[WifiManager] add public API to register callback on scan result

Bug: 142680108
Test: atest android.net.wifi
Test: atest com.android.server.wifi

Change-Id: I370a972c166242d31d21672c9d8023258664968a

6 files changed, 202 insertions, 2 deletions

diff --git a/api/current.txt b/api/current.txt
index 677e8c2209c2..04c5220d59d2 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -29936,6 +29936,7 @@ package android.net.wifi {
     method @Deprecated public int addNetwork(android.net.wifi.WifiConfiguration);
     method @RequiresPermission(android.Manifest.permission.CHANGE_WIFI_STATE) public int addNetworkSuggestions(@NonNull java.util.List<android.net.wifi.WifiNetworkSuggestion>);
     method public void addOrUpdatePasspointConfiguration(android.net.wifi.hotspot2.PasspointConfiguration);
+    method @RequiresPermission(android.Manifest.permission.ACCESS_WIFI_STATE) public void addScanResultsListener(@NonNull java.util.concurrent.Executor, @NonNull android.net.wifi.WifiManager.ScanResultsListener);
     method public static int calculateSignalLevel(int, int);
     method @Deprecated public void cancelWps(android.net.wifi.WifiManager.WpsCallback);
     method public static int compareSignalLevel(int, int);
@@ -29971,6 +29972,7 @@ package android.net.wifi {
     method @Deprecated public boolean removeNetwork(int);
     method @RequiresPermission(android.Manifest.permission.CHANGE_WIFI_STATE) public int removeNetworkSuggestions(@NonNull java.util.List<android.net.wifi.WifiNetworkSuggestion>);
     method @Deprecated @RequiresPermission(anyOf={"android.permission.NETWORK_SETTINGS", "android.permission.NETWORK_CARRIER_PROVISIONING"}) public void removePasspointConfiguration(String);
+    method @RequiresPermission(android.Manifest.permission.ACCESS_WIFI_STATE) public void removeScanResultsListener(@NonNull android.net.wifi.WifiManager.ScanResultsListener);
     method @Deprecated public boolean saveConfiguration();
     method public void setTdlsEnabled(java.net.InetAddress, boolean);
     method public void setTdlsEnabledWithMacAddress(String, boolean);
@@ -30046,6 +30048,10 @@ package android.net.wifi {
     method public void setReferenceCounted(boolean);
   }
 
+  public static interface WifiManager.ScanResultsListener {
+    method public void onScanResultsAvailable();
+  }
+
   public class WifiManager.WifiLock {
     method public void acquire();
     method public boolean isHeld();
diff --git a/wifi/java/android/net/wifi/IScanResultsListener.aidl b/wifi/java/android/net/wifi/IScanResultsListener.aidl
new file mode 100644
index 000000000000..bec74a620380
--- /dev/null
+++ b/wifi/java/android/net/wifi/IScanResultsListener.aidl
@@ -0,0 +1,27 @@
+/*
+ * 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;
+
+/**
+ * Interface for Wi-Fi scan result available callback.
+ *
+ * @hide
+ */
+oneway interface IScanResultsListener
+{
+    void onScanResultsAvailable();
+}
diff --git a/wifi/java/android/net/wifi/IWifiManager.aidl b/wifi/java/android/net/wifi/IWifiManager.aidl
index b7e109463dab..13377390fc04 100644
--- a/wifi/java/android/net/wifi/IWifiManager.aidl
+++ b/wifi/java/android/net/wifi/IWifiManager.aidl
@@ -28,6 +28,7 @@ import android.net.wifi.IActionListener;
 import android.net.wifi.IDppCallback;
 import android.net.wifi.ILocalOnlyHotspotCallback;
 import android.net.wifi.INetworkRequestMatchCallback;
+import android.net.wifi.IScanResultsListener;
 import android.net.wifi.ISoftApCallback;
 import android.net.wifi.ITrafficStateCallback;
 import android.net.wifi.ITxPacketCountListener;
@@ -227,4 +228,8 @@ interface IWifiManager
     oneway void forget(int netId, in IBinder binder, in IActionListener listener, int callbackIdentifier);
 
     oneway void getTxPacketCount(String packageName, in IBinder binder, in ITxPacketCountListener listener, int callbackIdentifier);
+
+    void registerScanResultsListener(in IBinder binder, in IScanResultsListener Listener, int listenerIdentifier);
+
+    void unregisterScanResultsListener(int listenerIdentifier);
 }
diff --git a/wifi/java/android/net/wifi/WifiManager.java b/wifi/java/android/net/wifi/WifiManager.java
index 5496e83811f8..dd9ee3b4d793 100644
--- a/wifi/java/android/net/wifi/WifiManager.java
+++ b/wifi/java/android/net/wifi/WifiManager.java
@@ -5104,4 +5104,90 @@ public class WifiManager {
             throw e.rethrowFromSystemServer();
         }
     }
+
+    /**
+     * Base class for scan results listener. Should be implemented by applications and set when
+     * calling {@link WifiManager#addScanResultsListener(Executor, ScanResultsListener)}.
+     */
+    public interface ScanResultsListener {
+
+        /**
+         * Called when new scan results available.
+         * Caller should use {@link WifiManager#getScanResults()} to get the scan results.
+         */
+        void onScanResultsAvailable();
+    }
+
+    private class ScanResultsListenerProxy extends IScanResultsListener.Stub {
+        private final Executor mExecutor;
+        private final ScanResultsListener mListener;
+
+        ScanResultsListenerProxy(Executor executor, ScanResultsListener listener) {
+            mExecutor = executor;
+            mListener = listener;
+        }
+
+        @Override
+        public void onScanResultsAvailable() {
+            mExecutor.execute(mListener::onScanResultsAvailable);
+        }
+    }
+
+    /**
+     * Add a listener for Scan Results. See {@link ScanResultsListener}.
+     * Caller will receive the event when scan results are available.
+     * Caller should use {@link WifiManager#getScanResults()} to get the scan results.
+     * Caller can remove a previously registered listener using
+     * {@link WifiManager#removeScanResultsListener(ScanResultsListener)}
+     * <p>
+     * Applications should have the
+     * {@link android.Manifest.permission#ACCESS_WIFI_STATE} permission. Callers
+     * without the permission will trigger a {@link java.lang.SecurityException}.
+     * <p>
+     *
+     * @param executor  The executor to execute the listener of the {@code listener} object.
+     * @param listener listener for Scan Results events
+     */
+
+    @RequiresPermission(ACCESS_WIFI_STATE)
+    public void addScanResultsListener(@NonNull @CallbackExecutor Executor executor,
+            @NonNull ScanResultsListener listener) {
+        if (listener == null) throw new IllegalArgumentException("listener cannot be null");
+        if (executor == null) throw new IllegalArgumentException("executor cannot be null");
+        Log.v(TAG, "addScanResultsListener: listener=" + listener + ", executor=" + executor);
+        try {
+            IWifiManager iWifiManager = getIWifiManager();
+            if (iWifiManager == null) {
+                throw new RemoteException("Wifi service is not running");
+            }
+            iWifiManager.registerScanResultsListener(
+                    new Binder(),
+                    new ScanResultsListenerProxy(executor, listener),
+                    mContext.getOpPackageName().hashCode());
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Allow callers to remove a previously added listener. After calling this method,
+     * applications will no longer receive Scan Results events.
+     *
+     * @param listener listener to remove for Scan Results events
+     */
+    @RequiresPermission(ACCESS_WIFI_STATE)
+    public void removeScanResultsListener(@NonNull ScanResultsListener listener) {
+        if (listener == null) throw new IllegalArgumentException("listener cannot be null");
+        Log.v(TAG, "removeScanResultsListener: listener=" + listener);
+
+        try {
+            IWifiManager iWifiManager = getIWifiManager();
+            if (iWifiManager == null) {
+                throw new RemoteException("Wifi service is not running");
+            }
+            iWifiManager.unregisterScanResultsListener(mContext.getOpPackageName().hashCode());
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }
diff --git a/wifi/java/com/android/server/wifi/BaseWifiService.java b/wifi/java/com/android/server/wifi/BaseWifiService.java
index 4ca2a16252d6..94fb5ae4d61c 100644
--- a/wifi/java/com/android/server/wifi/BaseWifiService.java
+++ b/wifi/java/com/android/server/wifi/BaseWifiService.java
@@ -26,6 +26,7 @@ import android.net.wifi.IDppCallback;
 import android.net.wifi.ILocalOnlyHotspotCallback;
 import android.net.wifi.INetworkRequestMatchCallback;
 import android.net.wifi.IOnWifiUsabilityStatsListener;
+import android.net.wifi.IScanResultsListener;
 import android.net.wifi.ISoftApCallback;
 import android.net.wifi.ITrafficStateCallback;
 import android.net.wifi.ITxPacketCountListener;
@@ -515,4 +516,15 @@ public class BaseWifiService extends IWifiManager.Stub {
             ITxPacketCountListener callback, int callbackIdentifier) {
         throw new UnsupportedOperationException();
     }
+
+    @Override
+    public void registerScanResultsListener(
+            IBinder binder, IScanResultsListener listener, int listenerIdentifier) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void unregisterScanResultsListener(int listenerIdentifier) {
+        throw new UnsupportedOperationException();
+    }
 }
diff --git a/wifi/tests/src/android/net/wifi/WifiManagerTest.java b/wifi/tests/src/android/net/wifi/WifiManagerTest.java
index 885139b99b5f..f8a0c8f5fab8 100644
--- a/wifi/tests/src/android/net/wifi/WifiManagerTest.java
+++ b/wifi/tests/src/android/net/wifi/WifiManagerTest.java
@@ -59,6 +59,7 @@ import android.net.wifi.WifiManager.LocalOnlyHotspotSubscription;
 import android.net.wifi.WifiManager.NetworkRequestMatchCallback;
 import android.net.wifi.WifiManager.NetworkRequestUserSelectionCallback;
 import android.net.wifi.WifiManager.OnWifiUsabilityStatsListener;
+import android.net.wifi.WifiManager.ScanResultsListener;
 import android.net.wifi.WifiManager.SoftApCallback;
 import android.net.wifi.WifiManager.TrafficStateCallback;
 import android.os.Binder;
@@ -102,13 +103,14 @@ public class WifiManagerTest {
     android.net.wifi.IWifiManager mWifiService;
     @Mock ApplicationInfo mApplicationInfo;
     @Mock WifiConfiguration mApConfig;
-    @Mock IBinder mAppBinder;
     @Mock SoftApCallback mSoftApCallback;
     @Mock TrafficStateCallback mTrafficStateCallback;
     @Mock NetworkRequestMatchCallback mNetworkRequestMatchCallback;
     @Mock OnWifiUsabilityStatsListener mOnWifiUsabilityStatsListener;
+    @Mock ScanResultsListener mScanResultListener;
+    @Mock Executor mCallbackExecutor;
+    @Mock Executor mExecutor;
 
-    private Executor mExecutor;
     private Handler mHandler;
     private TestLooper mLooper;
     private WifiManager mWifiManager;
@@ -1711,4 +1713,66 @@ i     * Verify that a call to cancel WPS immediately returns a failure.
         mLooper.dispatchAll();
         verify(externalListener).onFailure(WifiManager.BUSY);
     }
+
+    /**
+     * Verify an IllegalArgumentException is thrown if listener is not provided.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testAddScanResultsListenerWithNullListener() throws Exception {
+        mWifiManager.addScanResultsListener(mCallbackExecutor, null);
+    }
+
+    /**
+     * Verify an IllegalArgumentException is thrown if executor is not provided.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testAddScanResultsListenerWithNullExecutor() throws Exception {
+        mWifiManager.addScanResultsListener(null, mScanResultListener);
+    }
+
+    /**
+     * Verify client provided listener is being called to the right listener.
+     */
+    @Test
+    public void testAddScanResultsListenerAndReceiveEvent() throws Exception {
+        ArgumentCaptor<IScanResultsListener.Stub> callbackCaptor =
+                ArgumentCaptor.forClass(IScanResultsListener.Stub.class);
+        Executor executor = new SynchronousExecutor();
+        mWifiManager.addScanResultsListener(executor, mScanResultListener);
+        verify(mWifiService).registerScanResultsListener(any(IBinder.class),
+                callbackCaptor.capture(), anyInt());
+        callbackCaptor.getValue().onScanResultsAvailable();
+        verify(mScanResultListener).onScanResultsAvailable();
+    }
+
+    /**
+     * Verify client provided listener is being called on the right executor.
+     */
+    @Test
+    public void testAddScanResultsListenerWithTheTargetExecutor() throws Exception {
+        ArgumentCaptor<IScanResultsListener.Stub> callbackCaptor =
+                ArgumentCaptor.forClass(IScanResultsListener.Stub.class);
+        mWifiManager.addScanResultsListener(mExecutor, mScanResultListener);
+        verify(mWifiService).registerScanResultsListener(any(IBinder.class),
+                callbackCaptor.capture(), anyInt());
+        callbackCaptor.getValue().onScanResultsAvailable();
+        verify(mExecutor).execute(any(Runnable.class));
+    }
+
+    /**
+     * Verify client removeScanResultsListener.
+     */
+    @Test
+    public void testRemoveScanResultsListener() throws Exception {
+        mWifiManager.removeScanResultsListener(mScanResultListener);
+        verify(mWifiService).unregisterScanResultsListener(anyInt());
+    }
+
+    /**
+     * Verify client removeScanResultsListener with null listener will cause an exception.
+     */
+    @Test(expected = IllegalArgumentException.class)
+    public void testRemoveScanResultsListenerWithNullListener() throws Exception {
+        mWifiManager.removeScanResultsListener(null);
+    }
 }