bluetooth: android: Initial Low Energy Discovery Sessions.

device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java

Index: device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
diff --git a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
index 36387f47c8f198db5f34bc93def243130375f5f1..f8c45fe5d013c88647598c83ed5567b7c8605018 100644
--- a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
+++ b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/Wrappers.java
@@ -5,14 +5,25 @@
 package org.chromium.device.bluetooth;
 
 import android.Manifest;
+import android.annotation.TargetApi;
 import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.le.BluetoothLeScanner;
+import android.bluetooth.le.ScanCallback;
+import android.bluetooth.le.ScanFilter;
+import android.bluetooth.le.ScanResult;
+import android.bluetooth.le.ScanSettings;
 import android.content.Context;
 import android.content.pm.PackageManager;
+import android.os.Build;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 import org.chromium.base.Log;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Wrapper classes around android.bluetooth.* classes that provide an
  * indirection layer enabling fake implementations when running tests.
@@ -22,6 +33,7 @@ import org.chromium.base.Log;
  * pass through to the Android object and instead provide fake implementations.
  */
 @JNINamespace("device")
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
 class Wrappers {
     private static final String TAG = "cr.Bluetooth";
 
@@ -30,6 +42,7 @@ class Wrappers {
      */
     static class BluetoothAdapterWrapper {
         private final BluetoothAdapter mAdapter;
+        protected final BluetoothLeScannerWrapper mScanner;
 
         /**
          * Creates a BluetoothAdapterWrapper using the default
@@ -39,6 +52,13 @@ class Wrappers {
          */
         @CalledByNative("BluetoothAdapterWrapper")
         public static BluetoothAdapterWrapper createWithDefaultAdapter(Context context) {
+            final boolean hasMinAPI = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP;
+            if (!hasMinAPI) {
+                Log.i(TAG, "BluetoothAdapterWrapper.create failed: SDK version (%d) too low.",
+                        Build.VERSION.SDK_INT);
+                return null;
+            }
+
             final boolean hasPermissions =
                     context.checkCallingOrSelfPermission(Manifest.permission.BLUETOOTH)
                             == PackageManager.PERMISSION_GRANTED
@@ -49,17 +69,34 @@ class Wrappers {
                 return null;
             }
 
+            // Only Low Energy currently supported, see BluetoothAdapterAndroid class note.
+            final boolean hasLowEnergyFeature =
+                    Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2
+                    && context.getPackageManager().hasSystemFeature(
+                               PackageManager.FEATURE_BLUETOOTH_LE);
+            if (!hasLowEnergyFeature) {
+                Log.i(TAG, "BluetoothAdapterWrapper.create failed: No Low Energy support.");
+                return null;
+            }
+
             BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
             if (adapter == null) {
                 Log.i(TAG, "BluetoothAdapterWrapper.create failed: Default adapter not found.");
                 return null;
             } else {
-                return new BluetoothAdapterWrapper(adapter);
+                return new BluetoothAdapterWrapper(
+                        adapter, new BluetoothLeScannerWrapper(adapter.getBluetoothLeScanner()));
             }
         }
 
-        public BluetoothAdapterWrapper(BluetoothAdapter adapter) {
+        public BluetoothAdapterWrapper(
+                BluetoothAdapter adapter, BluetoothLeScannerWrapper scanner) {
             mAdapter = adapter;
+            mScanner = scanner;
+        }
+
+        public BluetoothLeScannerWrapper getBluetoothLeScanner() {
+            return mScanner;
         }
 
         public boolean isEnabled() {
@@ -82,4 +119,91 @@ class Wrappers {
             return mAdapter.isDiscovering();
         }
     }
+
+    /**
+     * Wraps android.bluetooth.BluetoothLeScanner.
+     */
+    static class BluetoothLeScannerWrapper {
+        private final BluetoothLeScanner mScanner;
+
+        public BluetoothLeScannerWrapper(BluetoothLeScanner scanner) {
+            mScanner = scanner;
+        }
+
+        public void startScan(
+                List<ScanFilter> filters, ScanSettings settings, ScanCallbackWrapper callback) {
+            mScanner.startScan(filters, settings, callback);
+        }
+
+        public void stopScan(ScanCallbackWrapper callback) {
+            mScanner.stopScan(callback);
+        }
+    }
+
+    /**
+     * Wraps android.bluetooth.le.ScanCallback. The ScanCallback methods:
+     *  - onBatchScanResults
+     *  - onScanResult
+     * are implemented to wrap the incoming android.bluetooth.le types into their
+     * wrapper types and then call the wrapper versions:
+     *  - onBatchScanResultWrappers
+     *  - onScanResultWrapper
+     *  Subclasses must implement these Wrapper versions.
+     *
+     *  The Wrapper name variations are used because Java doesn't support
+     *  overloading by differing Generics.
+     */
+    public abstract static class ScanCallbackWrapper extends ScanCallback {
+        public abstract void onBatchScanResultWrappers(List<ScanResultWrapper> results);
+        public abstract void onScanResultWrapper(int callbackType, ScanResultWrapper result);
+
+        @Override
+        public void onBatchScanResults(List<ScanResult> results) {
+            ArrayList<ScanResultWrapper> resultsWrapped =
+                    new ArrayList<ScanResultWrapper>(results.size());
+            for (ScanResult result : results) {
+                resultsWrapped.add(new ScanResultWrapper(result));
+            }
+            onBatchScanResultWrappers(resultsWrapped);
+        }
+
+        @Override
+        public void onScanResult(int callbackType, ScanResult result) {
+            onScanResultWrapper(callbackType, new ScanResultWrapper(result));
+        }
+    }
+
+    /**
+     * Wraps android.bluetooth.le.ScanResult.
+     */
+    static class ScanResultWrapper {
+        private final ScanResult mScanResult;
+
+        public ScanResultWrapper(ScanResult scanResult) {
+            mScanResult = scanResult;
+        }
+
+        public BluetoothDeviceWrapper getDevice() {
+            return new BluetoothDeviceWrapper(mScanResult.getDevice());
+        }
+    }
+
+    /**
+     * Wraps android.bluetooth.BluetoothDevice.
+     */
+    static class BluetoothDeviceWrapper {
+        private final BluetoothDevice mDevice;
+
+        public BluetoothDeviceWrapper(BluetoothDevice device) {
+            mDevice = device;
+        }
+
+        public String getAddress() {
+            return mDevice.getAddress();
+        }
+
+        public String getName() {
+            return mDevice.getName();
+        }
+    }
 }