getValue();
+        assertNotNull(sentMessage);
+
+        assertEquals(1, mBidirectionalAsyncChannelServer.getClientMessengers().size());
+        Messenger scannerMessenger =
+                mBidirectionalAsyncChannelServer.getClientMessengers().iterator().next();
+
+        Message responseMessage = Message.obtain();
+        responseMessage.what = WifiScanner.CMD_OP_SUCCEEDED;
+        responseMessage.arg2 = sentMessage.arg2;
+        scannerMessenger.send(responseMessage);
+        mLooper.dispatchAll();
+
+        verify(mExecutor).execute(any());
+        verify(mScanListener).onSuccess();
+    }
+
+    /**
+     * Tests that upon registration failed, {@link ScanListener#onFailure(int, String)} is called.
+     */
+    @Test
+    public void testRegisterScanListenerFailed() throws Exception {
+        mWifiScanner.registerScanListener(mExecutor, mScanListener);
+        mLooper.dispatchAll();
+
+        ArgumentCaptor<Message> messageArgumentCaptor = ArgumentCaptor.forClass(Message.class);
+        verify(mHandler).handleMessage(messageArgumentCaptor.capture());
+        Message sentMessage = messageArgumentCaptor.getValue();
+        assertNotNull(sentMessage);
+
+        assertEquals(1, mBidirectionalAsyncChannelServer.getClientMessengers().size());
+        Messenger scannerMessenger =
+                mBidirectionalAsyncChannelServer.getClientMessengers().iterator().next();
+
+        {
+            Message responseMessage = Message.obtain();
+            responseMessage.what = WifiScanner.CMD_OP_FAILED;
+            responseMessage.arg2 = sentMessage.arg2;
+            responseMessage.obj = new WifiScanner.OperationResult(
+                    WifiScanner.REASON_NOT_AUTHORIZED, DESCRIPTION_NOT_AUTHORIZED);
+            scannerMessenger.send(responseMessage);
+            mLooper.dispatchAll();
+        }
+
+        verify(mExecutor).execute(any());
+        verify(mScanListener).onFailure(
+                WifiScanner.REASON_NOT_AUTHORIZED, DESCRIPTION_NOT_AUTHORIZED);
+
+        // CMD_OP_FAILED should have caused the removal of the listener, verify this
+        {
+            Message responseMessage = Message.obtain();
+            responseMessage.what = WifiScanner.CMD_SCAN_RESULT;
+            responseMessage.arg2 = sentMessage.arg2;
+            responseMessage.obj = mParcelableScanData;
+            scannerMessenger.send(responseMessage);
+            mLooper.dispatchAll();
+        }
+        // execute() called once before, not called again
+        verify(mExecutor, times(1)).execute(any());
+        // onResults() never triggered
+        verify(mScanListener, never()).onResults(any());
+    }
+
+    /**
+     * Tests that when the ScanListener is triggered, {@link ScanListener#onResults(ScanData[])}
+     * is called.
+     */
+    @Test
+    public void testRegisterScanListenerReceiveScanResults() throws Exception {
+        mWifiScanner.registerScanListener(mExecutor, mScanListener);
+        mLooper.dispatchAll();
+
+        ArgumentCaptor<Message> messageArgumentCaptor = ArgumentCaptor.forClass(Message.class);
+        verify(mHandler).handleMessage(messageArgumentCaptor.capture());
+        Message sentMessage = messageArgumentCaptor.getValue();
+        assertNotNull(sentMessage);
+
+        assertEquals(1, mBidirectionalAsyncChannelServer.getClientMessengers().size());
+        Messenger scannerMessenger =
+                mBidirectionalAsyncChannelServer.getClientMessengers().iterator().next();
+
+        Message responseMessage = Message.obtain();
+        responseMessage.what = WifiScanner.CMD_SCAN_RESULT;
+        responseMessage.arg2 = sentMessage.arg2;
+        responseMessage.obj = mParcelableScanData;
+        scannerMessenger.send(responseMessage);
+        mLooper.dispatchAll();
+
+        verify(mExecutor).execute(any());
+        verify(mScanListener).onResults(mScanData);
+    }
+
+    /**
+     * Tests that after unregistering a scan listener, {@link ScanListener#onResults(ScanData[])}
+     * is not called.
+     */
+    @Test
+    public void testUnregisterScanListener() throws Exception {
+        mWifiScanner.registerScanListener(mExecutor, mScanListener);
+        mWifiScanner.unregisterScanListener(mScanListener);
+        mLooper.dispatchAll();
+
+        assertEquals(1, mBidirectionalAsyncChannelServer.getClientMessengers().size());
+        Messenger scannerMessenger =
+                mBidirectionalAsyncChannelServer.getClientMessengers().iterator().next();
+
+        ArgumentCaptor<Message> messageArgumentCaptor = ArgumentCaptor.forClass(Message.class);
+        verify(mHandler, times(2)).handleMessage(messageArgumentCaptor.capture());
+        Message sentMessage = messageArgumentCaptor.getValue();
+        assertNotNull(sentMessage);
+
+        Message responseMessage = Message.obtain();
+        responseMessage.what = WifiScanner.CMD_SCAN_RESULT;
+        responseMessage.obj = mParcelableScanData;
+        responseMessage.arg2 = sentMessage.arg2;
+        scannerMessenger.send(responseMessage);
+        mLooper.dispatchAll();
+
+        verify(mExecutor, never()).execute(any());
+        verify(mScanListener, never()).onResults(mScanData);
+    }
 }